Thermal-Mechanical Model for Predicting the Wind and Seismic Response of Viscoelastic Dampers

Abstract

This paper presents a simplified coupled thermal-mechanical model for the modelling of viscoelastic dampers with temperature- and frequency-dependent properties subjected to long-term and short-term dynamic loading due to wind and earthquakes. In this numerical model, the self-heating effect caused by molecular-level friction in the viscoelastic (VE) material is captured explicitly using a finite volume thermal diffusion model based only on the physical properties of the steel and VE material. The thermal model is coupled to a single degree of freedom (SDOF) mechanical model, which produces an efficient computational scheme for time-history analyses of VE dampers under both long-term and short-term loading scenarios. The predictions from the proposed model are compared with full-scale experimental results of long-duration wind loading ranging from design level events to extremely rare events, and for shorter but more intense seismic loading scenarios. It is shown that results obtained using this proposed simplified model with idealized geometry predicted well the dynamic response of the damper for all ranges of experimental results thus validating a robust physics based tool for predicting the response of VE dampers.