A REFINED HIGHER-ORDER THEORY AND ITS FINITE ELEMNT METHOD FOR THICK LAMINATED PLATES

In order to improva the accuracy of the shear deformation theory of thick laminated plates,an improved higher order theory is developed.The Legendre polynomials are introduced into the approximate displace ment distributions across the plate thickness,and a finite element model is suggested from the original equations.This theory has the same independent arguments as that in the second order shear deformation Yheory proposed by Whitney,Sun,and Engblom,etal.,but proposes the parabolic distribution of the transverse shear strains-through the thickness of the plate.The accuracy of the present theory is examined by applying it to bending problems of laminated plates which was solved exactly by Pagano.The results are compared with three-dimensional elasticity solutions,the second order shear deformation theory and some other higher order shear deformation theory solutions.The present theory shows the deflections and stress more accurately than that obtained from the previous works in the structural analysis of laminated plate with small apan with respect to thickness.