A Photoelastic Study of Stress Distribution During Orthogonal Cutting—Part 1: Workpiece Stress Distribution

1971 ◽  
Vol 93 (2) ◽  
pp. 527-537 ◽  
Author(s):  
S. Ramalingam ◽  
L. L. Lehn
Keyword(s):  
Stress Distribution ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Infinite Plate ◽  
Cutting Parameters ◽  
Surface Damage ◽  
Rake Angle ◽  
Plate Edge ◽  
Line Load ◽  
State Of Stress

This paper examines the stress distribution in the workpiece as a function of the cutting parameters associated with orthogonal cutting. It is shown that the state of stress which prevails in the workpiece during orthogonal cutting with a tool having a rake angle α, is equivalent to that which will prevail in a semi-infinite plate when a line load is applied to its edge in tension at an angle complementary to the rake angle, measured from the plate edge outer normal in the counterclockwise direction. The effect of this stress field on the surface damage accompanying metal cutting is discussed.

The Effect of Prior Cutting Conditions on the Shear Mechanics of Orthogonal Machining

1998 ◽  
Vol 120 (1) ◽  
pp. 13-20 ◽  
Author(s):  
R. Stevenson ◽  
D. A. Stephenson
Keyword(s):  
Material Properties ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Rake Angle ◽  
Cnc Machining ◽  
Machining Process ◽  
Depth Of Cut ◽  
Prior History ◽  
Machining Conditions ◽  
The Difference

It has been proposed several times in the metal-cutting literature that the machining process is non-unique and that the instantaneous machining conditions depend on the prior machining conditions (e.g. depth of cut, rake angle etc.). To evaluate the validity of this concept, a series of experiments was conducted using a highly accurate CNC machining center. For these experiments, the machining conditions were changed during the course of an orthogonal cutting experiment in a repeatable manner and the measured forces compared as a function of prior history. Tests were conducted on several tempers of 1100 aluminum and commercial purity zinc to evaluate the effect of material properties on the machining response. It was found that the change in measured cutting forces which could be ascribed to prior machining history was less than 3 percent and that material properties, particularly work hardening response, had no discernible effect on the magnitude of the difference.

Temperature Field Numerical Analysis of Machining Process Based on the Finite Element Analysis

2014 ◽  
Vol 621 ◽  
pp. 611-616 ◽  
Author(s):  
Yan Juan Hu ◽  
Yao Wang ◽  
Zhan Li Wang
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Temperature ◽  
Cutting Parameters ◽  
Element Model ◽  
Machining Process ◽  
Element Analysis ◽  
Mechanical Coupling

In order to study the temperature field distribution in the process of machining, the finite element theory was used to establish the orthogonal cutting finite element model, and the key technologies were discussed simultaneously. By using ABAQUS software for cutting AISI1045 steel temperature field of numerical simulation, the conclusion about changing rule of cutting temperature field can be gotten. The results show that this method can efficiently simulate the distribution of temperature field of the workpiece, cutter and scraps, which is effected by thermo-mechanical coupling in metal work process. It provides the theory evidence for the intensive study of metal-cutting principle, optimizing cutting parameters and improving processing technic and so on.

scholarly journals Analysis of critical negative rake angle and friction characteristics in orthogonal cutting of AL1060 and T2

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987806 ◽  
Author(s):  
Yanchun Ding ◽  
Guangfeng Shi ◽  
Hua Zhang ◽  
Guoquan Shi ◽  
Dongdong Han
Keyword(s):  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Tools ◽  
Flow Characteristics ◽  
Rake Angle ◽  
Machined Surface ◽  
Friction Characteristics ◽  
Model Based ◽  
Stagnant Region ◽  
Cutting Experiments

The stagnant region often appears in front of the tool cutting edge, which is caused by mechanical inlay and excessive pressing in plastic metal cutting with large negative rake angle tools at a low speed. It results in the change of the effective negative rake angle which can affect the flow characteristics of material, the quality of machined surface and the abrasion loss of cutting tools. However, the critical negative rake angle model based on the existence of the stagnant region has not been reported yet. Therefore, in order to investigate the critical negative rake angle value considering the stagnant region, a critical negative rake angle model based on the principle of minimum required energy is established, and the correctness of the theoretical model is verified by orthogonal cutting experiments. At the same time, the influence of the critical value of the large negative rake angle tool on the machined surface quality is studied through different cutting experiments. These experimental results show that the deviations of both experimental and theoretical critical negative rake angle are less than 5% during the orthogonally cutting of the aluminium (AL1060) and copper (T2) materials by the negative rake angle tool. Meanwhile, the critical negative rake angle is related to the adhesive friction coefficient of tool–workpiece contact surface. The analysis of friction characteristics shows that the deviation values of both theoretical and experimental critical negative rake angle are proportional to the coefficient of adhesive friction and the thickness of the stagnant region. Critical negative rake angle has a significant effect on roughness and residual stress of the machined surface.

