Finite element simulation of high-speed cutting forces

A finite element model of a two-dimensional, orthogonal metal-cutting process is used to study the influence of the cutting speed on the cutting force and the chip formation process. The model uses a generic flow stress law. Friction is neglected as its speed dependence is only poorly known. It is shown that the experimentally observed decrease of the cutting force with the cutting speed and the plateau at high cutting speeds are reproduced by the simulation. The decrease is mainly caused by a change in the shear angle due to thermal softening. At large cutting speeds, segmented chips are produced. It is also shown by an analytical calculation that segmented chips at large cutting speeds are energetically more favourable than continuous chips.