An adaptive tuned vibration absorber based on multilayered MR elastomers

Abstract

Adaptive tuned vibration absorbers (ATVAs) featuring magnetorheological elastomers (MREs) have attracted considerable research interests because of the advantages of fast response, controllable frequency, and broad working range. Generally, the ATVA uses single layer of MRE sheet, which has some issues such as small oscillator stroke and being effective only on high frequency. In this research, an ATVA which incorporates multilayer MRE sheets was designed and prototyped. Its performance under various scan frequencies was tested on a horizontal vibration platform. A theoretical model was proposed to predict the MRE absorber performance. For the clear demonstration of the advantages of multilayered MRE absorber, two kinds of absorbers with only one layer of MRE were prepared as comparison. The experiments compared the vertical support capability and the tuning frequency range of these two ATVAs, which have clearly highlighted the capabilities of multilayered MRE absorber with larger oscillator stroke (as large as 13.6 mm) and lower working frequencies (as low as 3.2 Hz). The vibration absorption evaluation was conducted by mounting the multilayered MRE absorber on a single-degree-of-freedom system. The results identify that the ATVA with multilayered MREs could work lower than 10 Hz, which is very difficult for the one with single layer MRE. Additionally, the performance of the passive and adaptive tuned laminated MRE absorbers on attenuating a swept frequency vibration are presented, respectively. The ATVA was more effective than the passive absorber over a wide frequency range.

Development of magnetorheological elastomers–based tuned mass damper for building protection from seismic events

“…In other words, the passive TMD will enhance the building vibration level if the earthquake energy focuses on 3 Hz. In terms of the semi-active MRE TMD, it can vary its natural frequency to trace the excitation frequency based on the short time Fourier transform control algorithm (Sun et al, 2015b). Thus, the semi-active MRE TMD can reach all the most effective points and is shown as the red line in Figure 9 and Figure 10.…”

“…In terms of the sweep frequency excitation, the short time Fourier transform control algorithm can calculate the frequency of the excitation and then control the natural frequency of MRE TMD to trace it (Sun et al, 2015b). The short time Fourier transform control algorithm, however, is not the best option for earthquakes because it is a multiple frequency excitation.…”

Properties of Magnetorheological Elastomers in Crossed AC and DC Magnetic Fields

“…Due to the elasticity of the carrier matrix and the interaction of the magnetic component of the elastomers with the external magnetic field they can be used as elements with variable stiffness. The natural frequency of oscillations can be shifted by applying the external magnetic field [1][2][3][4][5]. The elastomers can also be utilized as an oscillating element.…”

A torsional MRE joint for a C-shaped robotic leg

“…On the other hand, to potentially improve energy efficiency while offering robustness closer to passively tuned devices in similar designs, semi-active materials such as MREs may be considered. It is for this reason that MRE has been widely used in adaptivetuned-vibration absorbers (ATVAs) [17][18][19][20][21][22], as well as other devices benefitting from controllable stiffness. On the far end of the spectrum in terms of stiffness variation capability, Li et al [15] designed a vibration isolator using MRE in a laminated structure capable of an increase in stiffness of up to 1630%.…”