The mechanical performance evaluation of recombinant bamboo with weakened metal connections under low-cyclic loading

Tearing failures often occur at the bolt position of the recombinant bamboo beam under a large bending moment and shear force due to its poor compressive strength perpendicular to the grain. In this study, three H-shaped weakened connections were designed to explore the mechanical performance of the recombinant bamboo frames under low cyclic loading. The weakened forms of the web were selected as variables, including elliptical, rhombic, and arc holes. Load-displacement hysteresis curves, skeleton curves, stiffness degradation, ductility analysis, equivalent viscosity damping coefficient, and failure modes of the recombinant bamboo frame with three weakened connections were compared and analyzed. The results show that the weakened connections achieved the purpose of the outward movement of the plastic hinge. The moment and shear force will lead to the stress concentration of connection with the rhombic hole, and buckling failure of connection with the arc hole is easy to occur. Comparatively, the ultimate bearing capacity and energy-dissipating capacity of connection with the elliptical hole are the best among the three weakened connections. In conclusion, the weakened shape and position have a great influence on seismic performance.