基于多尺度模型的复合材料厚板G_(13)剪切失效分析

针对复合材料厚板强度分析问题,通过对子层压板的刚度等效和应力/应变分解建立了一种多尺度分析模型,并引入了剪切非线性本构关系。实现了复合材料厚板结构在子层压板水平的有限元计算和铺层水平的失效判断。采用FORTRAN语言编写了适用于Abaqus/Explicit求解器的VUMAT子程序,用于模拟复合材料厚板剪切非线性响应以及面内失效,子层压板之间采用内聚力模型来模拟分层损伤。分别采用多尺度线性模型和非线性模型对厚层压板G_(13)剪切试验进行了数值预测,并与试验结果进行了对比。分析结果表明:线性计算模型在预测结构承载能力方面有较高的精度,但在预测整体载荷-位移响应时与试验值偏差较大;由多尺度非线性计算模型得到的破坏模式以及载荷-位移曲线均与试验结果吻合较好。

Failure analysis of thick composite laminates with multi-scale modelling under G13 out-of-plane shear loading

For strength analysis of thick composite laminate,a multi-scale model based on sub-laminate stiffness homogenizing and stress/strain decomposition was introduced,in which the shear nonlinearity was also considered.In this way,the thick laminate could be modelled at a sub-laminate level and the structural failure could be predicted at a ply level.A user-defined FORTRAN subroutine (VUMAT) was written to model the shear nonlinearity and intra-laminar failure,and the cohesive zone model was introduced to predict the delamination between two sub laminates.The strength and structural response of G13 out-of-plane shear test were predicted with both multi-scale linear and non-linear model.By comparison with the experimental results,it is found that the multi-scale linear model works well in predicting structural load capacity,but significantly differs from experimental results when predicting the global load-displacement response.For multi-scale non-linear model,both the failure mode and the load-displacement curve fit well with the experimental results.