EXPERIMENTAL-DETERMINATION OF DYNAMIC FORCES DURING TRANSIENT ORTHOGONAL CUTTING

A large set of orthogonal metal-cutting tests has been conducted for A luminum 2014-T6 using carbide and HSS tools over a wide range of cutti ng variables such as: spindle speed, fed and width of cut. The transie nt dynamic force behavior during the first few spindle revolutions aft er tool-workpiece contact was recorded and later analyzed in the time and frequency domains. Results show that, depending on the cutting con ditions and in most of the tests carried out, the cutting and thrust f orces reached their steady-state values in a number of spindle revolut ions ranging from one and a half to two. This result indicates that th e application of existing metal-cutting force models can not predict t he actual behavior of the forces during transient cutting conditions. A new dynamic force model is proposed in which the instantaneous force and depth of cut as well as their first-order time derivatives are in volved. This first-order linear differential equation is particularly important for advanced modeling for adaptive control purposes. Physica l implications of these results are briefly discussed.