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In the present work preparation and dynamic characterization of polymer-based magnetorheological elastomer (MRE) is studied for vibration isolator. The magnetorheological elastomer is prepared with silicone rubber and carbonyl iron particles. Dynamic characterization of polymer-based MRE is done under different of Magnetic field, strain amplitude and frequency with rheometer. Experiment is carried out to find the shift frequency of MRE vibration isolator. Results shows the shear modules and loss factor of MRE changes with change in frequency, strain amplitude and magnetic field. the shift frequency of the 6 Hz from 30 Hz to 36 Hz that more effective in reducing the amplitude of vibration compared to passive isolator. [ABSTRACT FROM AUTHOR]

The paper presents free vibration of shape memory alloy hybrid composite beams by experimentally. The hybrid composite beams are fabricated using glass fiber with epoxy resin matrix implanted with the Ni-Ti SMA wires with diameter 0.47mm. The rectangular cross-section of beams with sizes, thickness, 3mm, width, 20mm and length 250mm are considered in the investigation. Free vibration test has been performed for the cantilever beams to investigate the effect on the fundamental natural frequency shift by changing the current as well as increasing the number of SMA wires. The fundamental natural frequency of the beam has shifted on higher side, 12.82% for single wire and 35.48% for two wires implant under the influence of current in comparison with no current state. Further, as supplied current increases in the SMA wire the natural frequency of beam increases helps in improving the stiffness and encourages to avoid resonance state. [ABSTRACT FROM AUTHOR]

This paper presents an investigation on modal characteristics of plane woven glass/carbon hybrid composite beams with fixed-free end condition by experimentally. The composite beam specimens are extracted from composite laminates of 16 layers with different hybrid configurations fabricated using vacuum bagging technique. Experimentations have been performed to measure vibrational characteristics of beams. Based on the investigation, it has been revealed that hybridisation affects the vibration characteristics. First two natural frequencies of beam are increased by the use of higher stiffness fibres in the upper layer. The damping effect in the beam with carbon fibre as middle layer is found to be higher as compared to the dedicated plain woven glass composites. [ABSTRACT FROM AUTHOR]

The focus of this work is to develop an in-house finite element (FE) code using programming software, MATLAB for analysing composite beam subjected to tensile loading. The composite beams are modelled by using two dimensional quadrilateral plane elements. The computed results obtained from developed code are validated by experimentally as per standard ASTM D3039M-14 and commercially available finite element tool, ABAQUS (V2016). The fabricated composite beams made up of plain woven glass epoxy with eight plies using vacuum bag technique. The computed results obtained from in-house FE code are in good agreement with the experimental and ABAQUS simulated results. Further, the developed code has the capability to support post processing in the form of graphical representation. [ABSTRACT FROM AUTHOR]

Friction stir welding (FSW) dissimilar joints of aluminium alloys of 2024-T351 and 7075-T651 were produced by reinforcing silicon carbide nano particle (SiCNP) in the rectangular cut groove made on the adjoining surface of the two dissimilar alloy plates joined in the butt configuration. A FSW tool of taper threaded cylindrical shape is used for producing the FSW dissimilar joints reinforced with SiCNP in the weld nugget zone (WNZ) and to produce metal matrix nano composite (MMNC) at the WNZ. In the experimental investigation, the constant FSW tool traverse speed of 40 mm/min and tool plunge depth of 6.2 mm/min is kept as constant, while the FSW tool rotation speed was varied from 400 rpm to 1800 rpm. The effect continuous varying tool rotation speed range from 400 rpm to 1800 rpm along the weld length and on the distribution of SiCNP in WNZ is analysed by conducting macro and microstructure study using optical microscopy (OM) and scanning electron microscopy (SEM) provided with energy dispersive spectrometry (EDS). In the experimental investigation, the combination of continuous varying FSW tool rotation speed range from 900rpm to 1150 rpm, constant tool traverse speed range 40 mm/min and tool plunge depth of 6.2 mm results in defect free, proper distribution of SiCNP and highest tensile properties for the FSW dissimilar joints. The highest ultimate tensile strength (UTS) of 380 MPa and yield strength (YS) of 150 MPa was observed for the combination of FSW tool rotation speed of 1000 rpm and tool traverse speed of 40 mm/min. The increasing in FSW tool rotation speed above 1250 rpm results in non homogeneous distribution of SiCNP in WNZ, excessive flash in the weld crown area and shows decreasing tendency in the tensile properties of the FSW dissimilar weld joints produced with reinforcing the SiCNP in the WNZ. [ABSTRACT FROM AUTHOR]