Experimental Validation of Nonlinear Compliant Contact Force Models

Abstract

Contact dynamics modeling continues to be an intensive research area with new applications of contact dynamics simulation arising in engineering practice. One approach to normal contact force modeling that has gained significant popularity is the compliant model in which the contact force between two objects is defined explicitly as a function of local deformation and its rate. Probably the most well-known model in this category is the Hunt and Crossley model, which employs a nonlinear damping term to model the energy dissipation during contact, with the damping coefficient related to the coefficient of restitution. This model prompted several investigations on how to evaluate the damping coefficient, in turn resulting in several variations on the original Hunt-Crossley model. In this paper, the authors aim to experimentally validate the Hunt-Crossley type of nonlinear contact force models and furthermore, to compare the experimental results to the model predictions obtained with different values of the damping coefficient. The paper reports our findings from the sphere to plate impact experiments, conducted for a range of initial impacting velocities, with measurements of impact forces and accelerations. The experimental forces are compared to those predicted from the contact dynamics simulation of the experimental scenario. The experiments, in addition to generating novel impact measurements, provide a number of insights into both the study of impact and the impact response.