A Plasticity Problem Involving Plane Strain and Plane Stress Simultaneously: Groove Formation in the Machining of High-Temperature Alloys

Although a plane strain plastic analysis represents a good approximation for the central portion of a metal-cutting chip, plane stress better approximates conditions at the free edges of the chip. Therefore the metal-cutting problem is reexamined using both plane strain and plane stress simultaneously. The analysis indicates that the material at the edges of the chip will become plastic at a lower value of stress than will be required by the central constrained region and that the energy per unit volume at the edges of the chip will be greater than at the center. The consequence of these results is discussed in terms of the wear groove frequently observed on a tool under the free edges of the chip, which is particularly troublesome when machining high-temperature alloys.