率相关晶体塑性模型的塑性各向异性分析

在Sarma和Zacharia的工作基础上，改进了单晶晶体弹粘塑性本构模型的积分算法，并采用改进的欧拉法结合迭代方法求解，特点是稳定性好计算效率较高．然后用上述模型及算法研究了:1）在单向拉伸和平面应变压缩变形下单晶塑性各向异性的特点；2）晶体模型中的主要材料参数（应变率敏感指数m和潜硬化比率q）和加载应变率对单晶塑性各向异性的影响；3）沿不同的晶体方向加载对滑移系启动的影响．

On Plastic Anisotropy of Constitutive Model for Rate-Dependent Single Crystal

An algorithm for single crystals was developed and implemented to simulate plastic anisotropy using a rate-dependent slip model. The proposed procedure was a slightly modified form of single crystal constitutive model of Sarma and Zacharia. Modified Euler method, together with Newton-Raphson method was used to integrate this equation which was stable and efficient. The model together with the developed algorithm was used to study three problems. First, plastic anisotropy was examined by simulating the crystal deformation in tension and plane strain compression respectively. Secondly, the orientation effect of some material parameters in the model and applied strain rate on plastic anisotropy for single crystal also is investigated. Thirdly, the influence of loading direction on the active slip system was discussed.