一种改进的最优准则法及其在结构优化设计中的应用

The Modified Optimality Criteria and Its Application in Structural Design

基于最优准则法提出了一种在优化迭代过程中设计变量越界的松弛处理方法,即允许在部分迭代步中设计变量大于上限值或小于下限值,只有当设计变量在连续多个迭代步中越界时才令其等于边界值,算例验证结果表明,在部分工况下,改进后的最优准则法能够获得更佳的优化计算结果。另一方面,推导了约束条件显式表达的简化算式,以简单的代数算式代替了传统算法中复杂耗时的符号积分运算,使得结构优化设计程序简单而高效。最后,通过一框架结构的优化设计算例验证了本文方法的有效性。

Based on the theory of Optimality Criteria（OC）,a modified optimization algorithm is presented in this paper,which permits the design variables to exceed their preset limiting value in optimization iteration cycles.Only when a design variable exceeds its limiting value for successive several times,the design variable will be set as the limiting value and regarded as an inactive variable.On the other hand,a simplified formula of constraints is deduced by using this formula,algebraic operations will take the place of symbols integral operations,which will save a lot of computation time.An example is shown to illustrate the efficiency of the modified OC method.The selected results show that in some particular conditions,the modified OC method can obtain a better optimal design than the traditional OC method.