复合材料加筋壁板的优化设计

本文用简化的方法,考虑了受压及压剪联合作用的复合材料加筋壁板的总体屈曲和局部屈曲、材料强度、刚度、轴向应变等因素以及其它工程要求的影响,用数学规划法提出壁板的优化设计问题,用乘子罚函数法求解。以石墨-环氧帽型加筋板为例,所得优化设计结果与NASA得出的最优曲线一致,证明了所用方法的可靠性,并可进一步推广应用于工程实践。

Optimal Design of Composite Material Stiffened Panel

The minimum-mass design of composite material stiffened panel subjected to longitudinal compression and shear loadings is presented in this paper. A set of simplified buckling equations is adapted and the semi-analytical formulas for critical loadings of the panel are established. The optimization of the stiffened panel is presented and solved as a nonlinear mathematical programing problem. The method of multipliers penalty function is used to determine the minimum-mass configuration of the graphite/epoxy hat-stiffened panel. The objective function is the mass of unit surface area per unit length of the panel(i.e. the mass index W/AL).The design requirements (constraints) considered are strenghth of the laminate, global/local buckling, stiffnesses, longitudinal strain of the stiffened panel and the upper and lower bounds on the cross-section dimensions. A series of optimum results by this procedure coincide well with available NASA design charts. It is shown that this simplified set of buckling equations have adequate precision for stability prediction optimization and hence could be used for the preliminary design of composite stiffened panel. The procedure given in this paper could be used for engineering application.