Reliability-based optimum design of cable-stayed bridges

Abstract

This paper presents a procedure for finding the reliability-based optimum design of cable-stayed bridges. The minimisation problem is stated as the minimisation of stresses, displacements, reliability and bridge cost. A finite-element approach is used for structural analysis. It includes a direct analytic sensitivity analysis module, which provides the structural behaviour responses to changes in the design variables. An equivalent multicriteria approach is used to solve the non-differentiable, non-linear optimisation problem, turning the original problem into the sequential minimisation of unconstrained convex scalar functions, from which a Pareto optimum is obtained. Examples are given illustrating the procedure.