Self-centering devices with damage-free, high energy-dissipation and variable stiffness characterization during earthquakes

Abstract

Over the last few years, significant progress has been made in innovative low-damage structures excited by strong earthquakes, thanks to the development of self-centering energy-dissipation devices (SCEDs). However, SCEDs still face several challenges: they require high prestressing forces or complex configuration, they have constant post-yield stiffness, which makes them difficult to achieve a reasonable balance between internal forces and displacement, and they have insufficient recoverability, such as energy-dissipation components have to be replaced after an earthquake. This study presents a novel SCED with springs, lead extrusion dampers, and a deformation-amplified system (SL-SCEDs) to address these inadequacies. The device is characterized by low damage, variable stiffness, high energy dissipation, and low prestressing force. The concept and working mechanism were illustrated. An analytical model was developed to quantify the hysteretic behavior. A numerical parametric study was subsequently conducted. To evaluate the effectiveness of SL-SCEDs, time history analyses were carried out based on solid piers, spherical steel bearings, friction pendulum bearing combined with circular steel dampers, and conventional SCEDs were selected for comparison. The results show that SL-SCEDs can effectively reduce the maximum bearing displacement by 44 %, and the residual displacement of SL-SCEDs is almost negligible, which is the best performance among the four earthquake-resistant systems. Additionally, the maximum shearing force of the pier equipped with SL-SCEDs is lower than traditional SCEDs (2 % ∼ 5 %) and slightly higher than spherical steel bearings (1 % ∼ 10 %). The anticipated performance objectives of SL-SCEDs are realized, demonstrating a promising pathway toward resilient structures.