压剪组合作用下复合材料壁板的后屈曲承载能力

通过复合材料加筋壁板后屈曲有限元分析,预测盒形薄壁结构在弯扭组合作用下的承载能力.壁板基于修正的一阶剪切理论,四边简支,变形时保持直线.后屈曲分析采用弧长法和基于渐近分析的路径转换技术.定义了三种逐渐破坏状态,利用Hoffman准则,考虑单层板的破坏对于刚度的影响,确定壁板的后屈曲承载能力.数值计算结果表明,复合材料加筋壁板屈曲后有相当大的后屈曲承载能力,预测结果与复合材料盒段弯扭组合试验结果符合良好.

Post-Buckling and Carrying Capacity of Stiffened Composite Panels Under Axial Compression/Shear

The post-buckling and carrying capacity of thin-walled box-like structures under bending and twisting was predicted by the finite element analysis of stiffened composite panels.Based on a revised first-order shear theory,the panels were considered as Mindlin plates supported simply along four edges,which remained straight during deformation.The arc-length method and branch-switching technique with asymptotic analysis were applied to postbuckling path tracking.Three states of progressive failure were defined and the postbuckling and carrying capacity of stiffened panels were determined considering the influence of lamina failure on stiffness in accordance to Hoffman criterion.The numerical results showed that carrying capacity of the stiffened composite panels is considerably high in postbuckling states,and a good agreement was found between the prediction of carrying capacity and the experimental results of the composite box-like structures under bending and twisting.