Experimental Investigation of an Incremental Contact Model for Hyperelastic Solids Using an In Situ Optical Interferometric Technique

The intricacies of rough surface contact are amplified by hyperelastic materials, primarily due to nonlinear enhancement caused by stress concentration. In previous studies, we proposed an incremental contact model for hyperelastic materials based on the tangent modulus and validated it through finite element simulations. This study proceeds with the experimental validation of the model. Initially, four hyperelastic rough surfaces were scanned and stitched together using a white light interferometer to obtain the whole surface topography. Subsequently, in situ optical interferometric techniques precisely measured the actual contact areas between these four samples and quartz glass, establishing the relationship between the load and contact area. Finally, by incorporating the surface topography into the incremental contact model for hyperelastic materials using profile theory, predictions of the relationship between load and contact area were made and compared with the experimental results. Significant agreement was found within nearly 90% of the relative contact area, which validated the model’s efficacy. The importance of this model extends to practical domains, such as wear, sealing, and contact surface safety research.