含分层损伤的复合材料格栅(AGS)板的非线性热屈曲分析

Nonlinear thermal buckling behavior of advanced composite grid stiffened plates with delamination

采用基于复合材料一阶剪切效应理论的有限元法分别研究了含分层损伤的复合材料层合光板、单向加筋板和格栅加筋(AGS)板的热屈曲性态。在分析中考虑材料热物理性质与温度相关特性,同时在分层前缘采用了位移约束条件以保证分层区域的各子板的变形相容要求。3种结构的典型算例分析和结果的比较表明,复合材料格栅(AGS)板具有很强的抗热屈曲的能力,但是,分层损伤将使其临界温度降低,同时还会导致热屈曲的模态发生改变。本文中提出的方法和所得结论对AGS结构的热承载能力预测和损伤容限设计将具有参考价值。

On the basis of the first order shear deformation theory, a nonlinear finite element analysis method has been developed to study the thermal buckling behavior of delaminated advanced composite grid plates. The temperature dependent thermal and mechanical properties of the composite were considered and a constrained model was established to ensure deformation compatibility between sub-laminates in the front of the delamination. Comparing the thermal critical temperature and buckling modes of the bare and single direction stiffened laminates with those of advanced grid stiffened laminates （AGS）, the result shows that the advanced grid composite laminates possess stronger thermal bucking resistance; however thermal critical temperature values are reduced and the corresponding buckling modes are also changed with increasing the delamination area. The methods and conclusions provided have the reference value for composite structure designers in load capacity prediction and damage tolerance design of AGS.