A Finite Element Study of Chip Formation in High-Speed Machining

A Lagrangian finite element model of orthogonal high-speed machining is developed. The model utilizes continuous remeshing to alleviate element distortion problems associated with the finite deformations encountered. The thermo-mechanically coupled model accounts for dynamic response of multiple discretized-bodies in contact, as well as interfacial heat transfer. Both ductile and brittle fracture initiation and propagation are accounted for during processing; an essential feature in determining shear-localized chip morphologies. No predetermined “line of separation” or slide-line contact has been assumed at the depth of cut near the tool tip. Rather, the work-piece material is allowed to soften and flow around the finite radius of the discretized cutting tool, fracturing only when the criterion is satisfied. Examples of continuous and shear-localized chip morphologies are given in the high-speed range.