在气动弹性约束下结构优化设计的罚函数法

本文运用内罚函数法,使一个在颤振、强度和最小尺度等约束条件下的翼面结构重量取极小值。文中比较了最速下降法、DFP变尺度法和BFGS变尺度法这三种无约束最优化算法;采用了以二次多项式逼近约束函数的二次插值法来进行一维搜索;给出了内罚函数法中所用到的各个收敛准则;指出并讨论了减少计算机运算时间的一些途径。 计算结果表明,对于带有气动弹性约束的较复杂的结构优化设计,罚函数法是一个有效的方法。

A PENALTY FUNCTION METHOD FOR STRUCTURAL OPTIMUM DESIGN WITH AEROELASTIC CONSTRAINTS

In this paper an interior penalty function method is applied to minimize the weight of a wing structure under the constraints of flutter, strength and minimum gage. Three unconstrained optimization methods'steepest descent method, DFP variable metric algorithm and BFGS variable metric algorithm, are compared with each other. The quadratic interpolation method with the constraints approximated by quadratic polynomials is used in the one-dimensional search. Respective convergent criterions used in the interior penalty function are presented. Several ways to reduce computer time are pointed out and discussed here.