在考虑结构几何非线性、气动非线性影响的基础上,由气动弹性问题的最普遍方程,获得大展弦比柔性复合材料机翼颤振问题的非线性稳定性分析方程.使用解析方式推导得到机翼的临界颤振速度、颤振频率对于设计变量的灵敏度表达式.展示了复合材料机翼的铺设构型和铺层角对气动弹性特性的影响,指出产生负弯扭耦合效果的机翼截面构型有利于机翼的气动弹性性能.以机翼颤振速度作为目标函数,复合材料铺层角为设计变量进行了气动剪裁优化设计,在得到最优化的铺层构型和铺层角的同时,也比较了本文解析敏度和数值差分敏度得到的优化结果.
The nonlinear government equations of the flutter problem of high-aspect-ratio flexible composite wing were derived from the most general aeroelastic equations with wing's structure geometrical and aerodynamic nonlinearity being considered. Then the gradients of flutter speed and frequency of wing with respect to the design variables were deduced with analytical method. The influence of the composite wing's configuration and ply angle on the flutter speed was revealed. It was concluded that the composite structure configuration that caused negative bending twist coupling was beneficial to wing's flutter performances. An optimization design of a high-aspect-ratio flexible composite wing model was done with the flutter speed as object function and the composite plies as design variables. The best configuration and plies were obtained and the results obtained with analytical gradients of this paper and numerical difference gradients were compared at the same time.