Axisymmetric Peeling of Thin Elastic Films: A Perturbation Solution

We study the mechanical behavior of a thin elastic film that is affixed to a rigid substrate and subjected to a transverse force using a shaft with a finite radius. This scenario, also referred to as axisymmetric peeling, is encountered frequently in conventional blister tests as well as in our daily lives when removing an adhesive film from a substrate. Our primary objective is to gain a quantitative understanding of how the shaft's radius influences the relationships between force and displacement, as well as between force and delamination areas. These relationships can serve as a dependable method to determine both the film's elastic modulus and the adhesion strength between the film and its substrate. In this work, we provide a simple perturbation solution to this geometrically nonlinear problem while avoiding any use of ad hoc assumptions that were previously required. As a result, our results are in excellent agreement with numerical simulations and offer improved accuracy compared to analytical solutions available in the literature.