薄壁加筋结构屈曲分析及优化设计

发布时间：2018-01-22 13:05

本文关键词： 薄壁加筋结构屈曲承载力加筋布局优化渐进结构优化多岛遗传算法　出处：《北京工业大学》2013年硕士论文　论文类型：学位论文

【摘要】：薄壁板壳结构广泛应用于工程实际之中，这种结构所用的材料不多，但却具有较大的承载能力。薄壁结构受载时常在未发生强度破坏就已发生失稳破坏，对其进行加筋可以有效提高其屈曲承载力。本文依据板壳结构线性屈曲和非线性屈曲理论，利用有限元分析方法，对加筋板和加筋圆柱壳结构进行了稳定性研究及优化设计。主要研究内容如下： (1)基于加筋板结构有限元分析技术与渐进结构优化(ESO)方法思想，提出一种易于实现的优化策略并建立优化模型，通过结构屈曲分析与渐进结构优化算法，实现结构单元“影响度”的计算以及拓扑优化工作的渐进，为实现ESO方法解决结构拓扑优化问题提供了一种较为简便的方法；研究了加筋平板的筋条分布，以屈曲承载力最大为目标，对受面内载荷的平板进行加筋布局优化，获得了加筋板在多种载荷下的筋条最优布局。 (2)以加筋圆柱壳屈曲承载力最大为目标，以纵向筋与环向筋筋条数目、蒙皮厚度以及筋条截面尺寸为设计变量，建立了加筋圆柱壳等体积下屈曲承载力最大的优化设计模型。采用ISIGHT多岛遗传算法与ANSYS APDL建立协同优化工作流程，实现了优化模型的求解。 (3)考虑结构缺陷的影响，通过对不同加筋数量的加筋圆柱壳进行非线性屈曲分析。得出结论：以特征值屈曲承载力作为优化目标所得的优化结果并非加筋圆柱壳结构真实承载力的最优解，线性屈曲承载力最大的加筋圆柱壳非线性屈曲承载力并非最大。
[Abstract]:Thin-walled plate-shell structure is widely used in engineering practice. The material used in this structure is not much, but it has a large load-bearing capacity. The thin-walled structure often has instability failure without strength failure. Reinforcement can effectively improve the buckling capacity. Based on the theory of linear buckling and nonlinear buckling of plate and shell structure, the finite element analysis method is used in this paper. The stability and optimization design of stiffened plate and stiffened cylindrical shell are studied. The main contents are as follows: 1) based on the idea of finite element analysis and progressive structural optimization (ESO) method for stiffened plate structure, an easy to implement optimization strategy and an optimization model are proposed. By means of structural buckling analysis and progressive structural optimization algorithm, the calculation of the "degree of influence" of structural elements and the asymptotic work of topology optimization are realized. It provides a simple and convenient method to solve the structural topology optimization problem by ESO method. In this paper, the distribution of stiffened plates is studied. With the aim of maximum buckling capacity, the stiffened plates subjected to in-plane loads are optimized, and the optimum layout of stiffened plates under various loads is obtained. (2) the maximum buckling capacity of stiffened cylindrical shells is taken as the objective, the number of longitudinal and circumferential stiffeners, the thickness of skin and the section size of stiffened cylindrical shells are taken as design variables. The optimal design model for the maximum buckling capacity of stiffened cylindrical shells in equal volume is established. The ISIGHT multi-island genetic algorithm and ANSYS APDL are used to establish the cooperative optimization workflow. The optimization model is solved. 3) considering the influence of structural defects. The nonlinear buckling analysis of stiffened cylindrical shells with different number of stiffeners is carried out. The results obtained by using the eigenvalue buckling capacity as the optimization objective are not the optimal solutions of the real bearing capacity of stiffened cylindrical shells. The nonlinear buckling capacity of stiffened cylindrical shells with the largest linear buckling capacity is not the largest.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU33

【相似文献】