针对传统内聚力损伤模型(CZM)无法考虑层内裂纹对界面分层影响的缺点,提出了一种改进的适用于复合材料层合板低速冲击损伤模拟的CZM。通过对界面单元内聚力本构模型中的损伤起始准则进行修正,考虑了界面层相邻铺层内基体、纤维的损伤状态及应力分布对层间强度和分层扩展的影响。基于ABAQUS用户子程序VUMAT,结合本文模型及层合板失效判据,建立了模拟复合材料层合板在低速冲击作用下的渐进损伤过程的有限元模型,计算了不同铺层角度和材料属性的层合板在低速冲击作用下的损伤状态。通过数值模拟与试验结果的对比,验证了本文方法的精度及合理性。
In order to overcome the disadvantage of traditional cohesive zone damage model(CZM)that it cannot present the effect of intralaminar cracks on delamination interface,a modified CZM has been developed for simulation of damage process of composite laminates subject to low-velocity impact.By means of the modification of the damage initiation criteria of cohesion constitutive model used in interface element,the influences of damage status and stress distribution of matrix and fiber in neighboring interface layers on interlaminar strength and delamination propagation have been taken into account.The proposed model,combined with intralaminar failure criterion,was implemented to ABAQUS as a user defined subroutine VUMAT to simulate the progressive damage process of composite laminate under low-velocity impact.In order to valid the accuracy and rationality of this method,the damage status of composite laminates with different ply orientations and material properties are compared with test results.