基于累积失效法的含损伤格栅加筋板非线性屈曲状态分析

Nonlinear Buckling Analysis of Damaged Advance Grid Stiffen Structure with Progressive Failure Method

分别采用基于Mindlin一阶剪切理论八节点层合板单元和三节点层合梁单元来模拟蒙皮和肋骨,用累积失效法研究了在压缩载荷作用下蒙皮内含分层损伤复合材料正交格栅加筋板的非线性屈曲性态,分析中考虑了加载过程中蒙皮和肋骨纤维断裂、基体损伤和纤维-基体剪切失效造成的刚度退化,并采用了非线性接触单元模型处理蒙皮分层上下子板间的接触效应。通过典型算例,讨论了蒙皮铺设方式、蒙皮分层的面积和深度、肋骨与蒙皮的刚度比,累积失效行为等因素对格栅加筋板非线性屈曲性态的影响。

The composite skin and ribs were modeled with eight node composite laminate and three node beam element by Mindlin＇s first order shear theory, respectively. The progressive failure analysis was adopted to study the buckling behavior of composite grid stiffen plate with embedd delaminations and matrix crack subjected to compression loading. The failure of the skin and the ribs, the damage of matrix and the degradation caused by fiber-matrix shear were considered. A nonlinear contact element was employed to avoid the overlap of upper and lower sub-laminates. By some typically numerical examples, the effects of delamination size and delamination depth in the skin, the stiffness variation of the stiffeners, and the progressive failure behavior on the buckling behaviors of the grid stiffen plate were discussed.