Development and tests of novel repairable multi-stage yielding steel slit dampers for seismic mitigation

This paper develops a novel repairable multi -stage yielding steel slit damper (denoted as RMYD) for seismic mitigations of engineering structures. The configuration and desired nonlinear behavior of RMYDs were first presented. Then, 7 specimens were designed to investigate the hysteretic performance of the proposed RMYD under cyclic loading, and the effects of design parameters of the RMYD and the loading protocols were studied through parametric tests. The experimental results show that the RMYD specimens can obtain the desired multi -stage yield behavior with stable hysteretic responses and excellent ductilities under cyclic loading. The repaired RMYD specimen can show the nearly same hysteretic responses as the original one, confirming the excellent repairability of the proposed RMYD. Moreover, the RMYD specimen under near -fault loading protocols shows stable multi -stage hysteretic responses, demonstrating the reliable damage -control and hysteretic energy -dissipation capacities under near -fault earthquakes. Finally, the design recommendations were provided for practical applications. The excellent ductility, multi -stage yield capacity, hysteretic energy -dissipation capacity, and postearthquake repairability make the proposed RMYD a promising and practical damper for seismic mitigation of engineering structures.