In this paper, the orthotropic sandwich plates having orthotropic faces and core, unequal face thicknesses and dissimilarities in face materials (including different Poisson ratios for facings) are considered. The stress-strain relations and differential equations are derived for bending of such plates by applying the variational principle of complementary energy. Various formulae and a few numerical results are obtained for bending of a simply supported plate under action of uniaxial compression and uniformly distributed transverse load. The validity of Vianello approximation is also studied and the results are discussed.
NOMENCLATURE
The notations used in the present paper have been arranged alphabetically as given below: a length of plate parallel to x-axis. b width of plate parallel to y-axis. 2 2 h core thickness. hx, h2 distances of neutral plane of the plates from the mid-planes of top and bottom facings respectively. 4P k = F~ k,, uniaxial buckling parameter defined by equation (36). m, n number of longitudinal and lateral half waves for plate respectively. q transverse loading per unit area of plate. qo uniformly distributed loading on plate. qm, constant defined in equation (27). t~, l2 thickness of top and bottom faces respectively. w deflection of plate parallel to z-axis. x, y, z coordinate axes. D~, D, D~y stiffnesses defined by equations ( 15), ( 16), ( 17) respectively. [Ext, Eye] ,] principal moduli of elasticity of orthotropic [Ex2, Eye] J faces, top and bottom respectively.
4n2Dy Fy--b2 G1, G2 moduli of rigidity in xy-plane for top and bottom faces respectively. G~:~, G~,:~ moduli of rigidity of orthotropic core in xz-plane and yz-plane respectively. 1 complementary energy of plate. I~ modified complementary energy of plate.