An Inverse Identification Method for the Characterization of Elastic Conforming Contact Behavior During Flat Punch Indentation

Background The flat punch indentation problem is a typical prototype of conforming contact which can be frequently encountered in many applications. Its characterization is of great difficulty as the interface is embedded and the stress is highly concentrated at the contact boundary. Objective In this work, an inverse identification method is developed for reconstructing the interfacial stress during flat punch indentation from the measured displacement field. Methods This method consists of a modeling procedure and a characterization procedure. In the modeling, the basic tendencies of interfacial stress distributions are established and the relationship between the stress and displacement are formulated. In the characterization, the parameters in the model, including the profiles of contact interface and the stress distributions are optimized by matching the calculated displacement to the experiment data. Segmentation-aided digital image correlation is implemented for the displacement acquisition near the contact interface. An optimization framework is developed so the different kinds of parameters can be accurately obtained. Results Both of simulated experiment and real-world experiment are carried out, and results show that the proposed method can accurately characterize the elastic contact behavior. Conclusions The modeling merely constrains the tendencies rather than gives a close-form solution of interfacial stress and the identification only requires the measurement of local displacement, which can greatly increase its applicability in applications.