Identification of Contact Stress on Non-conforming Contact Interface Based on Local Displacement Measurement

The experimental identification of contact stress is important in many areas. In this paper, we present an inverse method for identifying the stress distribution on non-conforming contact interface based on local displacement measurements. A mechanical model is established to formulate the relationship between the contact stress and the displacement field near the interface. An optical method, named segmentation-aided digital image correlation is utilized to measure the near-field displacement. The contact stress is then inversed by finding the optimal model that best matches the measurements. Three model parameters, i.e., the contact center, contact length and maximum contact stress, are identified through an optimization procedure. The parameters are initialized by an image processing method and then iteratively refined by minimizing the discrepancy between the model predictions and the measured displacements. Both simulated and real-world experiments are conducted and the results verify the effectiveness of the proposed method.