空间梁板结构可靠性优化的全局最优解

基于可靠性分析理论,用改进的一次二阶矩法给出了空间梁板结构安全余量对各设计变量敏度分析的表达式,由PNET法给出了结构系统可靠性函数对设计变量的一、二阶敏度表达式,以及Hessian矩阵中各元素的具体形式,据此能确定结构系统可靠性函数的凸凹性,为判断基于结构系统可靠性优化所得解是否为全局最优解提供了理论基础。算例表明,对空间梁板结构系统基于可靠性的结构优化问题,可靠性指标合理的解多为全局最优解。

Global Optimal Solution of Space Beam-Plate Structural Reliability Optimization

The safety margin sensitivity of space beam-plate structure to each variable was given by using improved first two-order matrix method based on the theory of structural system reliability analysis in this paper,and so were the first and second order sensitivity of the structural system reliability function to each variable and the expression of each element in Hessian matrix.From these,the knaggy character of structural system reliability could be judged,which would provide the theory foundation to judge that the optimal solution based on the structural reliability optimization was global optimal solution or not.A numerical example showed that the optimization problem solution of space beam-plate structures based on the structural system reliability was the global optimal solution on condition that the structural system had rational reliability index under mostly case.