Modeling of Frictional Elastic Fixture–Workpiece System for Improving Location Accuracy

Abstract

The function of a fixture is to locate and hold the workpiece repeatedly and accurately for manufacturing processes. Location accuracy and holding forces are important factors to be considered in the design and application of fixtures. In this paper, by introducing the contact stiffness between the workpiece and fixturing elements, a fixture-workpiece model is presented in which both the workpiece and fixture elements are treated as deformable, and friction forces are also taken into consideration. On the basis of this model, the relationships between location accuracy and holding forces of a fixture are investigated. A generalized method is proposed to minimize the deformation of the fixtured workpiece and its locating errors (linear and angular inaccuracy) by applying optimal clamping forces.