Modeling and inverse identification method for the characterization of elastic–plastic contact behavior during flat punch indentation

In this work, an inverse identification method is developed for the experimental characterization of the elastic–plastic contact in indentation problem. The method consists of a modeling procedure and an identification procedure. In the modeling, a discrete interfacial stress model is developed and the 2D frictional flat but round punch condition (of which frictionless, sharp corner contact is a special case) is formulated. Only the tendencies of stress distributions are required to be constrained in the model which can highly increase the scope of application. In the identification, an alternative optimization scheme is proposed in which the contact parameters can be inversed by matching the modeled displacement to the experimental data. A displacement-based yield criterion is developed so the plastic domain can be recognized without solving the stress or strain. The proposed method can characterize all of the contact parameters only by using the easy-acquired displacements. Simulation and experiments show that the proposed method can accurately characterize the contact from noisy measurements. • An inverse identification method for characterizing the elastic–plastic indentation. • Displacement based yield criterion and contact parameters identification. • A more general interfacial stress model for indentation problem is formulated. • An optimization scheme for inversing the parameters from noisy measurements.