Assoc. Prof. Elżbieta Pieczyska, Ph.D., Dr. Habil., Eng.

Department of Experimental Mechanics (ZMD)
Division of Applied Thermomechanics (PTS)
position: professor IPPT
telephone: (+48) 22 826 12 81 ext.: 369
room: 039
e-mail: epiecz

Doctoral thesis
1998Wpływ umocnienia cyklicznego materiału na efekt termosprężysty stali austenitycznej 
supervisor -- Prof. Wojciech Nowacki, Ph.D., Dr. Habil., Eng., IPPT PAN
543 
Habilitation thesis
2010-01-28Analiza doświadczalna właściwości termomechanicznych stopów TiNi oraz poliuretanu z pamięcią kształtu 943
 
Supervision of doctoral theses
1.2015-05-27Dunić Vladimir  
(UDK, Serbia)
Development and implementation of thermo-mechanical constitutive model for numerical analysis of shape memory alloys 

Recent publications
1.Pieczyska E.A., Staszczak M., Kowalczyk-Gajewska K., Maj M., Golasiński K., Golba S., Tobushi H., Hayashi S., Experimental and numerical investigation of yielding phenomena in a shape memory polymer subjected to cyclic tension at various strain rates, POLYMER TESTING, ISSN: 0142-9418, DOI: 10.1016/j.polymertesting.2017.04.014, Vol.60, pp.333-342, 2017
Abstract:

This paper presents experimental and numerical results of a polyurethane shape memory polymer (SMP) subjected to cyclic tensile loading. The goal was to investigate the polymer yielding phenomena based on the effects of thermomechanical coupling. Mechanical characteristics were obtained with a testing machine, whereas the SMP temperature accompanying its deformation process was simultaneously measured in a contactless manner with an infrared camera. The SMP glass transition temperature was approximately 45oC; therefore, when tested at room temperature, the polymer is rigid and behaves as solid material. The stress and related temperature changes at various strain rates showed how the SMP yield limit evolved in subsequent loading-unloading cycles under various strain rates. A two-phase model of the SMP was applied to describe its mechanical response in cyclic tension. The 3D Finite Element model of a tested specimen was used in simulations. Good agreement between the model predictions and experimental results was observed for the first tension cycle.

Keywords:

Shape memory polymer, Tension cyclic loading, Thermomechanical coupling, Yield limit, Thermoelastic effect, Constitutive model

Affiliations:
Pieczyska E.A.-IPPT PAN
Staszczak M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Maj M.-IPPT PAN
Golasiński K.-IPPT PAN
Golba S.-University of Silesia (PL)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
2.Golasiński K.M., Pieczyska E.A., Staszczak M., Maj M., Furuta T., Kuramoto S., Infrared thermography applied for experimental investigation of thermomechanical couplings in Gum Metal, Quantitative InfraRed Thermography Journal, ISSN: 1768-6733, DOI: 10.1080/17686733.2017.1284295, pp.1-8, 2017
Abstract:

Results of initial investigation of thermomechanical couplings in innovative β-Ti alloy called Gum Metal subjected to tension are presented. The experimental set-up, consisting of testing machine and infrared camera, enabled to obtain stress–strain curves with high accuracy and correlate them to estimated temperature changes of the specimen during the deformation process. Both ultra-low elastic modulus and high strength of Gum Metal were confirmed. The infrared measurements determined average and maximal temperature changes accompanying the alloy deformation process, allowed to estimate thermoelastic effect, which is related to the alloy yield point. The temperature distributions on the specimen surface served to analyse strain localization effects leading to the necking and rupture.

Keywords:

Gum Metal, thermomechanical coupling, nonlinear elasticity, yield point, infrared camera

Affiliations:
Golasiński K.M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Furuta T.-Toyota Central Research & Development Laboratories (JP)
Kuramoto S.-Ibaraki University Japan (JP)
3.Pieczyska E.A., Staszczak M., Maj M., Kowalczyk-Gajewska K., Golasiński K., Cristea M., Tobushi H., Hayashi S., Investigation of thermomechanical couplings, strain localization and shape memory properties in a shape memory polymer subjected to loading at various strain rates, SMART MATERIALS AND STRUCTURES, ISSN: 0964-1726, DOI: 10.1088/0964-1726/25/8/085002, Vol.25, No.8, pp.085002-1-15, 2016
Abstract:

This paper presents experimental and modeling results of the effects of thermomechanical couplings occurring in a polyurethane shape memory polymer (SMP) subjected to tension at various strain rates within large strains. The SMP mechanical curves, recorded using a testing machine, and the related temperature changes, measured in a contactless manner using an IR camera, were used to investigate the polymer deformation process at various loading stages. The effects of thermomechanical couplings allowed the determination of the material yield point in the initial loading stage, the investigation of nucleation and development of the strain localization at larger strains and the estimation of the effects of thermoelastic behavior during the unloading process. The obtained stress–strain and thermal characteristics, the results of the dynamic mechanical analysis and estimated values of the shape fixity and shape recovery parameters confirmed that the shape memory polymer (T g = 45°C) is characterized by good mechanical and shape memory properties, as well as high sensitivity to the strain rate. The mechanical response of the SMP subjected to tension was simulated using the finite element method and applying the large strain, two-phase model. Strain localization observed in the experiment was well reproduced in simulations and the temperature spots were correlated with the accumulated viscoplastic deformation of the SMP glassy phase.

Keywords:

shape memory polymer, thermomechanical coupling, infrared camera, tension test, strain rate, strain localization, constitutive model

Affiliations:
Pieczyska E.A.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Golasiński K.-IPPT PAN
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
4.Staszczak M., Pieczyska E., Maj M., Kukla D., Tobushi H., Infrared thermographic analysis of shape memory polymer during cyclic loading, MEASUREMENT SCIENCE AND TECHNOLOGY, ISSN: 0957-0233, DOI: 10.1088/0957-0233/27/12/124007, Vol.27, No.12, pp.124007-1-6, 2016
Abstract:

In this paper we present the effects of thermomechanical couplings occurring in polyurethane shape memory polymer subjected to cyclic tensile loadings conducted at various strain rates. Stress–strain characteristics were elaborated using a quasistatic testing machine, whereas the specimen temperature changes accompanying the deformation process were obtained with an infrared camera. We demonstrate a tight correlation between the mechanical and thermal results within the initial loading stage. The polymer thermomechanical behaviour in four subsequent loading-unloading cycles and the influence of the strain rate on the stress and the related temperature changes were also examined. In the range of elastic deformation the specimen temperature drops below the initial level due to thermoelastic effect whereas at the higher strains the temperature always increased, due to the dissipative deformation mechanisms. The difference in the characteristics of the specimen temperature has been applied to determine a limit of the polymer reversible deformation and analyzed for various strain rates. It was shown that at the higher strain rates higher values of the stress and temperature changes are obtained, which are related to higher values of the polymer yield points. During the cyclic loading a significant difference between the first and the second cycle was observed. The subsequent loading-unloading cycles demonstrated similar sharply shaped stress and temperature profiles and gradually decrease in values.

Keywords:

thermomechanical couplings, infrared camera, shape memory polymer, tension, strain rate, thermoelastic effect, yield point

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.-IPPT PAN
Maj M.-IPPT PAN
Kukla D.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
5.Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Gradys A., Majewski M., Cristea M., Tobushi H., Hayashi S., Thermomechanical properties of polyurethane shape memory polymer–experiment and modelling, SMART MATERIALS AND STRUCTURES, ISSN: 0964-1726, DOI: 10.1088/0964-1726/24/4/045043, Vol.24, pp.045043-1-16, 2015
Abstract:

In this paper extensive research on the polyurethane shape memory polymer (PU-SMP) is reported, including its structure analysis, our experimental investigation of its thermomechanical properties and its modelling. The influence of the effects of thermomechanical couplings on the SMP behaviour during tension at room temperature is studied using a fast and sensitive infrared camera. It is shown that the thermomechanical behaviour of the SMP significantly depends on the strain rate: at a higher strain rate higher stress and temperature values are obtained. This indicates that an increase of the strain rate leads to activation of different deformation mechanisms at the micro-scale, along with reorientation and alignment of the molecular chains. Furthermore, influence of temperature on the SMP's mechanical behaviour is studied. It is observed during the loading in a thermal chamber that at the temperature 20°C below the glass transition temperature (Tg) the PU-SMP strengthens about six times compared to the material above Tg but does not exhibit the shape recovery. A finite-strain constitutive model is formulated, where the SMP is described as a two-phase material composed of a hyperelastic rubbery phase and elastic-viscoplastic glassy phase. The volume content of phases is governed by the current temperature. Finally, model predictions are compared with the experimental results.

Keywords:

shape memory polyurethane, thermomechanical couplings, infrared camera, temperature change, dynamic mechanical analysis, strain rate, constitutive model

Affiliations:
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Staszczak M.-IPPT PAN
Gradys A.-IPPT PAN
Majewski M.-IPPT PAN
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
6.Pieczyska E.A., Mechanical behavior and infrared imaging of ferromagnetic NiFeGaCo SMA single crystal subjected to subsequent compression cycles, MECCANICA, ISSN: 0025-6455, DOI: 10.1007/s11012-013-9868-7, Vol.50, pp.585-590, 2015
Abstract:

In this paper, an experimental study of thermomechanical coupling related to pseudoelastic deformation of ferromagnetic shape memory alloy (FSMA) is presented. NiFeGaCo single crystal was subjected to subsequent loading–unloading compression cycles. The stress–strain parameters were recorded by mechanical and laser extensometers. Fast and sensitive infrared camera was used in order to record infrared radiation emitted by the sample surface during the deformation process and to calculate temperature changes related to both exothermic forward and endothermic reverse martensitic transformations. Thanks to the applied techniques, we could investigate a nucleation and development of the stress-induced martensitic transformation. The obtained thermograms exposure localized character of the transformation, initiating in form of inclined bands of higher temperature and developing throughout the sample. The elaborated average temperature change of the SMA sample surface reflects an instantaneous rate of the transformation development. High repeatability of both mechanical and temperature changes obtained in the subsequent loading cycles indicates good thermomechanical properties of the FSMA crystal and confirms high accuracy of the measurement.

Keywords:

Ferromagnetic shape memory alloy, NiFeGaCo, Phase transformation, Transformation bands, Mechanical properties, Compression test, Cyclic loading, Infrared camera, Temperature change, Thermomechanical coupling

Affiliations:
Pieczyska E.A.-IPPT PAN
7.Pieczyska E.A., Staszczak M., Maj M., Tobushi H., Hayashi S., Investigation of thermal effects accompanying tensile deformation of Shape Memory Polymer PU-SMP, Measurement Automation Monitoring, ISSN: 0032-4140, Vol.61, No.6, pp.203-205, 2015
Abstract:

Experimental results of effects of thermomechanical couplings occurring in shape memory polymer subjected to tension are presented. Stress-strain curves were recorded by testing machine, while their related temperature changes were measured with infrared camera. The mechanical and thermal characteristics were used to investigate the polymer properties. Three various stages were distinguished during the deformation process. The first, elastic, is accompanied by a drop in the specimen temperature; the second, plastic, is associated with change of the material structure and the temperature increase; the third stage, related to the specimen rupture and damage mechanisms, is accompanied by the significant increase in temperature.

Keywords:

shape memory polymer, tension, thermomechanical coupling, temperature change, infrared camera

Affiliations:
Pieczyska E.A.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
8.Staszczak M., Pieczyska E.A., Maj M., Urbański L., Odriozola I., Martin R., Thermomechanical Properties of Vulcanized Rubber investigated by Testing Machine and Infrared Camera, Measurement Automation Monitoring, ISSN: 0032-4140, Vol.61, No.6, pp.206-209, 2015
Abstract:

Experimental results of effects of thermomechanical couplings occurring both in natural vulcanized rubber and rubber with self-healing polyurethane subjected to tension at different strain rates are presented. Mechanical characteristics were recorded by testing machine, while the sample temperature changes accompanying the deformation process was measured by infrared camera. The goal was to investigate influence of self-healing polyurethane on the rubber mechanical and thermomechanical properties. It was found that the introduction of the self-healing polyurethane ensures the higher elasticity and the lower tensile strength of the rubber. It was also confirmed that the material is very sensitive to the strain rate; the higher the strain rate, the higher the values of the stress and temperature increases have been obtained.

