Abstract
The basic criterion in precision machining is to machine a workpiece that satisfies dimensional accuracies and low tolerance variations. Precise machining demands the work-piece to be rigidly fixed, which in turn requires high clamping forces. The clamping forces, as well as cutting forces, result in deformation of the workpiece. This deformation of the work-piece hinders the final goal of the machinist, which is to machine within low dimensional and geometric tolerance band-widths. In this paper an analytical, yet practical, nonlinear optimization model is developed which ensures the rigidity of work-holding and guarantees the precision and accuracy of machining results by proper fixturing. Principles of statics, kinematics, stress-strain, and geometric constraints are applied in developing the model. The model consists of constraints in order to (1) minimize the deformation of the workpiece, (2) compute the fixturing and cutting forces under which there is no slippage, and (3) ensure the applicability of Coulomb’s law of friction. A computer program is developed to demonstrate the capability of this model. A given workholding configuration for a specific part geometry is verified when a solution of the model is found.