The Geometry of the Shear Zone in Metal Cutting

1968 ◽  
Vol 90 (2) ◽  
pp. 420-424 ◽  
Author(s):  
R. F. Scrutton
Keyword(s):  
Strain Rate ◽  
Shear Zone ◽  
Slip Line ◽  
Metal Cutting ◽  
Logarithmic Spiral ◽  
Line Field ◽  
Slip Line Field ◽  
Starting Point ◽  
Fundamental Quantity ◽  
Spiral Trajectories

The choice of a suitable trajectory shape and slip-line field for the shear zone must be influenced by the degree of work hardening and thermal softening, and is necessarily difficult. Although probably incorrect, the geometry of a polar slip-line field is described in terms of the properties of circular and logarithmic spiral trajectories, as this affords a suitable starting point. It is then assumed that the fundamental quantity is the trajectory shape, and it is shown that a slip-line field may be determined which corresponds to any given set of spiral trajectories. The choice of spirals is limited by the condition of volume continuity. The results of Kececioglu (1960) [4] are reexamined in the light of more recent theories of the shear zone and the experimentally determined strain-rate values are shown to be incorrectly derived. A suitable trajectory shape must first be adopted before calculating the value of the strain rate in terms of the width of the zone.

Identification of Friction Factors for Chamfered and Honed Tools Through Slip-Line Field Analysis

2006 ◽  
Author(s):  
Yigˇit Karpat ◽  
Tugˇrul O¨zel
Keyword(s):  
Slip Line ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Edge ◽  
Material Behavior ◽  
Field Analysis ◽  
Machining Performance ◽  
Line Field ◽  
Slip Line Field ◽  
Friction Factors

Analysis of tool-chip friction for tools with edge design in metal cutting helps to understand the complex material behavior around the cutting edge of the tool. The results of this analysis can be used to identify optimum tool edge design to achieve the most desirable machining performance. In this study, slip-line field analysis approach is used to investigate the average friction factor at the tool-chip interface and the dead metal zone phenomenon in orthogonal cutting for chamfered and honed tools. In an experimental set-up, an orthogonal cutting test of AISI 4340 steel is performed. Measured forces are utilized in identifying the friction factors at the tool-interface for both chamfered and honed tools for varying feed rates. Comparison of predicted and measured forces indicates good agreements. The results of this study can be utilized in designing friction at tool-chip interface for Finite Element simulations of machining with edge design tools. This study can also be extended to waterfall hone tools to identify the most optimum cutting edge geometry.

scholarly journals Flow along Tool-Chip Interface in Orthogonal Metal Cutting

1966 ◽  
Vol 8 (1) ◽  
pp. 36-41 ◽  
Author(s):  
H. E. Enahoro ◽  
P. L. B. Oxley
Keyword(s):  
Steady State ◽  
Contact Zone ◽  
Slip Line ◽  
Metal Cutting ◽  
Field Model ◽  
The Body ◽  
Line Field ◽  
Slip Line Field ◽  
Chip Flow ◽  
Orthogonal Metal Cutting

In recent papers it has been suggested that over part of the tool-chip contact zone the chip does not slide but sticks to the tool, chip flow taking place by shear within the body of the chip. Sticking contact is inconsistent with steady state cutting and in this paper a slip-line field model of chip flow is presented which does not include sticking contact and which is consistent with the relevant experimental observations.

Direct mapping of deformation in punch indentation and correlation with slip line fields

2009 ◽  
Vol 24 (3) ◽  
pp. 760-767 ◽  
Author(s):  
T.G. Murthy ◽  
J. Madariaga ◽  
S. Chandrasekar
Keyword(s):  
Strain Rate ◽  
Slip Line ◽  
Large Strain ◽  
Shear Bands ◽  
Indentation Hardness ◽  
Large Area ◽  
Line Field ◽  
Slip Line Field ◽  
Perfectly Plastic ◽  
Analysis Technique

