Publikacje odnotowane przez trzy miesiące

1.Czerkies M., Korwek Z., Prus W., Kochańczyk M., Jaruszewicz-Błońska J., Tudelska K., Błoński S., Kimmel M., Brasier A.R., Lipniacki T., Cell fate in antiviral response arises in the crosstalk of IRF, NF-κB and JAK/STAT pathways, Nature Communications, ISSN: 2041-1723, DOI: 10.1038/s41467-017-02640-8, Vol.9, pp.493, 2018
Czerkies M., Korwek Z., Prus W., Kochańczyk M., Jaruszewicz-Błońska J., Tudelska K., Błoński S., Kimmel M., Brasier A.R., Lipniacki T., Cell fate in antiviral response arises in the crosstalk of IRF, NF-κB and JAK/STAT pathways, Nature Communications, ISSN: 2041-1723, DOI: 10.1038/s41467-017-02640-8, Vol.9, pp.493, 2018

Abstract:
The innate immune system processes pathogen-induced signals into cell fate decisions. How information is turned to decision remains unknown. By combining stochastic mathematical modelling and experimentation, we demonstrate that feedback interactions between the IRF3, NF-κB and STAT pathways lead to switch-like responses to a viral analogue, poly(I:C), in contrast to pulse-like responses to bacterial LPS. Poly(I:C) activates both IRF3 and NF-κB, a requirement for induction of IFNβ expression. Autocrine IFNβ initiates a JAK/STAT-mediated positive-feedback stabilising nuclear IRF3 and NF-κB in first responder cells. Paracrine IFNβ, in turn, sensitises second responder cells through a JAK/STAT-mediated positive feedforward pathway that upregulates the positive-feedback components: RIG-I, PKR and OAS1A. In these sensitised cells, the ‘live-or-die’ decision phase following poly(I:C) exposure is shorter—they rapidly produce antiviral responses and commit to apoptosis. The interlinked positive feedback and feedforward signalling is key for coordinating cell fate decisions in cellular populations restricting pathogen spread.

Keywords:
cellular signalling networks, innate immunity, regulatory networks, stochastic modelling

(45p.)
2.Rojek J., Zubelewicz A., Madan N., Nosewicz S., The discrete element method with deformable particles, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 0029-5981, DOI: 10.1002/nme.5767, pp.1-33, 2018
Rojek J., Zubelewicz A., Madan N., Nosewicz S., The discrete element method with deformable particles, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, ISSN: 0029-5981, DOI: 10.1002/nme.5767, pp.1-33, 2018

Abstract:
This work presents a new original formulation of the discrete element method (DEM) with deformable cylindrical particles. Uniform stress and strain fields are assumed to be induced in the particles under the action of contact forces. Particle deformation obtained by strain integration is taken into account in the evaluation of interparticle contact forces. The deformability of a particle yields a nonlocal contact model, it leads to the formation of new contacts, it changes the distribution of contact forces in the particle assembly, and it affects the macroscopic response of the particulate material. A numerical algorithm for the deformable DEM (DDEM) has been developed and implemented in the DEM program DEMPack. The new formulation implies only small modifications of the standard DEM algorithm. The DDEM algorithm has been verified on simple examples of an unconfined uniaxial compression of a rectangular specimen discretized with regularly spaced equal bonded particles and a square specimen represented with an irregular configuration of nonuniform-sized bonded particles. The numerical results have been verified by a comparison with equivalent finite elementmethod results and available analytical solutions. The micro-macro relationships for elastic parameters have been obtained. The results have proved to have enhanced the modeling capabilities of the DDEM with respect to the standard DEM.

Keywords:
average stress, deformable particles, discrete element method, elastic constants, micro-macro relationships, nonlocal contact model

(40p.)
3.Tůma K., Stupkiewicz S., Petryk H., Rate-independent dissipation in phase-field modelling of displacive transformations, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, ISSN: 0022-5096, DOI: 10.1016/j.jmps.2018.02.007, Vol.114, pp.117-142, 2018
Tůma K., Stupkiewicz S., Petryk H., Rate-independent dissipation in phase-field modelling of displacive transformations, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, ISSN: 0022-5096, DOI: 10.1016/j.jmps.2018.02.007, Vol.114, pp.117-142, 2018

Abstract:
In this paper, rate-independent dissipation is introduced into the phase-field framework for modelling of displacive transformations, such as martensitic phase transformation and twinning. The finite-strain phase-field model developed recently by the present authors is here extended beyond the limitations of purely viscous dissipation. The variational formulation, in which the evolution problem is formulated as a constrained minimization problem for a global rate-potential, is enhanced by including a mixed-type dissipation potential that combines viscous and rate-independent contributions. Effective computational treatment of the resulting incremental problem of non-smooth optimization is developed by employing the augmented Lagrangian method. It is demonstrated that a single Lagrange multiplier field suffices to handle the dissipation potential vertex and simultaneously to enforce physical constraints on the order parameter. In this way, the initially non-smooth problem of evolution is converted into a smooth stationarity problem. The model is implemented in a finite-element code and applied to solve two- and three-dimensional boundary value problems representative for shape memory alloys

Keywords:
Phase-field method, Microstructure, Martensite, Twinning, Non-smooth optimization

(40p.)
4.Kowalczyk-Gajewska K., Maździarz M., Atomistic and mean-field estimates of effective stiffness tensor of nanocrystalline copper, International Journal of Engineering Science, ISSN: 0020-7225, DOI: 10.1016/j.ijengsci.2018.04.004, Vol.129, pp.47-62, 2018
Kowalczyk-Gajewska K., Maździarz M., Atomistic and mean-field estimates of effective stiffness tensor of nanocrystalline copper, International Journal of Engineering Science, ISSN: 0020-7225, DOI: 10.1016/j.ijengsci.2018.04.004, Vol.129, pp.47-62, 2018

Abstract:
The full elasticity tensor for nano-crystalline copper is derived in molecular simulations by performing numerical tests for a set of generated samples of the polycrystalline material. The results are analysed with respect to the anisotropy degree of the overall stiffness tensor resulting from the limited number of grain orientations and their spatial distribution. The dependence of the overall bulk and shear moduli of an isotropized polycrystal on the average grain diameter is analysed. It is found that while the shear modulus decreases with grain size, the bulk modulus shows negligible dependence on the grain diameter and is close to the bulk modulus of a single crystal. A closed-form mean-field model of effective elastic properties for a bulk nano-grained polycrystal with cubic grains, i.e. made of a material with cubic symmetry, is formulated. In the model all parameters are based on the data for a single crystal and on the averaged grain size without any need for additional fitting. It is shown that the proposed model provides predictions of satisfactory qualitative and quantitative agreement with atomistic simulations.

