Direct Extraction of Work of Adhesion from Contact Experiments: Generalization of JKR Theory to Flexible Structures and Large Deformation

Contact experiments using flexible structures have been devised to enhance the sensitivity of adhesion measurements. Evaluation of the work of adhesion often requires specific mechanical models of the flexible structures, which invariably make approximate assumptions on the deformation and material properties. In this paper, we extend a previous method that can extract work of adhesion directly from the data of indentation experiments. The extended method is applicable to a wide variety of contact-mechanics-based tests including adhesive contact of flexible structures. Furthermore, it is valid for small deformation as well as large deformation where geomatical and material nonlinearities are not negligible. We also establish a general expression of the energy release rate in terms of the compliance of the contacting structures. For the case of a spherical indenter in contact with a half space and assuming linear elasticity, the Johnson-Kendall-Roberts theory is recovered.