Experimental Characterization of Frictional Line Contact by Digital Image Correlation and Inverse Method

Abstract

Line contact usually causes stress concentration, resulting in the wear and failure of materials and structures. The characterization of the contact phenomenon thus plays an important role in the safety evaluation of materials and structures. In this paper, an inverse method is developed that can identify the principal parameters in contact by employing the experimentally measured displacements and mathematical optimization. Basing on the contact theory, the relationship between the contact parameters and displacements on the interface is modeled. The parameters are then inversed by matching the modeled displacements to the experimentally measured data through optimization. Only the displacements on the surface of the contact member are required in this method, which can be easily measured by a segmentation-aided digital image correlation approach. By utilizing the proposed method, the contact between a cylinder and a plate is characterized and the variations of the contact parameters associated with the applied loads and cylinder’s radius are discussed. Error estimation is carried out by implementing the proposed method with the finite element simulated data. Results show that the proposed method can provide reliable identification results under the influence of different kinds of disturbances.