含多个分层复合材料层合板后屈曲性态研究

基于Mindlin假定下的大变形板／壳理论，采用参考面单元和虚拟杆单元相结合的非线性有限元方法，建立了分析含多个穿透分层损伤层合板后屈曲行为的有限元计算模型，并给出了考虑接触后非线性屈曲方程的迭代算法，从而研究考虑层间接触效应的多分层层合板的后屈曲性态。文中着重讨论了分层的深度、数目和尺寸对含多分层合板后屈曲性态的影响。大量数值分析结果证明了该模型的有效性，并且得到了一些对层合板结构设计和对含分层损伤层合板评估有益的结论。

Postbuckling of laminated composite with multiple delaminations

Based on Mindlin assumption and the moderate large-deformation plate/shell theory, a nonlinear numerical model is presented to analyze the post-buckling behavior of a composite panel embedded with multiple penetrating delaminations. A 4-node reference surface plate/shell element combining with a virtual bar element is employed to numerically solve the nonlinear buckling equations using a revising arc-length iteration scheme. The virtual bar element is used to take into account the contact effect on the interface between the two adjacent sub-beams, i.e., to prevent the two adjacent sub-delaminations penetrating into each other. Numerical examples demonstrate the effectiveness of the proposed model and iteration algorithm. The effect of depth, number and size of delaminations on the post-buckling properties of delaminated panels is emphatically studied and some salient conclusions are drawn in this paper.