Teresa Frąś, Ph.D., Eng.


Doctoral thesis
2013-06-21Modélisation de la surface d'écoulement des matériaux incluant l'anisotropie initiale et l'effet différentiel des contraintes, approche expérimentale et numérique  (UL/AGH)
supervisor -- Prof. Ryszard Pęcherski, Ph.D., Dr. Habil., Eng., IPPT PAN
supervisor -- M. Alexis Rusinek, ENIM
662
 
Recent publications
1.Fras T., Murzyn A., Pawłowski P., Defeat mechanisms provided by slotted add-on bainitic plates against small-calibre 7.62 mm x 51 AP projectiles., INTERNATIONAL JOURNAL OF IMPACT ENGINEERING, ISSN: 0734-743X, DOI: 10.1016/j.ijimpeng.2017.01.015, Vol.103, pp.241-253, 2017
Abstract:

Thin steel plates with an array of holes, i.e. perforated plates, are used as a passive add-on improving protective properties of armours against small-calibre projectiles. A number of holes in such plates increases the probability of asymmetrical contact between the plate and the projectile, due to which small-calibre projectiles may be destabilized or fragmented before they reach the main-armour. The aim of the study is to analyse the defeat mechanisms provided by 4-mm-thick slotted super-bainitic plates (Pavise™ SBS 600P) against hard-core 7.62mm P80 0.30 AP×51 (0.308 Win) projectiles. To show the dependence between the hit-point and projectile failure, moments when projectiles hit the pre-armour plate were recorded by an ultra-high speed camera and their behaviour after the impact was captured by the flash X-ray radiography. The obtained results complemented by the Lagrangian FEM analysis confirm that slotted steel plates have high protection effectiveness against small-calibre projectiles.

Keywords:

Light-weight ballistic protectionPerforated add-on armourSuper-bainitic steelArmour-piercing (AP) projectile

Affiliations:
Fras T.-IPPT PAN
Murzyn A.-French-German Research Institute of Saint-Louis (DE)
Pawłowski P.-IPPT PAN
2.Frąś T., Colard L., Pawłowski P., Perforation of aluminum plates by fragment simulating projectiles (FSP), THE INTERNATIONAL JOURNAL OF MULTIPHYSICS, ISSN: 1750-9548, DOI: 10.1260/1750-9548.9.3.267, Vol.9, No.3, pp.267-286, 2015
Abstract:

The paper describes the ballistic impact test, in which fragment simulating projectiles (FSPs) of a 20-mm-diameter have been used against 40-mmthick plates made of an aluminum alloy AA7020-T651. To perforate plates, the projectiles must have reached a velocity higher than 890 m/s. Based on the performed ballistic test, the plugging failure mode is numerically modeled using the LS-DYNA software package. Results obtained due to the calculations in the Finite Element Method (FEM) are compared with the results from the Smoothed Particle Hydrodynamics (SPH). A condition of geometrical similarity between the target deformed experimentally and its numerical representation is introduced to evaluate the performed simulations.

Keywords:

Ballistic impact test, Fragment simulating projectile (FSP), Plugging failure mode, Smooth Particle Hydrodynamics (SPH), Optical scanning

Affiliations:
Frąś T.-IPPT PAN
Colard L.-French-German Research Institute of Saint-Louis (DE)
Pawłowski P.-IPPT PAN
3.Frąś T., Rusinek A., Pęcherski R.B., Bernier R., Jankowiak T., Analysis of friction influence on material deformation under biaxial compression state, TRIBOLOGY INTERNATIONAL, ISSN: 0301-679X, DOI: 10.1016/j.triboint.2014.06.019, Vol.80, pp.14-24, 2014
Abstract:

The biaxial compression test, based on the concept presented in [1] and on the technique of the channel-die test [2] and [3], is discussed as an experimental method allowing evolution of the friction conditions from the dry-film lubrication, by using MoS2 grease, to the dry conditions to be analysed. This article gives an outline of the experimental set-up, its validation and the technique of the test results analysis. The analysis of friction is based on the experimental data coupled with the numerical simulation of the performed tests and on the theoretical approach introduced in [4]. The Oxygen-Free High Conductivity (OFHC) copper in the ‘as-received’ state in contact with the 42CrMo4 steel are chosen as the materials used for the experimental investigation.

