The effect of an improved passive bumper on the seismic response of the base-isolated structure: Numerical simulations and optimization design

In this paper, a passive bumper, called Flexible Limit Protective Device (FLPD) which was proposed by the author before, was improved to better control the seismic response of the base-isolated structure when the isolation layer exceeds its limit deformation. To distinguish from the FLPD, the improved FLPD is called a Flexible Energy Dissipating Device (FEDD), and the FEDD has stronger dissipation capacity than the FLPD. Above all, the compression behavior of FEDDs is experimentally investigated and the experiment data of FEDDs are compared to that of FLPDs. Subsequently, the nonlinear model of FEDDs is obtained and verified using the experimental data. This obtained model was used to study the effect on the seismic response of the base isolated structure (multi-degree-of-freedom system), namely isolator displacement and inter-story drift angle. An elite non-dominated sorting algorithm method (NSGA-II) is applied to optimize the design of FEDDs, the gap between isolators and FEDDs and stiffness of FEDDs. Finally, the seismic response of base-isolated buildings equipped with FEDD with optimal parameters is numerically simulated. The results show that FEDDs with optimal parameters can effectively reduce the isolator displacements, and keep the inter-story drift angle within the safe range when the isolation layer exceeds its limit deformation during earthquakes.

Automated summary

In this paper, the Flexible Limit Protective Device (FLPD) was improved to a Flexible Energy Dissipating Device (FEDD) to better control the seismic response of base-isolated structures. Experimental investigation and numerical simulation were conducted to study the compression behavior and optimize the design of FEDDs. The results showed that FEDDs with optimal parameters effectively reduced isolator displacements and kept the inter-story drift angle within a safe range during earthquakes.