Dual-mechanism approach to the prediction of machining forces: Part 1 - model development and calibration

A cutting-process model that addresses the shearing and ploughing mechanisms separately yet simultaneously is presented. The model is developed such that it is readily applicable in an industrial setting, its coefficients have physical meaning, and it can be calibrated with a limited quantity of orthogonal cutting data. The total cutting and thrust forces are each the summation of its individual components that act on the rake face and clearance face. These components are calculated using the rake and effective clearance angles from the normal and friction forces acting on each of these tool surfaces. These normal and friction forces are calculated by the shearing and ploughing portions of the model, respectively, using four empirical coefficients. To calculate the clearance face forces, the interference volume is required, the calculation of which is made possible by a geometrical representation of the cutting edge-clearance face interference region which requires the depth of tool penetration, which is determined using a fifth empirical model. The calibration algorithm required to fit the empirical models for the five model coefficients is presented including a method developed to perform the necessary total machining force decomposition. Some implications of knowing the individual rake and clearance face forces as predicted using this model through the decomposition capability are also discussed.