In the current paper, buckling and vibration behaviours of thin-walled box columns in a thermal environment made of functionally graded materials are investigated, using finiteelement method based on classical laminated plate theory. The four node thin-plate element with five degrees of freedom is employed in the study. The box column is considered as assemblages of plates, and a continuously graded variation in composition of the ceramic and metal phases across the plate wall thickness in terms of a simple power law distribution is implemented. The effects of temperature dependent material properties on the critical buckling and the free vibration response are studied. The analysis is carried out under thermal environment for clamped-damped boundary condition and results are presented. © IMechE 2008.

Natrajan Ganesan

Boundary conditions

Buckling

Degrees of freedom (mechanics)

finite element method

Thermal effects

vibration analysis

BOX COLUMN

Free vibration

THERMAL ENVIRONMENTS

Functionally graded materials

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IIT Madras

Finite-element buckling and vibration analysis of functionally graded box columns in thermal environments

Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications

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

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

Buckling of laminated composite thin walled rectangular box beam configurations has been studied. The increasing use of composite materials in the construction of aeronautical and civil engineering structures has generated a special interest in the analysis of elastic stability of laminated composite structure subjected to inplane loadings. The effect of number of layers, lay-up sequence and fibre angle on the buckling load is studied for symmetric and anti-symmetric lay-ups.Buckling of laminated composite thin walled rectangular box beam configurations has been studied. The increasing use of composite materials in the construction of aeronautical and civil engineering structures has generated a special interest in the analysis of elastic stability of laminated composite structure subjected to inplane loadings. The effect of number of layers, lay-up sequence and fibre angle on the buckling load is studied for symmetric and anti-symmetric lay-ups.

Composite Structures

Some studies on buckling of laminated composite thin walled box beams

The thermal buckling of laminated composite plates is analysed using the finite element method based on the Reissner-Mindlin first order shear deformation theory. The nine-node Lagrangian isoparametric element is employed for the thermal buckling analysis of symmetric cross-ply, symmetric angle-ply and quasi-isotropic laminates subjected to uniform temperature distribution. The effects of modulus ratio, fibre orientation, length to thickness ratio, aspect ratio and various boundary conditions on the critical temperature are analysed. The influence of the stress distribution on the variation of the critical temperature with fibre orientation is studied for different boundary conditions. Also, the variation of critical temperature with shear correction factor is considered. © 1994.

Computers and Structures

Thermal buckling of laminated composite plates

Buckling analysis of composite laminates for critical temperatures under thermal loads is reported here. The formulation is based on linear theory and the finite element method using semiloof elements. The governing equation for critical temperature corresponding to the bifurcation budding is obtained by equating the second variation of total potential energy to zero. The validation checks on the program are carried out using results on homogeneous isotropic plates available in the literature. Results are presented for: 1. (1) cross-ply and angle-ply laminations with symmetry and antisymmetry stacking, 2. (2) simply supported, clamped and combination of boundary conditions, 3. (3) different aspect ratios, 4. (4) various moduli ratios, 5. (5) uniform and linearly varying temperature across thickness, 6. (6) varying ratios of coefficients of linear thermal expansion, and 7. (7) varying number of layers for given laminate thickness. Certain conclusions have been drawn based on these results. © 1989.

Journal	Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications
ISSN	14644207
Open Access	No