In this study, the free vibration analysis of carbon nanotubes reinforced magnetorheological elastomer (CNT-MRE) sandwich beam has been presented. The sandwich specimens are made of thin elastic strips integrated with CNT-MRE core. The viscoelastic properties of MRE and CNT-MRE are identified using ASTM E756-05 standard test. The natural frequencies and damping factors of with and without CNT reinforced MRE sandwich beams have been measured experimentally at various magnetic fields under cantilever condition. The measured natural frequencies are validated through the 3D finite element model. Further, the variations of natural frequencies with the influence of different levels of magnetic fields, boundary conditions, and core-skin thickness ratios of the CNT-MRE sandwich beam are studied. The analysis results demonstrate that the presence of carbon nanotubes improves the vibration behavior of MR elastomer.

In this study, dynamic analysis of three-layered sandwich beam with thin orthotropic skins and multiwall carbon nanotubes reinforced magnetorheological elastomer (MWCNT-MRE) core have been investigated. The laminates are made of glass fiber/epoxy composites with ply orientation of [0/90] _s and are prepared using vacuum-assisted hand layup process. Experiments are performed to investigate the vibration characteristics of MWCNT-MRE and MRE sandwich structures by applying the various magnetic field intensities under different end conditions. Further, the laminated composite MWCNT-MRE and MRE sandwich beams are modeled using ABAQUS finite element software and validated through experimental results in terms of natural frequencies. Also, the present finite element model is validated with available literature in terms of natural frequencies. A very good agreement is observed between the results of the experimental method and those extracted from numerical simulation. Also, the influence of applied magnetic field levels, core thickness ratio, ply orientation, and various boundary conditions on the vibration behavior of laminated composite MWCNT-MRE and MRE sandwich beams are analyzed.

In this present study, the dynamic characterization and instability analysis of a rotating composite magnetorheological fluid sandwich plate under periodic in-plane loading are investigated. The governing differential equation of motion of a rotating composite magnetorheological fluid sandwich plate is derived based on classical laminated plate theory and presented in the finite element formulation. The effectiveness of the developed finite element formulation is demonstrated by comparing the results in terms of natural frequencies and parametric resonance frequencies available in literature. Various parametric studies are performed to investigate the influences of magnetic field intensity, setting angle and rotating speeds on the variation of natural frequencies and instability regions of rotating laminated composite magnetorheological fluid sandwich plate under periodic in-plane loading. It can be observed that the natural frequencies increase with increase in rotating speed and magnetic field irrespective of the modes considered. It can also be observed that the effect of variation in setting angle of non-rotating magnetorheological elastomer sandwich plate on the buckling load is minimal at various magnetic fields. However, it is observed that the buckling load increases with increase in magnetic field. Further, it can be observed that normalized width of principal and secondary instability regions decreases with increase in rotating speed and magnetic field considered.