Keywords:
Molecular statics, Elasticity, Polycrystal, Effective medium, Nano-crystalline copper

(40p.)
5.Jarecki L., Pecherski R.B., Kinetics of oriented crystallization of polymers in the linear stress-orientation range in the series expansion approach , Express Polymer Letters, ISSN: 1788-618X, DOI: 10.3144/expresspolymlett/2018.29, Vol.12, No.4, pp.330-348, 2018
Jarecki L., Pecherski R.B., Kinetics of oriented crystallization of polymers in the linear stress-orientation range in the series expansion approach , Express Polymer Letters, ISSN: 1788-618X, DOI: 10.3144/expresspolymlett/2018.29, Vol.12, No.4, pp.330-348, 2018

Abstract:
An analytical formula is derived for the oriented crystallization coefficient governing kinetics of oriented crystallization under uniaxial amorphous orientation in the entire temperature range. A series expansion approach is applied to the free energy of crystallization in the Hoffman-Lauritzen kinetic model of crystallization at accounting for the entropy of orientation of the amorphous chains. The series expansion coefficients are calculated for systems of Gaussian chains in linear stress-orientation range. Oriented crystallization rate functions are determined basing on the ‘proportional expansion’ approach proposed by Ziabicki in the steady-state limit. Crystallization kinetics controlled by separate predetermined and sporadic primary nucleation is considered, as well as the kinetics involving both nucleation mechanisms potentially present in oriented systems. The involvement of sporadic nucleation in the transformation kinetics is predicted to increase with increasing amorphous orientation. Example computations illustrate the dependence of the calculated functions on temperature and amorphous orientation, as well as qualitative agreement of the calculations with experimental results.

Keywords:
modeling and simulation, kinetics of oriented crystallization, amorphous orientation, sporadic nucleation, predetermined nucleation

(35p.)
6.Kopeć M., Wang K., Politis D.J., Wang Y., Wang L., Lin J., Formability and microstructure evolution mechanisms of Ti6Al4V alloy during a novel hot stamping process, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ISSN: 0921-5093, DOI: 10.1016/j.msea.2018.02.038, pp.1-20, 2018
Kopeć M., Wang K., Politis D.J., Wang Y., Wang L., Lin J., Formability and microstructure evolution mechanisms of Ti6Al4V alloy during a novel hot stamping process, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ISSN: 0921-5093, DOI: 10.1016/j.msea.2018.02.038, pp.1-20, 2018

Abstract:
A novel hot stamping process for Ti6Al4V alloy using cold forming tools and a hot blank was presented in this paper. The formability of the material was studied through uniaxial tensile tests at temperatures ranging from 600 to 900 °C and strain rates ranging from 0.1 to 5 s-1. An elongation ranging from 30% to 60% could be achieved at temperatures ranging from 750 to 900°C respectively. The main microstructure evolution mechanisms varied with the deformation temperature, including recovery, phase transformation and recrystallization. The hardness of the material after deformation first decreased with the temperature due to recovery, and subsequently increased mainly due to the phase transformation. During the hot stamping tests, qualified parts could be formed successfully at heating temperatures ranging from 750 to 850°C. The forming failed at lower temperatures due to the limited ductility of the material. At temperatures higher than 900°C, extensive phase transformation of α to β occurred during the heating. During the transfer and forming, the temperature dropped significantly which led to the formation of transformed β, reduction of the formability and subsequent failure. The post-form hardness distribution demonstrated the same tendency as that after uniaxial tensile tests.

Keywords:
titanium alloys, Ti6Al4V, hot stamping, microstructure

(35p.)
7.Maździarz M., Mrozek A., Kuś W., Burczyński T., Anisotropic-Cyclicgraphene: A New Two-Dimensional Semiconducting Carbon Allotrope, Materials, ISSN: 1996-1944, DOI: 10.3390/ma11030432, Vol.11, No.3, pp.432, 2018
Maździarz M., Mrozek A., Kuś W., Burczyński T., Anisotropic-Cyclicgraphene: A New Two-Dimensional Semiconducting Carbon Allotrope, Materials, ISSN: 1996-1944, DOI: 10.3390/ma11030432, Vol.11, No.3, pp.432, 2018

Abstract:
A potentially new, single-atom thick semiconducting 2D-graphene-like material, called
Anisotropic-cyclicgraphene , has been generated by the two stage searching strategy linking molecular
and ab initio approach. The candidate was derived from the evolutionary-based algorithm and
molecular simulations was then profoundly analysed using first-principles density functional theory
from the structural, mechanical, phonon, and electronic properties point of view. The proposed
polymorph of graphene (rP16-P1m1) is mechanically, dynamically, and thermally stable and can
achieve semiconducting with a direct band gap of 0.829 eV.

Keywords:
carbon; graphene; graphyne; ab initio calculations; Semiconductors

(35p.)
8.Suchorzewski J., Korol E., Tejchman J., Mróz Z., Experimental study of shear strength and failure mechanisms in RC beams scaled along height or length, ENGINEERING STRUCTURES, ISSN: 0141-0296, DOI: 10.1016/j.engstruct.2017.12.003, Vol.157, pp.203-223, 2018
Suchorzewski J., Korol E., Tejchman J., Mróz Z., Experimental study of shear strength and failure mechanisms in RC beams scaled along height or length, ENGINEERING STRUCTURES, ISSN: 0141-0296, DOI: 10.1016/j.engstruct.2017.12.003, Vol.157, pp.203-223, 2018

Abstract:
The paper presents results of laboratory experiments carried out on longitudinally reinforced concrete beams subjected to four-point bending. Beams of separately varying height and length were analyzed to investigate the size effect on nominal strength and post-critical brittleness. Beams were scaled in the height direction in the first test series and in the length direction in the second series. Due to lack of geometrical similarity, different failure mechanisms were exhibited. Load-deflection diagrams and crack paths were registered during experiments. The digital image correlation technique was applied to visualize strain localization on the concrete surface. The crack opening and crack slip displacements were also measured. The beam response was characterized by two non-dimensional parameters ηa = a/D and ηb = b/D defined as the ratios of shear and bending spans to the beam depth D assumed as the size parameter and the reinforcement position parameter ηc = c′/D. Two major failure mechanisms were observed: flexural failure in the central beam zone combined with plastic yielding of the reinforcement and the diagonal shear crack failure in external shear zones. Two distinct modes of shear failure can be specified depending on the dominance of crack opening or crack closure contact zones. Two different effective stresses associated with failure mechanisms were defined to specify the beam strength’s dependence on ηa, ηb, ηc and D. Some analytical formulae specifying the critical shear stress dependence on ηa, ηc and strengths ratio of reinforcement and concrete were presented at the end of paper and compared with experimental data.

