Research on the vibration transmission characteristics of quasi-periodic impedance layered structure constructed by magnetorheological fluid

Abstract

In this work, the theoretical and experimental study on vibration transmission in quasi-periodic impedance layered structures built by magnetorheological (MR) fluid is conducted. Based on the MR effect of MR fluid, the quasi-periodic layered structures formed by low and high impedance layers following Fibonacci, Thue-Morse and multiperiodic sequences are constructed, respectively. These different quasi-periodic patterns can be flexibly obtained by controlling the arrangement style and magnetic field strength of electromagnets outside the MR fluid. The vibration transfer model is established based on the transfer matrix method and the trends of vibration level difference with different parameters are analyzed. Furthermore, experiments are performed to estimate the vibration transmissivity of the proposed structures. It indicates that the developed quasi-periodic impedance layered structures can exhibit greater damping effect on vibrations by appropriately increasing the magnetic field strength and thickness ratio of low to high impedance layers. Moreover, there exist quasi-periodic impedance patterns whose attenuation effect on vibration is better than that of periodic pattern in the frequency range studied in this paper (20~200Hz). This means that the introducing of the particular quasi-periodicity increases the transmission loss of vibrations in a certain frequency range. This investigation is conducive to further expand the application of MR materials and quasi-periodic structures in the field of vibration control.

A novel adjustable magnetorheological fluid gradient material of low frequency vibration isolation: a theoretical and experimental study

“…It can be seen that the TMF can change the nature of the mechanical impedance of the gradient material by changing the interaction between the particle layers inside the MRF, which suggests that the mechanical impedance of the gradient material can be adjusted by adjusting the parameters of the TMF, to change its vibration transfer characteristics. However, the mechanical impedance cannot visually express the attenuation performance of gradient materials against external excitation, so it is necessary to calculate further the vibration level difference based on mechanical impedance and characterize the vibration transmission properties of gradient materials under the action of the TMF through the vibration level difference [12][13][14].…”

“…At the same time, the vibration level difference can well reflect the vibration pression effect of adjustable gradient materials. Therefore, this paper adopts the vibration level difference as the evaluation index of vibration transfer characteristics of adjustable gradient materials [12][13][14].…”

“…The results show that the gradient plate can significantly reduce sound power more than an isotropic plate. Liu et al [12] and Si et al [13] constructed an impedance-layered structure. They studied its vibration transfer characteristics by controlling the MRF impedance through an external magnetic field.…”

Study on the influence of composition parameters of magnetorheological fluid on its vibration transmission characteristics

“…They concluded that the energy storage modulus of MRF increases linearly with frequency. Si et al [8] constructed a quasi-periodic structure using MRF by changing the thickness and arrangement of the MRF's high and low impedance layers and investigated its vibration transfer characteristics, and found that the quasi-periodic structure has better vibration attenuation in a specific frequency range. Liu et al [9] and Zhao et al [7,10] built a modulable impedance structure based on the rheological properties of the MRF, equated the MRF to a saturated porous medium using Biot theory and equivalent medium theory, established the transmission model of elastic waves in the modulable impedance structure and solved it numerically.…”

“…The interaction between the components of MRF can well explain the shear and chain formation mechanism by analyzing them. However, for the vibration transfer properties of MRF, the influence of the composition parameters has not been investigated from a microscopic perspective [7,8,10,19,20].…”