有限塑性应变与应变率及其在晶体塑性中的表示

FINITE PLASTIC STRAIN AND ITS RATE AND THEIRREPRESENTATION IN CRYSTAL PLASTICITY

首先对变形梯度的弹塑性乘积分解的唯一性问题进行了分析．结果表明在放松了的或中间构形上所定义的应变对应着唯一的乘积分解，即Ｌｅｅ分解，尔后分析研究了该类型的应变及应变率，建立了客观塑性应变率与变形率之间的关系．最后在不同构形中给出了塑性应变在晶体塑性中的表示，建立了塑性滑移率与塑性应变及应变率之间的关系．

In this paper, the uniqueness for the elastic-plastic multiplicative decomposition ofdeformation gradient is investigated. It is shown that finite elastic-plastic strain defined in relaxedconfiguration corresponds to unique Lee's decomposition. The properties are analyzed for this kindof strain. The objective plastic strain rates are supposed in different configurations, respectively.The relations between the objective plastic strain rate and the objective plastic deformation rateare presented. These relations are useful and convenient in the studies and applications of elastoplasticity involving finite deformation. According to the relations of deformation rate and plasticstrain rate, the representations of plastic strain rate and plastic strain in crystal plasticity are presented, which give the relations between plastic slipping rate, plastic strain rate and plastic strainin different configurations. These relations will provide the potentiality for the further studies andapplications of crystal plasticity.