Nonlinear Analysis of Rectangular Laminated Plates Using Large Deflection Theory

Dynamic Relaxation (DR) method is presented for the geometrically nonlinear laterally loaded, rectangular laminated plates. The analysis uses the Mindlin plate theory which accounts for transverse shear deformation. A FORTRAN program has been compiled. The convergence and accuracy of the DR solutions for elastic large deflection response are established by comparison with various exact and approximate solutions. New numerical results are generated for uniformly loaded square laminated plates which serve to quantify the effects of shear deformation, material anisotropy, fiber orientation, and coupling between bending and stretching. It was found that linear analysis seriously over predicts deflection of plates. The shear deflection depends greatly on a number of factors such as length to thickness ratio, degree of anisotropy, number of layers and aspect ratio. It was also found that coupling between bending and stretching can increase or decrease the bending stiffness of a laminate depending on whether it is positive or negative