RELIABILITY-BASED STRUCTURAL OPTIMIZATION USING IMPROVED 2-POINT ADAPTIVE NONLINEAR APPROXIMATIONS

The objective of this paper is to conduct reliability-based structural optimization in a multidisciplinary environment. An efficient reliabi lity analysis is developed by approximating the limit-state functions using two-point adaptive nonlinear approximation. The nonlinear approx imation is constructed by using the function values and the first-orde r gradients at two points of the limit-state function, and its nonline arity index is automatically changed for different problems. The reduc tion in computational cost realized in safety index calculation and op timization are demonstrated through two structural problems. This pape r presents the safety index computation, analytical sensitivity analys is of the reliability constraints and optimization using frame and tur bine blade examples. (C) 1998 Elsevier Science B.V. All rights reserve d.