In the present study, the dynamic performance of the sandwich plate with magneto rheological elastomer (MRE) as the core layer and tapered laminated composite plates as the face layers is investigated. Various MRE tapered laminated composite sandwich plate models are formulated by dropping-off the plies longitudinally in top and bottom composite layers to yield tapered plates as the face layers and uniform MRE layer as the core layer. The governing equations of motion of tapered composite MRE sandwich plates are derived using classical laminated plate theory and solved numerically. Further, silicon based MRE is being fabricated and tested to obtain the shear and loss moduli using MR rheometer. The efficacy of the finite element formulation is validated by carrying out experiments on the various prototypes of tapered composite silicon based MRE sandwich plates and comparing the results in terms of natural frequencies obtained at various magnetic fields with those obtained numerically and with available literature. Also, the effects of magnetic field, taper angle of the top and bottom layers, aspect ratio, ply orientations and various end conditions on the various dynamic properties of tapered laminated composite MRE sandwich plate are investigated. Further, the transverse vibration responses of three different tapered composite MRE based sandwich plates under harmonic force excitation are analyzed at various magnetic fields. © 2016 IOP Publishing Ltd.

Vasudevan R

Department of Design and Automation

School of Mechanical Engineering

Vellore Campus

Ramesh Babu Vemuluri

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Dynamic analysis of tapered laminated composite magnetorheological elastomer (MRE) sandwich plates

Smart Materials and Structures

This study investigates numerically and experimentally the effect of longitudinal ribbon reinforcement in conventional honeycomb structure on the various dynamic characteristics of a hybrid composite sandwich plate. Longitudinal strips are considered to be embedded along the transverse directions at various locations of a honeycomb core material without and with carbon nanotubes (CNT) reinforcement in a composite sandwich plate. The governing differential equations of motion of the various hybrid honeycomb composite sandwich plate configurations with strips inserted in conventional honeycomb structures as core layer having top and bottom face composite layers are derived using higher order shear deformation theory (HSDT) and solved numerically using a four noded rectangular finite element. Further, experimental investigations are performed by fabricating the various strips embedded hybrid honeycomb core material with and without CNT reinforcement to evaluate the shear and loss moduli using the alternative dynamic approach. The efficacy of the developed finite element formulation is demonstrated by comparing the experimental and numerical results obtained in terms of natural frequencies and loss factors for the various prototypes of honeycomb composite sandwich plates. Also, the effect of variation in CNT content and thickness of longitudinal ribbon reinforcement in conventional honeycomb core material and ply orientation of the face sheets on the various dynamic properties of hybrid composite structures are studied under various end conditions. This study proposes that the ribbon reinforcement location and the addition of CNTs in honeycomb core materials strongly influence the stiffness, damping and transverse vibration displacements of the ribbon reinforced hybrid composite sandwich plates. © 2019 Elsevier Ltd

Thin-Walled Structures

Assessment of dynamic properties of hybrid ribbon reinforced multifunctional composite sandwich plates: Numerical and experimental investigation

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. © The Author(s) 2018.

Journal of Sandwich Structures & Materials

Dynamic characterization and parametric instability analysis of rotating magnetorheological fluid composite sandwich plate subjected to periodic in-plane loading

This study investigates the optimal locations of magnetorheological elastomer (MRE) segments in partially treated tapered composite MRE sandwich plates to maximize the natural frequencies and the loss factors. Various partially treated tapered composite MRE sandwich plate configurations are developed by dropping-off the plies longitudinally in top and bottom orthotropic (composite) layers with uniform core layer thickness. The core layer is made of natural rubber and MRE. The classical laminated plate theory is used to derive the governing differential equations of motion of the various partially treated MRE tapered composite sandwich plate configurations. The equations of motion are solved by using finite element formulation. Various cases of optimization problems are formulated and solved using genetic algorithm (GA) in order to obtain optimal locations to yield maximum natural frequencies and loss factors corresponding to the first five modes. The proposed methodology is validated by comparing the results evaluated in identifying optimal locations of MR fluid pockets filled in between uniform composite face layers, available in literature. It is observed that according to the user/designer requirements on achieving the optimal functions and their maximum value, the optimal locations of MRE pockets vary. It has also been demonstrated that the end conditions of the sandwich plate could play an important role in identifying the optimal locations of the MRE pockets. Further, it is observed that the optimal locations of MRE pockets are influenced by the ply drop off and resin locations. Hence it is concluded that the efficient design layout of a partially treated tapered composite MRE sandwich plate configurations would provide the guidelines for the designer to control the vibration effectively. © 2018

