An elastic contact model for the prediction of workpiece-fixture contact forces in clamping

The design and evaluation of machining fixture performance requires accurat e knowledge of workpiece-fixture contact forces since they strongly impact workpiece accuracy during clamping and machining. This paper presents an el astic contact model for the prediction of workpiece-fixture contact forces due to clamping. The fixture and workpiece are considered to be elastic bod ies in the vicinity of the contact region. The model is formulated as a con strained quadratic program by applying the principle of minimum total compl ementary energy. The model predicts the normal force, and the magnitude and direction of the tangential (friction) force at each workpiece-fixture con tact due to clamping forces. Experimental verification of the model under d ifferent clamping loads shows good agreement bent een predicted and measure d normal and tangential contact forces. The model can be used to analyze fi xture performance in terms of the contact forces and contact region deforma tion.