离散变量桁架结构优化设计的组合算法  

Combinatorial algorithm to solve minimum weight design problems of truss structures with discrete variables

作　　者：许强[1] 孙焕纯[1] 

机构地区：[1]大连理工大学工程力学系

出　　处：《大连理工大学学报》1991年第6期625-633,共9页Journal of Dalian University of Technology

摘　　要：对桁架结构离散变量的优化没计提出了一种算法。方法主要分三个步骤：（１） 进行局部优化得到各离散变量的下界；（２）采用“二次射线步”找到一个“基点”； （３）在“基点”附近用（０，１）组合规划进行寻优。本方法能够解决局部约束（应 力、稳定以及截面尺寸约束）和整体约束（位移、频率禁区等）问题。本方法是一个 组合算法，在结构重分析之后的优化阶段不需解任何方程，从而节省了机时．针对本 方法，用ＦＯＲＴＲＡＮ－７７ 语言自编了电算程序。通过大量考题的验证，本方法计算 速度快、收敛一致，且优化结果较好。A simple algorithm is presented to solve the minimum weight design problems of truss structures with discrete variables. This method has mainly three procedures, (1 )making local optimization to obtain the lower limit of every discrete variable; ( 2 ) adopting 'twice scaling steps' to find a 'BASIC POINT' (3) using the zero-one programming at the 'BASIC POINT' to find the optimum point. In the problem, there are many constraints such as stress, stability, displacement, frequency-prohibited-band, and the constructional requirement of section sizes. Because the method is a combinatorial algorithm, it is not needed to solve any equation in the optimization step, and the calculating amount is greatly saved. The microcomputer code with FORTRAN-77 language is made. Several examples arc calculated, and the results obtained show that this method has higher accuracy ,and converges Lastly and identically for various initial designs.

关 键 词：桁架 最佳化 变量 离散 二次射线步 

分 类 号：TU375.51[建筑科学—结构工程]