考虑剪切非线性影响的复合材料连续损伤模型及损伤参数识别

Continuum damage model and damage parameter identifications for composites considering the effect of shear nonlinearity

在复合材料正交各向异性连续损伤力学的基础上,引入由应变描述的连续综合变量,损伤演化方案采用综合变量的指数函数。考虑复合材料剪切非线性,通过非线性损伤因子在全局损伤出现之前将其引入本构方程。编写了VUMAT实施损伤模型,介绍连续损伤模型中材料参数的取值方法。对无法通过试验获得的损伤参数,采用遗传算法原理,定义个体适应度为试验及模拟载荷-位移曲线误差,通过编写MATLAB程序调用ABAQUS有限元模型实施参数反演方法。选择了常用铺层结构的复合材料带孔层合板进行仿真参数识别分析,验证了基于遗传算法参数识别方法的可行性。

The strain based integrated continuous variables were introduced and used to describe the evolution of damage. The shear nonlinearity of the composite materials was taken into considerations by introducing a nonlinear damage factor in the constitutive equations. The proposed continuum damage model was then implemented into the ABAQUS via VUMAT. The method to determine the parameters was explained in detail. Damage parameters which cannot be obtained by experiment were identified by using the genetic algorithms. The individual fitness was defined by the difference between the experimental and simulated load displacement curves. The parameters inversion method was carried out by the developed MATLAB program to call ABAQUS to perform the finite element analysis. A common composite laminated plate with a hole was selected to identify parameters by using the proposed model. Numerical results reveal the feasibility of the proposed parameter identification method.