Keywords:

vulcanized rubber, self-healing polyurethane, tension test, thermomechanical couplings, temperature changes, infrared camera

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Urbański L.-IPPT PAN
Odriozola I.-IK4-CIDETEC (ES)
Martin R.-IK4-CIDETEC (ES)
9.Dunić V., Pieczyska E.A., Tobushi H., Staszczak M., Slavković R., Experimental and numerical thermo-mechanical analysis of shape memory alloy subjected to tension with various stress and strain rates, SMART MATERIALS AND STRUCTURES, ISSN: 0964-1726, DOI: 10.1088/0964-1726/23/5/055026, Vol.23, pp.055026-1-11, 2014
Abstract:

TiNi shape memory alloy (SMA) is experimentally and numerically investigated in tension tests under different loading rates. The thermomechanical behaviour of the SMA, related to the stress-induced martensitic transformation (SIMT) noticed during the experimental tests, is analysed and the observations are considered for numerical analysis. Initiation, development and saturation of the SIMT are monitored by a fast and sensitive infrared camera. The estimated temperature changes of the SMA sample, related to the exothermic martensitic forward and endothermic reverse transformation, have been analysed with the focus on the rate-dependent response and on the influence of the heat transfer on the mechanical behaviour. The effectively modified constitutive model, proposed by Lagoudas, is implemented in structural PAK finite element method (FEM) software and is thermomechanically coupled with the heat transfer FEM software in a partitioned approach. The experimental results are quantitatively and qualitatively reproduced by the numerical FEM model, which verifies the efficiency and accuracy of the proposed investigation method.

Keywords:

shape memory alloy, stressinduced martensitic transformation, modelling, TiNi, tension, infrared camera, temperature changes

Affiliations:
Dunić V.-University of Kragujevac (XS)
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Staszczak M.-IPPT PAN
Slavković R.-University of Kragujevac (XS)
10.Takeda K., Matsui R., Tobushi H., Pieczyska E.A., Transformation-Induced Relaxation and Stress Recovery of TiNi Shape Memory Alloy, Materials, ISSN: 1996-1944, DOI: 10.3390/ma7031912, Vol.7, pp.1912-1926, 2014
Abstract:

The transformation-induced stress relaxation and stress recovery of TiNi shape memory alloy (SMA) in stress-controlled subloop loading were investigated based on the local variation in temperature and transformation band on the surface of the tape in the tension test. The results obtained are summarized as follows. (1) In the loading process, temperature increases due to the exothermic martensitic transformation (MT) until the holding strain and thereafter temperature decreases while holding the strain constant, resulting in stress relaxation due to the MT; (2) In the unloading process, temperature decreases due to the endothermic reverse transformation until the holding strain and thereafter temperature increases while holding the strain constant, resulting in stress recovery due to the reverse transformation; (3) Stress varies markedly in the initial stage followed by gradual change while holding the strain constant; (4) If the stress rate is high until the holding strain in the loading and unloading processes, both stress relaxation and stress recovery are large; (5) It is important to take into account this behavior in the design of SMA elements, since the force of SMA elements varies even if the atmospheric temperature is kept constant.

Keywords:

shape memory alloy, superelasticity, titanium-nickel alloy, subloop, stress relaxation, stress recovery, martensitic transformation

Affiliations:
Takeda K.-Aichi Institute of Technology (JP)
Matsui R.-Aichi Institute of Technology (JP)
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
11.Pieczyska E.A, Staszczak M., Dunić V., Slavković R., Tobushi H., Takeda K., Development of Stress-Induced Martensitic Transformation in TiNi Shape Memory Alloy, Journal of Materials Engineering and Performance, ISSN: 1059-9495, DOI: 10.1007/s11665-014-0959-y, Vol.23, No.7, pp.2505-2514, 2014
Abstract:

TiNi shape memory alloy (SMA) was subjected to tension at strain-controlled test on quasistatic testing machine. The nucleation, development, and saturation of the stress-induced martensitic transformation were investigated, taking into account the obtained dependency of mechanical parameters and the specimen temperature changes measured by an infrared camera (IR). Three kinds of data obtained by the IR system were analyzed: the temperature distribution on the SMA sample surface, the temperature changes derived as average from the chosen sample area, and the temperature profiles obtained along the sample length. The temperature distribution shows nucleation of the transformation process and a creation of the transformation bands. The average temperature reflects the effects of thermomechanical coupling, accompanying exothermic martensitic forward and endothermic reverse transformation. The temperature profiles revealed the temperature difference between the band and the rest of the sample. The experimental results were supported with finite element method numerical analysis (FEM). The FEM software components for structural and heat transfer problems, coupled in partitioned approach, were used for thermomechanical analysis.

Keywords:

finite element modeling, infrared camera, material testing, martensitic transformation, TiNi shape memory alloy, tension, thermomechanical couplings

Affiliations:
Pieczyska E.A-IPPT PAN
Staszczak M.-IPPT PAN
Dunić V.-University of Kragujevac (XS)
Slavković R.-University of Kragujevac (XS)
Tobushi H.-Aichi Institute of Technology (JP)
Takeda K.-Aichi Institute of Technology (JP)
12.Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Urbański L., Tobushi H., Hayashi S., Cristea M., Mechanical and Infrared Thermography Analysis of Shape Memory Polyurethane, Journal of Materials Engineering and Performance, ISSN: 1059-9495, DOI: 10.1007/s11665-014-0963-2, Vol.23, No.7, pp.2553-2560, 2014
Abstract:

Multifunctional new material—polyurethane shape memory polymer (PU-SMP)—was subjected to tension carried out at room temperature at various strain rates. The influence of effects of thermomechanical couplings on the SMP mechanical properties was studied, based on the sample temperature changes, measured by a fast and sensitive infrared camera. It was found that the polymer deformation process strongly depends on the strain rate applied. The initial reversible strain is accompanied by a small drop in temperature, called thermoelastic effect. Its maximal value is related to the SMP yield point and increases upon increase of the strain rate. At higher strains, the stress and temperature significantly increase, caused by reorientation of the polymer molecular chains, followed by the stress drop and its subsequent increase accompanying the sample rupture. The higher strain rate, the higher stress, and temperature changes were obtained, since the deformation process was more dynamic and has occurred in almost adiabatic conditions. The constitutive model of SMP valid in finite strain regime was developed. In the proposed approach, SMP is described as a two-phase material composed of hyperelastic rubbery phase and elastic-viscoplastic glassy phase, while the volume content of phases is specified by the current temperature.

Keywords:

constitutive model, dynamic mechanical analysis, shape memory polyurethane, strain rate, temperature change, thermomechanical couplings

Affiliations:
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Staszczak M.-IPPT PAN
Urbański L.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
13.Pieczyska E.A., Thermomechanical aspects of the nucleation and development of stress-induced martensitic transformation in shape memory alloys, Annual Report - Polish Academy of Sciences, ISSN: 1640-3754, Vol.2014, pp.74-77, 2014
Abstract:

Due to the dynamic development of technology and the increasing demand for materials, as well as growing environmental awareness, particular interest has recently been focused on multifunctional smart materials, able serve various purposes, such as working, sensing, and crack-healing. , is group includes shape memory materials: alloys, polymers and composites. Among these, shape memory alloys (SMAs) have attracted an especially high level of attention because of their unique properties, such as the shape memory eG ect and superelasticity, related to large recovery strain, stress, and energy storage and dissipation, which are important for their application as actuators, elements of dampers, or earthquake protection systems. , e SMA properties are caused by a stress- or temperature-induced crystallographically reversible martensitic transformation between a high-symmetry austenite and a low-symmetry martensite structure, related to changes in shape and size. These properties, together with high sensitivity to temperature, allow the SMA to combine sensor and actuator functions, thus enabling miniaturization and various applications in biomedicine (cardiosurgical stents, guidewires, orthodontic braces), aircraft (joining elements, morphing), spacecraft (automatic doors), and the car and housing industries (sensors and actuators, conditioners, overheating protectors). In order to design shape memory elements for an application, thermomechanical properties are very important (Tobushi et al., 2013). Such research has been carried out for years at the Institute of Fundamental Technological Research (IFTR): thermodynamic description by B. Raniecki, and A. Ziółkowski, micromechanics by H. Petryk and S. Stupkiewicz, as well as the experimental approach coordinated by W. K. Nowacki and L. Dietrich in collaboration with their Japanese partners S. Miyazaki and H. Tobushi. The results obtained using an infrared camera have turned out to be especially interesting, including for researchers from other centers. the high sensitivity (0.025K) and frequency (538Hz) of the camera, and most importantly the long tradition and extensive experience of the IFTR in experimental research on thermomechanical couplings in metals, all contributed to unique results on SMA properties being obtained.

Keywords:

shape memory alloy, infrared camera, localised transformation

Affiliations:
Pieczyska E.A.-IPPT PAN
14.Pieczyska E.A., Kowalczyk-Gajewska K., Maj M., Staszczak M., Tobushi H., Thermomechanical investigation of TiNi shape memory alloy and PU shape memory polymer subjected to cyclic loading, Procedia Engineering, ISSN: 1877-7058, DOI: 10.1016/j.proeng.2014.06.264, Vol.74, pp.287-292, 2014
Abstract:

In applications to sensors, actuators, guide wires, special grips for handicapped people, a shape memory alloy (SMA) or shape memory polymer (SMP) are used as working elements that perform cyclic motions. In order to evaluate the reliability of the shape memory materials (SMM), cycling and fatigue deformation properties are investigated. Since the SMM are very sensitive to temperature, not only mechanical properties but also their related temperature changes accompanying the deformation process should be taken into account. The presented paper embraces experimental investigation of effects of thermomechanical couplings occurring in shape memory alloy and shape memory polymer subjected to various kinds of cycling loading. The deformation was carried out on MTS 858 Testing machine. The strain was measured by a mechanical extensometer, so the stress-strain characteristics were elaborated with high accuracy. Furthermore, a fast and sensitive FLIR Co Phoenix infrared (IR) measurement system was used in order to record infrared radiation from the sample surface. It enables obtaining temperature distribution of the sample as a function of the deformation parameters. For each strain cycle, an increase in temperature during the loading and the temperature decrease during the unloading processes was observed. It was found that the temperature increment recorded during the cyclic deformation depends on the strain rate, the kind of the material and the test conditions. The higher the strain rate the higher the stress and temperature changes were obtained, since the deformation process was more dynamic and has occurred in almost adiabatic conditions. It was shown that various deformation mechanisms are active during various loading stages.

Keywords:

shape memory alloy, shape memory polymer, cyclic deformation, thermomechanical coupling, infrared camera

Affiliations:
Pieczyska E.A.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Maj M.-IPPT PAN
Staszczak M.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
15.Pieczyska E.A., Tobushi H., Kulasiński K., Development of transformation bands in TiNi SMA for various stress and strain rates studied by a fast and sensitive infrared camera, SMART MATERIALS AND STRUCTURES, ISSN: 0964-1726, DOI: 10.1088/0964-1726/22/3/035007, Vol.22, No.3, pp.035007-1-8, 2013
Abstract:

TiNi shape memory alloy (SMA) was subjected to tension at various strain rates for stress- and strain-controlled tests. The nucleation, development and saturation of the stress-induced martensitic transformation were investigated, based on the specimen temperature changes, measured by a fast and sensitive infrared camera. It was found that the initial, macroscopically homogeneous phase transformation occurs at the same stress level for all strain rates applied, regardless of the loading manner, while the stress of the localized transformation increases with the strain rate. At higher strain rate, a more dynamic course of the transformation process was observed, revealed in the creation of numerous fine transformation bands. An inflection point was noticed on the stress–strain curve, dividing the transformation range into two stages: the first heterogeneous, where transformation bands nucleate and evolve throughout the sample; the second, where the bands overlap, related to significant temperature increase and an upswing region of the curve. In the final part of the SMA loading a decrease of the average sample temperature revealed the saturation stage of the transformation. It was also observed that nucleation of the localized martensitic forward transformation takes place in the weakest area of the sample in both approaches, whereas the reverse transformation always initiates in its central part.

