Additive manufacturing (AM) process builds the parts, layer by layer precisely from Computer-Aided Design (CAD) models, whereas traditional subtractive manufacturing process removes layers from materials to attain the desired shape. Of late Rapid prototyped (RP) parts are used for the direct production of components for manufacturing and testing in the industries. Understanding material, machine used along with the process variables that affect the strength of the final part gains importance as the parts can be printed directly from CAD data and effectively integrated into structures. The main aim of this investigation is to present the mechanical characterization and free vibration analysis of various 3D printed Engineering Plastic Materials. Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), and Polycarbonate–Acrylonitrile Butadiene Styrene (PC-ABS) materials are used in this study. Spools are prepared from plastic pellets using wire extruder. Tensile tests have been performed on dog bone specimens to evaluate strength, fractured specimen’s surfaces which are further evaluated using Field Emission Scanning Electron Microscope (FESEM) to explore fracture of the raster and bonding between layers. From the experimental results it’s noticed that the PC-ABS material exhibits improved elastic limit and load-carrying capacity compared with ABS and PC. Three types of beams are fabricated using different materials and modal analysis has been conducted to predict the stiffness of beams in terms of natural frequencies under clamped free (CF) and clamped clamped (CC) end conditions. Higher natural frequencies observed with PC-ABS is compared with the rest of the materials.

In this study, the vibration responses of a partially treated laminated composite magnetorheological (MR) fluid sandwich plate have been investigated. The governing differential equations of motion for a partially treated laminated sandwich plate embedding MR fluid and rubber as the core layer and the laminated composite plate as the face layers are presented in finite element formulation. The validity of the developed finite element formulation is demonstrated by comparing the results in terms of natural frequencies derived from the present finite element formulation with the experimental measurements. Various configurations of a partially treated laminated composite MR fluid sandwich plate are considered to study the effect of location and size of the MR fluid segment under various boundary conditions. The effect of magnetic field on the variation of natural frequencies and loss factor of the partially treated laminated composite MR fluid sandwich plate are also analyzed for various configurations at different boundary conditions. The free vibration mode shapes of various configurations of a partially treated laminated composite MR fluid sandwich plate are also presented. The forced vibration responses of the various configuration of a partially treated laminated composite MR fluid sandwich plate are also analyzed under harmonic force excitations. This analysis suggests that the natural frequency, loss factor and transverse displacements of the partially treated laminated composite MR fluid sandwich plate are strongly influenced by the location and size of the MR fluid segment apart from the intensities of the applied magnetic field. The application of the partial treatment alters the deflection pattern of the sandwich plate, particularly the location of peak deflection, which shows that it can be applied to critical components of a large structure to realize a more efficient and compact vibration control mechanism with variable damping.

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.