新的复合材料格栅加筋板的平铺等效刚度法

针对薄壁复合材料格栅加筋结构的受力特点,在改进原有力学假设的基础之上,推导了一种新的平铺等效刚度计算方法,它充分考虑了筋条和面板之间的相互作用.通过格栅单元结构布局形式的参数化表示,建立了通用的力学分析模型;该模型可用于分析各种结构布局形式和面板铺层方式下的结构总体屈曲问题,故对于航空航天结构设计非常有用.结合Rayleigh-Ritz方法,推导出了求解格栅加筋板屈曲载荷的通用线性特征方程;最后,分析了多种类型格栅结构的算例,并与现有的各种方法进行了比较,结果更为精确,因而对格栅加筋结构的优化设计具有很好的应用价值.

A NEW SMEARED STIFFENER THEORY FOR GRID-STIFFENED COMPOSITE PANELS

An improved basic mechanical hypothesis was proposed to account for the mechanical behavior of grid stiffened composite panels. With such hypothesis, a new smeared stiffener approach was developed to effectively take into consideration the stiffener-skin interaction effects. The parametrized representation of grid unit cell was described, and the corresponding mechanical model was estabilished. Such generalized model can be used for global buckling analysis of grid-stiffened structures with different types of grid layouts. Therefore, it is very useful for aerospace structural design. Using Rayleigh-Ritz method combined with the developed smeared stiffener approach, the eigen function for the global buckling load of grid stiffened panels was derived. Finally, various test examples with different grid patterns were analyzed and the results were compared with those obtained with existing methods. It is shown that the developed approach has better accuracy and thus can be used for optimal design of grid stiffened composite structures.