Keywords:

shape memory alloy, various strain rates, stress- and strain-controlled tests, stress-induced martensitic transformation, fast and sensitive infrared camera, transformation bands, localized martensitic forward transformation, reverse transformation

Affiliations:
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Kulasiński K.-IPPT PAN
16.Tobushi H., Pieczyska E., Miyamoto K., Mitsui K., Torsional deformation characteristics of TiNi SMA tape and application to rotary actuator, JOURNAL OF ALLOYS AND COMPOUNDS, ISSN: 0925-8388, DOI: 10.1016/j.jallcom.2011.10.108, Vol.577S, pp.S745-S748, 2013
Abstract:

In order to develop novel shape memory actuators, the torsional deformation of a shape memory alloy (SMA) tape and the actuator models driven by the tape were investigated. The results obtained can be summarized as follows. In the SMA tape subjected to torsion, the martensitic transformation appears along the edge of the tape due to elongation of the edge of the tape and grows to the central part. The fatigue life in both the pulsating torsion and the alternating torsion is expressed by the unified relationship of the dissipated work in each cycle. Based on an opening and closing door model and a solar-powered active blind model, the two-way rotary driving actuator with a small and simple mechanism can be developed by using torsion of the SMA-tape.

Keywords:

Shape memory alloy, Actuator, Two-way, Tape, Torsion, Fatigue

Affiliations:
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.-IPPT PAN
Miyamoto K.-Churyo Engineering Co. (JP)
Mitsui K.-Masupuro Denkoh Corp. (JP)
17.Takeda K., Matsui R., Tobushi H., Pieczyska E.A., Creep and creep recovery under stress-controlled subloop loading in TiNi shape memory alloy, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.65, No.5, pp.429-444, 2013
Abstract:

If a shape memory alloy (SMA) is subjected to the subloop loading under the stress-controlled condition, creep and creep recovery can appear based on the martensitic transformation. In the design of SMA elements, these deformation properties are important since the deflection of SMA elements can change under constant load. The conditions for the progress of the martensitic transformation are discussed based on the kinetics of the martensitic transformation for the SMA. The creep deformation properties are investigated experimentally for TiNi SMA. The creep strain rate increases in proportion to the martensitic transformation strain; the creep recovery strain rate increases in proportion to the reverse transformation strain.

Keywords:

shape memory alloy, superelasticity, subloop, transformation band, creep, creep recovery, strain rate, local deformation

Affiliations:
Takeda K.-Aichi Institute of Technology (JP)
Matsui R.-Aichi Institute of Technology (JP)
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
18.Staszczak M., Pieczyska E.A., Maj M., Urbański L., Tobushi H., Hayashi S., Właściwości mechaniczne oraz zmiany temperatury polimeru z pamięcią kształtu w procesie rozciągania, POMIARY AUTOMATYKA KONTROLA, ISSN: 0032-4140, Vol.59, No.9, pp.1002-1005, 2013
Abstract:

This paper presents experimental evaluation of a new polyurethane shape memory polymer (PU-SMP) produced by SMP Technologies Inc. It discusses mechanical characteristics and temperature changes of the SMP specimens subjected to tension test performed at room temperature with various strain rates. Basing on the mechanical data and the relevant temperature changes, we have studied the thermomechanical properties of the PU-SMP and influence of the strain rate on the strain localization behavior. Finally, we have identified the material parameters for the one-dimensional rheological model of the SMP.

Keywords:

shape memory polyurethane, tension test, dynamic mechanical analysis, infrared camera, temperature change, thermomechanical properties, rheological model

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Urbański L.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
19.Takeda K., Tobushi H., Miyamoto K., Pieczyska E.A., Superelastic Deformation of TiNi Shape Memory Alloy Subjected to Various Subloop Loadings, MATERIALS TRANSACTIONS, ISSN: 1345-9678, DOI: 10.2320/matertrans.M2011288, Vol.53, No.1, pp.217-223, 2012
Abstract:

This paper investigates the superelastic deformation behaviors of a TiNi shape-memory alloy (SMA) tape subjected to various subloop loadings in relation to local temperature variations and observed surface changes during a tension test. The results obtained are: (1) Upper and lower stress plateaus appear during loading and unloading accompanying the spreading and shrinking of the stress-induced martensitic transformation (SIMT) bands. In the case of unloading from the upper stress plateau under low stress rate, strain increases due to the spreading of the SIMT bands at the start of the unloading. (2) If stress at the upper stress plateau is held constant, creep deformation appears with the spread of the SIMT bands. The volume fraction in the martensitic phase increases in proportion to the increase in strain. (3) Where the strain is made to vary at the stress plateaus during loading or unloading, a return point memory effect can be seen in the reloading stress-strain curve. The spreading or shrinking of the SIMT bands starts from the boundary of the previous SIMT bands remaining from the preceding process. (4) The inclination angle of the SIMT band boundaries to the tensile axis of the tape is 33° for an aspect ratio of 5. The inclination angle is 42° in the center of the tape and 37° in the vicinity of the end secured by the grip, for an aspect ratio of 10.

Keywords:

shape memory alloy, superelasticity, titanium-nickel alloy, subloop, transformation band, creep deformation, local deformation

Affiliations:
Takeda K.-Aichi Institute of Technology (JP)
Tobushi H.-Aichi Institute of Technology (JP)
Miyamoto K.-Churyo Engineering Co. (JP)
Pieczyska E.A.-IPPT PAN
20.Pieczyska E.A., Tobushi H., Kulasiński K., Takeda K., Impact of Strain Rate on Thermomechanical Coupling Effects in TiNi SMA Subjected to Compression, MATERIALS TRANSACTIONS, ISSN: 1345-9678, Vol.53, No.11, pp.1905-1909, 2012
Abstract:

In this study, the thermomechanical coupling effects accompanying stress-induced martensitic transformation in TiNi shape memory alloy subjected to compression test were investigated. The mechanical characteristics were elaborated and the temperature changes related to the exothermic martensitic forward transformation and the endothermic reverse one were measured in a contactless manner by a fast and sensitive infrared camera. The obtained temperature changes of the specimen depend on the strain rate applied. At higher strain rate, greater temperature changes were observed, because the heat flow to the surroundings was lower and the process was closer to adiabatic conditions. The temperature changes of the shape memory alloy significantly influence its stressstrain characteristics. Moreover, the energy dissipated during a compression cycle was calculated for various strain rates. The study revealed that both the loading work and recoverable strain energy increase with increasing strain rate, while the dissipated energy fraction decreases.

Keywords:

shape memory alloy, compression test, exothermic/endothermic transformation, infrared camera, energy dissipation

Affiliations:
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Kulasiński K.-IPPT PAN
Takeda K.-Aichi Institute of Technology (JP)
21.Pieczyska E.A., Tobushi H., Takeda K., Stróż D., Ranachowski Z., Kulasiński K., Kúdela Jr. S., Luckner J., Martensite transformation bands studied in TiNi shape memory alloy by infrared and acoustic emission techniques, KOVOVE MATERIALY-METALLIC MATERIALS, ISSN: 0023-432X, Vol.50, pp.309-318, 2012
Abstract:

TiNi shape memory alloy (SMA) specimens have been subjected to tension carried out at various strain rates. The goal was to investigate a nucleation and development of the stressinduced martensitic transformation by infrared (IR) and acoustic emission (AE) techniques. Therefore, both the infrared radiation and acoustic emission data were recorded using a fast infrared camera and acoustic emission set-up, respectively. It has been shown that the initial, macroscopically homogeneous transformation initiates in the elastic stage of the deformation even before the stress-strain curve knee and formation of the localized transformation bands. It has also been found that the homogeneous transformation occurs at similar stress level for all strain rates applied, while the localized martensitic transformation depends on the strain rate. Nucleation and development of the localized transformation bands, detected by the infrared camera, were confirmed by acoustic emission technique. The differences between the IR and AE activities were recorded during the TiNi SMA loading and unloading process, manifesting different dynamics of the stress-induced martensitic forward and reverse transformation.

Keywords:

shape memory alloy, TiNi, superelasticity, martensitic transformation, tension test, acoustic emission

Affiliations:
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Takeda K.-Aichi Institute of Technology (JP)
Stróż D.-other affiliation
Ranachowski Z.-IPPT PAN
Kulasiński K.-IPPT PAN
Kúdela Jr. S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Luckner J.-IPPT PAN
22.Takeda K., Tobushi H., Pieczyska E.A., Transformation-Induced Creep and Creep Recovery of Shape Memory Alloy, Materials, Vol.5, pp.909-921, 2012
23.Tobushi H., Hayashi S., Pieczyska E.A., Date K., Nishimura Y., Three-way actuation of shape memory composite, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.63, pp.443-457, 2011
24.Pieczyska E.A., Dutkiewicz J., Masdeu F., Luckner J., Maciak R., Investigation of thermomechanical properties of ferromagnetic NiFeGa shape memory alloy subjected to pseudoelastic compression test, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, Vol.56, No.2, pp.401-408, 2011
25.Pieczyska E.A., Tobushi H., TiNi shape memory alloy tension at various temperatures - infrared imaging of shape memory effect and pseudoelasticity, MECHANICS AND CONTROL, ISSN: 2083-6759, Vol.30, No.1, pp.20-26, 2011
26.Takeda K., Tobushi H., Miyamoto K., Pieczyska E.A., Subloop Superelastic Deformation of TiNi Shape Memory Alloy, Transactions of the Japan Society of Mechanical Engineers, Series A: Solid Mechanics and Material Engineering, Vol.77, No.781, pp.1509-1517, 2011
27.Tobushi H., Pieczyska E.A., Miyamoto K., Mitsui K., Shape-Memory Alloy Thin Strip Rotary Actuator, MATERIALS SCIENCE FORUM, ISSN: 0255-5476, Vol.674, pp.219-224, 2011
28.Tobushi H., Hayashi S., Pieczyska E.A., Date K., Nishimura Y., Three-Way Shape Memory Composite Actuator, MATERIALS SCIENCE FORUM, ISSN: 0255-5476, Vol.674, pp.225-230, 2011
29.Pieczyska E.A., Activity of stress-induced martensite transformation in TiNi shape memory alloy studied by infrared technique, JOURNAL OF MODERN OPTICS, ISSN: 0950-0340, Vol.57, No.18, pp.1700-1707, 2010
30.Pieczyska E.A., Tobushi H., Date K., Miyamoto K., Torsional deformation and fatigue properties of TiNi SMA thin strip for rotary driving element, JSME INTERNATIONAL JOURNAL SERIES A-SOLID MECHANICS AND MATERIAL ENGINEERING, ISSN: 1344-7912, Vol.4, No.8, pp.1306-1314, 2010
31.Tobushi H., Pieczyska E.A., Nowacki W.K., Date K., Miyamoto K., Two-way rotary shape memory alloy thin strip actuator, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, Vol.48, No.4, pp.1043-1056, 2010
Abstract:

In order to develop a two-way rotary shape memory alloy thin strip actuator, the torsional deformation and fatigue properties of a TiNi SMA thin strip were investigated. The results obtained are summarized as follows. (1) In the SMA thin strip subjected to torsion, the MT appears along the edge of the strip due to elongation of the edge of the strip and grows to the central part. (2) The number of cycles to failure decreases with an increase in the maximum angle of twist in torsion fatigue. The fatigue life in pulsating torsion is longer than that in alternating torsion by five times. The fatigue limit exists in a certain value of dissipated work of the strip in each cycle. (3) Based on the two-way motion of a lifting actuator model driven by two kinds of SMA thin strip, it is confirmed that the two-way rotary actuator with a small and simple mechanism can be developed by using the SMA thin strips.

Keywords:

shape memory alloy, thin strip, torsion, cyclic deformation, fatigue, rotary actuator, two-way motion

Affiliations:
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
Nowacki W.K.-IPPT PAN
Date K.-Ochiai Nexus Co. (JP)
Miyamoto K.-Churyo Engineering Co. (JP)
32.Pieczyska E.A., Nowacki W.K., Tobushi H., Hayashi S., Thermomechanical properties of shape memory polymer subjected to tension in various conditions, QIRT Journal An International Journal on IR thermography, ISSN: 1768-6733, Vol.6, No.2, pp.189-205, 2010
33.Tobushi H., Pieczyska E.A., Ejiri Y., Sakuragi T., Thermomechanical properties of shape-memory alloy and polymer and their composite, MECHANICS OF ADVANCED MATERIALS AND STRUCTURES, ISSN: 1537-6494, DOI: 10.1080/15376490902746954, Vol.16, pp.236-247, 2009
Abstract:

The shape memory effect and superelasticity appear in shape memory alloy (SMA). The large amount of strain by more than several hundreds percent can be recovered in shape memory polymer (SMP). The shape recovery and shape fixity can be used in SMP elements. These characteristics of shape memory materials (SMMs) can be applied to intelligent elements in various fields. In order to use these characteristics and design the SMM elements properly, it is important to understand the thermomechanical properties of SMAs and SMPs. The deformation behaviors of SMMs differ depending on the thermomechanical loading conditions. The main factors which affect these properties are strain rate, stress rate, temperature, subloop loading, temperature-controlled condition, strain holding condition and cyclic loading. In the present paper, the thermomechanical properties of TiNi shape memory alloy, polyurethane-shape memory polymer and their composite are discussed.

