Optimum Design of Socket Joint Systems for Space Structures using Second Order Approximation Method

Abstract

Optimum design of a socket type joint for space structures is achieved by numerical optimisation techniques. The weight of the joint is considered as the objective function and the design variables are the mean radius and thickness of the joint. The design constraints are taken as the applied loads not allowed to exceed the ultimate bearing capacity of the joint as well as some geometric requirements. The structural analysis is carried out by a finite element program employing elasto-plastic analysis. To verify the analysis due to various assumptions, the results are compared with some available experimental results. By incorporating the analysis program with a numerical optimisation method, the optimal values of variables are achieved while all the constrains are satisfied. In order to reduce the computational burden of the optimisation process a number of first and second order approximation concepts are presented. Thus, the lengthy non-linear analysis is not needed for the optimisation process in the specified move limits.