Keywords:
Concrete beams, Longitudinal reinforcement, Four-point bending, Failure modes, Height or length variation, Size effect

(35p.)
9.Pieczyska E.A., Maj M., Golasiński K., Staszczak M., Furuta T., Kuramoto S., Thermomechanical Studies of Yielding and Strain Localization Phenomena of Gum Metal under Tension, Materials, ISSN: 1996-1944, DOI: 10.3390/ma11040567, Vol.11, No.567, pp.1-13, 2018
Pieczyska E.A., Maj M., Golasiński K., Staszczak M., Furuta T., Kuramoto S., Thermomechanical Studies of Yielding and Strain Localization Phenomena of Gum Metal under Tension, Materials, ISSN: 1996-1944, DOI: 10.3390/ma11040567, Vol.11, No.567, pp.1-13, 2018

Abstract:
This paper presents results of investigation of multifunctional -Ti alloy Gum Metal subjected to tension at various strain rates. Digital image correlation was used to determine strain distributions and stress-strain curves, while infrared camera allowed for us to obtain the related temperature characteristics of the specimen during deformation. The mechanical curves completed by the temperature changes were applied to analyze the subsequent stages of the alloy loading. Elastic limit, recoverable strain, and development of the strain localization were studied. It was found that the maximal drop in temperature, which corresponds to the yield limit of solid materials, was referred to a significantly lower strain value in the case of Gum Metal in contrast to its large recoverable strain. The temperature increase proves a dissipative character of the process and is related to presence of w and a” phases induced during the alloy fabrication and their exothermic phase transformations activated under loading. During plastic deformation, both the strain and temperature distributions demonstrate that strain localization for higher strain rates starts nucleating just after the yield limit leading to specimen necking and rupture. Macroscopically, it is exhibited as softening of the stress-strain curve in contrast to the strain hardening observed at lower strain rates.

Keywords:
gum metal, yield limit, thermomechanical coupling, infrared thermography, digital image correlation, strain localization

(35p.)
10.Mościcki T., Hoffman J., Szymański Z., Laser ablation in an ambient gas: Modelling and experiment, JOURNAL OF APPLIED PHYSICS, ISSN: 0021-8979, DOI: 10.1063/1.5010413, Vol.123, pp.083305-1-083305-8, 2018
Mościcki T., Hoffman J., Szymański Z., Laser ablation in an ambient gas: Modelling and experiment, JOURNAL OF APPLIED PHYSICS, ISSN: 0021-8979, DOI: 10.1063/1.5010413, Vol.123, pp.083305-1-083305-8, 2018

Abstract:
The laser ablation of graphite in ambient argon is studied both experimentally and theoretically in conditions corresponding to the initial conditions of carbon nanotube synthesis by the laser vaporization method. The results of the experiment show that the maximum plasma temperature of 24 000 K is reached 25 ns after the beginning of the laser pulse and decreases to about 4000–4500 K after 10 μs. The maximum electron density of 8 × 1025 m−3 is reached 15 ns from the beginning of the laser pulse. The hydrodynamic model applied shows comparable plasma temperatures and electron densities. The model also replicates well a shock wave and plume confinement—intrinsic features of supersonic flow of the ablated plume in an ambient gas. The results show that the theoretical model can be used to simulate nanosecond laser ablation in an ambient gas from the beginning of the process up to several microseconds.

(30p.)
11.Schabowicz K., Jóźwiak-Niedźwiedzka D., Ranachowski Z., Kudela Jr. S., Dvorak T., Microstructural characterization of cellulose fibres in reinforced cement boards, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2018.01.018, Vol.18, No.4, pp.1068-1078, 2018
Schabowicz K., Jóźwiak-Niedźwiedzka D., Ranachowski Z., Kudela Jr. S., Dvorak T., Microstructural characterization of cellulose fibres in reinforced cement boards, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2018.01.018, Vol.18, No.4, pp.1068-1078, 2018

Abstract:
The microscopic analysis of the different cellulose fibre cement composites is presented. The observations of the fibres in optical microscope in transmitted light and in scanning electron microscope are described. The micro computed tomography (micro-CT) and SEM were used to determine the distribution of the fibres in the matrix. The investigated fibre cement boards were produced by extrusion process and panels were cured in natural conditions. The main goal of the research was application of different microscopic methods to analyze the fibres distribution as a result of a different methods of their production. Micro-CT was used for 3D visualization of fibres distribution in three different fibre cement boards. It was possible to determine the average diameter of the fibres and their concentration using the high-resolution mode of micro-CT scanning procedure. Finally, a procedure which can be applied as a useful tool for analysis of the different procedures used in production of fibre cement boards is described. This procedure can be successfully used in the quality control system of cellulose fibre distribution in cement composites

Keywords:
Cellulose fibre reinforced cement boards, Microstructure, Fibre distribution, X-ray microtomography, SEM-EDS analysis

(30p.)
12.Mucha M., Wcisło B., Pamin J., Kowalczyk-Gajewska K., Instabilities in membrane tension: Parametric study for large strain thermoplasticity, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2018.01.008, Vol.18, No.4, pp.1055-1067, 2018
Mucha M., Wcisło B., Pamin J., Kowalczyk-Gajewska K., Instabilities in membrane tension: Parametric study for large strain thermoplasticity, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2018.01.008, Vol.18, No.4, pp.1055-1067, 2018

Abstract:
This paper deals with the numerical analysis of localized deformation for a rectangular plate in membrane tension, modelled with large strain thermoplasticity. The aim is to determine the influence of selected factors on the localization phenomena, which can result from geometrical, material, and thermal softening. Two types of boundary conditions are considered: plane stress and plane strain, as well as two yield functions, Huber–Mises–Hencky and Burzyński–Drucker–Prager, with selected values of friction angle. First, isothermal conditions are considered and next, a conductive case with thermal softening is studied. Moreover, three types of plastic behaviour are analysed: strain hardening (with different values of hardening modulus), ideal plasticity, and strain softening. Numerical tests, performed using AceGen/FEM packages, are carried out for the rectangular plate under tension with an imperfection, using three finite element discretizations. The results for plane strain in the isothermal model show that with the decrease of linear hardening modulus, we can observe stronger mesh sensitivity, while for plane stress, mesh sensitivity is visible for all cases. Furthermore, for the thermomechanical model the results also depend on the mesh density due to insufficient heat conduction regularization

