Generalized mechanics and dynamics of metal cutting operations for unified simulations

This paper presents the unified modeling of mechanics and dynamics of metal cutting operations such as turning, boring, drilling and milling. The distribution of chip thickness along the cutting edges of tools are evaluated using the generalized geometric and kinematic model of the operations [1]. The effect of relative vibrations between the cutting edge and workpiece segments are considered. The force contributed by each oblique cutting edge segment is evaluated from shear stress, shear angle and friction coefficient defined in orthogonal cutting data base. The tool cutting loads are evaluated by summing the differential cutting forces along all engaged cutting edges using the generalized geometric transformations presented in [1]. The chatter stability is solved in modal coordinate system, and the forced vibration marks left on the finish surface are predicted in discrete time domain. The process damping, multiple-regenerative phase delays which depend on the tool geometry and operations are considered. The application of the proposed unified mechanics and dynamics model is demonstrated experimentally in drilling, milling with indexable cutters and various end mills, and in opening large holes with multi-functional drilling/boring heads.