Composite Structures

Structural optimization of tapered composite sandwich plates partially treated with magnetorheological elastomers

This study investigates the dynamic performance of the partially treated magnetorheological elastomer tapered composite sandwich plates. Various partially treated tapered magnetorheological elastomer laminated composite sandwich plate models are formulated by dropping-off the plies longitudinally in top and bottom composite face layers to yield tapered plates as the face layers. The uniform rubber and magnetorheological elastomer materials are considered as the core layer. The governing differential equations of motion of the various partially treated magnetorheological elastomer tapered composite sandwich plate configurations are derived using classical laminated plate theory and solved numerically. Further, silicon-based magnetorheological elastomer and natural rubber are being fabricated and tested to identify the various mechanical properties. The effectiveness of the developed finite element formulation is demonstrated by comparing the results obtained with experimental tests and available literature. Also, various partially treated magnetorheological elastomer tapered laminated composite sandwich plates are considered to the study the effect of location and size of magnetorheological elastomer segment on various dynamic properties under various boundary conditions. The effects of magnetic field on the variation of natural frequencies and loss factors of the various partially treated magnetorheological elastomer tapered laminated composite sandwich plate configurations are analysed at different boundary conditions. Also, the effect of taper angle of top and bottom layers, aspect ratio, ply orientations on the natural frequencies of different configurations are analysed. Further, the transverse vibration responses of three different partially treated magnetorheological elastomer tapered laminated composite sandwich plate configurations under harmonic excitation are analysed at various magnetic fields. This analysis suggests that the location and size of the magnetorheological elastomer segments strongly influence the natural frequency, loss factor and transverse displacements of the partially treated magnetorheological elastomer tapered laminated composite sandwich plates apart from the intensities of the applied magnetic field. This shows the applicability of partial treatment to critical components of a large structure to achieve a more efficient and compact vibration control mechanism with variable damping. © 2016, © The Author(s) 2016.

Dynamic characterization of tapered laminated composite sandwich plates partially treated with magnetorheological elastomer

This study investigates the dynamic properties of a laminated composite magnetorheological (MR) fluid sandwich plate. The governing differential equations of motion of a sandwich plate embedding a MR fluid layer as the core layer and laminated composite plates as the face layers are presented in a finite element formulation. The validity of the developed finite element formulation is demonstrated by comparing the results in terms of the natural frequencies derived from the present finite element formulation with those in the available literature. Various parametric studies are also performed to investigate the effect of a magnetic field on the variation of the natural frequencies and loss factors of the MR fluid composite sandwich plate under various boundary conditions. Furthermore, the effect of the thickness of the MR fluid layer and the ply orientation of the composite face layers on the variation of the natural frequencies and loss factors are studied. The free vibration mode shapes under various boundary conditions of a MR fluid laminated composite sandwich plate are also presented. The forced vibration response of a MR fluid composite plate is investigated to study the dynamic response of the sandwich plate under harmonic force excitations in various magnetic fields. The study suggests that the natural frequency increases with increasing magnetic field, irrespective of the boundary conditions. The reduction in peak deflection at each mode under a harmonic excitation force with variation of the applied magnetic field shows the effectiveness of the MR fluid layer in reducing the vibration amplitude of the composite sandwich plate. © 2014 IOP Publishing Ltd.

Journal	Data powered by TypesetSmart Materials and Structures
Publisher	Data powered by TypesetIOP Publishing
ISSN	0964-1726
Open Access	0