Experimental and analytical investigation of the influence of compressive load on rate-dependent high-damping rubber bearings

Abstract

High-damping rubber bearings (HDRBs) have been widely accepted as a relatively novel type of seismic isolation devices in civil infrastructures construction, they are known to possess significant rate-dependent behavior and accommodate the gravitational load of the superstructure in typical applications. Hence, it necessitates better understanding of the mechanical behavior of HDRBs under coupling effect of compression and shear. The objective of the paper was to conduct experimental and analytical investigation to characterize the influence of compressive load on rate-dependent HDRBs. Firstly, a series of material tests including multi-step relaxation and monotonic shear tests were carried out on high-damping rubber, the strain rates and compressive stresses applied on specimens were varied and analyzed. Then, on the basis of experimental investigation, the classical Zener model was extended and a rate-dependent analytical model of HDRBs allowing for the consideration of compressive load was proposed. Finally, comparing the numerical simulations and experimental data obtained from both material tests and full-scale bearing tests, a reasonably good agreement was observed and the validity of the proposed model was demonstrated.