复合材料层板低速冲击后剩余压缩强度

对两种材料体系和铺层的复合材料层合板进行低速冲击后压缩强度试验 , 以研究低速冲击后层合板的压缩破坏机理。讨论了表面凹坑深度、 背面基体裂纹长度、 损伤面积以及剩余压缩强度与冲击能量的关系。在试验研究的基础上 , 建立了复合材料低速冲击后剩余强度估算的一种椭圆形弹性核模型。该模型将冲击损伤等效为一刚度折减的椭圆形弹性核 , 采用含任意椭圆核各向异性板杂交应力有限元分析含损伤层合板的应力应变状态 ,并应用点应力判据预测层板的压缩(或压、 剪)剩余强度。理论分析与试验结果对比表明 , 该模型简单有效。 

Residual compressive strength of composite laminates after low-velocity impact

The compressive failure tests were carried out on the composite laminates after low velocity impact damage to study compressive failure mechanisms of laminates after low velocity impact damage. The effects of impact energy on the front surface dent depth, back surface resin crack length, damage area and residual compressive strength were studied. Based on the experiment, a reduced stiffness inclusion model was developed to predict the residual compressive strength of composite laminates after low velocity impact. In this model, the damage was considered as a soft elliptical zone of the material. A hybrid stress finite element with an arbitrary elliptical inclusion for anisotropic plates was programmed to compute the stress distribution. The point stress criterion was used to determine whether the post-impact laminates are compressed to failure or not. Good agreement between ptedicted residual compressive strength and experimental results is obtained.