Ph.D. Thesis Defense by Rogelio L. Hecker
Monday, November 11, 2002

(Dr. Steven Liang, advisor)

"Part Finish Modeling and Process Cycle Design and Control of Cylindrical Grinding"

Abstract

A model of the grinding process based on a probabilistic analysis of the chip thickness is presented. The normal force, the tangential force, and the grinding power were predicted and validated using empirical data from both surface and cylindrical grinding. The model includes tool properties (static grain density and grin geometry), material properties (grain interface friction and material hardness), and grinding kinematic conditions (depth of cut and wheel and workpiece tangential velocity). The dynamic effects generated by the local grain force and by the total grinding force are included in the model by an analytical formulation. A surface roughness model based on the predicted chip thickness is formulated and validated with empirical data.

A grinding cycle is proposed by combining power control during the stock removal stage and velocity control during the final stage. The grinding power model and the surface roughness model of the part were used to simulate the process and find the optimal settings for the cycle. The desired grinding power for stock removal was subject to maximum machine capabilities and workpiece burn. The feed of the final stage was found based on the final part requirements such as surface roughness and the theoretical out-of-roundness. This grinding cycle was implemented and tested in an open architecture machine.