In this paper, vibration and damping of composite sandwich box column containing viscoelastic layer (VEL) or electrorheological fluid (ER) core with constraining layer and their performance comparison is carried out. The finite element based modal strain energy method is used for predicting the modal loss factor and frequency of laminated composite box columns with integral viscoelastic/ER fluid layers. Effects of core thickness, orientation of the fiber in the base plate and constraining layer, applied voltage and stacking sequence on the vibration behavior of composite sandwich box column for clamped-free boundary condition are studied in the paper. The performance comparison of vicsoelastic layer damping and ER layer damping is also investigated. © 2009 Elsevier Ltd. All rights reserved.

Natrajan Ganesan

Applied voltages

Base plates

BOX COLUMNS

COMPOSITE SANDWICHES

CONSTRAINING LAYER

ELECTRORHEOLOGICAL

Finite element

FLUID LAYER

FREE BOUNDARY CONDITIONS

MODAL LOSS FACTORS

Modal strain energy

Performance comparison

SANDWICH BOX COLUMN

Stacking sequence

VIBRATION BEHAVIOR

Viscoelastic

VISCOELASTIC LAYERS

Damping

Electrorheological fluids

Laminated composites

Nanofluidics

Strain energy

Vibration control

Rheology

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Materials and Design

The local (plate)/global (beam) vibration and damping behavior of composite thin-walled box member subjected to vibratory environment are studied and presented in this paper. This investigation is carried out by the use of 3D beam and thin plate finite elements and the corresponding modal frequencies/damping values of composite box beam are predicted by modal strain energy method. Application examples illustrate the ability of the 3D beam and thin plate element to predict both local and global modal frequencies/damping of hollow box sections. The influence of L/h ratio, b/h ratio and ply angle on the frequency and loss factor of composite box beam is investigated. In addition, an attempt has also been made to investigate the effect of temperature on the composite damping characteristics of rectangular box type section. © 2009 Elsevier Masson SAS. All rights reserved.

European Journal of Mechanics, A/Solids

Global and local behaviour based composite damping studies on thin-walled box structure

In this paper, the vibration and damping of a hollow sandwich box column containing a viscoelastic layer (VEL) or an electrorheological (ER) or magnetorheological (MR) fluid core with a constraining layer are analyzed and a comparison of performance is made. The hollow sandwich box column comprises two skin plates and a VEL/ER/MR fluid core layer. The finite element method is used to study the vibration and damping behaviors of the column. The natural frequencies and modal loss factors are obtained by solving the complex eigenvalue problem. The modal dampings and natural frequencies of the column are calculated for various electric as well as magnetic fields and their performance is compared with that of the viscoelastic core layer for the clamped-free boundary condition. Effects of core thickness, electric voltage and magnetic field on the vibration behavior of the sandwich box column are investigated. © 2008 World Scientific Publishing Company.

International Journal of Structural Stability and Dynamics

Vibration and damping studies on a hollow sandwich box column with a viscoelastic/electrorheological/magnetorheological fluid core layer by the finite element method

Composite sandwich structures have extensive applications due to their high strength and structural efficiency. Skew fibre-reinforced composite laminates are used as important structural elements in modern structural design, particularly in the aerospace industry. Natural frequency of these skew laminates is of primary significance to structural designers. The present article studies the free vibration and damping characteristics of sandwich skew plates consisting of composite stiff layers with viscoelastic (VEL) or electrorheological fluid (ER) core, using finite element method. The vibration behavior of these core materials is critically compared. Detailed analysis was conducted by varying the boundary conditions, core to stiff layer thickness ratios and stacking sequence. The inherent composite damping and the damping due to VEL (or ER fluid) core are investigated. The influence of electric field on the frequency and loss factor were also examined. © 2006 Elsevier Ltd. All rights reserved.

Composite Structures

Critical comparison of viscoelastic damping and electrorheological fluid core damping in composite sandwich skew plates

Thin walled box sections are used as load bearing members in various industries, aircraft structures and marine vessels. To avoid undesirable effects of the surrounding vibration environment, the structure can be designed to have natural frequency removed from the range of exciting frequency or by introducing damping. In the present study the vibration and damping behaviour of layered composite box beams is analysed using the finite element method. The finite element formulation is based on first order shear deformation theory, which takes shear deformation of the beam into consideration. The effect of the number of layers, end conditions and fiber angle on frequency and loss factor is studied for two materials, namely, graphite-epoxy and glass-epoxy. © 1998 Academic Press.

Journal of Sound and Vibration

Vibration and damping analysis of thin-walled box beams

Cylindrical shells with a constrained damping layer treatment are studied using three theories. The finite element method is made use of in the study. The nondimensional frequencies and loss factors predicted by the three theories are compared and the theories are evaluated. The importance of inclusion of the extensional effects in the core and its effect on the loss factor is brought out in this study. © 1995 by ASME.

Journal of Vibration and Acoustics, Transactions of the ASME

Vibration and damping analysis of cylindrical shells with constrained damping treatment—a comparison of three theories

Sandwich Triangular Plate Element Based On A Modified Ahmed Approach

Vibration and damping of composite sandwich box column with viscoelastic/electrorheological fluid core and performance comparison

Journal	Materials and Design
ISSN	02641275
Open Access	No