Evaluation of Damage Distribution in Elements of Dual Frames

Researches show that the strength criterion is inadequate for design of structures against seismic loads. Since structures yield and experience plastic deformation under strong ground motion, considering structural damage with inelastic behavior may be a considerable criterion for design and control of the structures.In this paper, three steel structures with dual system consisting of intermediate moment resisting frames and concentrically braced ones were selected and designed based on ASD method of UBC-97. Then, for evaluating inelastic behavior, these structures were subjected to three earthquake records and the nonlinear dynamic analyses were done by the PERFORM 3D (VER 4.0.1) software. Next, hysteretic energy and damage measure were computed for all members of the structures in all stories. Finally, it has been tried to find a method for reducing the damage of structural elements and making the damage distribution uniform among structural members of each story.