A multi-term semi-energy finite strip method for post-buckling analysis of composite plates

In this paper a finite strip approach based on the concept of a rigorous post-buckling solution for composite plates, namely the semi-energy approach, is presented. Moreover, in semi-energy finite strip approach, the out-of-plane displacement field of the finite strip is the only displacement which is postulated by a deflected form. The postulated deflected form is substituted into von K´arm´an’s compatibility equation which is solved exactly to obtain the corresponding forms of the mid-plane stresses and displacements. The solution of von K´arm´an’s compatibility equation and the postulated out-of-plane deflected form are then used to evaluate the potential energy of the related finite strip. Finally, by invoking the principle of minimum potential energy, the equilibrium equations of the finite strip are derived. The developed finite strip method (FSM) is applied to analyse the post-buckling behaviour of laminated composite plates. As far as, the validity and numerical efficiency of the developed semi-energy FSM is concerned, the results obtained from semi-energy FSM approach are compared with those obtained from a fairly conventional and well exploited finite strip technique, namely the full-energy finite strip method. The study of the results revealed that the developed semi-energy FSM provides a very higher convergence and stress distribution properties in comparison with the full-energy solution by incorporating considerably less number of degrees of freedom. This means that from the computational economy point of view, the developed semi-energy FSM is superior to the full energy FSM. Copyright q 2006 John Wiley & Sons, Ltd