This study investigates the dynamic properties of the thickness tapered laminated composite plate. The governing differential equations of motion of the various configurations of a thickness tapered composite plate are presented in the finite element formulation using classical laminated plate theory. The validity of the developed finite element formulation is demonstrated by comparing the natural frequencies evaluated using the present finite element method with those derived from the experimental measurements and presented in available literature. Various parametric studies are also performed to investigate the effect of taper configuration, aspect ratio, taper angle and ply orientation on free vibration responses of the structures. The comparison of the free vibration mode shapes of uniform and various tapered configurations of tapered laminated composite plates are also presented. Influences of taper angle on the free vibration fundamental mode shapes under various boundary conditions and various ply configurations are also presented. The forced vibration response of a composite plate is also investigated to study the dynamic response of tapered composite plate under the harmonic force excitation in various tapered configurations. It is concluded that the dynamic properties of a composite plate could be tailored by dropping of the plies to yield various tapered composite plate. © The Author(s) 2014.

Edwin Sudhagar P

Department of Design and Automation

School of Mechanical Engineering

Vellore Campus

Vasudevan R

Ananda Babu A

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 characterization of thickness tapered laminated composite plates

Journal of Vibration and Control

Evolution of the laminated woven natural fiber fabric-reinforced polymer composite structures makes a way to the development of the non-uniform laminated composite structures in order to achieve the stiffness variation throughout the structure. An attempt is made in this work to carry out the experimental and numerical investigations on the dynamic characteristics of the thickness-tapered laminated woven jute/epoxy and woven aloe/epoxy composite plates. The governing differential equations of motion for the thickness-tapered laminated composite plate are developed using the h-p version FEM based on higher order shear deformation theory. The validation of the present finite element formulation is carried out by comparing the natural frequencies obtained using the finite element formulation with those natural frequencies determined experimentally. The developed model is further validated with the available literature works on tapered composite plate to confirm the efficiency of h-p version FEM. This work also explores the study of the vibrational characteristics of composite plates under the influence of plant fiber’s transverse isotropic material characteristics and porosity associated with plant fiber composites through the elastic constants evaluated in the author’s previous work. Also the influences of aspect ratios, ply orientations, and taper angles under various end conditions on the natural frequencies of the woven jute/epoxy composite plate are studied using the present finite element formulation. The forced vibration response of the thickness-tapered laminated woven jute/epoxy composite plate under the harmonic force excitation is carried out considering CFCF and CFFF end conditions. © 2018, © 2018 Japan Society for Composite Materials, Korean Society for Composite Materials and Informa UK Limited, trading as Taylor & Francis Group.

Advanced Composite Materials

Dynamic characterization of the thickness-tapered laminated plant fiber-reinforced polymer composite plates

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

In this study, the free and forced vibration responses of rotating delaminated thickness tapered (non-uniform) composite plates are investigated. The governing differential equations of motion of the various models of a rotating mid-plane delaminated thickness tapered laminated composite plate are presented in the finite element formulation based on classical laminated plate theory (CLPT) including the various rotational effects. The finite element formulation developed for the free vibration analysis of rotating delaminated tapered composite plate is validated by comparing the natural frequencies evaluated using the present finite element method (FEM) with those obtained from the experimental measurements. Various parametric studies are also performed to study the effect of taper models, rotational speed, length and location of delamination on the dynamic characteristics of the tapered composite structure. It was observed that the percentage of decrease in natural frequencies of delaminated composite plate when compared to intact composite plate at lower modes is lesser than those compared to higher modes irrespective taper models and rotating speeds considered. Further, it was noticed that the decreasing percentage of natural frequencies of the mid-plane delaminated different taper models of composite plate over intact plate increase in the order of TM2, TM1, TM3 and uniform composite. © 2016 Elsevier Masson SAS

Aerospace Science and Technology

Vibration analysis of rotating delaminated non-uniform composite plates

In this study, the dynamic instability analysis of rotating delaminated thickness tapered composite plates with different taper configurations subjected to periodic in-plane loads is performed. The governing differential equations of motion of the various configurations of a rotating thickness mid-plane delaminated tapered laminated composite plate are presented in the finite element formulation based on classical laminated plate theory including various rotational effects. The finite element formulation developed for the dynamic instability analysis of rotating delaminated tapered composite plate is validated by comparing the parametric exciting frequencies evaluated using the present finite elementmethod (FEM) with those presented in available literature and comparing the natural frequencies of rotating delaminated tapered composite plate evaluated using the present FEM with experimentally measured results. Various parametric studies are also performed to study the effect of taper configurations, rotational speed, delamination length, delamination location and in-plane periodic loads on stability of the structure. It was seen that the influences of rotating speed on the principalDIR spectra among taper configurations and uniform plate are significant and the normalized width of principal and second instability regions of parametric resonance frequencies increase in the order of uniform, TC3, TC2 and TC1 for all the rotating speeds. © Springer-Verlag Berlin Heidelberg 2016.

Archive of Applied Mechanics

Dynamic instability analysis of rotating delaminated tapered composite plates subjected to periodic in-plane loading

Procedia Engineering

Influence of ply-drop location on the fatigue behaviour of tapered composites laminates

Structural Engineering and Mechanics

Free vibration analysis of rotating tapered blades using Fourier-p superelement

Strength of Materials

Investigation into nonlinear vibrations of composite plates using the R-function theory

Vibration analysis of tapered composite beams using a higher-order finite element. Part I: Formulation

Vibration analysis of tapered composite beams using a higher-order finite element. Part II: parametric study

Journal	Data powered by TypesetJournal of Vibration and Control
Publisher	Data powered by TypesetSAGE Publications
ISSN	1077-5463
Open Access	0