Hysteretic behavior of resilient hinged wall enhanced with FRP bars

Abstract

To further improve the seismic resilience of resilient hinged walls (RHWs), in this study, an RHW is enhanced with fiber reinforced polymer bars (FRP bars). In the resulting RHW with FRP bars (RHW-FRP), two resilient hinge devices are symmetrically installed in the corners, and steel bars and FRP bars are installed in a hybrid arrangement in both the wall boundary elements and the middle wallboard. The analysis results indicate that the RHW-FRP exhibits less residual drift and a higher bearing capacity than the RHW. The hybrid layout between the FRP bars and steel bars in both the boundary elements and the middle wallboard of the RHW-FRP is recommended to achieve the optimal enhancement of the seismic resilience of the wall while ensuring economic viability. With this hybrid layout, the bearing capacity of the RHW-FRP can be improved to the same level as that of a conventional wall of the same size, and the residual drift ratio of the wall can be further controlled to about 0.42 % when the wall drift ratio reaches 3 %. Increasing the number of FRP bars in the wall boundary elements is found to have less influence on the hysteretic behavior of the wall, whereas increasing the number of FRP bars in the middle wallboard can significantly increase the wall bearing capacity. With the increase of the axial compression ratio of the wall, the RHW-FRP will exhibit a higher bearing capacity but more residual drift. Moreover, while increasing the strength of the concrete used in the wallboard will improve the wall bearing capacity at a small drift, the bearing capacity may degrade at a larger drift due to the early crush of the concrete.