Experiment and numerical simulation on the performance of multiple unidirectional single-particle dampers under seismic excitation

This study designed and manufactured a 1/5-scale model of a three-story steel frame structure. Various types of ground motions, including non-long period (NLP) ground motions, near-fault pulse type (NFPT) ground motions, and non-pulse long-period (NPLP) ground motions, were selected following the site conditions of the structure. The multiple unidirectional single-particle damper (MUSPD) and its layout schemes were then designed. A series of shaking table tests for the three-story steel frame with and without MUSPD were performed. Subsequently, a mechanical model of the multi-degree-of-freedom structure with MUSPDs was established, and a corresponding numerical simulation method was proposed. The results revealed that MUSPDs achieved an average damping rate of 18.24% for peak and 27.41% for Root Mean Square (RMS). Notably, MUSPD exhibited a superior damping effect on the RMS of the structure compared to the peak. The distributing floor particle mass according to the first-order mode of the structure resulted in excellent damping performance. Additionally, determining the particle movement distance for each floor involved calculating the optimal distance using a single-degree-of-freedom structure. MUSPDs exhibited a better damping effect under NLP ground motions compared to NFPT and NPLP ground motions. The shaking table test results confirmed the rationality and feasibility of the proposed numerical simulation method, demonstrating a high level of accuracy.