Analysis and Design of Seismic Robustness of FRP-Reinforced Frame based on Interlayer Displacement

Abstract

For a structure, robustness is a high-level performance index since it takes account of the effects of impact, explosion, earthquake and other instantaneous dynamic actions on the structure safety. In this work, layer is taken as the tie between the column and the frame. Two concepts, namely, “layer importance coefficient” of the column and “layer vulnerability coefficient” of the frame, are introduced. Based on these, the method for calculating the seismic robustness is proposed and analyzes the seismic robustness of three FRP-reinforced frame models. The results show that: The robustness of the frame with the 1st layer column reinforced with two layer CFRP (carbon fiber reinforced polymer) (F20RC) and the 1st and 2nd layer column reinforced with one layer CFRP (F11RC), respectively are better than that of the 1st layer column reinforced with one layer CFRP (F10RC). As the intensity of earthquake action increases, the seismic robustness index decreases. When UBC97’s acceleration-related parameter Ca = 0.36 and velocity-related parameter Cv = 0.36, the robustness coefficient of the three models F20RC, F11RC, F10RC are 36.5, 37.2, 34.1, respectively. When Ca = 0.6, Cv = 0.6, that of F20RC, F11RC, F10RC are 24.2, 20.4, 19.5, respectively. Finally, the procedure for designing the FRP-reinforced frame based on the seismic robustness is presented and demonstrated.