Evaluating the mechanical behavior of post-tensioned recombinant bamboo frame with metal energy-dissipating connections

The low lateral stiffness and brittle failure mode of heavy recombinant bamboo structures with bolted connections remain a concern that limits its widespread application in seismic areas. Metal energy-dissipating connections with reduced beam sections are proposed, which can move the plastic hinges outward from the beam-to-column interface and improve the ductility of the frame. To improve the lateral stiffness, post-tensioned cross cables are introduced into the recombinant bamboo frame. The mechanical behavior of post-tensioned recombinant bamboo frames with metal energy-dissipating connections were studied. Two frames, including Frame 1 (without post-tensioned cross cables) and Frame 2 (with post-tensioned cross cables), were fabricated and tested. The results show that the weakened connections all yield at the reduced beam section, and the final failures also occur here. The hysteresis curves of Frames 1 and 2 both have pinching phenomena, but those of Frame 1 is more obvious. The post-tensioned cross cables reduce the slippage of Frame 2, so the hysteresis curve is fuller. Comparing the two skeleton curves, the stiffness and bearing capacity of Frame 2 have been significantly improved. The effect of the slippage in Frame 1 is revealed in the stiffness degradation, when the displacement of Frame 1 is greater than 15 mm, the viscous damping coefficient decreases suddenly. On the contrary, the viscous damping coefficient of Frame 2 continues to increase with the displacement increases. In conclusion, Frame 2 has greater lateral stiffness and bearing capacity, as well as good recovery and energy consumption capacities.