Abstract: This paper constructs an optimization design model for random truss structures with displacements and system reliability constraints. By the method of reliability assignment and reassignment, the difficult problem of disposing the structure system reliability constraints is solved. Based on sensitivity information, the given system failure probability can be disassembled to the sum of all element failure probabilities in the method. And the reliability analysis based on FEM is processed by utilizing the random factor method. In the optimization process, the penalty function method which includes sensitivity information is adopted. Finally, a numerical example shows that the method in this paper is valid and feasible.

Key words: random truss structures, systematic reliability, reliability distribution, random factor method, optimization design