M. N. M. Allam

EFFECT OF TRANSVERSE NORMAL AND SHEAR DEFORMATION ON A FIBER-REINFORCED VISCOELASTIC BEAM RESTING ON TWO-PARAMETER ELASTIC FOUNDATIONS

This article investigates the effect of transverse normal and shear deformations on a fiber-reinforced viscoelastic beams resting on two-parameter (Pasternaks) elastic foundations. The results are obtained by the refined sinusoidal shear deformation beam theory and compared with those obtained by the simple sinusoidal shear deformation beam theory, Timoshenko first-order shear deformation beam theory as well as Euler-Bernoulli classical beam theory. The effects of foundation stiffness on bending of viscoelastic composite beam are presented. The effective moduli methods are used to derive the governing equations of viscoelastic beams. The influences of several parameters, such as length-to-depth ratio, foundation stiffness, time parameter and other parameters on mechanical behavior of composite beams resting on Pasternaks foundations are investigated. Numerical results are presented and conclusions are formulated.

Thermo-Mechanical Bending Response of Exponentially Graded Thick Plates Resting on Elastic Foundations

The trigonometric shear and normal deformations plate theory is used to study the thermo-mechanical bending analysis of exponentially graded (EG) thick rectangular plates resting on Pasternak elastic foundations. Material properties of the plate are assumed to be graded in the thickness direction according to an exponential law distribution, meaning that Lame coefficients vary exponentially in a given fixed z-direction. The governing equations are derived from the principle of virtual displacements. The analytical solutions are obtained by using Navier technique and the effects of stiffness of the foundations, thermal loading, and gradient index on thermo-mechanical responses of the plates are discussed. Numerical results for the bending response for EG rectangular plates are investigated and some of them are compared with those available in the literature.

EFFECTS OF TRANSVERSE SHEAR AND NORMAL STRAINS ON FG PLATES RESTING ON ELASTIC FOUNDATIONS UNDER HYGRO-THERMO-MECHANICAL LOADING

The influence of temperature and moisture on the bending behavior of composite functionally graded material (FGM) plates resting on elastic foundations is investigated. A transverse shear and normal deformation theory are used with five unknown functions as opposed to six or even greater numbers in the case of other shear and normal deformation theories. An accurate solution is presented in the hygrothermal response of the FG plate with simply-supported edges and resting on elastic foundations. The interaction between the plate and the elastic foundations is considered and included in the equilibrium equations. The influences of Winkler and Pasternak foundation parameters, temperature, moisture concentration, thickness stretching, shear deformation, plate aspect ratio, side-to-thickness ratio, and volume fraction distribution on the plate bending characteristics are studied in detail. Numerical results for the hygro-thermo-mechanical response of the FG rectangular plates is investigated and some of them are compared with those available in the literature.