带脱层的复合材料层板的屈曲分析

用基于Mindlin 板理论的有限元方法进行了带脱层损伤的复合材料层板的屈曲载荷分析。为了获得物理上可能的屈曲模态, 即避免上下脱层的相互贯穿, 在接触区域引入一些假想弹簧, 并给出了这些假想弹簧刚度系数的计算公式和接触计算的迭代格式, 通过这些弹簧对原始刚度矩阵进行修正可以有效地求解屈曲载荷特征值分析中的接触问题。数值计算结果表明了本算法的有效性和引入接触分析对这类屈曲分析的重要性。同时, 还对脱层的大小、形状、位置和脱层的纤维铺层方向对屈曲载荷的影响进行了研究。 

BUCKLING ANALYSIS OF DELAMINATED LAMINATES

This paper is concerned with the buckling load analysis of laminates with a pre existing delamination, using the finite element method based on the Mindlin plate theory. To obtain the physically possible buckling mode, i.e. to avoid the penetration between two delaminated layers, some artificial springs are introduced into the contacting area. Moreover, the formulations for calculating the stiffness parameters of these springs and iterative process for contact analysis are presented. The global structural stiffness matrix can be modified by employing these springs and the penetration between two delaminated layers can be overcome effectively. Numerical results demonstrate the effectiveness of this method and the importance of the contact analysis in the buckling analysis. The effects of various sizes, shapes and positions of the delamination and the fiber angle of delaminated layer on the buckling load are also investigated.