Damage Assessment And Design Of Resistance To Collapse For High-rise Steel Structure Due To Strong Earthquakes

Damage is the main reason to destroy the structural function and cause its collapse. The damage analysis based on damage index appears to be the future direction of structural seismic capacity evaluation and design. In this paper, the seismic performance evaluation of both the member and the whole structure are conducted through one-parameter and two-parameter damage model, respectively, and the collapse-resistant design of a steel frame under strong earthquake is also carried out, the main work are as follows:(1) Based on a large number of literature at home and abroad, the advantages and disadvantages, scope of application and collapse analysis methods of one-parameter and two-parameter damage model are described in detail;(2) The performance evaluation of an 8-story steel braced frame structure under strong earthquake is carried out through a one-parameter damage model, and the damage evolution and failure mechanism of the member and the structure are analyzed;(3) An elasto-plastic damage material model considering strength and stiffness reduction due to damage accumulation is developed and built in LS-DYNA program, and the damage index of an 8-story steel braced frame with damage accumulated material model and normal material model are compared;(4) A double parameter damage model based on equivalent plastic strain and specific energy is proposed to overcome the shortage of the single parameter damage model, and a 9-story benchmark model is analyzed under different intensities of earthquake, results indicate that the collapse process of the structure can be presented by the damage model proposed;(5) The tie force method (TFM) is applied to redesign the steel frame under strong earthquake, and the effectiveness of TFM is proved by the damage evaluation analysis of member and structure using the proposed double parameter damage model before and after redesigning.