Keywords:

shape memory alloy, shape memory polymer, composite, cyclic loading, strain rate, fatigue

Affiliations:
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
Ejiri Y.-other affiliation
Sakuragi T.-Aichi Institute of Technology (JP)
34.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Luckner J., Tobushi H., Martensite and reverse transformation during simple shear of niti shape memory alloy, STRAIN, ISSN: 0039-2103, Vol.45, pp.93-100, 2009
35.Tobushi H., Pieczyska E.A., Nowacki W.K., Sakuragi T., Sugimoto Y., Torsional deformation and rotary driving characteristics of SMA thin strip, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.61, pp.241-257, 2009
Abstract:

The torsional deformation properties of a TiNi shape-memory alloy thin strip were investigated. The results obtained are summarized as follows. (1) The martensitic transformation starts at the edge of the thin strip. (2) The torsional deformation properties change slightly under thermomechanical cycling. (3) The fatigue life in pul- sating torsion is longer than that in alternating torsion. (4) A simple rotary driving element can be developed by using the SMA thin strip.

Keywords:

shape memory alloy, thin strip, torsion, cyclic deformation, fatigue, rotary driving element

Affiliations:
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
Nowacki W.K.-IPPT PAN
Sakuragi T.-Aichi Institute of Technology (JP)
Sugimoto Y.-Aichi Institute of Technology (JP)
36.Tobushi H., Pieczyska E.A., Nowacki W.K., Sugimoto Y., SMA thin strip for rotary-driving element, SOLID STATE PHENOMENA, ISSN: 1012-0394, DOI: 10.4028/www.scientific.net/SSP.154.47, Vol.154, pp.47-52, 2009
Abstract:

If a shape-memory alloy (SMA) thin strip is applied as an element subjected to torsion, a rotary driving element with a simple mechanism can be developed. The torsion tests were carried out for the SMA thin strip. Torque and recovery torque, both increase in proportion to the angle of twist and temperature. The recoverable strain energy increases in proportion to temperature. The dissipated work decreases slightly with an increase in temperature. A means of opening and closing a door with an element driven by an SMA thin strip is demonstrated.

Keywords:

Rotary Driving Element, Shape Memory Alloy Actuator, Strain Energy, Thin Strip, Torsion

Affiliations:
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
Nowacki W.K.-IPPT PAN
Sugimoto Y.-Aichi Institute of Technology (JP)
37.Pieczyska E.A., Termomechaniczne aspekty przemiany fazowej w stopie TiNi z pamięcią kształtu indukowanej naprężeniem, POMIARY AUTOMATYKA KONTROLA, ISSN: 0032-4140, Vol.55, No.11, pp.958-961, 2009
38.Dutkiewicz J.M., Maziarz W., Czeppe T., Lityńska L., Nowacki W.K., Gadaj S.P., Luckner J., Pieczyska E.A., Powder metallurgy technology of niti shape memory alloy, JOURNAL DE PHYSIQUE IV, ISSN: 1155-4339, DOI: 10.1140/epjst/e2008-00654-6, Vol.158, pp.59-65, 2008
Abstract:

Powder metallurgy technology was elaborated for consolidation of shape memory NiTi powders. The shape memory alloy was compacted from the prealloyed powder delivered by Memry SA. The powder shows Ms = 10°C and As = -34°C as results from DSC measurements. The samples were hot pressed in the as delivered spherical particle's state. The hot compaction was performed in a specially constructed vacuum press, at temperature of 680°C and pressure of 400 MPa. The alloy powder was encapsulated in copper capsules prior to hot pressing to avoid oxidation or carbides formation. The alloy after hot vacuum compaction at 680°C (i.e. within the B2 NiTi stability range) has shown similar transformation range as the powder. The porosity of samples compacted in the as delivered state was only 1%. The samples tested in compression up to ε = 0.06 have shown partial superelastic effect due to martensitic reversible transformation which started at the stress above 300 MPa and returned back to ε = 0.015 after unloading. They have shown also a high ultimate compression strength of 1600 MPa. Measurements of the samples temperature changes during the process allowed to detect the temperature increase above 12°C for the strain rate 10-2 s-1 accompanied the exothermic martensite transformation during loading and the temperature decrease related to the reverse endothermic transformation during unloading.

Keywords:

Powder metallurgy technology, shape memory alloys, DSC measurements, compression test, exothermic martensite transformation, endothermic reverse transformation

Affiliations:
Dutkiewicz J.M.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Maziarz W.-other affiliation
Czeppe T.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Lityńska L.-other affiliation
Nowacki W.K.-IPPT PAN
Gadaj S.P.-other affiliation
Luckner J.-IPPT PAN
Pieczyska E.A.-IPPT PAN
39.Pieczyska E.A., Tobushi H., Nowacki W.K., Gadaj S.P., Sakuragi T., Subloop deformation behavior of TiNi shape memory alloy subjected to stress-controlled loadings, MATERIALS TRANSACTIONS, ISSN: 1345-9678, Vol.48, No.10, pp.2679-2686, 2007
Abstract:

The main characteristics which appear in shape memory alloys (SMAs) are the shape memory effect and superelasticity. In applications of SMAs, the thermomechanical properties of SMAs are most important. The return-point memory does not appear under the stress-controlled conditions. Creep and stress relaxation can be induced due to the phase transformation in the subloop loading under the stress-controlled conditions. In order to design the SMA elements properly, it is important to understand the influence of the thermomechanical loading conditions on the nucleation and progress of the phase transformation and the corresponding deformation behaviors. In the present paper, the conditions for the nucleation and progress of the phase transformation are investigated for SMAs subjected to the subloop loadings under the stress-controlled conditions. The uniaxial tension tests for the TiNi SMAs were carried out in the superelastic region under the various thermomechanical loading conditions. The thermomechanical conditions for the progress of the phase transformation are discussed in the subloop loading under the stresscontrolled conditions. Strain increases during unloading and decreases during reloading under the stress-controlled subloop loading. These pseudoviscoelastic behaviors are important for the precise control of SMA elements.

Keywords:

shape-memory alloy, titanium-nickel alloy, subloop, superelasticity, creep, stress relaxation, neutral loading

Affiliations:
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Nowacki W.K.-IPPT PAN
Gadaj S.P.-other affiliation
Sakuragi T.-Aichi Institute of Technology (JP)
40.Pieczyska E.A., Nowacki W.K., Sakuragi T., Tobushi H., Superelastic deformation properties of shape memory alloy, KEY ENGINEERING MATERIALS, ISSN: 1662-9795, Vol.340-341, pp.1211-1216, 2007
41.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Tobushi H., Phase-transformation fronts evolution for strain- and stress- controlled tension tests in TiNi Shape Memory Alloy, EXPERIMENTAL MECHANICS, ISSN: 0014-4851, Vol.46, pp.531-542, 2006
Abstract:

Nucleation and development of phase transformation fronts in TiNi shape memory alloy subjected to the stress- and strain-controlled tension tests were investigated. A thermovision camera was applied to register the distribution of infrared radiation emitted by the specimen and to find its temperature variations. During the loading, narrow bands of considerably higher temperature corresponding to the martensitic phase, starting from the central part of the specimen and developing towards the specimen grips, under both approaches, were registered. The inclined bands of heterogeneous temperature distribution were observed also during the unloading process of the SMA, while the reverse transformation accompanied by temperature decrease took place. Thermomechanical aspects of martensitic and reverse transformations for various strain rates were analyzed under both stress- and strain-controlled tests.

Keywords:

Shape memory alloy, Martensitic transformation, Phase transformation front, Temperature change, Stress-controlled test, Strain-controlled test, Infrared thermography

Affiliations:
Pieczyska E.A.-IPPT PAN
Gadaj S.P.-other affiliation
Nowacki W.K.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
42.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Tobushi H., Superelastic deformation behaviors based on phase transformation bands in TiNi shape memory alloy, MATERIALS TRANSACTIONS, ISSN: 1345-9678, Vol.47, No.3, pp.670-676, 2006
Abstract:

Properties and characteristics of superelastic deformation behavior based on Lu¨ders-Like phase transformation bands in TiNi shape memory alloy (SMA) are presented. Temperature distributions accompanying the stress-induced phase transformations in the SMA are found using the infrared technique and employed for the investigation into nucleation and further development of the bands of martensitic and reverse transformations. Based on the temperature and the relevant mechanical characteristics it is noticed that just after crossing a certain threshold stress, narrow bands of considerably higher temperature, about 8K, corresponding to the martensitic phase, appear starting from the central part of the specimen and developing towards the both specimen borders. A few such bands parallel to each other occur at higher stresses and move towards the specimen grips, as well as their next generation, developing in almost perpendicular direction. The heterogeneous field of the temperature distribution was observed also during the unloading process, while the reverse transformation occurred, also inhomogeneous and related to the significant temperature decrease. Based on the tests carried out with various strain rates, an influence of the strain rate on the mechanical behavior was presented. Thermomechanical aspects of the martensitic and the reverse transformations were discussed.

Keywords:

superelastic deformation, shape memory alloy, phase transformation bands, temperature change, infrared camera

Affiliations:
Pieczyska E.A.-IPPT PAN
Gadaj S.P.-other affiliation
Nowacki W.K.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
43.Pieczyska E.A., Pęcherski R.B., Gadaj S.P., Nowacki W.K., Nowak Z., Matyjewski M., Experimental and theoretical investigations of glass fibre reinforced composite subjected to uniaxial compression for a wide spectrum of strain rates, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.58, pp.273-291, 2006
Abstract:

Results of static and dynamic compression tests for two types of glass fibrereinforced polypropylene composites are presented. Stress-strain curves showing the influence of the strain rate on the composite mechanical properties have been obtained.
A three-dimensional description of the material behavior during the deformation has been developed. The material constitutive parameters have been calculated.
Specification of the parameters and description of the methods used for their identification have been worked out. The results are discussed in terms of the deformation processes and the material non-homogeneity.

