Development of Rectangular Vibration Isolators with Double Core Systems for Structures

Abstract

AbstractOne of the best techniques for isolating structures from the ground is the seismic isolation technique. Nowadays, square and circular base isolators are the most frequently employed shapes. Nevertheless, these configurations are not applicable for the wall-like structures; since the applied loads are not distributed in a way that provides a uniform support condition along the shear walls. To address this issue, attempts were made to develop novel rectangular isolators with lead/rubber cores. A total of five large-scale rectangular isolators were experimentally tested and subsequently subjected to finite element analysis. A rectangular seismic isolator having double lead cores was proposed to improve its effectiveness. Exposure to lead-containing materials has been shown to have poisonous effects on both the human health and environment. To avoid this, an isolator having double rubber cores was developed. Moreover, the rubber cores are wrapped with one layer of CFRP sheet and stainless steel tube to enhance the damping ratio of the rectangular isolators. Thereafter, the novel isolators were implemented in a 10-storey tunnel-form building using nonlinear dynamic analyses. The seismic performance of the buildings was then studied by conducting Incremental Dynamic Analyses. The experimental outcomes demonstrated that confining the rubber cores by stainless steel tube and CFRP sheet increased the energy absorption along the length of the isolators by 15 and 7%, respectively. Moreover, the damping ratios of the rectangular isolator with double lead cores have also increased by 36 and 47% along its length and width, respectively.