Vibration Reduction Performance and Mechanical Model of Circular Cavity Non-Packed Particle Damper

As a passive vibration reduction technology with excellent vibration reduction performance and durability, particle dampers have good application prospects for improving the resilience of structures under wind or earthquake. Moreover, considering the uncertainty of the external excitation direction and the uncontrollability of particles motion direction, the particle damper with a circular cavity exhibits better adaptability in practical engineering. In this manuscript, the circular cavity non-packed particle damper (CNPPD) was selected as the research object. The vibration reduction performance and equivalent mechanical model of CNPPD were discussed in succession. First, the vibration table test of the CNPPD story steel frame under harmonic and seismic excitation was designed and carried out. Comparative tests with two types of rectangular cavity particle dampers were also designed to better analyze the vibration reduction performance of CNPPD. The mechanical model of CNPPD was established subsequently based on the analysis of the particles motion mode. The vibration reduction performance and energy development of CNPPD under free vibration, harmonic, and seismic excitation at the optimal filling ratio are discussed numerically in the end. The results indicate that the particles motion mode can be roughly divided into local impact mode, overall impact mode, and quasi-liquefaction mode. Particle groups have different energy dissipation capabilities under different forms of motion. The proposed equivalent mechanical model can basically explain the vibration reduction performance of CNPPD, which provides a relevant basis for the application of particle dampers in civil engineering.