1 Introduction

The role of machining process modelling is recognised in industry, due to the relevant advantages that an effective and reliable theoretical model can supply. Such a model would in fact represent a very powerful tool to design cutting tools and to select the cutting conditions, dramatically reducing the amount of trial and error expensive experimental tests, which are normally carried out for this purpose.

Within this framework the potentialities linked to the use of advanced numerical models and in particular finite element techniques have been recognised by a large number of researchers all over the world [STR 85], [STR 90], [SHI 95], [MAR 95], [VAZ 98]. Nevertheless, it is worth pointing out that up to now no general and reliable models have been developed and that the industrial applicability of FEM techniques for a quantitative analysis of machining presents large difficulties. In particular, the characterisation of material behaviour at the strain, strain rate and temperature which occur during the cutting process, the definition of the frictional conditions at the chip-tool interface and the development of effective chip separation criteria probably represent the most relevant and still partially unsolved problems.

In the paper attention is focused on some basic aspects of friction modelling in cutting and in particular on the influence of friction modelling on the effectiveness of the numerical simulation of the process. The paper is...