Abstract:The floor response spectrum is essential for the seismic design of non-structural components and can generally be obtained through time-history analysis or direct methods. However, time-history analysis is time-consuming and cannot meet the efficiency requirements during the preliminary engineering design phase. The commonly used direct methods can only consider the elastic stage when calculating the floor response spectrum and cannot accurately reflect the actual structure's elastoplastic behavior under seismic action. To address the above issues, widely used reinforced concrete (RC) frame structures in China were selected as the research object, and a three-dimensional refined finite element model was employed to conduct the elastoplastic floor response spectrum analysis. The effects of three key factors—floor height, damping ratio of non-structural components, and structural ductility coefficient—on the floor response spectrum results were investigated sequentially. Additionally, based on the Peter Fajfar method, an elastoplastic floor response spectrum direct method was developed, and a dynamic amplification factor formula applicable to RC frame structures in China was proposed. Finally, by comparing the floor response spectrum obtained by time-history analysis for a three-story frame structure, the proposed method in this study was verified to rapidly and accurately estimate the floor response spectrum of RC frame structures in China, thereby providing an efficient simplified method for the seismic design of non-structural components.
