変態塑性および移動硬化則を含む焼入れ残留応力解析における陰的積分の効果

抄録

The thermo-elastoplastic analysis considering the phase transformation has been widely used to predict the residual stress and distortion going with the heat treatment. In the heat treatment simulation, transformation plasticity should be treated implicitly, because which is considered to have relevance to current stress field. Furthermore, complex mechanical response caused by temperature change and phase transformation often leads to stress reversals, which possibly requires kinematic hardening models in the heat treatment simulation. However, few previous studies consider both fully-implicit formulation and kinematic hardening model in the thermo-elastoplasitic analysis including transformation plasticity. In this paper, therefore, thermo-elastoplastic constitutive relations considering the transformation plasticity and kinematic hardening are formulated with the return mapping algorithm, and heat treatment simulations of the steel cylinder are performed based on the proposed formulation. The calculated residual stresses show good agreement with the XRD measurements, and the capability of the fully implicit stress integration with the kinematic hardening model is demonstrated.