复合材料层合板的二次失稳和破坏研究

 本文采用考虑横向剪切效应的三角形拟协调罚函数单元,推导了带有初始挠度的复合材料层合板在后屈曲阶段的增量平衡方程和相应的切线刚度矩阵,以及非线性特征方程,并以数值计算研究了单元的精度和收敛性,二次分支点的存在性和边界条件、加载方式及铺层次序对二次失稳和破坏载荷的影响。

SECONDARY BIFURCATION AND FAILURE STUDY OF COMPOSITE LAMINATES

A fifteen-variables quasi-conforming triangle element technique including transverse shear effect for penalty-finite element method is used in this paper to work out the postbuckling incremental equilibrium equation the corresponding tangent stiffness matrix and nonlinear eigen-equation of composite laminates with inital imperfection. By using numerical calculations, the precision and convergence of the element, the existence of the secondary bifurcation point the effect of boundary conditions, the loading forms and ply configurations on the secondary buckling and failure load are also studied. An effective method is proposed for engineering designers to analyse the instability and even the failure load of structures.