针对复合材料加筋板结构的布局和铺层优化问题,发展了一种二级优化设计技术。第一级采用基于近似模型技术的布局优化方法,以筋条形式、个数、截面形状和铺层厚度作为设计变量,以结构质量最轻为目标函数,实现加筋板结构布局形式和截面尺寸的布局优化;第二级借助于等效弯曲刚度法和遗传算法,考虑层合板的制造和工艺约束,以层合板的各铺层角作为设计变量,以层合板弯曲刚度系数与上一级优化所给最优弯曲刚度系数之间的误差最小为目标,实现了复合材料加筋板在固定铺层层数下的铺层顺序优化;在二级优化的基础上,通过协调稳定性约束,实现综合优化。算例表明:采用二级优化设计方法,可以很好地实现复合材料加筋板的布局优化设计。
A layout optimum design formation for composite stiffened panel is proposed.This formation is composed of three steps.Firstly,a parametric finite element model is set up and the approximate model is used to construct the objective function of layout variables and size variables,and then to optimize the objective function by minimizing the mass of the panel to obtain the layout and size of the stiffened panel under the given stacking sequence.Secondly,the equivalent bending stiffness and the genetic algorithm are employed to deal with the ply stacking sequence optimization,where the requirements of manufacture and technics are considered.And finally the results from the layout optimization and stacking sequence optimization are collaboratively optimized and thus the optimal composite stiffened panel is determined.The optimization design of a composite stiffened panel under compressive and shear loading is conducted to demonstrate the effectiveness.