Performance of a semi-active/passive integrated isolator based on a magnetorheological elastomer and spring

Abstract

The paper reports an investigation on a semi-active/passive integrated vibration isolator utilizing magnetorheological elastomer (MRE) and a spring. To overcome the main shortcoming of passive isolation system, i.e. lack of adaptability, the semi-active/passive integrated isolator (SAPII) based on MRE and spring is designed and prototyped. The magnetic circuit is optimized by finite element analysis to fully unlock the unique feature of MRE. The dynamic response characteristic of the SAPII is experimentally investigated under sweep frequency test. A dynamic model of the SAPII vibration isolation system is established on the basis of Kelvin model. The model parameters, such as equivalent stiffness and equivalent damping, are identified from experimental data. A ON-OFF control law based on the minimal displacement transmissibility is designed for isolation control of the sinusoid excitation. Two control laws, i.e. ON-OFF control and fuzzy logic control, are designed for vibration isolation of random excitation. Finally, the effectiveness of these control laws is verified by numerical simulation and experiment.

Magnetorheological Effect of Magnetoactive Elastomer with a Permalloy Filler

“…The dependence of their macroscopic rheological properties on external magnetic fields is one of their fascinating features, which is attractive from the viewpoint of practical applications and challenging for scientific study. Opening the possibility to control their behavior with the help of moderate magnetic fields ranging from ~50 to ~600 mT, it makes these composites usable as magnetocontrollable active and passive devices such as actuators and dampers [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. Thus, employing magnetorheological/magnetoactive elastomers (MREs/MAEs) as the operating element in shock-absorbing devices seems to be a sound design concept.…”

“…As may be noticed from the literature, among other materials, which might be used for the fabrication of magnetorheological (MR) materials including carrageenan [ 9 ], polyurethane [ 17 , 36 ], and copolymer gels SEBC [ 34 ], leadership has stably been held by silicone rubber [ 1 , 3 , 12 , 14 , 16 , 18 , 23 , 32 , 36 ]. Partly it is caused by the convenience of controlling the polymerization degree and thus the stiffness of the matrix [ 32 ].…”

“…Multiple experiments performed on MRE have resulted in a significant collection of research data pointing to a strong relationship between the rheological characteristics of the material and magnetic field. Partly, the results were obtained from studies on damping devices [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ] or from investigations dedicated to the magnetorheological effect [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. For instance, influenced by a field of 0.8 T, a silicone and carbonyl iron-based sample initially polymerized in a field of 1.5 T demonstrated an increase of its shear modulus (G′) from 0.25 to 2.5 MPa [ 1 ].…”

“…Similarly, an MR gel absorber with a tunable frequency range from 56 to 67 Hz was reported in [ 9 ]; influenced by a magnetic field of 100 mT, it exhibited a 44% change of gel stiffness. Likewise, stiffness increase observed in MRE may reach 321.5%; the resonant frequency of a semi-active/passive integrated isolator can be tuned from 30 Hz (no applied magnetic field) to 51 Hz (a magnetic field is applied) [ 12 ]. A similar effect was described in [ 13 ]: Application of a 220 mT magnetic field resulted in a shift of the resonant frequency of an MRE-based absorber from 30 to 50 Hz.…”

Magnetic Particle Filled Elastomeric Hybrid Composites and Their Magnetorheological Response

“…Their results showed that the MR elastomer isolator system relatively reduced resonances and payload velocities by 16–30%, when compared to passive systems. Recently, Du et al [ 139 ] reported an investigation on a semi-active/passive integrated vibration isolator by using an MR elastomer and spring. The frequency sweep test in their study illustrated that the resonant frequencies of the semi-active/passive integrated vibration isolator were able to be controlled from 30.0 Hz–51.0 Hz when the magnetic field was applied.…”