Keywords:
Thermoplasticity, Large strains, Strain localization, Parametric study

(30p.)
13.Lumelskyj D., Rojek J., Tkocz M., Detection of strain localization in numerical simulation of sheet metal forming, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2017.08.004, Vol.18, No.2, pp.490-499, 2018
Lumelskyj D., Rojek J., Tkocz M., Detection of strain localization in numerical simulation of sheet metal forming, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2017.08.004, Vol.18, No.2, pp.490-499, 2018

Abstract:
This paper presents an investigation on the detection of strain localization in numerical simulation of sheet metal forming. Two methods to determine the onset of localized necking have been compared. The first criterion, newly implemented in this work, is based on the analysis of the through-thickness thinning (through-thickness strain) and its first time derivative in the most strained zone. The limit strain in the second method, studied in the authors’ earlier works, is determined by the maximum of the strain acceleration. The limit strains have been determined for different specimens undergoing deformation at different strain paths covering the whole range of the strain paths typical for sheet forming processes. This has allowed to construct numerical forming limit curves (FLCs). The numerical FLCs have been compared with the experimental one. Mesh sensitivity analysis for these criteria has been performed for the selected specimens. It has been shown that the numerical FLC obtained with the new criterion predicts formability limits close to the experimental results so this method can be used as a potential alternative tool to determine formability in standard finite element simulations of sheet forming processes.

Keywords:
Sheet forming, Formability, Forming limit diagram, Strain localization, Numerical simulation

(30p.)
14.Krajewski M., Brzozka K., Tokarczyk M., Kowalski G., Lewinska S., Slawska-Waniewska A., Lin W.S., Lin H.M., Impact of thermal oxidation on chemical composition and magnetic properties of iron nanoparticles, Journal of Magnetism and Magnetic Materials, ISSN: 0304-8853, DOI: 10.1016/j.jmmm.2018.03.047, Vol.458, pp.346-354, 2018
Krajewski M., Brzozka K., Tokarczyk M., Kowalski G., Lewinska S., Slawska-Waniewska A., Lin W.S., Lin H.M., Impact of thermal oxidation on chemical composition and magnetic properties of iron nanoparticles, Journal of Magnetism and Magnetic Materials, ISSN: 0304-8853, DOI: 10.1016/j.jmmm.2018.03.047, Vol.458, pp.346-354, 2018

Abstract:
The main objective of this work is to study the influence of thermal oxidation on the chemical composition and magnetic properties of iron nanoparticles which were manufactured in a simple chemical reduction of Fe3+ ions coming from iron salt with sodium borohydride. The annealing processing was performed in an argon atmosphere containing the traces of oxygen to avoid spontaneous oxidation of iron at temperatures ranging from 200 °C to 800 °C. The chemical composition and magnetic properties of as-prepared and thermally-treated nanoparticles were determined by means of X-ray diffractometry, Raman spectroscopy, Mössbauer spectroscopy and vibrating sample magnetometry. Due to the magnetic interactions, the investigated iron nanoparticles tended to create the dense aggregates which were difficult to split even at low temperatures. This caused that there was no empty space between them, which led to their partial sintering at elevated temperatures. These features hindered their precise morphological observations using the electron microscopy techniques. The obtained results show that the annealing process up to 800 °C resulted in a progressive change in the chemical composition of as-prepared iron nanoparticles which was associated with their oxidation. As a consequence, their magnetic properties also depended on the annealing temperature. For instance, considering the values of saturation magnetization, its highest value was recorded for the as-prepared nanoparticles at 1 T and it equals 149 emu/g, while the saturation point for nanoparticles treated at 600 °C and higher temperatures was not reached even at the magnetic field of about 5 T. Moreover, a significant enhancement of coercivity was observed for the iron nanoparticles annealed over 600 °C.

Keywords:
Chemical composition, Chemical reduction, Iron nanoparticle, Magnetic properties, Oxidation

(30p.)
15.Balevičius R., Mróz Z., Modeling of combined slip and finite sliding at spherical grain contacts, GRANULAR MATTER, ISSN: 1434-5021, DOI: 10.1007/s10035-017-0778-6, Vol.10, pp.1-27, 2018
Balevičius R., Mróz Z., Modeling of combined slip and finite sliding at spherical grain contacts, GRANULAR MATTER, ISSN: 1434-5021, DOI: 10.1007/s10035-017-0778-6, Vol.10, pp.1-27, 2018

Abstract:
The present paper is aimed at developing the analytical description of the interaction of two contacting spheres for several classes of slip and sliding trajectories, typical in the experimental testing. The analysis accounts for memory effects in the slip regime and configurational effects in the sliding regime, expressed in terms of an active loading surface and memory surfaces within the space of contact forces. Analytical relations for contact response are derived for linear and piecewise-linear motion trajectories of the sphere. The problem of multiple contact interaction of the sphere moving over the regularly packed granular bed is also considered analytically. It is demonstrated that the dual contact activation-separation processes occur within the combined slip–sliding modes, essentially affecting the distribution of contact tractions. The results obtained are relevant for the class of contact problems requiring analysis of interaction of slip and sliding displacements, in particular in testing grain contact interaction aimed at specification of elastic, frictional and wear parameters.

Keywords:
Sphere–sphere contact, Memory rules, Slip and sliding, Displacement and force control, Monotonic and reciprocal sliding, Friction, Granular bed

(30p.)
16.Radziejewska J., Sarzyński A., Strzelec M., Diduszko R., Hoffman J., Evaluation of residual stress and adhesion of Ti and TiN PVD films by laser spallation technique, OPTICS & LASER TECHNOLOGY, ISSN: 0030-3992, DOI: 10.1016/j.optlastec.2018.02.014, Vol.104, pp.140-147, 2018
Radziejewska J., Sarzyński A., Strzelec M., Diduszko R., Hoffman J., Evaluation of residual stress and adhesion of Ti and TiN PVD films by laser spallation technique, OPTICS & LASER TECHNOLOGY, ISSN: 0030-3992, DOI: 10.1016/j.optlastec.2018.02.014, Vol.104, pp.140-147, 2018

Abstract:
The laser spallation technique was applied for measurement of residual stress and adhesion of thin films. Two films of different properties, ductile and soft Ti, and hard and brittle TiN, were studied. The films were produced on 304 steel substrate by PVD method. The residual stress value obtained by laser spallation technique LST were compared with stress value from X-ray diffraction method. Good agreement of stress values measured by both methods was attained. Additionally, the interface strength of the films was tested by laser adhesion spallation technique LASAT with use of VISAR system. It was shown that shock wave induced by a nanosecond laser pulse adequately determines properties of PVD thin films on metal substrate

