| 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) |
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| 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, 2014Abstract:
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) |
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| 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, 2014Abstract:
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) |
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