The free vibration and damping characteristics of three-layered conical shells with a viscoelastic core constrained by isotropic facings are studied using the finite element method. Results are presented for shells with various geometric and physical parameters. Three boundary conditions are considered in the analysis: clamped-clamped, simply supported and clamped at the small end and free at the other. © 1994 Academic Press Limited.

T. C. Ramesh

Natrajan Ganesan

finite element method

Vibrations (mechanical)

Viscoelasticity

CONICAL SHELLS

Free Vibrations

Shells (structures)

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IIT Madras

Journal of Sound and Vibration

In this article, buckling and vibration behavior of a functionally graded material (FGM) sandwich beam having constrained viscoelastic layer (VEL) is studied in thermal environment by using finite element formulation. The FGM sandwich beam is assumed to be clamped on both edges. The material properties of FGM are functionally graded in thickness direction according to volume fraction power law distribution. Temperature dependent material properties of FGM stiff layer and shear modulus of viscoelastic layer are considered to carry out buckling and vibration analysis. Numerical studies involving the understanding the effect of power law index, core to stiff layer ratio on the thermal buckling temperature as well as on vibration has been carried out. In addition influence of temperature on natural frequencies and loss factors have been examined for FGM sandwich beam. © 2006 Elsevier Ltd. All rights reserved.

Thermoelastic buckling and vibration behavior of a functionally graded sandwich beam with constrained viscoelastic core

The modal strain energy method is used to study the energy dissipation pattern in vibrating cylindrical shells with a viscoelastic damping layer, for various circumferential and axial modes. The effect of tank size, boundary condition and height of contained fluid on the distribution pattern is also investigated. The regions of energy dissipation concentration are identified. The effect of redistribution of the (initially uniformly distributed) constrained viscoelastic material by concentrating it in the above regions is studied.

Computers and Structures

Study on energy dissipation pattern in vibrating fluid filled cylindrical shells with a constrained viscoelastic layer

A semianalytical finite element for doubly curved, multilayered shells of revolution, based on an extension of the displacement field proposed by Wilkins et al., is proposed. Numerical analysis is done to study the vibration and damping characteristics of multilayered fluid filled shells with alternating elastic and viscoelastic layers. The effect of varying the number of viscoelastic layers on the vibration and damping characteristics is also studied. The effect of the fluid is incorporated by the added mass concept. The effect of shear parameter on natural frequency and modal loss factor is studied for various circumferential and axial modes.

Vibration and damping analysis of multilayered fluid filled cylindrical shells with constrained viscoelastic damping using modal strain energy method

The finite element code is developed based on the displacement field proposed by Wilkins et al. to find out the natural frequencies and loss factors of fluid filled cylindrical shells with a constrained viscoelastic layer in between two facings made of composite material. The fluid effect on the natural frequencies and loss factors are taken care of by the added mass of the fluid on the structure. Effects of the fluid height, ratio of core to facing thickness and facing fibre orientation on the natural frequencies and loss factors of cylindrical shells are presented.

Journal	Journal of Sound and Vibration
ISSN	0022460X
Open Access	No