板壳加筋结构的组合优化

提出了一种将结构加筋布局优化和结构参数优化相结合的优化方法。该方法先对结构中的加强筋进行布局优化,然后再优化结构参数。在加筋布局优化中,用单元应变能密度灵敏度作为删除单元的准则。在参数优化中,目标函数和约束函数被近似地表示为二阶表达式,并用改进的DFP(Davidon,Fletcher and Powell)方法来求优化解。为了降低计算复杂度,采用组合近似(CA)方法对修改后的结构位移和应力进行重分析,并应用该方法对储水箱结构进行了结构优化设计。数值结果表明,该方法处理板壳加筋结构优化问题十分有效,而且容易在计算机上实现。

Combined Optimization method of plate-shell structures with stiffeners

An optimization method which combines layout optimization of stiffeners with structural parameters optimization was discussed.The first step is to optimize the layout of stiffeners of the structure,and then the structural parameters were optimized.In layout optimization of stiffeners,the strain energy density sensitivity of the element was used to determine which elements of stiffeners should be deleted.In structural parameters optimization,the object function and the constraint functions were approximated by the second-order Taylor expansion.Improved DFP(Davidon,Fletcher and Powell)method was presented to solve optimal problem.In order to reduce computational effort,the combined approximation(CA) method was used to perform the reanalysis to update the displacements and stresses of the structure.Present method was applied to a bunker.The numerical results show that the optimization method is effective for optimization of plate-shell structure with stiffeners,and it is easy to implement on a computer.