Keywords:

static and dynamic compression tests, glass fibrereinforced polypropylene composites, Stress-strain curves, constitutive model, three-dimensional description

Affiliations:
Pieczyska E.A.-IPPT PAN
Pęcherski R.B.-IPPT PAN
Gadaj S.P.-other affiliation
Nowacki W.K.-IPPT PAN
Nowak Z.-IPPT PAN
Matyjewski M.-other affiliation
44.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Tobushi H., Stress relaxation during superelastic behavior of TiNi shape memory alloy, INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS, ISSN: 1383-5416, Vol.23, pp.3-8, 2006
45.Pieczyska E.A., Poliuretan z pamięcią kształtu - badania rozciągania oraz prostego ścinania, PRZEGLĄD MECHANICZNY, ISSN: 0033-2259, Vol.65, pp.38-45, 2006
46.Pieczyska E.A., Tobushi H., Gadaj S.P., Nowacki W.K., Hoshito K., Makino Y., Martensite and reverse transformations in TiNi shape memory alloy by advance infrared technique, Journal of the Japanese Society for Experimental Mechanics, Vol.6, pp.175-180, 2006
47.Pieczyska E.A., Własności poznawcze i aplikacyjne polimerów stopów z pamięcią kształtu, NIT. Nauka, Innowacje, Technika, ISSN: 1731-4291, Vol.1, pp.4-10, 2006
48.Pieczyska E.A., Gadaj S.P., Nowacki W.K., Hoshito K., Makino Y., Tobushi H., Characteristics of energy storage and dissipation in TiNi shape memory alloy, SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, ISSN: 1468-6996, Vol.6, No.8, pp.889-894, 2005
Abstract:

The characteristics of energy storage and dissipation in TiNi shape memory alloys were investigated experimentally based on the superelastic properties under various thermomechanical loading conditions. The influence of strain rate, cyclic loading and temperature-controlled condition on the characteristics of energy storage and dissipation of the material was investigated. Temperature on the surface of the material was observed and the influence of variation in temperature on the characteristics was clarified. The results obtained can be summarized as follows. (1) In the case of low strain rate, the stress plateaus appear on the stress-strain curves due to the martensitic transformation and the reverse transformation during loading and unloading. In the case of high strain rate, the slopes of the stress–strain curves are steep in the phase-transformation regions during loading and unloading. The recoverable strain energy per unit volume increases in proportion to temperature, but the dissipated work per unit volume depends slightly on temperature. In the case of low strain rate, the recoverable strain energy and dissipated work do not depend on both strain rate and the temperature-controlled condition. (2) In the case of high strain rate, while the recoverable strain energy density decreases and dissipated work density increases in proportion to strain rate under the temperature-controlled condition, the recoverable strain energy density increases and dissipated work density decreases under the temperature-uncontrolled condition. In the case of the temperature-uncontrolled condition, temperature varies significantly due to the martensitic transformation and therefore the characteristics of energy storage and dissipation differ from these under the temperature-controlled condition. (3) In the case of cyclic loading, both the recoverable strain energy and dissipated work decrease in the early 20 cycles, but change slightly thereafter. (4) The influence of strain rate, cyclic loading and the environment on the characteristics of energy storage and dissipation is important to be considered in the design of shape memory alloy elements. q 2005 Elsevier Ltd. All rights reserved. Keywords: Shape memory ally; Superelasticity; Energy storage; Energy dissipation; Damping; Strain rate; Cyclic deformation; Titanium–nickel alloy; Environment

Keywords:

Shape memory ally, Superelasticity, Energy storage, Energy dissipation, Damping, Strain rate, Cyclic deformation, Titanium–nickel alloy, Environment

Affiliations:
Pieczyska E.A.-IPPT PAN
Gadaj S.P.-other affiliation
Nowacki W.K.-IPPT PAN
Hoshito K.-other affiliation
Makino Y.-other affiliation
Tobushi H.-Aichi Institute of Technology (JP)
49.Gadaj S.P., Nowacki W.K., Pieczyska E.A., Tobushi H., Temperature measurement as a new technique applied to the phase transformation study in a TiNi shape memory alloy subjected to tension, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, Vol.50, No.3, pp.661-674, 2005
50.Gadaj S.P., Nowacki W.K., Pieczyska E.A., Temperature changes of the polymer fibrous belts subjected to mechanical loading, ENGINEERING TRANSACTIONS (ROZPRAWY INŻYNIERSKIE), ISSN: 0867-888X, Vol.53, No.2, pp.147-163, 2005
51.Pieczyska E., Wyznaczenie początku odkształcenia plastycznego na podstawie analizy zmian temperatury, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.30, pp.1-18, 1995
52.Gadaj S.P., Oliferuk W., Pieczyska E., Emisja akustyczna podczas deformacji plastycznej stali węglowej, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.5, pp.1-15, 1988
53.Gadaj S.P., Kaczmarek J., Oliferuk W., Pieczyska E., Wpływ obróbki powierzchniowej na proces magazynowania energii podczas rozciągania stali 1H18N9T, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.28, pp.1-9, 1983
54.Choroś J., Gadaj S.P., Kaczmarek J., Oliferuk W., Pieczyska E., Emisja akustyczna towarzysząca przemianom fazowym w deformowanej stali 1H18N9T, Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.31, pp.1-16, 1982

List of recent monographs
1.
312
Tobushi H., Matsui R., Takeda K., Pieczyska E.A., Mechanical Properties of Shape Memory Materials, Nova Science Publishers, Inc., 400 Oser Avenue, Suite 1600, Hauppauge, N.Y. 11788-3619, USA, pp.1-271, 2013
2.
81
Pieczyska E.A., Analiza doświadczalna właściwości termomechanicznych stopów TiNi oraz poliuretanu z pamięcią kształtu, IPPT Reports on Fundamental Technological Research, 3, pp.1-214, 2008
List of chapters in recent monographs
1.
521
Pieczyska E.A., Tobushi H., Advances in Shape Memory Materials, In Commemoration of the Retirement of Profesor Hisaaki Tobushi, rozdział: Thermomechanical Coupling and Localization Effects Examined in Shape Memory Alloys and Polymers by Fast and Sensitive Infrared Camera, Springer International Publishing, series Advanced Structured Materials, 73, pp.173-189, 2017
2.
449
Pieczyska E.A., Maj M., Furuta T., Kuramoto S., Advances in Mechanics: Theoretical, Computational and Interdisciplinary Issues, rozdział: Gum Metal - unique properties and results of initial investigation of a new titanium alloy - extended paper, CRC Press/Balkema, Taylor & Francis Group, M. Kleiber et al. (Eds.), pp.469-472, 2016
3.
16
Gambin B., Lekszycki T., Kowalczyk T., Kowalewski T.A., Ziółkowski A., Pieczyska E., Stupkiewicz S., Scenariusze rozwoju technologii nowoczesnych materiałów metalicznych, ceramicznych i kompozytowych, rozdział: Biomateriały. Rola i strategia badawcza IPPT PAN w powstaniu nowoczesnych technologii materiałów współpracujących z ludzkimi tkankami, Wydawnictwo Naukowe Instytutu Technologii Eksploatacji PIB, 1, pp.181-222, 2010
4.
146
Nowacki W.K., Gadaj S.P., Pieczyska E.A., Tobushi H., Foundation of materials design, rozdział: Thermomechanical properties of TiNi shape memory alloy, Research Signpost (India), Kurzydłowski K.J., Major B., Zięba P. (Eds.), pp.195-240, 2006
Editor of monographs
1.
522
Sun Q.P., Matsui R., Takeda K., Pieczyska E.A., Advances in Shape Memory Materials, In Commemoration of the Retirement of Profesor Hisaaki Tobushi, Springer International Publishing, series Advanced Structured Materials, 73, pp.1-241, 2017

Conference papers
1.Dunić V., Slavković R., Pieczyska E., Thermo-mechanical numerical analysis of transformation-induced stress relaxation during pseudoelastic behavior of SMA, SEECCM, 4th South-East European Conference on Computational Mechanics, 2017-07-03/07-05, Kragujevac (XS), No.T.4.7, pp.28-1-28-6, 2017
Abstract:

A stress relaxation phenomenon is observed by coupled thermo-mechanical numerical analysis of SMA subjected to uniaxial test. The thermo-mechanical coupling is realized in the partitioned approach. The software components for the structural analysis (PAKS) and the heat transfer (PAKT) based on the Finite Element Method (FEM) have been used. The latent heat production is correlated with the amount of the martensitic volume fraction. The thermo-mechanical numerical analysis of a belt type specimen has been investigated for the strain controlled loading with the break during the martensitic transformation. The thermally induced martensitic transformation induced the significant stress change during the loading break what was expected according to the experimental results from literature.

Keywords:

shape memory alloys, stress relaxation, thermo-mechanical coupling, phase transformation, partitioned coupling

Affiliations:
Dunić V.-University of Kragujevac (XS)
Slavković R.-University of Kragujevac (XS)
Pieczyska E.-IPPT PAN
2.Pieczyska E.A., Staszczak M., Maj M., Kowalczyk-Gajewska K., Cristea M., Tobushi H., Hayashi S., Thermomechanical analysis of shape memory polyurethane PU-SMP, 6th International Conference on Mechanics and Materials in Design, 2015-07-26/07-30, Ponta Delgada (PT), pp.783-786, 2015
Abstract:

Experimental results of effects of thermomechanical couplings occurring in polyurethane shape memory polymer (PU-SMP) during tension at different strain rates are presented. Stress-strain curves were recorded by MTS 858 testing machine. The temperature changes were estimated by using a fast and sensitive infrared camera (Phoenix FLIR IR System). The stress and temperature vs. strain characteristics obtained during the tension enable to investigate the SMP deformation process and distinguish 3 different stages: the first, accompanied by a drop in temperature called thermoelastic effect, related to a limit of the material reversible deformation, the second plastic stage, associated with change of the material structure and significant increase in temperature, and the third - related to the mechanisms of damage - a breaking of the polymer chains, leading to the specimen rupture.

Keywords:

shape memory polymer, thermomechanical coupling, tension, infrared camera

Affiliations:
Pieczyska E.A.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
3.Pieczyska E.A., Staszczak M., Maj M., Tobushi H., Hayashi S., Thermal effects accompanying tensile deformation of shape memory polymer PU-SMP, 11th Conference on Thermography and Thermometry in Infrared, 2015-09-22/09-24, Ustroń (PL), pp.60-65, 2015
Abstract:

In the paper experimental results of the effects of thermomechanical couplings occurring in polyurethane shape memory polymer (PU-SMP), produced by SMP Techno Tokyo, subjected to tension with various strain rates are presented. Stress-strain curves were recorded by MTS 858 testing machine with a high accuracy, while using a fast and sensitive infrared camera (Phoenix FLIR IR System) enables to obtain the temperature distribution on the specimen surface, estimate the average temperature and investigate effects of the strain localization during the deformation process. The higher the strain rate the higher the changes in the stress and in temperature are observed, since the deformation mechanisms occur in more dynamic manner and the loading process is closer to adiabatic conditions.

Keywords:

shape memory polymer, thermomechanical couplings, tension, infrared camera, thermoelastic effect, yield point, temperature distribution, strain localization, strain rate, adiabatic conditions

Affiliations:
Pieczyska E.A.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
4.Staszczak M., Pieczyska E.A., Maj M., Urbański L., Odriozola I., Martin R., Właściwości termomechaniczne gumy wulkanizowanej badane za pomocą maszyny wytrzymałościowej oraz kamery termowizyjnej, 11th Conference on Thermography and Thermometry in Infrared, 2015-09-22/09-24, Ustroń (PL), pp.66-67, 2015
Abstract:

Praca przedstawia wyniki doświadczalnych badań efektów sprzężeń termomechanicznych w naturalnej, wulkanizowanej gumie z różną zawartością poliuretanu o właściwościach samo-naprawiania, tzw. „self-healing‖ podczas obciążania z różnymi prędkościami deformacji. Próbki rozciągano na maszynie wytrzymałościowej wysokiej klasy, co pozwoliło otrzymać charakterystyki mechaniczne z wysoką dokładnością, a szybka i czuła kamera termowizyjna pozwoliła otrzymać w sposób bezstykowy zmiany temperatury próbek związane z ich odkształcaniem. Stwierdzono, że im więcej dodatku poliuretanu, tym wyższa sprężystość gumy oraz niższa jej wytrzymałość. Ponadto, otrzymane wyniki potwierdziły wysoką wrażliwość materiału na prędkość deformacji: im wyższa prędkość, tym wyższe wartości naprężenia oraz zmian temperatury.

Keywords:

efekty sprzężeń termomechanicznych, wulkanizowana guma, poliuretan self-healing, prędkość deformacji, maszyna wytrzymałościowa, kamera termowizyjna

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Urbański L.-IPPT PAN
Odriozola I.-IK4-CIDETEC (ES)
Martin R.-IK4-CIDETEC (ES)
5.Staszczak M., Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Kukla D., Tobushi H., Hayashi S., Infrared thermography analysis of thermomechanical shape memory polymer behavior – initial loading stage, AITA, 13th International Workshop on Advanced Infrared Technology and Applications, 2015-09-29/10-02, Pisa (IT), pp.115-118, 2015
Abstract:

Experimental results of effects of thermomechanical couplings occurring in polyurethane shape memory polymer (PU-SMP) subjected to cyclic loading at various strain rates are presented. Stress-strain characteristics were recorded by the testing machine, whereas the specimen temperature changes were measured by a fast and sensitive infrared camera. The influence of strain rate on the polymer thermomechanical behaviour was studied. It was found that the SMP is very sensitive to the strain rate. The higher the strain rate, the higher the values of the stress and temperature changes were obtained. In the initial stage of deformation a drop in temperature called thermoelastic effect, determining a limit of the material reversible deformation, was investigated.

