Effect of confinement and interfacial adhesion on peeling of a flexible plate from an elastomeric layer

The finite element method and a cohesive zone model are used to analyze plane strain interfacial debonding of an elastomeric layer from an overhanging deformable plate when it is peeled off by applying a normal displacement at the edge of the overhang. The commercial software, ABAQUS, is employed in this work that is focused on understanding the collective role of the following two non-dimensional parameters: (i) the confinement parameter, α, defined in terms of the flexural rigidity of the plate, and the modulus and the thickness of the interlayer, and (ii) the adhesion parameter, ϕ, defined in terms of the cohesive zone parameters and the modulus to thickness ratio of the interlayer. The interfacial adhesion is characterized by a bilinear traction-separation (TS) relation. Numerical experiments reveal that when α is greater than αc, damage initiates at an interior point on the interface and at the interface corner on the traction-free edge irrespective of the value of ϕ. However, ϕ must be greater than ϕc for the debonding to become wavy/undulatory. The critical value, ϕc, of the adhesion parameter agrees with the necessary condition found in our previous work on debonding of an elastomeric layer from a rigid block when it is uniformly pulled outward. For α < αc, damage/debonding initiates only from the interface corner, and no wavy debonding ensues. The peak peeling force prior to the initiation of an internal debond is found to be a monotonically increasing function of ϕ/α, suggesting its potential use as a design variable and as a guide for determining the TS parameters. Results of a few additional numerical experiments in which the elastomeric layer can debond from both adherends provide insights into designing a demolding process for a sandwiched elastomeric layer.