A Methodology for Reliability-based Multi-criteria Optimal Structural Design

Abstract

A general framework for optimal design based on multiple, possibly conflicting, design criteria is presented which is well-suited for performance-based design of structural systems operating in an uncertain dynamic environment. Reliability-based design criteria are used to maintain user-specified levels of structural safety by properly taking into account the uncertainties in the modeling and seismic loads that a structure may experience during its lifetime. Code-based requirements are easily incorporated into the optimal design. The methodology is demonstrated with a simple example involving the design of a three-story steel-frame building for which the ground motion uncertainty is characterized by a probabilistic response spectrum developed from available attenuation formulas and seismic hazard models.