Keywords:

Biaxial compression, Friction modelling, OFHC copper

Affiliations:
Frąś T.-other affiliation
Rusinek A.-National Engineering School of Metz (ENIM) (FR)
Pęcherski R.B.-other affiliation
Bernier R.-National Engineering School of Metz (ENIM) (FR)
Jankowiak T.-other affiliation
4.Frąś T., Nishida M., Rusinek A., Pęcherski R., Fukuda N., Description of the Yield State of Bioplastics on Examples of Starch-Based Plastics and PLA/PBAT Blends, ENGINEERING TRANSACTIONS (ROZPRAWY INŻYNIERSKIE), ISSN: 0867-888X, Vol.62, No.4, pp.329-354, 2014
Abstract:

The present work concerns the description of the yield state of biodegradable materials. As examples, biodegradable polymers are chosen – cornpole CRP-M2, starch fatty acid ester, and PLA/PBAT, poly(lactic acid) (PLA) blended with poly(butylene adipate/terephthalate) (PBAT) [1, 2]. These biodegradable, plant-derived bioplastics are a promising alternative to petroleum-based plastics. To describe the onset of plasticity in the bioplastics under discussion, Burzyński ’s hypothesis of material effort has been applied [3, 4]. The applied criteria account for the differential strength effect and for the shear correction resulting from the difference between experimental and theoretical values, obtained as a result of the Huber-Mises approach [5, 6]. In general, these properties of yield state are characteristic for polymers. The description of yield state for bioplastics is an issue that has hardly been investigated, which illustrates the novel nature of this paper in which this topic is discussed

Keywords:

bioplastics, strength differential effect, shear correction, yield surface, Burzyński yield condition

Affiliations:
Frąś T.-IPPT PAN
Nishida M.-Nagoya Institute of Technology (JP)
Rusinek A.-National Engineering School of Metz (ENIM) (FR)
Pęcherski R.-IPPT PAN
Fukuda N.-Aichi Center for Industry and Science Technology (JP)
5.Frąś T., Nowak Z., Perzyna P., Pęcherski R.B., Identification of the model describing viscoplastic behaviour of high strength metals, INVERSE PROBLEMS IN SCIENCE AND ENGINEERING, ISSN: 1741-5977, DOI: 10.1080/17415977.2010.531474, Vol.19, No.1, pp.17-30, 2011
Abstract:

Ultrafine grained (UFG) and nanocrystalline metals (nc-metals) are studied. Experimental investigations of the behaviour of such materials under quasistatic as well as dynamic loading conditions related with microscopic observations show that in many cases the dominant mechanism of plastic strain is a multiscale development of shear deformation modes. The comprehensive discussion of these phenomena in UFG and nc-metals is given in M.A. Meyers, A. Mishra and D.J. Benson [Mechanical properties of nanocrystalline materials, Progr. Mater. Sci. 51 (2006), pp. 427–556], where it has been shown that the deformation mode of nanocrystalline materials changes as the grain size decreases into the ultrafine region. For smaller grain sizes (d < 300 nm) shear band development occurs immediately after the onset of plastic flow. Significant strain-rate dependence of the flow stress, particularly at high strain rates, was also emphasized. Our objective is to identify the parameters of Perzyna constitutive model, a new description of viscoplastic deformation, which accounts for the observed shear banding. The viscoplasticity model proposed earlier by Perzyna [Fundamental problems in viscoplasticity, Adv. Mech. 9 (1966), pp. 243–377] was extended in order to describe the shear banding contribution in Z. Nowak, P. Perzyna, R.B. Pecherski [Description of viscoplastic fow accounting for shear banding, Arch. Metall. Mater. 52 (2007), pp. 217–222]. The shear banding contribution function, which was introduced formerly by Pe¸cherski [Modelling of large plastic deformation produced by micro-shear banding, Arch. Mech. 44 (1992), pp. 563–584] and applied in continuum plasticity accounting for shear banding in R.B. Pecherski [Macroscopic measure of the rate of deformation produced by micro-shear banding, Arch. Mech. 49 (1997), pp. 385–401] plays pivotal role in the viscoplasticity model. The derived constitutive equations were identified and verified with the application of experimental data provided in the article by D. Jia, K.T. Ramesh and E. Ma [Effects of nanocrystalline and ultrafne grain sizes on constitutive behavior and shear bands in iron, Acta Mat. 51 (2003), pp. 3495–3509], where quasistatic and dynamic compression tests with UFG and nanocrystalline iron specimens of a wide range of mean grain size were reported. Numerical simulation of the compression of the prismatic specimen was made by the ABAQUS FEM program with UMAT subroutine. Comparison with experimental results proved the validity of the
identified parameters and the possibilities of the application of the proposed description for other high strength metals.

