含孔层合板考虑边界效应的拉伸强度分析

1.引言 早在1974年和1975年Whitney与Nuismer就提出了预测含孔层合板拉伸强度的点应力准则和平均应力准则,他们假定的某一特征长度是与材料性能有关系。1977年Karlak只就准各向同性碳/环氧层合板的两种铺层顺序在特征长度中引进了考虑铺层顺序影响的

ANALYSIS OF TENSILE STRENGTH OF LAMINATES WITH A HOLE TAKING INTO ACCOUNT THE EDGE-EFFECT

An analysis of the tensile strength of 0/90]5, C45/ - 45]5, and π/4 laminates with a hole of various finite width and the hole diameter is presented. It is found that, the tensile strength of laminates with a hole relates to not only material property, geometry size of sample, but also ply condition. A strength calculate formulation and a method of modification is also given to allow for the edge-effect of the general symmetrical π/4 laminates with a hole. This is an empirical approach based on the result of experiments. This approach is different compared to former approaches based on model for strength of materials or fracture mechanics. It is a approach based on model for mechanics of composite materials, which considered ply-condition of composite materials.