(Dr. Shreyes Melkote, advisor)

"Prediction of Ring Deformation Due to Fixturing in the Turning Process"

Abstract

The modeling of deformation for thin ring-shaped workpieces was examined to enable smaller form tolerances on round features produced using the turning process. To predict the deformations of ring shaped workpieces, an analytical model was developed that predicts deformation for an entire ring subject to any in-plane loading conditions. In addition to this model, a finite element model was created that considers the bending of a ring due to loading similar to three-jaw chucking. The strengths and capabilities of these models were verified for different ring thicknesses and loads by measuring the deformations produced using a specialty deflection fixture. The deflection fixture produces repeatable loads that are similar to those produced by a three-jaw chuck. To demonstrate the applicability of these models to the turning process, a thin ring-shaped workpiece was clamped in a three-jaw chuck and the resulting deformation was compared to the models' predictions. In addition, rings were turned using the three-jaw chuck and the geometric quality of the cut profile was related to the predictions made by the models.