Energy-based design optimization of steel building frameworks using nonlinear response history analysis

Presented in this paper is a design optimization method for steel building frameworks subjected to seismic loading using a nonlinear response history analysis procedure. Minimum weight, minimum seismic input energy and maximum hysteretic energy of fuse members are identified as the three design objectives. Design constraints include the limits on inter-story drift and plastic rotation of member sections. The design optimization method employs a multi-objective genetic algorithm to search for optimal member section sizes from among commercially available steel section shapes. The design method is illustrated for a moment-resisting steel frame of a three-story building. It is concluded the proposed optimization methodology is an effective and efficient application of the capacity-design principle to building frameworks under earthquake loading.

► Seismic design optimization of steel frames using nonlinear time history analysis.
► To minimize cost and input energy and to maximize hysteresis energy of fuse members.
► A general computer-based method for applying the capacity design principle.
► Limit state design philosophy is realized in the structural system level.
► A design example of a three-story moment resisting frame is demonstrated.