混合硬化弹黏塑性边界元灵敏度分析

提出了基于一致切线算子概念的混合硬化弹黏塑性边界元法．该方法根据Perzyna弹黏塑性本构关
系，基于混合硬化模型，采用隐式欧拉计算格式，得出了两种常用流动函数下弹黏塑性的径向返回算法
和一致切线算子．利用直接微分方法，建立了灵敏度分析的边界元增量方程，同时还导出了混合硬化模
型应力径向返回的弹黏塑性灵敏度公式．算例和分析结果表明，不同黏塑性流动参数下所得的结果与利
用ANSYS有限元求解的差分法结果一致，弹性和弹塑性是弹黏塑性的两种极限情况．

Sensitivity analysis by elastic viscoplastic BEM with mixed strain hardening model

According to the Perzyna elastic viscoplastic constitutive relation and the mixed strain hardening models,a consistent tangent operator(CTO) concept-based implicit boundary element method(BEM) was presented.Using implicit Euler algorithm,the related elastic viscoplastic radial return algorithm(RRA) and the elastic viscoplastic CTO formula with two most common flow functions were developed.The elastic viscoplastic sensitivity formulation with the mixed strain-hardening model was derived by the direct differentiation approach.An incremental boundary integral equation for elastic viscoplastic sensitivity analysis was presented.Two numerical examples showed that the results of the stress sensitivity with different viscoplastic parameters agreed with the finite difference solution based on the ANSYS finite element method(FEM),and that the elastic problem and elastoplastic problem are both of the elastic viscoplastic limit cases.