Constraint approach to performance-based design of steel moment-resisting frames

An optimization method is proposed for performance-based design of steel moment-resisting frames. The multiple design requirements or targets are incorporated into a multiobjective programming problem, where a new formulation based on the constraint approach is presented for obtaining trade-off solutions. The maximum interstory drift angles against seismic motions of three levels are considered as hard targets that should be strictly constrained in the optimization problem. The maximum floor acceleration and total structural volume are conceived as soft targets that are incorporated as objective functions of the multiobjective programming problem. The proposed constraint approach is applied to two representative steel moment-resisting frames, and the characteristics of their optimal designs considering multiple design targets are investigated.