Keywords:

thermomechanical couplings, polyurethane shape memory polymer, cyclic loading, various strain rates, sensitive infrared camera, thermoelastic effect, thermoelastic effect, reversible deformation

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Kukla D.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
6.Pieczyska E., Maj M., Kowalczyk-Gajewska K., Staszczak M., Tobushi H., Hayashi S., Thermomechanical properties of shape memory alloys and polymers studied by advanced infrared techniques, PACAM, 14th Pan-American Congress of Applied Mechanics, 2014-03-24/03-28, Santiago (CL), pp.1-6, 2014
Abstract:

The paper presents experimental evaluation and modelling of effects of thermomechanical couplings in shape memory alloy (SMA) and shape memory polymer (SMP). TiNi SMA and polyurethane PU-SMP are subjected to tension on MTS Testing machine. Fast infrared camera (IR) Phoenix FLIR System enable obtaining temperature distribution and average temperature changes of the specimens during the deformation process. Mechanical and infrared characteristics recorded during the SMA loading show that after initial, macroscopically homogeneous deformation a localized transformation develops, accompanied by significant temperature changes. Inclined bands of higher temperature accompanying exothermic forward transformation are recorded during the loading, whereas bands of lower temperature related to endothermic reverse transformation are observed during the unloading process. The infrared imaging and average temperature of the SMA sample compared to their mechanical characteristics allow to investigate the current stage of the stress-induced transformation process. A decrease of the specimen temperature reveals the saturation stage of the transformation. Both mechanical and thermal effects significantly depend on the strain rate; the higher the strain rate, the higher the temperature and stress are obtained. Similar experimental methodology is applied to investigate effects of thermomechanical couplings in shape memory polyurethane subjected to tension at various strain rates. Constitutive model valid in finite strain regime is proposed, where the SMP is described as a two-phase material composed of hyperelastic rubbery phase and elastic-viscoplastic glassy phase, while the volume content of phases is specified by the current temperature. Experimental results and modelling show that the SMP deformation process strongly depends on the strain rate, much stronger than for metals and alloys. At higher strain rate higher stress and temperature changes are obtained, since the deformation process is more dynamic and occurs in almost adiabatic conditions. It is shown that during the SMP loading process various deformation mechanisms are active at various strain rates.

Keywords:

shape memory alloy, transformation bands, infrared camera, constitutive model, shape memory polymers, elastic modulus, yield stress, glass transition temperature, shape fixity, shape recovery

Affiliations:
Pieczyska E.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Staszczak M.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
7.Staszczak M., Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Cristea M., Tobushi H., Hayashi S., Mechanical and infrared thermography analysis of shape memory polymer - focus on thermoelastic effect, QIRT 2014, 12th International Conference on Quantitative Infrared Thermography, 2014-07-07/07-11, Bordeaux (FR), pp.183-1-9, 2014
Abstract:

Experimental results of effects of thermomechanical couplings occurring in polyurethane shape memory polymer (PU-SMP) subjected to cyclic loading at , are presented. Stress-strain characteristics were recorded by the testing machine, whereas the specimen temperature changes were measured by a fast and sensitive infrared camera. The influence of strain rate on the polymer thermomechanical behaviour is studied. It was found that PU-SMP is very sensitive to the strain rate. The higher the strain rate, the higher the values of stress and temperature changes were obtained. In the initial stage of deformation a drop in temperature called thermoelastic effect was recorded determining a limit of the material reversible deformation.

Keywords:

thermomechanical couplings, polyurethane shape memory polymer, cyclic loading, different strain rates, infrared camera, thermoelastic effect

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
8.Pieczyska E.A., Tobushi H., Takeda K., Kulasiński K., Kowalewski Z.L., Moćko W., Luckner J., Temperature assessment of TiNi shape memory alloy subjected to compression at quasistatic and dynamic strain rates, ICEM15, 15th International Conference on Experimental Mechanics, 2012-07-22/07-27, Porto (PT), No.1, pp.1145-1146, 2012
Abstract:

This work compares the thermomechanical behavior of TiNi shape memory alloy subjected to the compression test performed under various strain rates. The mechanical characteristics of the material were elaborated. The specimen temperature changes related to the exothermic martensitic forward and endothermic reverse transformation were measured in a contact-less manner by a very fast and sensitive infrared camera. It has been found that in this experimental conditions the stress-induced transformation and reorientation processes occurred homogeneously, since the temperature distribution observed on the specimen surface was uniform. The obtained temperature variation depends on the strain rate applied. At the higher strain rate the higher temperature changes were obtained, because the heat flow to the surroundings was lower and the process was closer to adiabatic conditions. The temperature changes influence significantly the SMA stress-strain curves and their mechanical properties.

Keywords:

shape memory alloy, various strain rates, compression tests, exothermic martensitic forward, endothermic reverse transformation, fast and sensitive infrared camera

Affiliations:
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Takeda K.-Aichi Institute of Technology (JP)
Kulasiński K.-IPPT PAN
Kowalewski Z.L.-IPPT PAN
Moćko W.-IPPT PAN
Luckner J.-IPPT PAN
9.Pieczyska E.A., Tobushi H., Temperature evolution in shape memory alloy during loading in various conditions, 10th International Conference on Quantitative InfraRed Thermography, 2010-07-27/07-30, Québec (CA), pp.861-868, 2010
10.Pieczyska E.A., Tobushi H., Infrared imaging of TiNi shape memory alloy subjected to deformation at various temperatures, ICEM 14, 14th International Conference on Experimental Mechanics, 2010-07-04/07-09, Poitiers (FR), Vol.6, pp.1-8, 2010

Conference abstracts
1.Pieczyska E.A., Golasiński K., Staszczak M., Maj M., Furuta T., Kuramoto S., A thermomechanical analysis of high elasto-plastic properties of gum metal at various strain rates, M2D, 7th International Conference on Mechanics and Materials in Design, 2017-06-11/06-15, Albufeira (PT), No.7002, pp.131-132, 2017
Abstract:

Mechanical characteristics obtained by MTS testing machine and digital image correlation (DIC) algorithm as well as the related temperature changes in a new B-Ti alloy - Gum Metal, subjected to tension in a wide spectrum of the strain rates, are presented The fast and sensitive infrared camera ThermaCam Phoenix allowed estimating temperature changes accompanying the specimen deformation process in contactless manner. The obtained mechanical curves confirm an ultra-low elastic modulus and high strength of Gum Metal. Furthermore, it was presented how the stress-strain characteristics change from hardening to softening depending on the strain rate. The thermoelastic effect, estimated by the IR technique was discussed according to the Gum Metal yield point.

Keywords:

gum metal, titanium alloy, tension test, strain rate, thermomechanical coupling

Affiliations:
Pieczyska E.A.-IPPT PAN
Golasiński K.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Furuta T.-Toyota Central Research & Development Laboratories (JP)
Kuramoto S.-Ibaraki University Japan (JP)
2.Pieczyska E., Golasiński K., Staszczak M., Maj M., Furuta T., Kuramoto S., High elasto-plastic properties of new titanium alloy gum metal in wide spectra of the strain rates, 17th International Conference on Experimental Mechanics, 2016-07-03/07-07, Rhodes (GR), No.388, pp.1-2, 2016
Abstract:

Results of investigation of mechanical properties and the related temperature changes in a β-Ti alloy, Gum Metal, subjected to tension in a wide spectrum of the strain rates are presented. The stress-strain curves have been obtained by MTS testing machine while fast and sensitive infrared camera Phoenix Flir Co. allowed estimating temperature changes accompanying the specimen deformation process. The obtained mechanical curves confirm an ultra- low elastic modulus and high strength of Gum Metal. The yield point was estimated with high accuracy basing on the thermoelastic effect measured by the advanced infrared technique. Furthermore, it was observed that the stress-strain characteristics change from hardening to softening beyond the Yield point depending on the strain rate applied.

Keywords:

Gum metal, Titanium alloy, Superelastic nonlinear properties, strain rate

Affiliations:
Pieczyska E.-IPPT PAN
Golasiński K.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Furuta T.-Toyota Central Research & Development Laboratories (JP)
Kuramoto S.-Ibaraki University Japan (JP)
3.Pieczyska E.A., Golasiński K., Staszczak M., Maj M., Furuta T., Kuramoto S., Gum metal subjected to cyclic tension loading analysed by fast and sensitive infrared camera, ICMFM18, XVIII International Colloquium MECHANICAL FATIGUE OF METALS, 2016-09-05/09-07, Gijón (ES), pp.1, 2016
Abstract:

Gum Metal, a new multifunctional titanium alloy combining high elasticity of rubber and strength of metal, has been mechanically and thermomechanically tested. The subsequent tension deformation cycles have been conducted. At the strain rate of 10-2s-1 and step of 0.005 - 37 loading-unloading cycles until rupture were performed. Comparison of stress and temperature changes vs. strain for 2nd, 20th and 36th loading-unloading cycles is discussed.

Keywords:

Gum Metal, cyclic loading, infrared camera, thermomechanical coupling

Affiliations:
Pieczyska E.A.-IPPT PAN
Golasiński K.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Furuta T.-Toyota Central Research & Development Laboratories (JP)
Kuramoto S.-Ibaraki University Japan (JP)
4.Golasiński K., Pieczyska E., Maj M., Staszczak M., Takesue N., Investigation of Gum Metal under compressive cyclic loading, Plastmet 2016, Jubileuszowe X Seminarium Naukowe ZINTEGROWANE STUDIA PODSTAW DEFORMACJI PLASTYCZNEJ METALI , 2016-11-22/11-25, Łańcut (PL), pp.41-42, 2016
Abstract:

Preliminary results of mechanical behavior of Gum Metal compressed along the swaging direction during cyclic loading were presented. The unique mechanical performance of Gum Metal - low Young’s Modulus and high strength were confirmed. During the cyclic loading the curves profiles change significantly with each cycle and reveal a clearly pronounced yield points for the 4th and further cycles. Compression tests along perpendicular direction to the swaging one will be considered for our future research.

Keywords:

Gum Metal, polycrystal, compression loading, cyclic loading, digital image correlation

Affiliations:
Golasiński K.-IPPT PAN
Pieczyska E.-IPPT PAN
Maj M.-IPPT PAN
Staszczak M.-IPPT PAN
Takesue N.-Fukuoka University (JP)
5.Golasiński K., Pieczyska E., Staszczak M., Maj M., Furuta T., Kuramoto S., Infrared thermography applied for experimental investigation of thermomechanical couplings in Gum Metal, QIRT 2016, XIII International Quantitative InfraRed Thermography Conference, 2016-06-04/06-08, Gdańsk (PL), pp.318-319, 2016
Abstract:

Results of investigation of thermomechanical couplings in innovative β-Ti alloy (Gum Metal) subjected to tension are presented. The experimental set-up, consisting of testing machine and infrared camera, enabled to obtain stress-strain curves with high accuracy and correlate them to estimated temperature changes of the sample during the deformation process. Both ultra-low elastic modulus and high strength of Gum Metal were confirmed. The infrared measurements determined average and maximal temperature changes accompanying the alloy deformation process, allowed to estimate thermoelastic effect, which is related to the alloy yield point. The temperature distributions on the sample surface served to analyze localization effects leading to the sample necking and rupture.

Keywords:

Gum metal, nonlinear elasticity, thermomechanical couplings

Affiliations:
Golasiński K.-IPPT PAN
Pieczyska E.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Furuta T.-Toyota Central Research & Development Laboratories (JP)
Kuramoto S.-Ibaraki University Japan (JP)
6.Golasiński K., Pieczyska E., Staszczak M., Maj M., Furuta T., Kuramoto S., Thermomechanical behavior of gum metal under cyclic loading, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P208, pp.1-2, 2016
Abstract:

This work presents thermomechanical characterization of a new multifunctional class of β-Ti alloy called Gum Metal subjected to cyclic tensile loading. Being developed in the Toyota Central R&D Laboratory (CRDL), Gum Metal has attracted remarkable attention due to its exceptional properties, i.e. low elastic modulus, high strength, nonlinear elastic deformation, excellent cold workability as well as Invar- and Elinvar-like behavior. Typical composition of Gum Metal is Ti-Nb-Ta-Zr-O, where oxygen content plays a key role. Its fabrication route consists of powder metallurgy forging method with subsequent cold working usually up to 90% in area reduction. The latter is critical for the unique mechanical performance but deformation mechanisms occurring in Gum Metal are unconventional and still unclear.

