材料的非线性混合硬化模型及其在身管自紧分析中的应用

根据高强度钢具有明显的鲍兴格效应,在非线性有限元分析程序NFAP中增加了初始各向同性的材料非线性混合硬化模型。本模型将材料的鲍兴格效应直观地反映到屈服面半径和随动角的连续变化上,同时此模型还可作为各向同性、随动和混合硬化的通用模型。通过对身管自紧的残余应力、残余应变及残余位移分析,证明其计算结果与实验结果相当吻合。

A NONLINEAR MIXED HARDENING MODEL OF MATERIAL AND ITS APPLICATION TO THE GUN AUTOFRATTAGE ANALYSIS

In this paper based on the fact that high strength steels have obvious Bauchinger Effect, a nonlinear mixed hardening model of initial isotropic material is added to the Nonlinear Finite Element Analysis Program NFAP. In this model the Bauchinger Effect of material is intuitively shown on the continuous variations of the yield surface radius and servo—angles. At the same time, this model may be used as a general model for the isotropic, servo and mixed hardening. It is proved that the computed results are in agreement with the experimental results by analysing the residual stress, strain and displacement of gun autofrettage.