Optimum energy-based design of BRB frames using nonlinear response history analysis

In this paper, an optimum design method for buckling restrained brace frames subjected to seismic loading is presented. The multi-objective charged system search is developed to optimize costs and damages caused by the earthquake for steel frames. Minimum structural weight and minimum seismic energy which including seismic input energy divided by maximum hysteretic energy of fuse members are selected as two objective functions to find a Pareto solutions that copes with considered preferences. Also, main design constraints containing allowable amount of the inter-story drift and plastic rotation of beam, column members and plastic displacement of buckling restrained braces are controlled. The results of optimum design for three different frames are obtained and investigated by the developed method.