Keywords:

Ultra fine grained metals, nanocrystalline metals, viscoplastic deformation, shear banding, shear banding contribution function, numerical simulation of compression test, identification of the model parameters

Affiliations:
Frąś T.-IPPT PAN
Nowak Z.-IPPT PAN
Perzyna P.-IPPT PAN
Pęcherski R.B.-IPPT PAN
6.Frąś T., Kowalewski Z.L., Pęcherski R.B., Rusinek A., Applications of Burzyński failure criteria - I. Isotropic materials with asymmetry of elastic range, ENGINEERING TRANSACTIONS (ROZPRAWY INŻYNIERSKIE), ISSN: 0867-888X, Vol.58, pp.1-10, 2010
Abstract:

The main idea of energy-based hypothesis of material effort proposed by Burzyński is briefly presented and the resulting failure criteria are discussed. Some examples, based on the own studies, which depict applications of these criteria are discussed and visualisations of limit surfaces in the space of principal stresses are presented.

Keywords:

Burzyński yield condition, yield surface, strength differential effect, energy-based yield criteria

Affiliations:
Frąś T.-IPPT PAN
Kowalewski Z.L.-IPPT PAN
Pęcherski R.B.-IPPT PAN
Rusinek A.-National Engineering School of Metz (ENIM) (FR)
7.Frąś T., Pęcherski R., Applications of the Burzyński hypothesis of material effort for isotropic solids, MECHANICS AND CONTROL, ISSN: 2083-6759, Vol.29, No.2, pp.45-50, 2010
Abstract:

The paper contains a short presentation of main idea of energy-based hypothesis of material effort proposed by Burzyński with discussion of the resulting failure criteria. Some examples illustrating applications of these criteria are discussed and visualisations of limit surfaces in the space of principal stresses are presented.

Keywords:

Burzyński yield condition, yield surface, strength differential effect, energy-based yield criteria

Affiliations:
Frąś T.-IPPT PAN
Pęcherski R.-other affiliation

List of chapters in recent monographs
1.
335
Pęcherski R.B., Nalepka K.T., Frąś T., Nowak M., Constitutive Relations under Impact Loadings. Experiments, Theoretical and Numerical Aspects, rozdział: Inelastic Flow and Failure of Metallic Solids. Material Effort: Study Across Scales, Springer, CISM, Udine, T. Łodygowski, A. Rusinek (Eds.), 552, pp.245-285, 2014

Conference papers
1.Pawłowski P., Frąś T., Numerical and experimental investigation of asymmetrical contact between a steel plate and armour-piercing projectiles, LS-DYNA 2017, European LS-DYNA Conference 2017, 2017-05-09/05-11, Salzburg (AT), pp.1-9, 2017
Abstract:

Protection of combat-vehicles against impacts of small-calibre projectiles may be improved by the application of relatively thin and hard steel plates perforated by a plurality of holes. It is observed that due to the contact with a plate,the core of armour-piercing (AP) projectiles may be shattered, partially eroded or rotated, depending on the hit-position. The contact asymmetry is the strongest when a projectile hits a hole edge, its core undergoes bending and tends to fracture. The presented study discusses two methods of modelling of the contact and interactions between a bullet and a steel target. One of them is the explicit Lagrangian simulation of impacts of a fully represented AP projectile, another one is the semi-analytical model based on the integration of the motion equations of a 6 DOF rigid projectile. The results of numerical and semi-analytical approaches are compared with the ballistic impact experiment, in which the defeat mechanisms provided by 4-mm-thick slotted bainitic plates (Pavise™ SBS 600P) against hard-core 7.62 mm P80 0.30 AP x 51 (.308 Win) projectiles were verified, [1].

