Another article,
63, C. A. Mauch, L. K. Lauderbaugh, "Modeling the Drilling Process. An Analytical Model to Predict Thrust Force and
Torque," Computer Modeling and Simulation of Manufacturing Processes, Vol MD 20, Dallas, TX, 1990. pp. 59-65. ASME, New
York, NY. This paper introduces an analytical model that predicts thrust and torque levels for drilling. These predictions are based on
drill geometry, yield shear stress, and chip thickness. This model is presented in contrast to previous empirical models which require
large amounts of experimental data and are of questionable use outside of the experimental range. The model is developed by
dividing the drill tip into three regions with each region having a separate metal cutting model. The chisel edge comprises two of the
three regions. The inner chisel edge region is modeled as an indentation process: while the outer chisel edge region is modeled using
orthogonal cutting theory. In this paper a new analytical expression is developed to define the transition point between these two
regions. This expression was found to be in excellent agreement with empirical results of other researchers. Finally, the lip region of
the drill is modeled by dividing the region into N cutting elements and modeling each element with oblique cutting theory. The total
force and torque are then computed by summing the contributions from each of the three regions. Currently, the model can be used
for both conventional and splitpoint high speed steel drill tip geometries. However, the model can be easily extended to include other
geometries. Thrust and torque predictions from the analytical model are compared with experimental results that were generated by
using conventional and splitpoint drills to drill 2024-T351 aluminum. 8 Refs.
Tom