Enhanced base isolation with lever-type diamond-shaped TMDI

Abstract

Base isolation (BI) is a highly effective strategy for enhancing the seismic resilience of structures. However, excessive deformation in the BI layer can lead to stability concerns and potential damage. To mitigate this issue, vibration absorbers are often integrated into the system. This study introduces a novel BI-LD-TMDI system, which combines an inerter, a lever-diamond (LD) mechanism, and a tuned mass damper (TMD). The lever and diamond-shaped structure amplify the inertial mass effect, significantly improving the energy dissipation capacity of the absorber. Through dynamic modeling and theoretical optimization, simplified analytical design formulas are derived. The inertial amplification mechanism is systematically analyzed, identifying key influencing factors to guide practical design. The theoretical model and simplified optimal solution are further validated via finite element analysis (FEA). Time-history analysis demonstrates the superior performance of the proposed BI-LD-TMDI compared to conventional absorbers. The LD-TMDI exhibits an exceptional inertial amplification effect, enabling high energy dissipation with minimal added mass. This lightweight and highly efficient system demonstrates strong practical feasibility and promising potential for vibration control in civil structures.