A finite-element model with closed-form solutions to workpiece deflectionsin turning

Simulation models for workpiece deflections play an important role in deter mining conditions to maximize the part accuracy in machining processes as w ell as in analysing the dynamic response of the machining system. In this p aper, the cross-sectional deflection of the workpiece due to all cutting fo rce components (radial, axial and tangential) is determined using the finit e-element method. Three workpiece mounting types generally used in industri al practice are considered. The change in the workpiece diameter during mac hining can easily be taken into account with this model. Furthermore, the f inite-element reponses are derived in closed form which enables rapid and c ontinuous solutions along the part length. Numerical examples are treated f or which the workpiece deflections calculated from this model are compared with those computed only from the radial cutting force component as usually done by several simplified models. From the results obtained, the proposed model is generally recommended to improve turning simulations.