Commercial applications of Shape Memory Alloys (SMAs) typically involve cyclic thermo-mechanical loading, during which the response evolves due to combined deformation from phase transformation and plasticity. Such response is complex to predict due to tension/compression asymmetry in phase transformation and plasticity, as well as anisotropy inherent to the phase transformation. However the ability to predict the ratcheting response is beneficial to select appropriate training procedures for specific components. We present a robust finite element method (FEM] based implementation of coupled phase transformation [1], cyclic plasticity constitutive laws [2] for simulating macro-scale response in SMAs. This phenomenological model is unique in explicitly incorporating the mechanisms of martensite initiation, interaction between growing martensite plates that can lead to varying levels of hardening and gradual saturation of phase transformation at larger strains. The plastic constitutive law is able to simulate the Bauschinger effect and ratcheting behavior. The interaction between plasticity and phase transformation is explicitly accounted. The FEM formulation enables simulation of the structural mechanics of components such as tubes, including the effects of geometry and grips.
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