Keywords:

Gum metal, cyclic loading, titanium alloy, thermomechanical behavior

Affiliations:
Golasiński K.-IPPT PAN
Pieczyska E.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Furuta T.-Toyota Central Research & Development Laboratories (JP)
Kuramoto S.-Ibaraki University Japan (JP)
7.Staszczak M., Pieczyska E.A., Tobushi H., Thermomechanical analysis of polyurethane shape memory polymer in cyclic loading – shape recovery and shape fixity, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P189, pp.1-2, 2016
Abstract:

Recently shape memory polymers (SMP) have been attracting broad interest because they can change their shape in a predefined way when exposed to an appropriate stimulus. Among the shape memory polymers the largest group represent those, whose shape memory properties are triggered by temperature. The temperature at which the polymer returns to the original shape is usually its glass transition temperature (Tg). If the polymer is heated to the temperature above Tg, it can be deform easily. After cooling down below its Tg, followed by unloading to remove the stress, the modified shape is largely maintained (shape fixity). Heating again to temperature above the Tg enables the polymer to return to the original shape (shape recovery). Thermally responsive polymers found applications in various fields, e.g. in smart textiles, in medical devices, in actuators and sensors, heat-shrinkable tubes for electronics, etc. In order to guarantee sufficient reliability and predict the shape memory behavior of these materials it is important to obtain knowledge about the shape fixity and shape recovery properties.

Keywords:

Shape memory polymer, cyclic loading, shape fixity, shape recovery, thermomechanical analysis

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
8.Pieczyska E.A., Staszczak M., Tobushi H., Takeda K., Matsui R., Hayashi S., Shape memory polymer - influence of temperature, strain rate and the loading history on the stress-strain curves, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P194, pp.1-2, 2016
Abstract:

The mechanism of exhibiting shape memory property in polymer is different from that observed in shape memory alloy, since the crystallographic phase transformation does not occur in polymers. The functional characteristics of shape memory polymer (SMP), e.g. rigidity, elastic modulus and coefficient of thermal expansion, change significantly above and below its glass transition temperature (Tg) due to molecular motion of the polymer chains which differs drastically below and above Tg. These properties allow to apply SMP in biomedical, textile, housing, transportation, aviation industries. A goal of this paper is to discuss selected results of the SMP investigation and demonstrate how significantly its mechanical properties change in various conditions; influence of temperature, strain rate and loading history were taken into consideration.

Keywords:

Shape memory polymer, tensile test, strain rate, temperature change

Affiliations:
Pieczyska E.A.-IPPT PAN
Staszczak M.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Takeda K.-Aichi Institute of Technology (JP)
Matsui R.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
9.Takeda K., Matsui R., Tobushi H., Pieczyska E.A., Subloop deformation of shape memory alloy, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P059, pp.1-2, 2016
Abstract:

Shape memory alloys (SMAs) are remarkable materials characterized by the thermomechanical properties of shape memory effect and superelasticity. Since the properties like these characteristics are highly conducive to the functions of smart materials, their applications have attracted worldwide attention. The functional properties of an SMA appear based on the martensitic transformation (MT). Research up to now in this area has been mainly concerned with a full loop (or perfect loop) of the MT completion. However, in practical applications, temperature and stress are likely to vary in various ranges. If SMA elements are subjected to loads with a subloop (or partial loop, internal loop) in which temperature or stress varies in an incomplete MT range, the conditions for the start and finish of the MT as in a full loop are not satisfied. The present paper investigates superelastic deformation behaviors of TiNi alloy in various subloop loading conditions, in particular the dependence of the subloop deformation on the loading rate, and the characteristics of transformation-induced creep in the stress plateau region under constant stress.

Keywords:

Shape memory alloy, subloop deformation, temperature distribution, pseudoelastic behaviour

Affiliations:
Takeda K.-Aichi Institute of Technology (JP)
Matsui R.-Aichi Institute of Technology (JP)
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
10.Takeda K., Matsui R., Tobushi H., Pieczyska E.A., Design of rotary driving actuator by using torsional deformation of SMA tapes, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P057, pp.1-2, 2016
Abstract:

One of the main materials which have activated the research on the smart materials is shape memory alloy (SMA). The main characteristics of SMA are the shape memory effect (SME) and superelasticity (SE). In a recent study using the torsional deformation of a TiNi SMA tube, twist in the blades of rotary aircraft was investigated in order to improve the flight performance. In practical applications making use of SMA tapes, torsional deformation can be obtained simply by gripping both ends without any mechanical process. In the present study, in order to develop the rotary driving actuators of SMA tapes, the torsional deformation properties of TiNi SMA tapes are investigated. The graphical method to design the two-way rotary driving actuator by using torsional deformation of SMA tapes is proposed.

Keywords:

Shape memory alloy, torsion, rotary driving, actuator

Affiliations:
Takeda K.-Aichi Institute of Technology (JP)
Matsui R.-Aichi Institute of Technology (JP)
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
11.Golasiński K., Pieczyska E., Staszczak M., Furuta T., Kuramoto S., Thermomechanical Investigation of Gum Metal – a New Innovative Titanium Alloy for Biomedical Applications, The 10th International Congress of Societas Humboldtiana Polonorum “Longevity - a blessing or a curse”, 2016-06-30/07-02, Łódź (PL), pp.43, 2016
Keywords:

Gum metal, biomedical application, superelastic properties

Affiliations:
Golasiński K.-IPPT PAN
Pieczyska E.-IPPT PAN
Staszczak M.-IPPT PAN
Furuta T.-Toyota Central Research & Development Laboratories (JP)
Kuramoto S.-Ibaraki University Japan (JP)
12.Pieczyska E., Maj M., Furuta T., Kuramoto S., Gum Metal – unique properties and results of initial investigation of the new titanium alloy, PCM-CMM 2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.145-146, 2015
Abstract:

Initial results of effects of thermomechanical couplings in the β-Ti alloy, Gum Metal, subjected to tension are presented. An MTS testing machine allows obtaining stress-strain curves with high accuracy, while fast and sensitive infrared camera allows estimating temperature changes of the sample during the deformation process. The obtained mechanical characteristics confirm an ultra-low elastic modulus and high strength of the Gum Metal. The infrared measurements enable to indicate average or maximum temperature change accompanying the alloy deformation process, to estimate thermoelastic effect, related to the yield point in solids, whereas the temperature distribution on the sample surface enables to investigate localisation effects, leading to the sample necking and rupture.

Keywords:

Gum Metal, Titanium alloy, Elastic properties, Nonlinear elasticity, thermomechanical couplings, infrared camera

Affiliations:
Pieczyska E.-IPPT PAN
Maj M.-IPPT PAN
Furuta T.-Toyota Central Research & Development Laboratories (JP)
Kuramoto S.-Ibaraki University Japan (JP)
13.Kukla D., Staszczak M., Pieczyska E., Heljak M., Szlązak K., Święszkowski W., Cristea M., Tobushi H., Hayashi S., Evaluation of the properties of polymeric foams with shape memory under load, PCM-CMM 2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.143-144, 2015
Abstract:

The paper presents the results of experimental investigation on polymer foam with shape memory properties. The research is focused on characterization of the microstructure of the foam and understanding the mechanisms of deformation under static and dynamic loading. Up till now, selected experimental techniques have been applied. Dynamic Mechanical Analysis (DMA) allows determining the extent of the value of the glass transition temperature under different load conditions, which also reveals the transformation temperature range for the SMP foam. Scanning electron microscopy (SEM) shows the foam microstructure in various scales, while X-ray tomography gave 3D microstructure results presenting in addition mechanism of the cells deformation and changes in their geometry under 30 % and 50% strain. BOSE system enables obtaining the results on dynamic loading.

Keywords:

Shape memory polymer foam, Dynamic mechanical analysis, Glass transition temperature, X-ray tomography

Affiliations:
Kukla D.-IPPT PAN
Staszczak M.-IPPT PAN
Pieczyska E.-IPPT PAN
Heljak M.-other affiliation
Szlązak K.-other affiliation
Święszkowski W.-other affiliation
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
14.Staszczak M., Pieczyska E., Maj M., Kowalczyk-Gajewska K., Cristea M., Tobushi H., Hayashi S., Shape memory polymer – shape fixity and recovery in cyclic loading, PCM-CMM 2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.147-148, 2015
Abstract:

The paper concerns investigation of polyurethane shape memory polymer (SMP) properties. Shape fixity and shape recovery, important parameters for the SMP applications, were quantitatively estimated in thermomechanical cyclic loading; three subsequent thermomechanical loading cycles were performed. It was observed that the shape fixity is proper and does not depend on the cycle number. The obtained mean values of shape fixity parameters are 97-98 %. Although the shape recovery is poor (=83 %) in the first cycle of the thermomechanical loading, it is excellent in the subsequent cycles (=99-100 %). The evaluated parameters confirm good shape memory properties of the SMP.

Keywords:

Shape memory polyurethane, shape fixity, shape recovery, thermomechanical loading, cyclic loading

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
15.Takeda K., Matsui R., Tobushi H., Pieczyska E., Transformation-Induced Creep and Relaxation of TiNi Shape Memory Alloy, PCM-CMM 2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.151-152, 2015
Abstract:

If the shape memory alloy (SMA) is subjected to the subloop loading under the stress- or strain-controlled condition, transformationinduced creep or relaxation can appear based on the martensitic transformation (MT). In the design of SMA elements, these deformation properties are important since the deflection or force of SMA elements can change under constant load or constant strain. The conditions for the progress of the MT are discussed based on the kinetics of the MT for the SMA. The creep and relaxation properties are investigated experimentally for TiNi SMA. If the stress is kept constant at the upper stress plateau after loading with a high strain or stress rate up to the stress-holding start strain, the transformation-induced creep occurs due to the spread of the stress-induced martensitic transformation process. If the strain is kept constant at the upper stress plateau after loading with a high stress rate, the transformation-induced relaxation appears due to the exothermic MT until the holding strain and thereafter temperature decreases while holding the strain constant.

Keywords:

shape memory alloy, superelasticity, transformation-induced creep, transformation-induced relaxation

Affiliations:
Takeda K.-Aichi Institute of Technology (JP)
Matsui R.-Aichi Institute of Technology (JP)
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.-IPPT PAN
16.Pieczyska E., Staszczak M., Maj M., Kowalczyk-Gajewska K., Tobushi H., Właściwości termomechaniczne i zastosowania polimerów z pamięcią kształtu, XI Konferencja Nowe Kierunki Rozwoju Mechaniki, 2015-03-18/03-20, Sarbinowo (PL), pp.75-76, 2015
Abstract:

Polimery z pamięcią kształtu, podobnie jak niektóre stopy metali, wykazują efekt pamięci kształtu. Wykorzystuje się w nich różnicę właściwości termomechanicznych poniżej i powyżej temperatury zeszklenia Tg, w której polimer radykalnie zmienia swe własności, m.in. wartość modułu sprężystości. Materiały te posiadają możliwość szybkiej zmiany właściwości fizycznych w zależności od temperatury. Stają się miękkie po podgrzaniu powyżej Tg i pozwalają się łatwo formować, a podczas schłodzenia poniżej tej temperatury odzyskują poprzednią sztywność. Nadal pamiętają swój oryginalny kształt i wracają do niego podczas ponownego podgrzania powyżej Tg. Umożliwia to ich różnorodne praktyczne zastosowania, m.in. w przemyśle medycznym i farmaceutycznym, tekstylnym, spożywczym, lotniczym i kosmicznym.

Keywords:

Polimery z pamięcią kształtu, temperatura zeszklenia, wartość modułu sprężystości, kamera termowizyjna

Affiliations:
Pieczyska E.-IPPT PAN
Staszczak M.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
17.Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Tobushi H., Hayashi S., Cristea M., Thermomechanical analysis of shape memory polymer under cyclic loading and relaxation conditions, ICEM-16, 16th International Conference on Experimental Mechanics, 2014-07-07/07-11, Cambridge (GB), pp.1-2, 2014
Abstract:

Experimental evaluation and modeling of a new polyurethane shape memory polymer (SMP) subjected to cyclic tension and stress-relaxation tests are presented. The influence of effects of thermomechanical couplings on the SMP thermomechanical behaviour for various strain rates was studied, basing on the sample temperature changes measured by a fast and sensitive infrared camera. The constitutive model valid in finite strain regime was developed following [5]. In the proposed approach SMP is described as a two-phase material composed of hyperelastic rubbery phase and elastic-viscoplastic glassy phase while the volume content of phases is specified by the current temperature.

