Research On Seismic Performace Evaluation Method Of Steel Frame-Concrete Core Cube Based On Damage Index

The purpose of performance-based seismic design is to keep the damage of the structure in the target range, reduce economic losses and protect safety of life under different intensities earthquake. Therefore, how to predict the damage status of structure precisely in the earthquake is important. In this paper, an evaluation method of seismic performance based on damage spectrum for steel frame-concrete core cube system is proposed, the main contents are as follows:(1) A method for solving capacity curve of shear-bending structures based on simplified incremental dynamic analysis is researched. This method is combined by static analysis and dynamic analysis. First we simplify the structure into equivalent story model through static analysis, and then solve the capacity curve with incremental dynamic analysis. The comparison of the results computed by the simplified method, static Pushover method and IDA method demonstrates that the simplified method is accurate and has higher computational efficiency.(2) Based on Park-Ang damage model, the damage transformation relationship between MDOF and SDOF system of steel frame-concrete core cube structure is researched. The range of Dm Ds has been confirmed when the strength reduction factor, ultimate deformation ductility factor and the period of structure change. Based on statistic results, the damage transformation relationship between MDOF and SDOF system is obtained.(3) The seismic performance evaluation method for steel frame-concrete core cube structure is proposed based on the damage spectrum of SDOF system and the transformation relationship between MDOF system and SDOF system. A 15-story steel frame-concrete core cube structure shaking table test is employed to verify the proposed method. The results obtained by our method coincide with the result of experiment well. It demonstrated that the new method is reasonable.