Keywords:
Laser spallation technique, Residual stress, Adhesion, Thin layer, PVD, VISAR system

(25p.)
17.Małolepszy A., Błoński S., Chrzanowska-Giżyńska J., Wojasiński M., Płociński T., Stobiński L., Szymański Z., Fluorescent carbon and graphene oxide nanoparticles synthesized by the laser ablation in liquid, APPLIED PHYSICS A-MATERIALS SCIENCE AND PROCESSING, ISSN: 0947-8396, DOI: 10.1007/s00339-018-1711-5, pp.124-282, 2018
Małolepszy A., Błoński S., Chrzanowska-Giżyńska J., Wojasiński M., Płociński T., Stobiński L., Szymański Z., Fluorescent carbon and graphene oxide nanoparticles synthesized by the laser ablation in liquid, APPLIED PHYSICS A-MATERIALS SCIENCE AND PROCESSING, ISSN: 0947-8396, DOI: 10.1007/s00339-018-1711-5, pp.124-282, 2018

Abstract:
The results of synthesis of the fluorescent carbon dots (CDots) from graphite target and reduced graphene oxide (rGO) nanoparticles performed by the nanosecond laser ablation in polyethylene glycol 200 (PEG200) are shown. Two-step laser irradiation (first graphite target, next achieved suspension) revealed a very effective production of CDots. However, the ablation in PEG appeared to be effective with 1064 nm laser pulse in contrast to the ablation with 355 nm laser pulse. In the case of rGO nanoparticles similar laser irradiation procedure was less efficient. In both cases, received nanoparticles exhibited strong, broadband photoluminescence with a maximum dependent on the excitation wavelength. The size distribution for obtained CDots was evaluated using the DLS technique and HRTEM images. The results from both methods show quite good agreement in nanoparticle size estimation although the DLS method slightly overestimates nanoparticle’s diameter

(25p.)
18.Gawlicki M., Jankowski Ł., Identification of moving loads using the l1 norm minimization, AIP Conference Proceedings, ISSN: 0094-243X, DOI: 10.1063/1.5019092, pp.100007-1 -9, 2018
Gawlicki M., Jankowski Ł., Identification of moving loads using the l1 norm minimization, AIP Conference Proceedings, ISSN: 0094-243X, DOI: 10.1063/1.5019092, pp.100007-1 -9, 2018

Abstract:
This contribution deals with the inverse problem of indirect identification of moving loads. The identification is performed based on the recorded response of the loaded structure and its numerical model. A specific feature of such problems is a very large number of the degrees of freedom (DOFs) that can be excited and a limited number of available sensors. As a result, unless the solution space is significantly limited, the identification problem is underdetermined: it has an infinite number of exact, observationally indistinguishable solutions. We propose an approach based on the assumption of sparsity of the excitation, which can be expressed in the form of a requirement of a bounded l1 norm of the solution. As long as the loads are sparse, the approach allows them to be freely moving, without the usual assumption of a constant velocity. We first test the approach in a numerical example with 10% rms measurement noise. A good qualitative agreement of the numerical results allows to proceed with experimental investigations, and the moving load identification is then carried out based on the response measured experimentally on a lab test stand.

(15p.)
19.Frąś L.J., Pęcherski R.B., Modified split hopkinson pressure bar for investigations of dynamic behaviour of magnetorheological materials, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, DOI: 10.15632/jtam-pl.56.1.323, Vol.56, No.1, pp.323-328, 2018
Frąś L.J., Pęcherski R.B., Modified split hopkinson pressure bar for investigations of dynamic behaviour of magnetorheological materials, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, DOI: 10.15632/jtam-pl.56.1.323, Vol.56, No.1, pp.323-328, 2018

Abstract:
The magnetorheological fluid is a functional material that is changing its rheological properties and finally solidifies in a magnetic field. The dynamic behaviour, tested with the use of the Split Hopkinson Pressure Bar is an important issue for description of this material, which is commonly used in different kinds of shock absorbers. This note presents a new idea how to modify the known SHPB set up in order to investigate dynamic properties of magnetorheological materials.

Keywords:
Split Hopkinson Pressure Bar (SHPB), Magnetorheological Fluid (MRF), dynamic behaviour, solidification in magnetic field, ferroelements

(15p.)
20.Rokicki G., Kowalczyk T., Kaczorowski M., Sześcioczłonowe węglany cykliczne jako modyfikatory żywic epoksydowych, POLIMERY, ISSN: 0032-2725, DOI: 10.14314/polimery.2018.2.2, Vol.63, No.2, pp.90-101, 2018
Rokicki G., Kowalczyk T., Kaczorowski M., Sześcioczłonowe węglany cykliczne jako modyfikatory żywic epoksydowych, POLIMERY, ISSN: 0032-2725, DOI: 10.14314/polimery.2018.2.2, Vol.63, No.2, pp.90-101, 2018

Abstract:
Przedstawiono metodę modyfikacji żywic epoksydowych biscyklicznymi węglanami sześcioczłonowymi. Wykazano, że katalizowana kwasami Lewisa reakcja oksiranów z sześcioczłonowymi węglanami cyklicznymi przebiega głównie z wytworzeniem spiroortowęglanu pięcio-sześcioczłonowego. W jej wyniku powstają poli(etero-węglany), polietery i pięcioczłonowe węglany cykliczne. W niskiej temperaturze reakcja może ulec zahamowaniu na etapie spiroortowęglanu. Wykazano, że żywice epoksydowe zmodyfikowane dodatkiem 10 % mas. oligomeru uretanowego, zakończonego sześcioczłonowymi cyklicznymi węglanami lub biscyklicznym węglanem zawierającym resztę glikolu tri(oksyetylenowego), charakteryzują się udarnością o 66–83 % większą niż żywica niemodyfikowana, przy zachowanym poziomie wartości pozostałych cech wytrzymałościowych.

