Dynamic behavior modelling of a hybrid magnetorheological elastomer with encapsulated fluid for base vibration isolation

Abstract

Magnetorheological elastomers (MRE) based semi-active isolators utilize MREs whose mechanical properties, such as stiffness and damping, change in response to an external magnetic field. MREs implementation in semi-active isolation remains challenging due to their slow response time caused by the suspension of the magnetic particles inside the elastomeric matrix and limited damping capabilities. Hybrid MREs, a combination of MREs and MRFs, have been developed to improve semi-active isolation's material properties and performance. However, modelling the nonlinear and hysteretic behavior of hybrid MRE-based isolators remains a challenge and needs to be adequately addressed. To bridge the gap, this study presents a parametric model for a hybrid semi-active isolator's nonlinear and hysteretic behavior that utilizes a hybrid MRE (H-MRE). The behavior of conventional and hybrid MRE-based isolators are experimentally tested under varying loading conditions of excitation frequency and input current. Simulation models are created using combinations of three different phenomenological models, Bouc-Wen, Modified-Dahl and LuGre friction. The experimental data are used to optimize and fit the simulated response of each model, and hence optimal values of the MRE and MRF hysteresis parameters are determined. The parameter estimation results indicate that a combination of LuGre friction for the MRE and Bouc-Wen for the MRF improves the accuracy of predicting the dynamic behaviour of the hybrid isolator. The relationship between the model parameters and loading conditions is also investigated and described through polynomial equations of the third order. These findings could provide valuable insights for the system identification and control of hybrid semi-active isolators and pave the way for developing smart base isolation systems utilizing hybrid MREs in future research.