Experimental and numerical study of low-yield-point steel corrugated pipe dampers

Abstract

The traditional isolation devices often encounter challenges such as uncontrolled deformation in the isolation layer, limited vertical tensile capacity, and environmental risks associated with the use of lead, a heavy metal. This study investigated an innovative low-yield-point steel damper called the corrugated pipe damper (CPD), which was introduced into a seismic isolation layer to overcome the limitations of conventional dampers. To investigate the behavior of the CPDs under cyclic loading, 10 specimens were designed and subjected to quasi-static cyclic loading and fatigue loading. The failure modes, hysteretic curves, stiffness degradation, and energy dissipation capacity of the specimens were obtained. Results indicated that the CPD exhibited good horizontal deformation and energy dissipation capacities, and excellent seismic fatigue performance. The horizontal force-displacement curves exhibited obvious yielding and strengthening phenomena, with the displacement increasing gradually, the bearing capacity increasing rapidly at the beginning, decreasing significantly after yielding, and increasing rapidly when the displacement was large. As the height increased or the average diameter decreased, the bearing capacity, horizontal stiffness, and hysteresis energy decreased, whereas the yield displacement increased. Finite element models were subsequently validated using experimental data and developed to simulate the horizontal cyclic behavior of the CPDs. Based on the finite element analysis, the connection construction and improvements for CPDs were analyzed and recommended while also revealing the relationships between the vertical additional force and horizontal displacement, and the prediction equations for some mechanical performance indexes of the CPD were proposed by detailed parametric analysis.