Spring-controlled modified tuned liquid column ball damper for vibration mitigation of structures

Abstract

Passive-tuned mass and liquid dampers are a popular choice among structural vibration control systems for being reliable, economical, and easy to implement. Therefore, meticulous and rigorous efforts have been devoted by researchers to develop various configurations of these systems for the enhancement of vibration mitigation efficiency, architectural flexibility, and versatility of application. However, experimental validation of these configurations has always been a challenging task for researchers. In this paper, an experimental validation has been conducted for the fused versions of tuned mass and liquid column damper known as tuned liquid column ball spring sliding damper (TLCBSSD) and tuned liquid column ball spring rolling damper (TLCBSRD). In these modified versions the ball inside the horizontal section of the damper has been attached with a spring. A series of shake table tests have been performed on 4 story frame structure under harmonic and seismic excitations to evaluate the vibration control performance of proposed dampers. The damper was placed on the top story of each experimental setup. A detailed discussion and analysis have been done based on the RMS acceleration, displacement, and inter-story drift of each story subjected to harmonic and seismic loadings for all test cases. Both proposed systems reduced the RMS response of the structure at resonant and seismic excitations. The vibration response has been significantly reduced for both systems, compared to reference TLCBD, at harmonic loadings including frequencies 0.65 Hz, 1.17 Hz, 1.30 Hz, 1.43 Hz, and 1.95 Hz, especially at resonant loading. Moreover, a detailed comparison between the normalized frequency responses from experimental and numerical studies has been presented. Overall, the proposed fused versions of tuned mass and liquid column ball systems have outperformed the reference TLCBD.