机身整体壁板在轴压载荷下后屈曲计算及结构优化

以民机机身组装壁板为基准,设计了等重量的整体壁板结构,并分别建立了两种壁板的有限元模型.通过组装壁板轴压试验结果与非线性、大变形的有限元计算结果比较,对有限元模型进行了验证,两者结果吻合很好.在此基础上,有限元计算分析得出了组装壁板与整体壁板在轴压载荷下的破坏形式与承载能力的差异.结果表明,整体壁板承载能力比现有的组装壁板承载能力提高了18.4%.最后基于有限元模型与二次响应面模型对整体壁板尺寸进行优化,优化后壁板轴压承载能力不变,结构重量减轻了8.7%, 故为整体壁板设计提供了很好的依据.

POST-BUCKLING ANALYSIS AND STRUCTURE OPTIMIZATION OF INTEGRAL FUSELAGE PANEL SUBJECTED TO AXIAL COMPRESSION LOAD

Build-up panels for the commercial aircraft fuselage subjected to the axial compression load are studied by both experimental and theoretical methods. An integral panel is designed with the same overall size and weight as the build-up structure, and finite element models (FEMs) of these two panels are established. Experimental results of build-up panels agree well with the FEM results with the nonliearity and the large deformation, so FEMs are validated. FEM calculation results of these two panels indicate that the failure mode of the integral panel is different from that of the build-up panel, and the failure load increases by 18.4% up to post-buckling. Furthermore, the integral structure is optimized by using the multi-island genetic algorithm and the sequential quadratic programming. Compared with the initial design, the optimal mass is reduced by 8.7% and the strength is unchanged.