A model to predict friction forces at workpiece-fixture interfaces has been developed based on the equivalency of the frictional contact problem with a nonlinear friction law to that of a variation inequality problem. Nonlinear finite element method (FEM) has been employed to solve the variational inequality problem and to compute the friction forces at the contact interfaces. Experiments measuring interfacial friction forces have been conducted using a modular fixture test-bed developed at University of Illinois. Results from the model have been compared to those obtained from the experiments and are found to be in good agreement.