Keywords:
biscykliczne węglany sześcioczłonowe, modyfikacja żywicy epoksydowej, cykliczny węglan jako aktywny rozcieńczalnik, kationowa kopolimeryzacja oksiranów z sześcioczłonowymi cyklicznymi węglanami, polimeryzacja z otwarciem pierścienia

(15p.)
21.Kruk A., Gadomska-Gajadhur A., Dulnik J., Rykaczewska I., Ruśkowski P., Sebai A., Synoradzki L., Ocena właściwości użytkowych rusztowań komórkowych o strukturze gąbczastej oraz wzrostu na nich fibroblastów, POLIMERY, ISSN: 0032-2725, DOI: 10.14314/polimery.2018.4.3, Vol.63, No.4, pp.18-22, 2018
Kruk A., Gadomska-Gajadhur A., Dulnik J., Rykaczewska I., Ruśkowski P., Sebai A., Synoradzki L., Ocena właściwości użytkowych rusztowań komórkowych o strukturze gąbczastej oraz wzrostu na nich fibroblastów, POLIMERY, ISSN: 0032-2725, DOI: 10.14314/polimery.2018.4.3, Vol.63, No.4, pp.18-22, 2018

Abstract:
Zbadano wpływ dodatku ciekłych prekursorów porów na morfologię, porowatość i właściwości mechaniczne polilaktydowych rusztowań komórkowych. Rusztowania otrzymano metodą mokrej inwersji faz w wariancie freeze extraction. Oceniono cytotoksyczność wybranych rusztowań w stosunku do fibroblastów mysich oraz ich przydatność do hodowli komórkowych. Wykazano, że dodatek prekursora porów dopolilaktydu korzystnie zmienia morfologię wytworzonych rusztowań, jednocześnie pogarszając ich wytrzymałość mechaniczną. Stwierdzono, że polilaktydowe rusztowania komórkowe z powodzeniem mogą być wykorzystywane do hodowli komórkowych.

Keywords:
usztowania komórkowe, polilaktyd, hodowle komórkowe, fibroblasty

(15p.)
22.Kurp P., Widłaszewski J., Mucha Z., Laserowo-mechaniczne formowanie elementów cienkościennych, MECHANIK, ISSN: 0025-6552, DOI: 10.17814/mechanik.2018.2.30, No.2, pp.148-151, 2018
Kurp P., Widłaszewski J., Mucha Z., Laserowo-mechaniczne formowanie elementów cienkościennych, MECHANIK, ISSN: 0025-6552, DOI: 10.17814/mechanik.2018.2.30, No.2, pp.148-151, 2018

Abstract:
W niniejszym artykule autorzy przedstawiają założenia oraz wstępne wyniki badań doświadczalnych i symulacji numerycznych procesu formowania elementów cienkościennych z wykorzystaniem wiązki laserowej i obciążenia mechanicznego. Na podstawie założeń zaprojektowano i wykonano stanowisko do gięcia cienkościennych rur i dyfuzorów stożkowych stosowanych w budowie silników lotniczych. Metoda i stanowisko kształtowania, przetestowane w warunkach laboratoryjnych, a także wyniki analizy numerycznej procesu pokazują nowe możliwości formowania elementów cienkościennych

Keywords:
kształtowanie laserowe, obróbka laserowa, elementy cienkościenne, stopy niklu, metoda elementów skończonych

(11p.)
23.Pisarski D., Myśliński A., Online adaptive semi-active vibration damping of slender structures subject to moving loads, ICoEV 2017, International Conference on Engineering Vibration, 2017-09-04/09-07, Sofia (BG), DOI: 10.1051/matecconf/201814805006 , No.148, pp.1-6, 2018
Pisarski D., Myśliński A., Online adaptive semi-active vibration damping of slender structures subject to moving loads, ICoEV 2017, International Conference on Engineering Vibration, 2017-09-04/09-07, Sofia (BG), DOI: 10.1051/matecconf/201814805006 , No.148, pp.1-6, 2018

Abstract:
The paper deals with the adaptive optimal semi-active control of the slender vibrating structures subjected to the moving loads. The deflection of the structure is governed by Euler-Bernoulli beam equation approximated by the system of bilinear ordinary differential equations. The damping function of the structure support is chosen as the control function. The optimal control problem consists in finding such bang-bang control function to minimize the energy as well as the vibrations of the carrying structure. Although the switched optimal control is a very efficient tool in the reduction of structure vibrations it is very sensitive with respect to changes of the speed of the traveling load. This paper deals with the development of the adaptive descent type algorithm that enables the update of the optimal controls in real time based on the measured speed of the traveling load or structure’s state. The proposed algorithm uses reference optimal controls computed for the constant speeds and the set of functions describing the sensitivity of the system dynamics with respect to the measured parameters. Numerical computations are carried out for different speed scenarios of the moving load. The obtained numerical results indicate that the proposed adaptive controller can significantly outperform the reference optimal solutions.

24.Enayati M.S., Behzad T., Sajkiewicz P., Rafienia M., Bagheri R., Ghasemi-Mobarakeh L., A novel electrospun three-component Bionanocomposite for bone tissue engineering, ICNS7, 7th International Conference on Nanostructures , 2018-02-27/03-01, Teheran (IR), pp.1-3, 2018
Enayati M.S., Behzad T., Sajkiewicz P., Rafienia M., Bagheri R., Ghasemi-Mobarakeh L., A novel electrospun three-component Bionanocomposite for bone tissue engineering, ICNS7, 7th International Conference on Nanostructures , 2018-02-27/03-01, Teheran (IR), pp.1-3, 2018

Abstract:
In the present study, a full bionanocomposite scaffold from poly (vinyl alcohol) (PVA), nanohydroxy apatite (nHAp) and cellulose nanofibers (CNF) was fabricated by electospinning and its potential application for bone tissue engineering was investigated. Morphology of the electrospun scaffolds was seen by field emission scanning electron microscope (FE-SEM). Both nHAp and CNF enhanced the tensile modulus of the scaffolds; however, both tensile strength as well as slongation at break showed reduced behaviour. Porosity measurement showed that scaffolds had porosity more than 70% which is appropriate for tissue engineering scaffolds. Contact angle test proved high hydrophilicty of electrospun mats while nanofiller incorporation promoted hydrophilicity. Biodegradability was investigated in phosphate buffer saline (PBS). In vitro biomineralization in simulated body fluid (SBF) and MTT cytotoxicity analysis showed that addition of nHAp and CNF increased bioactivity and cell viability of the scaffolds. The obtained results offered a 3-component promising scaffold for bone tissue engineering.

