建立了一种复合材料层压板在准静态压痕力作用下的损伤阻抗的预测方法。首先分别针对基体破坏、分层、纤维断裂等失效模式引入相应的失效变量,并建立不同失效模式下的刚度折减方法,然后采用基于应变描述的Hashin和Yeh失效准则并结合有限元方法,对复合材料层压板在准静态压痕力作用下的破坏过程进行渐进损伤分析,在此基础上进一步预测了层压板的损伤阻抗。采用商用有限元软件ABAQUS/Standard的UMAT用户子程序实现数值模拟。计算结果表明,分层起始与扩展是导致载荷一位移曲线发生第1次卸载的主要原因,当接触力达到其最大值时出现较明显的纤维断裂。分层起始载荷和最大接触力的预测结果与实验数据吻合良好。
A method of predicting the damage resistance of composite laminates subjected to quasi-static indentation was proposed. Damage variables were introduced to represent the matrix crack, delamination and fiber breakage, respectively, and stiffness degradation criteria were proposed for different damage modes. A progressive damage analysis was conducted for composite laminates under quasi-static transverse compressive loading by using a strain- based Hashin and Yeh failure criterion as well as the finite element method. The damage resistance was predicted. The numerical analysis was implemented with a commercial finite element code, ABAQUS/standard, via its user subroutine UMAT. The numerical results indicate that the onset and propagation of the delamination induce a discontinuity in the slope of the force-displacement curve, and the fiber breakages are induced once the contact force reaches its maximum. The numerical results agree well with the test data for the delamination onset load and the maximum contact force.