An efficient approach for design optimization of structures involving fuzzy variables

We propose a new approach for solving design optimization problems of structures involving fuzzy variables. First, the possibilistic safety model of structures with fuzzy variables is investigated. A possibilistic safety index (PSI) is presented to compare different designs. This paper then presents the PSI-based design optimization (PSIBDO) model for structures with fuzzy variables. The optimization problem is a triple-loop nested problem, and the computational cost is high. To reduce the computation time, a technique called target performance-based design approach (TPBDA) is proposed to overcome difficulties encountered by the PSIBDO. With the proposed TPBDA, the triple-loop nested problem is reduced to a double-loop one, and the computational time is considerably reduced. Several examples are given to demonstrate the efficiency of the proposed approach.