Flexural analysis of laminated composite plates

The suitability of two higher order shear deformation theories developed for the flexural analysis of homogeneous plates under transverse loading has been examined for the stress analysis of laminated composite plates, including interlaminar stresses, in this paper. The in-plane displacements in both cases are assumed to be quintic in the thickness co-ordinate of the laminates, and nonparabolic and parabolic variations of transverse shear stresses across the thickness of the laminates are assumed for the first and second theories, respectively. The results are compared with the exact solution of Pagano given for a cylindrical bending problem. The study shows that transverse displacement, in-plane displacements, strains and stresses are accurately predicted in both cases. The special feature of the second theory is that transverse normal stress across the thickness of the laminate is reasonably accurately predicted using constitutive equations for the thick laminated plates of aspect ratios 20 and 25 though it shows an unrealistic discontinuity at the interfaces of the laminates. © 1999 Elsevier Science Ltd. All rights reserved.