Fabrication and investigation on field-dependent properties of natural rubber based magneto-rheological elastomer isolator

Abstract

This study presents a laminatedmagnetorheological elastomer (MRE) isolator which applies to vibration control in practice. The proposed isolator is fabricated with multilayer MRE sheets associated with the natural rubber (NR) as a matrix, and steel plates. The fabricated MRE isolator is then magnetically analysed to achieve high magnetic field intensity which can produce high damping force required for effective vibration control. Subsequently, the NR-based MRE specimen is tested to identify the field-dependent rheological properties such as storage modulus with 60 weight percentage of carbonyl iron particles. It is shown from this test that the MR effect of MRE specimen is quantified to reach up to 120% at 0.8 T. Following the design stage, the electromagnetic simulation using the finite element method magnetic (FEMM) software is carried out for analysing the magnetic flux distribution in the laminated MRE isolator. The laminated MRE isolator is then examined to a series of compression for static and dynamic test under various applied currents using the dynamic fatigue machine and biaxial dynamic testing machine. It is shown that the static compression force is increased by 14.5% under strong magnetic field compared to its off-state. Meanwhile, the dynamic compression test results show that the force increase of the laminated MRE isolator is up to 16% and 7% for low and high frequency respectively. From the results presented in this work, it is demonstrated that the fullscale concept of the MRE isolator can be one of the potential candidates for vibration control applications by tunability of the dynamic stiffness.

Role of Additives in Enhancing the Rheological Properties of Magnetorheological Solids: A Review

“…On the other hand, active vibration isolation involves the application of complex structures that utilize sensors and actuators to damp out the unwanted vibrations. Notably, a new class of semi‐active vibration absorbers consisting of magnetorheological (MR) materials can offer several unique advantages such as the real‐time control of stiffness and damping, as opposed to conventional rubber, which has fixed stiffness and damping . A comparison of various properties between conventional rubber and MR elastomers is presented in Table .…”

“…For instance, a strong particle interaction, resulting from an increase in the magnetic field, can lead to the formation of large particle aggregates. The common matrix materials for MR elastomers include natural rubber, silicone rubber, polybutadiene, polyurethane (PU), and polyisobutylene rubber . On the basis of curing conditions, MR elastomers can be classified into isotropic and anisotropic .…”

Fabrication and Characterization of Natural Rubber‐Based Magnetorheological Elastomers at Large Strain for Base Isolators

“…So far, several MRE-based isolation devices have been proposed [18][19][20][21][22][23][24][25][26][27][28]. Most of the proposed MRE-based base isolators utilized silicone rubber that cures at room temperature conditions without any special equipment.…”

“…Most of the proposed MRE-based base isolators utilized silicone rubber that cures at room temperature conditions without any special equipment. However, silicone rubber generates air bubbles on the contact surface, resulting in poor adhesion, which reduces the concentration of the magnetic field [28]. Chen et al [29] observed that the MRE using natural rubber is superior in mechanical properties to the MRE using silicone rubber.…”

“…And the proper shear modulus of the natural rubber-based elastomeric isolators for the building is 0.3 ∼ 1Mpa and that for bridge is 0.8 ∼ 1.2Mpa. Wahab et al [28] fabricated and evaluated a natural rubber-based MRE isolator. The device showed a good MR effect of 120% under a strain of 10% and a magnetic density of 0.8T.…”