含分层损伤复合材料层合板前后屈曲行为研究

 采用基于Mindlin一阶剪切理论的四节点板单元，分析了简支和固支两种边界条件下含圆形分层复合材料层合板前后屈曲行为。结果表明，尽管浅部分层的存在使层合板的前屈曲临界载荷大幅度下降，但层合板仍能继续承受很大的后屈曲载荷，这种情况下的前屈曲是由于分层部分的局部行为造成的。同时，在相同的铺设和分层厚度及边界条件下，分层半径越大，后屈曲临界载荷越低，固支下的后屈曲临界载荷比简支下的临界载荷高。

PRE POSTBUCKLING ANALYSIS OF COMPOSITE LAMINATES WITH DELAMINATION DAMAGE

A 4 node plate element based on Mindlin first order shea ring theory is presented to analyze the pre postbuckling behavior of composite laminates with circle delamination damage. For the configuration analyzed, moder ate strain levels, and without including delamination front contact effect, alth ough the local buckling load decreases greatly because of the presence of the th in delamination, the laminate can sustain a high postbuckling load. It is to say that pre buckling analysis is not sufficient to model the residual strength of laminate with delamination and post buckling analysis is necessary. The post buckling load of the laminate with all clamped boundary edges is much higher tha n that of the laminate with all simply supported edges. The stiffness of laminat e changes so slightly after local buckling that local buckling load can not be i dentified from the load displacement curve.