Bending, free vibrations and buckling of laminated composite and sandwich plates using a layerwise displacement model

This paper deals with the local-global analysis of laminated composite and sandwich plates using a layerwise displacement model [Reddy JN. A plate bending element based on a generalized laminated plate theory. Int J Numer Methods Eng 1989;28:2275-92]. The proposed model assumes piece-wise linear variation of in-plane displacement components and constant transverse displacement through thickness of the plate. It also includes the quadratic variation of transverse shear stresses within each layer of the plate. Using the assumed displacement field, strain-displacement relations and 3D constitutive equations of lamina, equations of motion are derived using Hamilton's principle. A original MATLAB computer program was coded for analytical and finite element solutions of the theory. The parametric effects of plate aspect ratio, side-to-thickness ratio, lamination angle schemes and degree of orthotropy on in-plane stresses, transverse shearing stresses, displacements, fundamental frequencies and critical buckling loads are shown. The accuracy of the present model is verified with existing results in the literature, as well as with the results of the previous author [Vuksanovic Dj. Linear analysis of laminated composite plates using single layer higher-order discrete models. Compos Struct 2000:48:205-11]