Buckling of unilaterally constrained plates: Applications to the study of delaminations in layered structures. (Q5959130)

The authors report results of a combined experimental and analytical investigation of buckling of unilaterally constrained finite rectangular elastic plates. The plates are modeled by using the classical plate theory and by employing the Kirchhoff-Love hypothesis. The presence of unilateral constraints is accounted for through the use of a nonlinear elastic foundation model that exhibits a deformation-sign-dependent force-displacement relation. Using Galerkin method, the resulting system of governing nonlinear equations is solved iteratively. Different boundary conditions are considered, compared and shown to be in good agreement with `exact' results reported earlier for infinite plates. The results from an experimental investigation reveal that the buckled plate may involve regions or points of contact with the substrate beneath the plate. The shadow moire technique shows clearly that the mode shape is periodic and contains points and/or regions of contact. The results obtained from the theoretical investigation fit the experimental values.NEWLINENEWLINE It is clear that the stiffness of a post-buckled plate with unilateral constraints is highly influenced by whether the buckled portion involves points (or regions) of contact or not. Thus, in analytical model development, the delamination buckling in layered plates and the possibility of the delaminated portion to contact the substance beneath cannot be excluded. The present study also demonstrates the validity of nonlinear foundation models in the buckling analysis of unilaterally constrained rectangular plates.