Thermo-mechanical response of an elastomeric isolation system using real-time hybrid simulation

Abstract

Elastomeric isolation systems are often used as seismic isolation devices for buildings and bridges. These systems are typically designed based on the nominal properties of the elastomer. However, key properties such as stiffness and damping can vary with environmental temperature, affecting the performance of the elastomeric isolation. The coupled thermo-mechanical dynamic behavior of the elastomer must be considered for accurate response evaluation. Experimental assessment of the coupled thermo-mechanical response in a laboratory setting presents a significant challenge. This paper presents a laboratory testing methodology for evaluating the thermo-mechanical dynamic response of elastomeric isolation systems using real-time hybrid simulation (RTHS). The test system consists of a superstructure resting on an elastomeric isolation system. In RTHS, the elastomeric isolation system itself is tested, while an electromagnetic shaker is used to resemble the behavior of different superstructures. The temperature around each elastomeric isolator is controlled using two L-shaped radiation heaters. The control strategy for the RTHS is validated through virtual simulations for different superstructures. After the numerical validation, experiments are conducted at different temperatures to demonstrate the impact of temperature on the dynamic response of the system. The proposed methodology proves to be effective and can be utilized for studying the coupled thermo-mechanical behavior of elastomeric isolation systems.