Partner: Prof. Radovan Slavković, PhD

University of Kragujevac (XS)

Recent publications
1.Dunić V., Pieczyska E.A., Kowalewski Z.L., Matsui R., Slavković R., Experimental and numerical investigation of mechanical and thermal effects in TiNi SMA during transformation-induced creep phenomena, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12060883, Vol.12, No.6, pp.883-1-13, 2019
Abstract:

The paper presents experimental and numerical results of the TiNi shape memory alloy (SMA) subjected to a modified program of force-controlled tensile loading. The time-dependent development of transformation strain under the constant-force conditions was investigated to describe transformation-induced creep phenomena. (2) Mechanical characteristics of the TiNi SMA were derived using a testing machine, whereas the SMA temperature changes accompanying its deformation were obtained in a contactless manner with an infrared camera. A 3D coupled thermo-mechanical numerical analysis, realized in a partitioned approach, was applied to describe the SMA mechanical and thermal responses. (3) The stress and related temperature changes demonstrated how the transformation-induced creep process started and evolved at various stages of the SMA loading. The proposed model reproduced the stress, strain and temperature changes obtained during the experiment well; the latent heat production is in correlation with the amount of the martensitic volume fraction. (4) It was demonstrated how the transformation-induced creep process occurring in the SMA under such conditions was involved in thermo-mechanical couplings and the related temperature changes.

Keywords:

TiNi shape memory alloy, phase transformation-induced creep, martensitic transformation, temperature change, thermomechanical couplings, infrared camera, thermo-mechanical coupled numerical analysis

Affiliations:
Dunić V.-University of Kragujevac (XS)
Pieczyska E.A.-IPPT PAN
Kowalewski Z.L.-IPPT PAN
Matsui R.-Aichi Institute of Technology (JP)
Slavković R.-University of Kragujevac (XS)
2.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)
3.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)

List of chapters in recent monographs
1.
550
Dunic V., Slavkovic R., Pieczyska E.A., Biomaterials in Clinical Practice, Advances in Clinical Research and Medical Devices, rozdział: Properties and Behavior of Shape Memory Alloys in the Scope of Biomedical and Engineering Applications, Springer International Publishing AG 2017, pp.303-331, 2017

Conference papers
1.Dunić V., Slavković R., Pieczyska E.A., 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), pp.T.4.7-1-6, 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.A.-IPPT PAN

Conference abstracts
1.Pieczyska E.A., Kowalewski Z.L., Dunic V., Slavkovic R., Matsui R., Investigation of mechanical and thermomechanical effects in shape memory alloy during transformationinduced creep phenomena, DAS 2019, 36th DANUBIA-ADRIA Symposium on Advances in Experimental Mechanics, 2019-09-24/09-27, Pilzno (CZ), pp.91-92, 2019
2.Pieczyska E.A., Dunić V., Slavkovic R., Kowalewski Z.L., Stress relaxation effects in TiNi SMA, SolMech 2018, 41st SOLID MECHANICS CONFERENCE, 2018-08-27/08-31, Warszawa (PL), pp.350-351, 2018
3.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)