Keywords:

Experimental evaluation, constitutive modeling, polyurethane shape memory polymer, cyclic tension, stress-relaxation tests, effects of thermomechanical couplings, thermomechanical behaviour, various strain rates, temperature changes, sensitive infrared camera, hyperelastic rubbery phase, elastic-viscoplastic glassy phase

Affiliations:
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Staszczak M.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
18.Dunić V., Pieczyska E.A., Busarac N., Slavković R., Slavković V., Partitioned thermo-mechanical coupling of SMA constitutive model, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.255-256, 2014
Abstract:

For many kinds of materials (e.q. metals, shape memory alloys, etc.), thermal changes coupled with the deformation process can have significant effect on the mechanical response and also on the accuracy of numerical analysis. In order to take them into account, monolithic coupling algorithms have been used, however a partitioned approach can also be applied. An advantage of the partitioned thermo-mechanical coupling is the possibility to re-use already developed software to simulate various kinds of multiphysics scenarios, i.e. various coupled fields: structure, heat transfer, fluids, magnetic, etc. To realize the partitioned approach, communication protocols for exchange of information between the used codes are needed [1]. To this end, Component Template Library (CTL) [2], developed at the Institute of Scientific Computing, TU Braunschweig, Germany, is used as a middleware between the FEM programs for the structural analysis (PAKS) and the heat transfer analysis (PAKT).

Keywords:

deformation process, shape memory alloys, mechanical response, numerical analysis, partitioned thermo-mechanical coupling, multiphysics scenarios, structural analysis

Affiliations:
Dunić V.-University of Kragujevac (XS)
Pieczyska E.A.-IPPT PAN
Busarac N.-University of Kragujevac (XS)
Slavković R.-University of Kragujevac (XS)
Slavković V.-University of Kragujevac (XS)
19.Kowalczyk-Gajewska K., Pieczyska E.A., Maj M., Staszczak M., Majewski M., Cristea M., Tobushi H., Two-phase model of shape memory polymers at finite strains: formulation and experimental verification, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.259-260, 2014
Abstract:

A constitutive model of SMP, formulated at large strain format, is developed. SMP is described as a two-phase material composed of a soft rubbery phase and a hard glassy phase. The volume fraction of each phase is postulated as a logistic function of temperature. Identification of model parameters has been performed using the experimental tensile loading-unloading tests with different strain rates conducted at thermal chamber at different temperatures.

Keywords:

shape-memory polymers, two-phase model, large strain framework

Affiliations:
Kowalczyk-Gajewska K.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Staszczak M.-IPPT PAN
Majewski M.-IPPT PAN
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
20.Pieczyska E.A., Ferromagnetic single crystal shape memory alloy subjected to subsequent compression cycles, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.263-264, 2014
Abstract:

The paper presents effects of thermomechanical coupling related to pseudoelastic deformation of NiFeGaCo single crystal of ferromagnetic shape memory alloy (FSMA) subjected to subsequent loading-unloading compression cycles. The stress-strain parameters were obtained by mechanical and laser extensometers, whereas infrared measurement system (IR) enabled measurement of the sample temperature during the SMA deformation process. The obtained thermograms exposure localized character of the stress-induced martensitic transformation (SIMT), initiating in form of inclined bands of higher temperature and developing throughout the sample. High repeatability of both mechanical and temperature changes obtained in the subsequent loading cycles indicates good thermomechanical properties of the FSMA crystal and confirms high accuracy of the measurement.

Keywords:

hermomechanical coupling, pseudoelastic deformation, NiFeGaCo single crystal, ferromagnetic shape memory alloy, subsequent loading-unloading compression cycles, infrared camera, transformation bands

Affiliations:
Pieczyska E.A.-IPPT PAN
21.Staszczak M., Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Cristea M., Tobushi H., Hayashi S., Estimation of shape fixity and shape recovery – crucial parameters for shape memory polymer applications, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.267-268, 2014
Abstract:

Shape memory polymers (SMP) are new unique and attractive materials which demonstrate shape memory properties. It means that the materials, as a result of an external stimulus such as temperature, can recover their original (permanent) shape from deformed (temporary) shape. The mechanical characteristics of SMP, e.g. the elastic modulus and the yield stress, change significantly below and above their glass transition temperature Tg. It can be explained by differences of molecular motion of the polymer chains below and above Tg [1, 2]. Two phenomena due to this can be observed in the SMP. The first one is a shape fixity which means that it is possible to fix a temporary shape by cooling the deformed SMP below Tg. The second phenomenon, called a shape recovery, denotes the property that the original shape, changed due to deformation, is recovered during subsequent heating above the SMP Tg temperature. Preliminary estimation of these two parameters, crucial to assess SMP potential applications, is the subject of this paper [1].

Keywords:

Shape memory polymers, elastic modulus, yield stress, glass transition temperature, shape fixity, shape recovery

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
22.Takeda K., Matsui R., Tobushi H., Pieczyska E.A., Stress relaxation and stress recovery of tini shape memory alloy in stress-controlled subloop loading, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.271-272, 2014
Abstract:

Shape memory polymers (SMP) are new unique and attractive materials which demonstrate shape memory properties. It means that the materials, as a result of an external stimulus such as temperature, can recover their original (permanent) shape from deformed (temporary) shape. The mechanical characteristics of SMP, e.g. the elastic modulus and the yield stress, change significantly below and above their glass transition temperature Tg. It can be explained by differences of molecular motion of the polymer chains below and above Tg [1, 2]. Two phenomena due to this can be observed in the SMP. The first one is a shape fixity which means that it is possible to fix a temporary shape by cooling the deformed SMP below Tg. The second phenomenon, called a shape recovery, denotes the property that the original shape, changed due to deformation, is recovered during subsequent heating above the SMP Tg temperature. Preliminary estimation of these two parameters, crucial to assess SMP potential applications, is the subject of this paper [1].

Keywords:

Shape memory polymers, elastic modulus, yield stress, glass transition temperature, shape fixity, shape recovery

Affiliations:
Takeda K.-Aichi Institute of Technology (JP)
Matsui R.-Aichi Institute of Technology (JP)
Tobushi H.-Aichi Institute of Technology (JP)
Pieczyska E.A.-IPPT PAN
23.Pieczyska E., Tobushi H., Hayashi S., Maj M., Kowalczyk-Gajewska K., Staszczak M., Cristea M., Thermomechanical Analysis of Shape Memory Polyurethane, 4th Integrity, Reliability and Failure of Mechanical Systems, 2013-06-23/06-27, Funchal (PT), pp.1-2, 2013
Abstract:

This paper presents experimental evaluation of a new polyurethane shape memory polymer (PU-SMP) produced by SMP Technologies Inc. It discusses mechanical characteristics and temperature changes of the SMP specimens subjected to tension test performed at room temperature with various strain rates. Basing on the mechanical data and the relevant temperature changes, we have studied the thermomechanical properties of the PU-SMP and influence of the strain rate on the strain localization behavior. Finally, we have identified the material parameters for the one-dimensional rheological model of the SMP.

Keywords:

shape memory polyurethane, tension test, dynamic mechanical analysis, infrared camera, temperature change, thermomechanical properties, rheological model

Affiliations:
Pieczyska E.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Staszczak M.-IPPT PAN
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
24.Pieczyska E.A., Tobushi H., Hayashi S., Maj M., Staszczak M., Shape memory alloys and polymers studied in tension by advanced infrared technique, DAS 30, 30th Danubia-Adria-Symposium on Advances in Experimental Mechanics, 2013-09-25/09-28, Primosten (HR), Vol.1, pp.24-25, 2013
Abstract:

In order to contribute to solving the problems of recourses, energy and environment of the earth, the development of multifunctional smart materials is required. In the intelligent materials, investigation of shape memory alloy (SMA) and shape memory polymer (SMP) has attracted high attention due to their functional properties and high potential in practical applications. In SMA, the shape memory property appears based on the martensitic transformation (MT) in which the crystal structure varies depending on the variation in stress or temperature. In SMP, the elastic modulus and the yield stress are high at temperatures below the glass transition temperature Tg and low at temperatures above Tg. The shape memory property appears based on the glass transition in which the characteristics of molecular motion vary depending on the variation in temperature. Among the shape memory polymers, the polyurethane has been most often practically used.
In this paper, investigation of stress-induced martensitic transformation in TiNi SMA and thermomechanical behavior of SMP (Tg = 19 C) in tension at room temperature (22 C) are presented.

Keywords:

shape memory alloy, shape memory polymer, thermomechanical couplings, tensile test, strain localisation

Affiliations:
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
Maj M.-IPPT PAN
Staszczak M.-IPPT PAN
25.Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Mechanical and Infrared Thermography Analysis of Shape Memory Polyurethane, International Conference on Shape Memory and Superelastic Technologies, 2013-05-20/05-24, Praga (CZ), pp.282-283, 2013
Abstract:

Initial experimental evaluation of a new polyurethane shape memory polyner (PU-SMP) subjected to uniaxial tension carrięd out at different stlain rates is presented. The stress and strain data were recorded and temperature changes from the SMP specimen surface was deternrined using fast and sensitive infrared camera. Basing on themechanical characteristics and their relevant temperature changes, the SMP thernromechanical properties have been stLrdied. lnfluence of the strain rate on the SMP temperature, its structure and behaviour are discussed. Identification of the PU-SMP parameters for onc-dimensional rheological model proposed by Tobushi et. ttl. will be performed.

Keywords:

Shape memory polymers, elastic modulus, yield stress, glass transition temperature

Affiliations:
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Kowalczyk-Gajewska K.-IPPT PAN
Staszczak M.-IPPT PAN
26.Pieczyska E.A., Tobushi H., Development of stress-induced martensitic transformation in TiNi Shape Memory Alloy, International Conference on Shape Memory and Superelastic Technologies, 2013-05-20/05-24, Praga (CZ), pp.225-226, 2013
Abstract:

A development manner of the stress-induced martensitic transformation (SIMT) associated with the unique properties of shape memory alloys (SMA) and their applications have been recently studied in several research centers !1. It is well known that the SIMT forward is exothermic whilst the reverse one exhibits endothermic propelty. The temperature changes were estinrated for simple shear [2], tension [3], and conrpression [4]. In this research, we focus on three SIMT aspects: the nucleation of the initial macroscopically honrogenous transforntation, the initiation and development ofthe localized bands, and the conditions ofthe transfornration saturation.

Keywords:

Shape memory alloys, stress-induced martensitic transformation, exothermic forward transformation, endothermic reverse transformation, infrared camera, temperature distribution, localized transformation bands

Affiliations:
Pieczyska E.A.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
27.Staszczak M., Pieczyska E.A., Maj M., Urbański L., Tobushi H., Hayashi S., Właściwości mechaniczne oraz zmiany temperatury polimeru z pamięcią kształtu w procesie rozciągania, TTP2013, X Konferencja TERMOGRAFIA I TERMOMETRIA W PODCZERWIENI, 2013-09-24/09-26, Lwów (UA), Vol.1, pp.91-92, 2013
Abstract:

W pracy przedstawiono wyniki badań efektów sprzężeń termomechanicznych poliuretanu z pamięcią kształtu podczas rozciągania z różnymi prędkościami. Zależności zmiany temperatury próbek od czasu wyznaczano za pomocą kamery termograficznej. Zaobserwowano dużą wrażliwość charakterystyk mechanicznych i zmian temperatury poliuretanu na prędkość deformacji. Wykorzystując efekt piezokaloryczny wyznaczano granice plastyczności dla różnych prędkości odkształcenia. Pokazano, że metoda bazująca na minimum temperatury próbki jest przydatna do wyznaczania granicy plastyczności materiałów polimerowych wykazujących nieliniową sprężystość.

Keywords:

poliuretan z pamięcią kształtu, efekty sprzężeń termomechanicznych, kamera termograficzna, efekt piezokaloryczny, granica plastyczności

Affiliations:
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Maj M.-IPPT PAN
Urbański L.-IPPT PAN
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)
28.Pieczyska E.A., Tobushi H., Takeda K., Kulasiński K., Luckner J., Thermomechanical Coupling and Transformation-Induced Stress relaxation Effects in TiNi Shape Memory Alloy, ICTAM XXIII, 23rd International Congress of Theoretical and Applied Mechanics, 2012-08-19/08-24, Beijing (CN), Vol.1, pp.1-2, 2012