Real-time hybrid shaking table testing method for the performance evaluation of a tuned liquid damper controlling seismic response of building structures

In this paper, a real-time hybrid shaking table testing method (RHSTTM) is experimentally implemented for evaluating the performance of a tuned liquid damper (TLD) controlling a seismically excited building structure. The RHSTTM does not require a physical building structural model in performing the experiment of a TLD–structure interaction system and it only uses a TLD and a shaking table. The structural responses of the interaction system are calculated numerically in real time using an analytical building model, a given earthquake record, and a shear force generated by the TLD, and the shaking table reproduces both the controlled and uncontrolled absolute acceleration of the TLD installed floor by modulating the feedback gain of the shear force signal measured by the load-cell positioned between the TLD and the shaking table. Comparison between the structural responses obtained by the RHSTTM and the conventional shaking table test of a single story steel frame with TLD indicates that the performance of the TLD can be accurately evaluated using the RHSTTM without the physical structural model. Finally, the uncontrolled and TLD-controlled structural responses of a three story structure are obtained by the RHSTTM in both time and frequency domains, showing that TLD can effectively mitigate the seismic responses of building structures.