An Analytical Finite Element Technique for Predicting Thrust Force and Torque in Drilling Process

Abstract

Metal cutting operations such as turning, milling and drilling are widely used in manufacturing to produce a variety of mechanical components. Drilling, a hole producing process, is especially important because it accounts for a large portion of overall machining operations. In addition, drilling problems can result in costly production waste because many drilling operations are usually among the final steps in fabricating a part. The present study is focus on predicting the thrust force and torque in drilling using high speed drills, with different diameters, on the AISI 1020 steel. An analytical finite element technique is develop for predicting the thrust force and torque in drilling with twist drills. The approach is based on representing the cutting forces along the cutting lips as a series of oblique sections. Also the cutting in the chisel region is treated as orthogonal cutting with different cutting speeds depending on the radial location. For each section, an Eulerian finite element model is used to simulate the cutting forces. The section forces are combined to determine the overall thrust force and drilling torque on the drills. Results of predicted forces and torques are compared with measured forces and torques. The forces and torques predicted by the FEM are in close agreement with the experimental observed forces and torques in drilling tests of AISI 1020 steel for several drill diameters, spindle speeds and feed rates.