微裂纹损伤对复合材料层板分层的影响

Effects of micro-crack damages on delamination of composite laminates

本文将双标量损伤模型推广 ,考虑层内及层间微裂纹损伤相互作用 ,建立了层合复合材料的多标量损伤本构关系 ,并将该本构关系应用于含贯穿分层层板的后屈曲分析 ,采用准三维有限元法研究了分层尖端场与极限损伤区演变的特点。结果表明 :损伤导致裂尖区层间应力奇异性消失 ,引起层间应力重新分布 ;损伤区的发展方向取决于分层上下表面层的铺设角 ;能量释放率不能反映损伤和分层扩展特征 ,因而有必要建立基于损伤演化的分层扩展准则。

Considering both intralaminar and interlaminar micro crack damages in composite laminates, a generalized multi scalar damage model is applied to the post buckling analysis of laminates with through width delamination. For various stacking sequences, the stress and damage fields at delamination tip and energy release rate are obtained by quasi 3D FEM to study influences of damages on delamination behavior. The numerical results indicate that the stress singularity at delamination tip vanishes and the stress redistribution occurs. The direction of limit damage growth depends on stacking angle θ of the ply above interface. The energy release rate can not predict delamination growing, so a delamination growth criterion based on damage evolutions is needed.