RELIABILITY-BASED STRUCTURAL OPTIMAL-DESIGN USING THE NEUMANN EXPANSION TECHNIQUE

The reliability-based structural optimization formulated using the advanced first order second moment (AFOSM) method contains a suboptimization process. This corresponds to obtaining the most probable failure point of the failure constraint and requires excessive computational work to solve the random state equation with random parameters in the stiffness matrix. This paper presents a numerically efficient method to reduce the computational effort by using the Neumann expansion technique to deal with the random state equation in the suboptimization process. Several examples of truss and beam structures with uncertainties in design variables and loads, including non-normal distributions, are taken. The results show the method can give accurate solutions and reduce computation time.