Three dimensional elasticity approach for delamination buckling of composite plates

An three dimensional elasticity approach is presented for the delamination buckling of simply supported orthotropic and laminated composite plates. The uniform prebuckling stress assumption is made for composite laminates, which assumes the membrane state during prebuckling. The delaminated plate is divided into three regions and in each region the closed-form expressions for the displacements and stresses are derived. The nonlinear eigenvalue problem used to solve for the critical load is therefore constructed by using continuity equations at region interfaces and at layer interfaces. The results obtained from the elasticity solution are compared with the critical loads furnished by the classical laminate theory. The approach automatically accounts for the transverse-shear and normal effects and provides a means of accurate assessment of various existing plate theories.