Effect of magneto-elastic force on magneto-dynamic model of viscoelastic-magnetorheological sandwiches

Abstract

A new numerical magneto-dynamic model of viscoelastic-magnetorheological sandwiches is developed and validated with experimental results. The novelty of the model is that, in addition to the magnetorheological effect of the core, it also contemplates the magneto-elastic force generated in the sandwich as a result of the interaction between the magnetic vibrating sandwich and the applied magnetic field. The numerical results show the effect of magneto-elastic force on the magneto-dynamic behaviour of the sandwich in decreasing the natural frequency of the structure. Increasing the intensity of the magnetic field, the natural frequency and the vibration amplitude of the sandwich decrease in the first vibration mode, which agrees with experimental results observed in the literature. To the author's best knowledge, this is the first time magneto-elastic force has been identified as the mechanism responsible for decreasing the natural frequencies of viscoelasticmagnetorheological sandwiches and that this magneto-dynamic behaviour has been represented.

In-core heat distribution control for adaptive damping and stiffness tuning of composite structures

“…Here the concept may rather be qualified as semi-active [26,27] or simply adaptive, since the characteristic time required to pass from one configuration to another (a few seconds) is much larger than the periods associated to the dynamical effects to be controlled. Recent works on damping control of sandwich structures based on magneto-elastic couplings [28,29], or smart honeycomb composite cores based on shape memory polymers [30] can also be considered as related to the investigations reported here.…”

Analyzing the influence of the core pre-structure on the dynamic response of a magnetorheological elastomer sandwich structure

“…Oriented pre-structures of the MRE layer attenuated vibration slightly across the low frequency bandwidth such that the layer dissipated energy via the microstructure of the viscoelastic layer by shearing deformation. The magnetic field intensity shows significant vibration suppression at low frequencies because of the magneto-elastic effect and magnetic effect [65].…”

“…The modified resonance frequency of the MRE-sandwich for variously oriented pre-structures and magnetic field intensity are listed in table 2. With increasing magnetic fields, the first resonance frequency of all oriented prestructure in MRE-sandwich core will be decremented more dramatically due to a magneto-elastic force on the CIPs contained in the elastomer [43,65]. It is noted that the micromechanism of the MRE-sandwich core exhibited shear motion due to the particle movement in the matrix during an application of a magnetic field [11].…”

“…The induced magnetic field decreased the transmissibility modulus of the MRE-sandwich structure in the first resonance frequency significantly, whereas there was no decrement in the second or third modes. Consequently, the energy dissipation results when the MRE-sandwich structure begins vibrating by two mechanisms: shear deformation and magnetic force interaction [65]. Figure 12 shows the storage modulus and loss factor of the oriented pre-structures with variation in the magnetic field.…”

“…Secondly, as metallic layers are made from aluminum, when they vibrate in the presence of a magnetic field, Eddy current appears, affecting the mechanical properties. Finally, the elastic and magnetic effects are coupled when the component is vibrating in the presence of a magnetic because the core is magnetic, whereas the layer is not [65].…”