Keywords:
Bionanocomposite, Scaffold, Electrospinning, Poly (vinyl alcohol) and Bone tissue engineering

25.Dulnik J., Sajkiewicz P., Crosslinking of bicomponent nanofibres from alternative solvent system, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.71, 2018
26.Urbanek O., Sajkiewicz P., Pierini F., Cell response on fibres surface properties induced by process parameters and post-treatment of electrospun nonwovens, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.62-63, 2018
27.Sajkiewicz P., Dulnik J., Kołbuk-Konieczny D., Denis P., Structure dependent cell activity on pcl/gelatin and pcl/collagen nanofibers electrospun from various solvents, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.45-46, 2018
28.Pierini F., Lanzi M., Nakielski P., Pawłowska S., Urbanek O., Kowalewski T.A., Electrospinning of polythiophene with pendant fullerene nanofibers for single-material organic solar cells, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.19-20, 2018
29.Pawłowska S., Nakielski P., Pierini F., Electrospun polyacrylamide hydrogel nanofibers: from nanocarriers to stimuli responsive nanomaterials, Electrospin2018, Electrospin2018 International Conference, 2018-01-16/01-18, Stellenbosch (ZA), pp.39, 2018
30.Wcisło B., Pamin J., Kowalczyk-Gajewska K., Menzel A., Numerical analysis of ellipticity condition for large strain plasticity, AIP Conference Proceedings, ISSN: 0094-243X, DOI: 10.1063/1.5019150, Vol.1922, No.1, pp.140008-1-140008-8, 2018
Wcisło B., Pamin J., Kowalczyk-Gajewska K., Menzel A., Numerical analysis of ellipticity condition for large strain plasticity, AIP Conference Proceedings, ISSN: 0094-243X, DOI: 10.1063/1.5019150, Vol.1922, No.1, pp.140008-1-140008-8, 2018

Abstract:
This paper deals with the numerical investigation of ellipticity of the boundary value problem for isothermal finite strain elasto-plasticity. Ellipticity can be lost when softening occurs. A discontinuity surface then appears in the considered material body and this is associated with the ill-posedness of the boundary value problem. In the paper the condition for ellipticity loss is derived using the deformation gradient and the first Piola-Kirchhoff stress tensor. Next, the obtained condition is implemented and numerically tested within symbolic-numerical tools AceGen and AceFEM using the benchmark of an elongated rectangular plate with imperfection in plane stress and plane strain conditions.

31.Ranachowski Z., Lewandowski M., Schabowicz K., Logoń D., Analysis of Acoustic Emission Signal Generated in Mechanically Loaded Reinforced and Non-Reinforced Concrete Specimens, OSA 2017, LXIV Open Seminar on Acoustics, 2017-09-11/09-15, Piekary Śląskie (PL), DOI: 10.1515/aoa-2017-0059, No.42_3, pp.552-552, 2017
32.Kossecka E., The effect of structure and thickness on periodic thermal capacity of building components, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.LIII, No.3, pp.527-539, 2007
Kossecka E., The effect of structure and thickness on periodic thermal capacity of building components, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.LIII, No.3, pp.527-539, 2007

Abstract:
Thermal capacity of building partitions and their internal thermal structure, that is location of materials of different thermal conductivity, density and specific heat, have an influence on dynamics of the heat transfer processes, caused by external and internal thermal excitations. Dynamic thermal characteristics of building components, which determine the periodic heat transfer processes, are admittances, transmittances and periodic thermal capacities. In this paper, properties of the periodic heat capacity of interior and exterior building partitions are examined: its dependence on structure, thickness of masonry layers, surface film resistances and period of temperature variations, and also its asymptotic values for high thickness and low frequency. For wall assemblies composed of lightweight materials, and also for massive walls of very low thickness, approximate proportionality takes place. For heavy structures, the dependence becomes curvilinear, and for very thick walls tends to the constant value, attaining maximum for a comparatively low thickness which is approximately twice the periodic penetration depth. For exterior walls, dependence on the thermal mass factor, and also on thickness of the interior massive layer, has a similar character. Maximum periodic heat capacity for walls with insulation outside appears for thickness of the masonry layer of only 10 – 12 cm, which is approximately value of the periodic penetration depth.

Keywords:
heat transfer, building walls, dynamic thermal characteristics, frequency response, periodic heat capacity

33.Kossecka E., Kośny J., Three-dimensional conduction z-transfer function coefficients determined from the response factors, ENERGY AND BUILDINGS, ISSN: 0378-7788, DOI: 10.1016/j.enbuild.2004.06.026, Vol.37, pp.301-310, 2005
Kossecka E., Kośny J., Three-dimensional conduction z-transfer function coefficients determined from the response factors, ENERGY AND BUILDINGS, ISSN: 0378-7788, DOI: 10.1016/j.enbuild.2004.06.026, Vol.37, pp.301-310, 2005

Abstract:
A method of derivation of the conduction z-transfer function coefficients from response factors, for three-dimensional wall assemblies, is described. Results of the conduction z-transfer function coefficients calculations are presented for clear walls and separated details which are listed in ASHRAE research project 1145-TRP: ‘‘Modeling Two- and Three-Dimensional Heat Transfer Through Composite Wall and Roof Assemblies in Hourly Energy Simulation Programs’’. Resistances, three-dimensional response factors and so-called structure factors, have been computed using the finite-difference computer code HEATING 7.2. The z-transfer function coefficients were then derived from a set of linear equations, constituting relationships with the response factors, which were solved using the minimum-error procedure. Test simulations show perfect compatibility of the heat flux calculated using three-dimensional response factors and three-dimensional ztransfer function coefficients, derived from the response factors.

Keywords:
Heat transfer, Thermal response, z-transfer function, Simulation, Building envelope

34.Kossecka E., Kośny J., Correlations between time constants and structure factors of building walls, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.I, No.1, pp.175-188, 2004
Kossecka E., Kośny J., Correlations between time constants and structure factors of building walls, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.I, No.1, pp.175-188, 2004

Abstract:
Two methods are proposed of the wall specimen time constant estimation, for the hot box apparatus testing. Directions of the American standard ASTM C 1363-97 are discussed. First method assumes numerical calculation of the response factors and deriving time constant from their ratios. The second one makes use of the approximate relation between the time constant and the product of resistance, capacity and the structure factor. Correlations between time constants and structure factors are examined.

35.Ruterana P., Singh P., Kret S., Jurczak G., Maciejewski G., Dłużewski P., Cho H.K., Choi R.J., Lee H.J., Suh E.K., Quantitative evolution of the atomic structure of defects and composition fluctuations at the nanometer scale inside InGaN/GaN heterostructures, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, ISSN: 0370-1972, Vol.241, No.12, pp.2643-2648, 2004
Ruterana P., Singh P., Kret S., Jurczak G., Maciejewski G., Dłużewski P., Cho H.K., Choi R.J., Lee H.J., Suh E.K., Quantitative evolution of the atomic structure of defects and composition fluctuations at the nanometer scale inside InGaN/GaN heterostructures, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, ISSN: 0370-1972, Vol.241, No.12, pp.2643-2648, 2004

Abstract:
The cover picture of this issue depicts indium composition fluctuations in InGaN/GaN multi quantum wells. The coded color strain distribution (left) was derived from finite element method calculations of the strain relaxation process and high‐resolution transmission electron microscopy (HRTEM) image simulations, superimposed on the HRTEM image of the quantum wells. The possible corresponding shape and εxx strain profiles in the indium rich clusters (right) hint at a concentration close to pure InN in their core. The paper by Pierre Ruterana et al. [1] was presented at the 5th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED‐2004), held in Gyeongju, Korea, 15–19 March 2004.

