Thermodynamic constitutive model for load-biased thermal cycling test of shape memory alloy

• Thermodynamic calculation model for martensitic transformation of shape memory alloy was proposed.
• Evolution of the self-accommodation was considered independently by a rate-dependent kinetic equation.
• Finite element calculation was conducted for B2–B19′ transformation of Ti–44.5Ni–5Cu–0.5 V (at.%).
• Three-dimensional numerical results predict the macroscopic strain under bias loading accurately.

This paper presents a three-dimensional calculation model for martensitic phase transformation of shape memory alloy. Constitutive model based on thermodynamic theory was provided. The average behavior was accounted for by considering the volume fraction of each martensitic variant in the material. Evolution of the volume fraction of each variant was determined by a rate-dependent kinetic equation. We assumed that nucleation rate is faster for the self-accommodation than for the stress-induced variants. Three-dimensional finite element analysis was conducted and the results were compared with the experimental data of Ti–44.5Ni–5Cu–0.5 V (at.%) alloy under bias loading.

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