Affiliations:
Pawłowski P.-IPPT PAN
Frąś T.-IPPT PAN
2.Frąś T., Roth M., Pawłowski P., Thermo-viscoplastic behavior of AA7020-T651 in application for modeling of dynamic loadings, ICCEE 2016, International Conference on Civil and Environmental Engineering, 2016-10-17/10-19, Hiroshima (JP), pp.1-8, 2016
Abstract:

The stress–strain behavior of the rolled AA7020 aluminum tempered in T651 conditions is studied at various strain rates and temperatures. Basing on tensile, shear and compression tests, the effects of strain and strain-rate hardening, thermal softening and plastic anisotropy are discussed. The parameters of the thermo-viscoplastic flow and fracture models proposed by Johnson and Cook are identified and validated basing on the numerical modeling.
The obtained constitutive relations may be applied to model more complex states of stresses resulted from different loading conditions.

Keywords:

AA7020-T651, flow and fracture models, metals under dynamic loadings, numerical simulation of metal deformation

Affiliations:
Frąś T.-IPPT PAN
Roth M.-Giessen University of Applied Sciences (DE)
Pawłowski P.-IPPT PAN

Conference abstracts
1.Frąś T., Roth M., Pawłowski P., Thermo-viscoplastic behavior of AA7020-T651 in application for modeling of dynamic loadings, ICCEE 2016, International Conference on Civil and Environmental Engineering, 2016-10-17/10-19, Hiroshima (JP), pp.1-2, 2016
Abstract:

The stress–strain behavior of the rolled AA7020 aluminum tempered in T651 conditions is studied at various strain rates and temperatures. Basing on tensile, shear and compression tests, the effects of strain and strain-rate hardening, thermal softening and plastic anisotropy are discussed. The parameters of the thermo-viscoplastic flow and fracture models proposed by Johnson and Cook are identified and validated basing on the numerical modeling.
The obtained constitutive relations may be applied to model more complex states of stresses resulted from different loading conditions.

Keywords:

AA7020-T651, flow and fracture models, metals under dynamic loadings, numerical simulation of metal deformation

Affiliations:
Frąś T.-IPPT PAN
Roth M.-Giessen University of Applied Sciences (DE)
Pawłowski P.-IPPT PAN
2.Frąś T., Luckner J., Nowak M., Nowak Z., Pęcherski R., Analiza procesu formowania blach z uwzględnieniem różnicy wytrzymałości przy ściskaniu i rozciąganiu, PLASMET/2012, VIII Seminarium Naukowe Zintegrowane Studia Podstaw Deformacji Plastycznej Metali, 2012-11-20/11-23, Łańcut (PL), pp.1-3, 2012
3.Frąś T., Luckner J., Nowak M., Nowak Z., Pęcherski R., Rusinek A., Stręk A., Zastosowanie kryteriów granicznych Burzyńskiego I. Metale i kompozyty metaliczno-ceramiczne II. Pianki metaliczne, PLASMET/2012, VIII Seminarium Naukowe Zintegrowane Studia Podstaw Deformacji Plastycznej Metali, 2012-11-20/11-23, Łańcut (PL), pp.1-4, 2012
4.Frąś T., Pęcherski R., Rusinek A., Experimental investigations of the influence of moderate strains and strain rates on the yield surface of OFHC copper, SolMech 2012, 38th Solid Mechanics Conference, 2012-08-27/08-31, Warszawa (PL), pp.122-123, 2012
5.Nowak Z., Frąś T., Nowak M., Pęcherski R.B., Analysis of the forming Processes Accounting for Asymmetry of Elastic Range, SolMech 2012, 38th Solid Mechanics Conference, 2012-08-27/08-31, Warszawa (PL), pp.92-93, 2012