APLICACIÓN DE MÉTODOS DE OPTIMIZACIÓN DE DISEÑO BASADA EN FIABILIDAD A ESTRUCTURAS CON CARGAS ALEATORIAS CORRELACIONADAS

Abstract

A deterministic optimization does not account for the uncertainties in the design variables and parameters. Modern competitive market demands have required the designers to introduce techniques to obtain optimized designs that are also reliable. In the past twenty-five years, researchers have proposed a variety of methods to obtain optimum and reliable designs. These methods are addressed in Reliability-Based Design Optimization (RBDO). There are various types of RBDO approaches: Double-Loop methods, Decoupled methods and Single-Loop methods. This paper studies the efficiency of several RBDO approaches applied to problems with dependent non-normal random input variables. Usually, the joint cumulative distribution function of this random vector is seldom available, and it is only characterized reliably up to the marginal distributions and a measure of dependence between such as the linear correlation matrix. Thus, Nataf transformation can be used with dependent random variables in RBDO problems. Several RBDO approaches are applied to a ten bar truss. The numerical efficiency and convergence are checked. Keywords: Structural Reliability, Reliability Based Design Optimization, Nataf Transformation, Copulas, Correlated random variables