THE DEVELOPMENT OF A MATHEMATICAL MODEL FOR PREDICTING THE DEPTH OF PLASTIC DEFORMATION IN A MACHINED SURFACE

ABSTRACT The development and verification of a mathematical model for the prediction of plastic deformation in a machined surface are presented. The main assumption for developing this model is that there is a linear relation between plastic strain and the depth to which it extends. The model relates the work required to shear the workpiece material to the work needed to compress the workpiece material ahead of the cutting tool. The resulting depth of plastic deformation in the machined surface is a function of the true stress-strain characteristics of the workpiece material, the shear stress and shear strain on the shear plane, and the distribution of plastic strain. Results of the model agree well with data found in the literature. An improvement of the model is suggested through application of actual distribution data of plastic strain and calculation of frictional behavior on the rake face of the tool.

[1]  Y. Matsumoto,et al.  The Effect of Hardness on Residual Stresses in Orthogonal Machining of AISI 4340 Steel , 1990 .

[2]  S. Kobayashi,et al.  Some Observations on the Shearing Process in Metal Cutting , 1959 .

[3]  S. R. S. Kalpakjian.  Manufacturing Processes for Engineering Materials , 1984 .

[4]  E. Brinksmeier.  State-of-the-art of non-destructive measurement of sub-surface material properties and damages , 1989 .

[5]  E. Brinksmeier,et al.  Optimization of Computer Controlled X-Ray Stress Analysis , 1981 .

[6]  T. Cook,et al.  Surface features and plasticity induced by tension-tension fatigue of Inconel 718 , 1986 .

[7]  M. E. Merchant.  Mechanics of the Metal Cutting Process. II. Plasticity Conditions in Orthogonal Cutting , 1945 .

[8]  P. J. Thompson,et al.  An apparent strain analysis of orthogonal cutting , 1969 .

[9]  P. Leskovar,et al.  Influences Affecting Surface Integrity in the Cutting Process , 1982 .

[10]  S. Ramalingam,et al.  On the Metal Physical Considerations in the Machining of Metals , 1972 .

[11]  G. W. Rowe,et al.  A quantitative comparison between residual stresses and fatigue properties of surface-ground bearing steel (En 31) , 1980 .

[12]  B. Cullity,et al.  Elements of X-ray diffraction , 1957 .

[13]  N. Zorev.  Metal cutting mechanics , 1966 .

[14]  W. König,et al.  Residual Stresses — Measurement and Causes in Machining Processes , 1982 .

[15]  T. Prasad,et al.  Residual stresses due to a moving heat source , 1985 .

[16]  M. M. El-Khabeery,et al.  Residual stress distribution caused by milling , 1989 .

[17]  J. T. Black.  Flow stress model in metal cutting , 1979 .

[18]  K. Weinmann,et al.  Mechanics of Tool-Workpiece Engagement and Incipient Deformation in Machining of 70/30 Brass , 1971 .

[19]  M. Y. Reddy,et al.  Plastic strain analysis of the machined surface region using fine grid etched by photoresist technique , 1989 .