Aperçu des différentes modélisations de la coupe

Approche thermomécanique de la coupe oblique et application aux procédés

The modelling of cutting

ISGMP, Université de Metz, Ecole Nationale d'ingénieurs de Metz, France

Abstract

A machining process appears to be a simple removal of a layer of workpiece material, however complex interactions of phenomena occur as this happens. For ductile materials, such as plain carbon steels, the removed layer is, for favorable cutting conditions, formed into a chip by plastic deformation. This plastic deformation is essentially due to intense shearing in a primary zone, where the material flow direction is sudden changed, and in a secondary zone, at the tool chip interface. Even for conventional cutting velocities, the strain rates are very important and the deformations are large. Plastic work is for its greatest part converted into heat, then the elevation of temperature is significant in the removed material. In addition, the heat generated by friction at the tool-chip interface leads to high values of the temperature. And finally the machining operation is influenced by the dynamics of the machine tool structure and the dynamics of the cutting process.

The challenge of the industry is to produce high quality with high productivity. Surface roughness, dimensional accuracy, form tolerance, stability regime of uncritical vibration are directly dependent on machining process conditions. The goal is to find a way to select the proper tooling, estimate tool change times, program tool paths, tool breakage, chip flow and chatter. All these tasks are made easier by a better understanding and by modelling of the cutting process. Simulation of machining will allow to predict machining performance for given conditions without going through expensive and time consuming experiments and will help to determine the optimal cutting conditions.

In this paper, a summary of different works performed in the area of metal cutting modelling is presented. A thermomechanical analytical model of oblique cutting is developed and its use to model the cutting processes is briefly exposed.