考虑内压影响的加筋柱壳高效屈曲优化

针对运载火箭贮箱结构,基于渐近均匀化法建立考虑内压的非等厚筋条的加筋壳承载力快速计算方法。首先,采用渐近均匀化法获得加筋单胞的等效刚度阵,进而基于瑞利-里兹法计算考虑内压的整体失稳载荷,并基于板壳理论发展了加筋柱壳的蒙皮和筋条局部失稳载荷计算方法。此外,基于自适应代理模型优化方法,开展了考虑多种失效模式的加筋柱壳承载力最大化设计,以最优设计为例,分析了内压对加筋柱壳整体失稳载荷的影响规律。

Efficient Buckling Optimization of Stiffened Cylindrical Shells Considering Internal Pressure

In this paper, a fast method for calculating the buckling load of stiffened cylindrical shells considering internal pressure is proposed. The asymptotic homogenization method is used to obtain the equivalent stiffness matrix of the stiffened unit cell. Based on the Rayleigh-Ritz method, the buckling load of the cylindrical shell under axial load and internal pressure is calculated. Based on the theory of plate and shell, the calculation method of local instability load of skin and stringers of stiffened cylindrical shells is developed. Furthermore, the design of maximizing buckling load considering multiple failure modes based on self-adaptive surrogate-based optimization is carried out for stiffened cylindrical shells. Taking the optimal solution as an example, the influence of internal pressure on buckling load of stiffened cylindrical shells is analyzed.