OPTIMUM PERFORMANCE-BASED DESIGN OF STEEL MOMENT RESISTANT FRAMES FOR SEISMIC EXCITATIONS

A methodology is presented for optimization of dynamic response of steel moment resistant frames subjected to seismic excitation, based on the concept of uniform distribution of deformation. In order to obtain the optimum distribution of structural properties, an iterative optimization procedure has been adopted. In this approach, the structural properties are modified so that inefficient material is gradually shifted from strong to weak areas of a structure. This process is continued until a state of uniform deformation is achieved. It is shown that the seismic performance of such a structure is optimal, and the structure behaves generally better than those designed by conventional methods. The efficiency of the proposed method has been emphasized for optimum performance-based design of 5, 10, and 15 story steel moment resistant frames subjected to five different strong ground motion records.