Keywords:
HRTEM, quantum well, composition fluctuation, strain distribution

36.Kossecka E., Kośny J., Z-transfer function coefficients for simulation of three-dimensional heat transfer in building walls, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.XLIX, No.4, pp.545-558, 2003
Kossecka E., Kośny J., Z-transfer function coefficients for simulation of three-dimensional heat transfer in building walls, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.XLIX, No.4, pp.545-558, 2003

Abstract:
A method of derivation of the conduction z-transfer function coefficients from response factors, for three-dimensional wall assemblies, is described.Results of the conduction z-transfer function coefficients calculations are presented for clear walls and separated details which are listed in ASHRAE research project 1145-TRP: “Modeling Two- and Three-Dimensional Heat Transfer Through Composite Wall and Roof Assemblies in Hourly Energy Simulation Programs”. Resistances, three-dimensional response factors and so-called structure factors, have been computed using the finite-difference computer code HEATING 7.2. The z-transfer function coefficients were then derived from a set of linear equations, constituting relationships with the response factors, which were solved using the minimum-error procedure.Test simulations show perfect compatibility of the heat flux calculated using three-dimensional response factors and three-dimensional z-transfer function coefficients, derived from the response factors.

37.Kossecka E., Kośny J., Influence of insulation configuration on heating and cooling loads in a continuously used building, ENERGY AND BUILDINGS, ISSN: 0378-7788, Vol.34, pp.321-331, 2002
Kossecka E., Kośny J., Influence of insulation configuration on heating and cooling loads in a continuously used building, ENERGY AND BUILDINGS, ISSN: 0378-7788, Vol.34, pp.321-331, 2002

Abstract:
This paper is focused on the energy performance of buildings containing massive exterior building envelope components. The effect of mass and insulation location on heating and cooling loads is analyzed for six characteristic wall configurations. Correlations between structural and dynamic thermal characteristics of walls are discussed. A simple one-room model of a building exposed to periodic temperature changes is analyzed to illustrate the effect of material configuration on the ability of a wall to dampen interior temperature swings. Whole-building dynamic modeling using DOE-2.1E is employed for the energy analysis of a one-story residential building with various exterior wall configurations for six different US climates. The best thermal performance is obtained when massive material layers are located at the inner side and directly exposed to the interior space. # 2002 Elsevier Science B.V. All rights reserved.

Keywords:
Building heat transfer, Structure factors, Frequency response, Thermal stability, Dynamic thermal performance

38.Kośny J., Kossecka E., Multi-dimensional heat transfer through complex building envelope assemblies in hourly energy simulation programs, ENERGY AND BUILDINGS, ISSN: 0378-7788, DOI: 10.1016/S0378-7788(01)00122-0, Vol.34, pp.445-454, 2002
Kośny J., Kossecka E., Multi-dimensional heat transfer through complex building envelope assemblies in hourly energy simulation programs, ENERGY AND BUILDINGS, ISSN: 0378-7788, DOI: 10.1016/S0378-7788(01)00122-0, Vol.34, pp.445-454, 2002

Abstract:
In most whole building thermal modeling computer programs like DOE-2, BLAST, or ENERGY PLUS simplified, one-dimensional, parallel path, descriptions of building envelope are used. For several structural and material configurations of building envelope components containing high thermal mass and/or two- and three-dimensional thermal bridges, one-dimensional analysis may generate serious errors in building loads estimation. The method of coupling three-dimensional heat transfer modeling and dynamic hot-box tests for complex wall systems with the whole building thermal simulations is presented in this paper. This procedure can increase the accuracy of the whole building thermal modeling.
Current thermal modeling and calculation procedures tend to overestimate the actual field thermal performance of today’s popular building envelope designs, which utilize modern building technologies (sometimes highly conductive structural materials) and feature large fenestration areas and floor plans with many exterior wall corners. Some widely used computer codes were calibrated using field data obtained from light weight wood frame buildings. The same codes are used now for thermal modeling of high mass buildings with significant heat accumulation effects. Also, the effects of extensive thermal shorts on the whole building thermal performance is not accurately reflected by the commonly used one-dimensional energy simulations that are the current bases for building envelopes and systems designing.

Keywords:
Thermal modeling, Thermal bridges, Hourly energy simulation programs

39.Kossecka E., The effect of structure on dynamic thermal characteristics of multilayer walls, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.XLII, No.3, pp.351-369, 1996
Kossecka E., The effect of structure on dynamic thermal characteristics of multilayer walls, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.XLII, No.3, pp.351-369, 1996

Abstract:
The effect of internal thermal structure on dynamic characteristics of multilayer walls is analyzed. Mathematical basis constitute the integral formulae for the heat flow across the surfaces of the wall. The notion of structure factors is introduced and the conditions they impose on response factors are derived, using the Laplace transform method. Simple examples of walls, representing different types of thermal resistance and capacity distribution, are analyzed to illustrate general relations between the structure factors and the response factors.

40.Kossecka E., de Wit R., Disclination dynamics, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.29, No.6, pp.749-767, 1977
41.Kossecka E., Mathematical theory of defects, Part I-Statics, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.26, No.6, pp.995-1010, 1974
Kossecka E., Mathematical theory of defects, Part I-Statics, ARCHIVES OF MECHANICS, ISSN: 0373-2029, Vol.26, No.6, pp.995-1010, 1974

Abstract:
The basic formulation of the theory of defects in the infinite, lineaarly elastic coninuum are discussed. The point of departure is the displacement desciption and the theory of surface defects, witch are represented by the elastic potentials of a double layer. The corresponding to it total distortion filed splits up into its regular part, called elastics and singular part, called plastic or initial. The elastic stress filed satisfies equilibrium equation σik3k=0, witch is the point of departure for the theory of initial deformations. Next we discuss the theory of dislocations, formulated with the help of elastic distortion filrd and the theory of disclinations formulated with the help of elastic bend-twis tensor. The transition to the general incompatibility problem is demonstrated together with the solution for an arbitrary anisotropy of the medium.