用非线性塑性模型标定LY 12-CZ薄板的损伤参数

The labeling of non-linear model parameters for ductile damage of LY12-CZ thin-slabs

重点研究了薄板材料的非线性L em a iter-Chaboche塑性损伤模型参数的测试与标定方法.首先,利用大圆弧变截面拉伸试样检测不同塑性损伤状态下材料弹性模量的变化,进而换算得到材料单轴塑性损伤演化曲线,即ω(E)-εP曲线;然后,参照L em a iter-Chaboche塑性损伤模型中的非线性塑性损伤演化方程,拟定一个相关三参数幂指数函数作为目标函数,并采用了数值迭代-拟合方法确定拟合参数;最后标定出了材料的非线性塑性损伤模型参数.文中还就LY 12-CZ薄板材料的损伤与破坏行为进行了实验测试与分析.

The testing methods for determining the uniaxial ductile damage and the techniques for labeling the material parameters of non-linear Lemaiter-Chaboche＇s ductile damage model were studied based on the experimental results. Firstly, the plastic damage variables were determined through tension tests on the necked-in specimens by measuring the damage elasticity modulus. Secondly, an exponential objective function with three related parameters was proposed according to the non-linear damage equation of Lemaiter-Chaboche＇s model and a numerical iterative-fit method was suggested for fitting the damage curves and determining the material damage constants. Finally, the ductile damage and failure behaviors of aluminum alloys LY12-CZ thin-slabs were investigated both analytically and experimentally.