Deformation field parameters in plane-strain indentation of a perfectly plastic solid with a punch have been mapped using particle image velocimetry, a correlation-based image analysis technique. Measurements of velocity and strain rate over a large area have shown that the deformation resembles that of the slip line field of Prandtl. A zone of dead metal is found to exist underneath the indenter adjoining which is a transition region of material flow similar to the centered-fan region in the slip line field. Shear bands demarcate the boundaries of these deformation regions. The observations suggest that a representative strain rate may be assigned to the indentation. By integrating the strain rate field along particle trajectories, the strains in the indentation region have been estimated. The strain values are seen to be large, 0.5 to 4, over a region extending to about twice the indenter half-width. A pocket of large strain, ∼4, is found to exist close to the edge of the indenter–specimen contact. Prandtl’s slip line field is modified based on the observations and used to estimate the strain field. The measurements of the deformation parameters are found to compare mostly favorably with the predictions of the slip line field and prior observations of indentation. The implications of these findings for analysis and interpretation of indentation hardness are briefly discussed.

Plane-Strain Plastic Flow of Strain-Rate Sensitive Materials

1974 ◽  
Vol 96 (3) ◽  
pp. 238-240 ◽  
Author(s):  
R. G. Fenton ◽  
B. Durai Swamy
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Plane Strain ◽  
Slip Line ◽  
Metal Flow ◽  
Stress Distributions ◽  
Line Field ◽  
Slip Line Field ◽  
Flow Problems ◽  
Iterative Calculation

A numerical method based on the modified Hencky and Geiringer equations is described for solving plane-strain metal flow problems of strain-rate sensitive materials. The slip-line field and flow-stress distributions are determined simultaneously using an iterative calculation.

A Slip Line Field Solution of the Free Oblique Continuous Cutting Problem in Conditions of Light Friction at Chip-Tool Interface

1980 ◽  
Vol 102 (4) ◽  
pp. 310-314 ◽  
Author(s):  
W. A. Morcos
Keyword(s):  
Plane Strain ◽  
Slip Line ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Parameters ◽  
Experimental Results ◽  
Line Field ◽  
Slip Line Field ◽  
Field Solution ◽  
Cutting Problem

Lee and Shaffer’s slip line field solution [11] for orthogonal cutting is generalized to the free oblique continuous cutting problem in plane strain. Comparison of the results as predicted by this solution with those of the plane strain modified Merchant model [8] and experimental results is achieved for some key metal cutting parameters. It is shown that in some respect, the plane strain modified Merchant model [8] predicts values of parameters which are closer to experimental results.

Slip Line Field Analysis of a Simple Plane Strain Closed-Die Forging

1989 ◽  
Vol 203 (2) ◽  
pp. 91-99
Author(s):  
M V Srinivas ◽  
P Alva ◽  
S K Biswas
Keyword(s):  
Velocity Field ◽  
Plane Strain ◽  
Slip Line ◽  
Field Analysis ◽  
Line Field ◽  
Slip Line Field ◽  
Die Forging ◽  
Closed Die Forging ◽  
Cavity Filling ◽  
Single Cavity

A slip line field is proposed for symmetrical single-cavity closed-die forging by rough dies. A compatible velocity field is shown to exist. Experiments were conducted using lead workpiece and rough dies. Experimentally observed flow and load were used to validate the proposed slip line field. The slip line field was used to simulate the process in the computer with the objective of studying the influence of flash geometry on cavity filling.

The Relation Between the Friction of Lubricated Rough Surfaces and Apparent Normal Pressure

1989 ◽  
Vol 111 (2) ◽  
pp. 260-264 ◽  
Author(s):  
P. Lacey ◽  
A. A. Torrance ◽  
J. A. Fitzpatrick
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Boundary Lubrication ◽  
Slip Line ◽  
Field Model ◽  
Rough Surfaces ◽  
Normal Pressure ◽  
Line Field ◽  
Slip Line Field ◽  
Asperity Contacts

Most previous studies of boundary lubrication have ignored the contribution of surface roughness to friction. However, recent work by Moalic et al. (1987) has shown that when asperity contacts can be modelled by a slip line field, there is a precise relation between the friction coefficient and the asperity slope. Here, it is shown that there is also a relation between the friction coefficient and the normal pressure for rough surfaces which can be predicted from a development of the slip line field model.

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