Thermomechanical oscillations in material flow during high-speed machining

This paper presents a nonlinear dynamics approach for predicting the transition from continuous to shear-localized chip formation in machining. Experiments and a simplified one-dimensional model of the flow both show that, as cutting speed is increased, a transition takes place from continuous to shear-localized chip formation in the flowfield of the material being cut. Initially, the process appears to be somewhat disordered. With further increases in cutting speed! the average spacing between shear bands increases monotonically, and the spacing becomes more regular and asymptotically approaches a limiting value that is determined by the cutting conditions and the properties of the workpiece material.