Analysis Of The Tool-Chip Contact Length And The Cutting Force In The Microcutting Applying The Slip-Line Theory

In metal cutting, studying the chip geometry shape is very important, which can show the mechanism of chip deformation and illustrate the processing of the metal cutting.A slip-line cutting model of tool-chip contact length is established in this paper. Based on Dewhurst and Collins's matrix technique for numerically solving slip-line problems and Powell's algorithm of nonlinear optimization, the mathematical formulation of the model is resolved, from which the matrix formulation of the every slip-line and the every slip-line angle is obtained. According to the slip-line model and its hodograph, the formulation of the tool-chip contact length and the cutting force are achieved.The average shear strain in slip-line region is given by the slipping theory and the elastic-plasticity theory, and the equation of the tool-chip contact length and the cutting force varied by temperature and shear strain is re-written by considering the work material's mechanical property. The variations of the chip-contact length and the cutting force varied respectively with the tool geometry, the cutting conditions and pressure edge conditions are predicted by Matlab calculating, and the formulation of the ratio of the tool-chip contact length and the chip thickness is derived by curve-fitting.The orthogonal cutting model taking into consideration the tool edge radius and the two rake faces tool is given by the finite element analysis software; The variations of the tool-chip contact length and the cutting force are attained by the mechanical thermal analysis, which is similar to the results above by the slip-line theory.