Chaboche率相关本构模型的数值积分算法

Numerical integration algorithm for the rate-dependent Chaboche model

为验证Chaboche率相关本构模型对循环塑性行为的描述能力,研究了有限元计算中本构关系的数值积分过程和Newton-Raphson迭代算法。编写了ABAQUS材料用户子程序UMAT,在此基础上对316不锈钢材料在600℃下的循环特性进行了有限元数值模拟。结果表明:该模型对材料率相关性、对称拉压循环特性及棘轮效应的描述与试验相吻合,验证了模型算法的高效性和计算程序的正确性,证实了模型可以合理描述材料在循环载荷下的塑性变形行为。

In order to demonstrate the validity of the rate-dependent Chaboche constitutive model for cyclic plastic behavior,the numerical integration process and Newton-Raphson algorithm for the constitutive equation in finite element analysis is introduced.With the algorithm,a user-defined material（UMAT） subroutine for ABAQUS was developed.Then the cyclic characteristics of 316 stainless steel at 600 ℃ were analyzed by the FEM（finite element method） simulation with ABAQUS.The rate-dependent plasticity,cyclic characteristic and ratcheting effect were simulated.The numerical results show that the cyclic characteristics predicted by the model are in good agreement with those observed in experiment.Therefore,the validity of the algorithm of the user subroutine is verified,and the plastic deformation predicted by the model is confirmed.