双分层损伤层合梁屈曲有限元分析

FE analysis of double delamination damage of composite beam buckling

采用参考面单元技术并引入虚拟杆单元,建立了含多个分层层合梁屈曲分析的有限元模型,通过数值实验验证了模型的正确性.着重研究不同边界条件、分层尺寸和位置对双分层梁压屈载荷的影响.当对称双分层损伤层合梁的最弱子层位于上、下表面时,压屈载荷由其最弱子层确定,且双分层和相应单分层的压屈载荷有极好的一致性;而当最弱子层位于中间层时,必须考虑接触效应,其压屈载荷较相应的单分层梁有明显降低.压屈载荷的等值线图可以清晰地描述任意双分层损伤层合梁的压屈载荷随分层位置的变化规律.

A FE model of composite beam embedded with double through thickness delaminations is constructed using the technology of reference surface finite element and virtual bar element. The presented model is testified by numerical examples. The effects of size and location of delamination on the buckling loads of the double delaminated beam are studied under different boundary conditions. The numerical results show that the buckling loads of a double delaminated beam depend on the thickness of the weakest sub-delamination when it is close to the outer surface of the beam. The identical buckling load is obtained for both the double and single delaminated beam when the weakest sub-delamination of the double delaminated beam is located in the same position of the beam as that of the single delaminated beam. Whereas it is necessary to consider the influences of contact effect when the middle sub-delamination is the weakest one, and the buckling loads change evidently compared to the corresponding single delaminated beam. The variable regularity of buckling loads of double delaminated beam can be clearly explained from the isoline figure in this paper.