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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 vacuumassisted 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.

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In the present study, vibration and damping characteristics of the multi‐walled carbon nanotubes (MWCNT) reinforced honeycomb embedded sandwich composite shell structures have been investigated numerically using finite element (FE) method. The efficacy of the FE method by deriving the governing equations using higher order theory is verified by comparing the natural frequencies assessed using ABAQUS 3D FE model. The influence of MWCNT reinforcement, support condition, and radius of curvature on the dynamic performance of honeycomb sandwich shell with carbon fiber reinforced polymer (CFRP) composite face sheets are explored. In addition, the optimal ply orientations of the various configurations of CFRP sandwich shells with MWCNT/GFRP honeycomb are identified using the developed FE model coupled with genetic algorithm (GA) to enrich the natural frequencies and loss factors. Further, it can be observed that the reinforcement of MWCNTs in honeycomb core, geometry of shell structure, and optimal ply orientations significantly influences the natural frequencies and loss factors of the sandwich composite shell structures.

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In this work, the dynamic behavior of the spherical magnetorheological elastomer (MRE) sandwich shell panel with multiwalled carbon nanotubes (MWCNT) reinforced composite face sheets is studied. The governing differential equation of motion for the (doubly curved) spherical sandwich shell panel is derived based on the Higher-Order Shear Deformation Theory (HSDT) kinematics. In the finite element framework, nine noded iso-parametric elements with nine Degrees of Freedom (DOFs) at each node are considered for solving the numerical problem. The finite element model of the multifunctional MR elastomer core spherical sandwich shell panel is validated against the existing works in terms of natural frequencies on different boundary conditions and magnetic field environment. The influence of MWCNT in the face sheet of the MR elastomer spherical sandwich shell panel is also studied through the structural rigidity. Detailed parametric investigations are performed to study the stiffness and damping characteristics of the shell panel with respect to the magnetic field intensities, thickness ratio, aspect ratio, ply orientation, and boundary conditions on the multifunctional MR elastomer core spherical sandwich shell panel. Also, the transverse vibration study of the MWCNT reinforced spherical sandwich shell with MR elastomer is carried out for different magnetic field intensities and curvatures to assess their effects on the structural performance. This study shows the applicability of the MR elastomer in sandwich shell structure for control of vibration and damping.