夹层圆柱壳结构的应力与总稳定性分析

  目的  因对于钛合金耐压夹层圆柱壳这种新型耐压结构研究得较少，其芯层拓扑形式有待优化确认，需开展芯层拓扑优化。  方法  首先，选择一个壁厚较大的无加筋圆柱壳作为分析对象，采用ANSYS轴对称单元计算结构的应力；然后，沿圆柱壳厚度方向划分为上、中、下3个区域，将中部区域的结构设为设计变量，并建立其芯层结构形式的两阶段拓扑优化数学模型；最后，基于Matlab建立遗传算法主控程序，针对无加筋圆柱壳芯层的布置，分别仅沿轴向、轴向与径向布置形式两个阶段进行拓扑优化，以验证上述耐压夹层圆柱壳加筋形式的合理性。  结果  优化方案芯层拓扑形式为等间距设置，垂直连接内壳和外壳的肋板。  结论  静水压力载荷下的耐压夹层圆柱壳结构是一种合理的耐压结构形式。

Stress and stability analysis of double shell structure

  Objectives   As a new type of pressure-resistant structure, the titanium alloy sandwich cylindrical shell has not yet been studied comprehensively. The topology of the core layer needs to be confirmed using the optimization method. This paper carries out the core topology optimization of titanium alloy pressure- resistant sandwich cylindrical shells.  methods  An unreinforced cylindrical shell with high thickness is selected as the analysis object, and the axisymmetric element is used to calculate the structural stresses via ANSYS. The cylindrical shell is divided into the upper, middle and lower regions along the thickness direction. The structures of the middle region are set as the design variables, and a two-stage topology optimization mathematical model of its core structure is proposed. Based on Matlab, the main control program of the genetic algorithm is established to carry out the core layout optimization of the unreinforced cylindrical shell along the axial direction only and both the axial direction and radial direction respectively.  results  The optimal core topological form consists of equidistant ribs connecting the inner shell and outer shell vertically.  Conclusions  A sandwich cylindrical shell under hydrostatic pressure is a reasonable pressure-resistant structure.