一个飞机结构优化设计软件

A Software for Optimum Designof an Aircraft Structure

本文根据有限元分析基础,研究薄壁结构在应力、位移、最小尺寸约束下结构最轻重量的优化设计问题。用Kuhn-Tucker(库恩-塔克)必要条件将多个位移约束简化为单一位移约束(称为最临界位移约束),建立位移约束下的优化设计准则.从而避免大批拉格朗日乘子的计算,并结合满应力优化设计准则,形成了在有效约束界面逐步逼近最优设计点的方法——包络法。用某型飞机后机身一段优化设计作为本文的实际应用,得到令人满意的结果。

Based on the finite element method,an optimization design of minimum weight of thin-walled structures under constraints of multiple load conditions and stress (displacement and size is studied in this paper. Using Kuhn-Tucker necessary conditions,a multi-displacement constrained problem is simplified to a single displacement constraint and called the most critical displacement constraint,eliminating the need to calculate a large set of lagrange multipliers for the effective constraints and deriving an optimization criterion. A recursion formula for stress and displacement constraints is incorporated into a designalgorithm——Envelope Method,which apporaches to the optimum design along the mosteffective constraint boundary. The method is applied successfully to optimum design of aft fuselage.