Novel MRE/CFRP sandwich structures for adaptive vibration control

Abstract

The physical properties of magnetorheological elastomers (MRE) are a complex issue and can be influenced and controlled in many ways, e.g. by applying a magnetic field, by external mechanical stimuli, or by an electric potential. In general, the response of MRE materials to these stimuli is crucially dependent on the distribution of the magnetic particles inside the elastomer. Specific knowledge of the interactions between particles or particle clusters is of high relevance for understanding the macroscopic rheological properties and provides an important input for theoretical calculations. In order to gain a better insight into the correlation between the macroscopic effects and microstructure and to generate a database for theoretical analysis, x-ray micro-computed tomography (X-μCT) investigations as a base for a statistical analysis of the particle configurations were carried out. Different MREs with quantities of 2-15 wt% (0.27-2.3 vol%) of iron powder and different allocations of the particles inside the matrix were prepared. The X-μCT results were edited by an image processing software regarding the geometrical properties of the particles with and without the influence of an external magnetic field. Pair correlation functions for the positions of the particles inside the elastomer were calculated to statistically characterize the distributions of the particles in the samples.

Collision and separation of nickel particles embedded in a polydimethylsiloxan matrix under a rotating magnetic field: A strong magneto active function

“…Magnetorheological elastomers (MREs) are hybrid materials, comprising an elastic non-magnetizable matrix, such as polydimethylsiloxane (PDMS), interspersed with magnetic fillers like iron oxide particles. First publications concerning such smart magnetorheological elastomers date back to the 1990s [1][2][3][4][5], though they still attract much attention today [6][7][8][9][10][11][12][13][14][15][16]. When applying a magnetic field, MREs undergo a reversible variation of their visco-elastic characteristics and/or undergo a reversible shape change that can be used for actuation.…”

“…Consequently, MREs offer much potential for applications in adaptive damping systems, sensors, valves, and other actuators. Their inclusion in artificial muscles, robots, medical instruments, and haptic applications is also common [6][7][8][9][10][11][12][13][14][15][16]. An efficient usage of MREs for applications would be strongly facilitated by a fundamental understanding of the macroscopic and internal mechanisms under applied magnetic fields: Their physical response to external magnetic fields depends on the influence of experimental parameters such as concentration and distribution of filler particles, matrix stiffness, magnetic field strength, etc.…”

Dynamic analysis of laminated composite sandwich beam containing carbon nanotubes reinforced magnetorheological elastomer

“…It was concluded that amplitude of vibration of the MRE beam was stabilized and the stiffness and damping also improved under applied magnetic field condition. Kozlowska et al [20] analyzed the free vibration behavior of CFRP/MRE-based sandwich beam using an experimental study. Kolekar et al [21] experimentally studied the free and forced vibration parameters of a sandwich beam with MR fluid.…”

Adaptive Damping of a Double‐Beam Structure Based on Magnetorheological Elastomer

“…However, the beams eventually synchronize their motion, and this way of damping becomes ineffective-the same as in the case of identical beams and initial conditions [1]. en, the shear deformation of the soft middle layer becomes the predominant mechanism of energy dissipation in a sandwich beam [2][3][4][5][6][7].…”