Experimental investigation of tuned liquid column ball damper's position on vibration control of structure using different fluids

The optimization of a tuned liquid column ball damper (TLCBD)'s position in the structure using different characteristics fluids has not been studied previously. Therefore, in this work, the vibration mitigation performance of a TLCBD at different locations in a four-story multi-degree of freedom structure has been studied using a shake table. The TLCBD has been placed at the 4th, 3rd, and 2nd story levels. For performance optimization in addition to changing the location of a damper in the structure, fluids of different densities and viscosities such as water, sugar solution, and motor oil have also been studied. Ten different cases have been investigated including an uncontrolled case and nine different controlled cases. During shake table testing, acceleration data has been recorded using G-link 200 wireless triaxial accelerometers and WSDA-1000 wireless data sensor aggregator. Then recorded acceleration data was analyzed in MATLAB to find the root-mean-square and absolute acceleration responses for all the cases. For a better interpretation of the results, the percentage reduction in the responses has also been determined. The responses in all different cases have been evaluated in the time as well as the frequency domain. Results confirmed that all nine controlled cases effectively reduced the vibration of the structure compared to the uncontrolled case. However, a significant improvement in the responses has been observed in the cases where the liquid damper is placed at the top of the structure. By placing the TLCBD at the top of the fourth story, RMS acceleration of the fourth story has been reduced 56.54%, 51.03%, and 54.60% for motor oil, sugar solution, and water respectively. Moreover, at each placing position, motor oil cases performed better than water and sugar solution cases.