Inerter assisted robustness of compliant liquid column damper
Dhirendra K. Pandey, Sudib Kumar Mishra
Abstract
Inerter-augmented tuned mass dampers (TMDI) demonstrated considerable performance robustness. A tuned liquid column damper (TLCD) offers reduced mass ratio than a TMD for identical efficiency. TLCD provides additional dissipation by flow through orifice. Motivated by these attributes, this study employs an inerter in conjunction with a TLCD. The compliance for installation of an inerter is availed by employing a compliant liquid column damper (CLCD) instead of a TLCD. The combined system is referred herein as the compliant liquid column inerter damper (CLCID). The effectiveness of the CLCID is demonstrated using a single degree of freedom (SDOF) structure and a multi-degree of freedom (MDOF) structure. Schematic of enabling structures are suggested to facilitate installation of inerter in low-rise and relatively tall buildings. The equations of motion for the SDOF/MODF structure and CLCID are derived and solved separately assuming a random earthquake model and recorded ground accelerations as input. The stochastic responses are employed in performing a design optimization for the CLCID parameters. The optimal performances are demonstrated subsequently under the recorded motions. The CLCID is shown to remarkably improve the control efficiency (from a range of 30%–40% in CLCD to 50%–80% in a CLCID). The efficiency of the CLCID under alternative placement of inerter between the top story and the ground/another story is demonstrated. The noted improvements show significant robustness, unparallel to the liquid dampers reported till date.