Seismic performance design of energy-dissipated structure system based on damage control and time-varying damping ratio

The installation of energy dissipation devices on building structures can significantly reduce seismic damage. A brief review of first, second and third generation performance-based seismic design (PBSD) theories, and a comparative analysis of existing PBSD methods for energy-dissipated structure systems confirms that design methods based on force, displacement, and energy are inadequate. A more comprehensive approach is the damage-based design method, which can evaluate the seismic performance of structures. However, due to the lack of an analytical relationship between the additional equivalent damping ratio (AEDR) of dampers and the damage degree of the main structure, the current performance design method can only predict the expected damage via an iterative adjustment analysis of damper's design parameters. The authors addressed this problem by analyzing the damage mechanism of the energy-dissipated structure system's core area from the perspective of energy dissipation. It is established an analytical relationship between the AEDR and the damage index of the main structure with dampers via a damage model based on the energy difference ratio and the time-varying AEDR calculation of dampers subjected to ground motions. With this new approach to seismic vulnerability analysis, the performance design flow of the seismic structure system is based on damage control. A case study verifies the accuracy of the damage-degree based AEDR calculation. The proposed damage-based method effectively controls the damage degree of the main structure to the expected damage target. This method is compatible with the displacement-based design method, and which also enriches the research contents of structural seismic design and damage analysis in the third generation PBSD.