一种非经典滑移模型及其应用

A NONCLASSICAL MODEL FOR SLIP AND ITS APPLICATION

采用由弹簧和塑性阻尼器构成的简单机械模型建立了不采用屈服判据的滑移本构方程 ,并利用KBW自洽理论和一种混合平均方案得到了多晶体弹塑性的分析方法 .此法不采用屈服判据 ,无需对滑移系的开动和滑移方向进行搜索 ,使计算过程简化 .分析了 31 6不锈钢在拉压 剪切二维塑性应变空间中典型路径下的循环响应特性 。

Plastic deformation inevitably induces nonhomogeneous microstructure, such as defects and residual distorsion, in crystal and polycrystal, and the energy stored in the corresponding residual microstress fields may partly be released in subsequent plastic deformation. With this notion, a nonclassical constitutive description for a slip system is formulated based on a simple mechanical model. The corresponding hardening law for a single crystal is then obtained and the corresponding approach for polycrystalline plasticity is proposed based on the KBW′s self consistent theory. The proposed model does not use yield criterion, the corresponding numerical analysis is therefore greatly simplified. A mixed averaging approach is used in the numerical analysis. The behavior of 316 stainless steel subjected to cyclic plastic straining along typical biaxial nonproportional paths are described and the results are in satisfactory agreement with experimental observation.