Analytical method to solve postbuckling behavior of delaminated composite plates.

Delamination can be introduced into a composite plate due to various causes owing to its weak interlaminar toughness. Complex and undersirable behaviors of the plate, that is, the lower buckling. stresses, crack propagation etc. are caused by the existence of the delamination. During the deformation, the delaminated surfaces can contact each other, which makes the usual approach like a theory of minimum potential energy useless. In the present paper, an analytical method suitable to obtain buckling and postbuckling behaviors of the delaminated plate under compressive and shear loads is proposed, which is derived by the use of variational principle from a theory of minimum potential energy. Rayleigh-Ritz approximation method is applied to estimate the postbuckling behavior.