塑性耗散功的强化描述及其应用

Dissipative Energy Based Description for Hardening and Its Application toNon-proportional Cyclic Plasticity

变形材料内部存在各种微缺陷及其残余微应力场,贮存于这些微应力场中的能量对后续塑性变形有着重要的影响。注意到在非比例循环过程中不同应变路径下的塑性耗散能量间存在明显的差别,提出了基于塑性耗散能量的非比例度及强化函数,将其嵌入所得到的非经典本构理论,得到了描述金属材料非比例循环塑性的一种非经典本构模型,发展相应的算法和程序,对奥氏体304不锈钢的非比例循环塑性进行了分析,得到了与实验较为一致的结果。

The heterogeneous nature of metallic materials result in residual microstress fields during plastic deformation.The energy stored in the residual microstress fields affects the subsequent plastic deformation. Based on this concept, a nonclassical constitutive model is developed. On the other hand, it is found that there exists difference of dissipative plastic energy between different plastic strain paths. A dissipative plastic energy based hardening parameter is proposed and introduced into the hardening function, which isthen embedded in the non-classical constitutive model. The stress responses of 304 stainless steel subjected to biaxial non-proportional loading are analyzed and the results coincide well with the experimental results.