Postbuckling analysis of delaminated composite beams by differential quadrature method

In this study the postbuckling response of a one-dimensional delaminated co mposite beam under axial compression is modeled by the method of differenti al quadrature. An across-the-width delamination is considered to be in an a rbitrary location through-the-thickness of the beam, and in between the bea m's end supports. The formulation incorporates the exact nonlinear curvatur e of the beam. To model the problem, the delaminated beam is divided into f our regions. The buckling is promoted by introducing an initial imperfectio n along the beam. Then the nonlinear differential equations describing the four regions of the beam and those defining the edge and interface boundary conditions are converted into a set of equivalent differential quadrature form. An are-length algorithm is used to solve the resulting system of nonl inear equations, and subsequently, the geometrically nonlinear responses of all regions are determined. The numerical results obtained from a series o f case studies confirm the efficiency and accuracy of the method. (C) 1999 Elsevier Science Ltd. All rights reserved.