Development of multi-layered electromagnetic system for improving base isolator using a magnetorheological elastomer

Abstract

Magnetorheological elastomer (MRE) is one of the smart materials whose stiffness and damping ratios can be controlled by applying a magnetic field. Several studies have been conducted on the utilization of MREs as base isolators in semi-active systems. A base isolator using a MRE utilizes an electromagnetic system to generate a magnetic field for the MRE. Generally, single-layered electromagnetic systems are used in MRE-based isolators. The single-layered electromagnetic system forms an inter-space between the MRE and the electromagnetic system to consider the deformation of the MRE. A larger inter-space is observed when the strain of the MRE is increased, which causes limitations owing to the excessive volume and electric power of the base isolator. Therefore, a electromagnetic system is proposed to overcome these limitations, in which the single-layered electromagnetic system is divided into several layers and behaves according to the deformation of the MRE. To validate the superiority of the proposed electromagnetic system, numerical analyses were conducted, using ANSYS Electronics, to compare its magnetic flux density, resistance, size, and volume. Based on the results of these analyses, dynamic characteristic tests were performed to compare the MR effects in each system.

Magnetorheological Elastomer‐Based Materials and Devices: State of the Art and Future Perspectives

“…A shift to higher resonant frequencies was observed when the current increased, and the experimental results showed a good agreement (within a relative error of 3–5%) with the FEM models. With respect to vibration isolators, there are several examples in the literature [ 107,108,129,130 ] that take advantage of the magnetoactive elastomers’ property of adaptively tune their damping capabilities and stiffness.…”

Performance enhancement of an MRE-based isolator using a multi-layered electromagnetic system

“…Lee et al [21] fabricated an MRE considering these factors, and based on this, an MRE was fabricated in this study. In addition, when performing dynamic characteristic tests under large strains of the MRE, the top and bottom layers of the MRE have a problem with tearing [11,15,24]. To address these limitations, hooked-shape steel plates were placed on the top and bottom of the steel plates, as shown in figure 3(a).…”

“…mechanical and civil engineering). Figure 1 shows three types of typical MRE-based isolators that can be classified according to the location of an electromagnetic system [9][10][11]. Figure 1(a) shows the MRE in a closed magnetic circuit formed by the electromagnetic system.…”

“…Figure 1(b) shows the MREs positioned between the electromagnetic systems. This type of system has the advantage of concentrating the magnetic MRE-based isolators according to the location of the electromagnetic system: (a) Hwang et al [9], (b) Behrooz et al [10], and (c) Li et al [11]. flux density in the MRE.…”

Preparation and magneto-mechanical properties of 3D microporous magnetorheological foam

“…Among them, the tunable magneto-mechanical properties bring a wide range of applications of MR devices in the field of intelligent vibration reduction. The dampers based on MR fluids and vibration isolators based on MR elastomers have been studied most extensively (Bai et al, 2013; Du et al, 2020; Fu et al, 2019a, 2020a; Han et al, 2020; Hwang et al, 2020; Jalali et al, 2020; Rustighi et al, 2021; Saleh et al, 2021; Wei et al, 2020; Yoon et al, 2021; Yu et al, 2021; Zhu et al, 2021).…”