The Influence of Extreme Speeds and Rake Angles in Metal Cutting

1963 ◽  
Vol 85 (1) ◽  
pp. 49-64 ◽  
Author(s):  
W. N. Findley ◽  
R. M. Reed
Keyword(s):  
Coefficient Of Friction ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Shear Plane ◽  
Rake Angle ◽  
Lateral Extrusion ◽  
Tool Force ◽  
Steep Decrease ◽  
Peak Value ◽  
Antimony Alloy

A study is presented of the effect of wide variations in speed of cutting and rake angle on orthogonal cutting of several metals—mainly a lead-antimony alloy. It was observed that enormous decreases in tool forces occurred in the lead-antimony with increase in speed from 6 to 3800 fpm, and decrease in rake angle from +30° to −60°. Explanations for these variations are proposed. An unusual observation was that a transition as speed increased from continuous to discontinuous chips occurred at large negative rake angles. Possible causes of this behavior are discussed. Another unusual observation was that a steep rise in tool force occurred with increase in speed for rake angles of 0° and +30°. The rise to a peak value was followed by an equally steep decrease in tool forces. Other observations discussed include the appearance of side spikes on the chips, chip curl, lateral extrusion of chips, influence of normal stress occurring on the shear plane, and the apparent coefficient of friction.

FEM Analysis of Residual Stress Distribution and Cutting Forces in Orthogonal Cutting with Different Initial Stresses

2014 ◽  
Vol 800-801 ◽  
pp. 380-384 ◽  
Author(s):  
Yuan Ma ◽  
Ding Wen Yu ◽  
Ping Fa Feng
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Compressive Stress ◽  
Cutting Forces ◽  
High Speed ◽  
Orthogonal Cutting ◽  
Fem Simulation ◽  
Fem Analysis ◽  
Cutting Parameters ◽  
Initial Stresses

Machining induced residual stress is influenced by many factors. Extensive studies on the influence of cutting parameters, tool parameters, as well as basic properties of materials have been carried out during the past decades, while another important factor, initial stress distribution in workpiece, was often ignored. In this paper a relatively complete FEM simulation on the formation mechanism of machining induced residual stress in high speed machining is carried out, illustrating the three stress zones affected by mechanical and thermal loads, and their influence on ultimate residual stress. And the influence of initial compressive stress on stress formation and cutting forces is analyzed. Initial compressive stress weakens the tensile effect caused by the shear deformation, and the residual stress tend to be more compressive with larger initial compressive stress. Cutting force becomes larger with the increase of initial compressive stress. And the results in this FEM study can be used to explain some unaccounted experimental phenomena in former researches.

Measuring fracture toughness from machining tests

2009 ◽  
Vol 223 (12) ◽  
pp. 2861-2869 ◽  
Author(s):  
Y Patel ◽  
B R K Blackman ◽  
J G Williams
Keyword(s):  
Fracture Toughness ◽  
Aluminium Alloy ◽  
Coefficient Of Friction ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Shear Plane ◽  
Rake Angle ◽  
Sufficient Information ◽  
The Coefficient Of Friction ◽  
Adhesion Toughness

An analysis of the forces involved in orthogonal cutting or machining is presented in which yielding on a shear plane is assumed. The fracture toughness Gc is included and it is observed that Gc may be determined by measuring the cutting and transverse forces together with the chip thickness for a range of cutting depths. This latter measurement enabled the shear plane angle ϕ to be determined experimentally. A simplified version of the analysis is also given in which ϕ is predicted by a cutting force minimization scheme. Neither scheme requires any details of the friction condition to be known since the transverse force is sufficient information for any type to be included in the analysis. A friction model including a coefficient of friction and an adhesion toughness is also utilized. Data for both polymer and metal cutting are taken from the literature and Gc is determined. In some datasets the tool rake angle α is also varied and the values of Gc and the yield stress σY are found to be independent of α. The force minimization method gives a good estimate of ϕ for most polymers. For metals (aluminium alloy, steel, and brass) the method worked well. For aluminium alloy Gc was independent of α and the predicted and measured ϕ values agreed. For steel and brass this was not so. Gc was mostly independent of α except at low values where high values of Gc were observed. A constant value of the coefficient of friction was observed for each α value but values for both the coefficient of friction and the adhesion toughness varied significantly with increasing rake angle.

An Experimental and Computational Study of Temperature and Strain Fields in Metal Cutting

2001 ◽  
Author(s):  
Alan T. Zehnder ◽  
Yogesh K. Potdar ◽  
Xiaomin Deng ◽  
Chandrakant Shet
Keyword(s):  
Spatial Resolution ◽  
Metal Cutting ◽  
Computational Study ◽  
Orthogonal Cutting ◽  
Critical Role ◽  
Rake Angle ◽  
General Purpose ◽  
Temperature Fields ◽  
Ir Detectors ◽  
Strain Fields

Abstract Metal cutting is a thermo-mechanically coupled process in which plasticity induced heating and friction play a critical role. In this paper, we outline a methodology that combines high resolution experiments with numerical simulations. The simulations were performed with a general purpose finite element code. With this code we evaluate the effects of chip-tool interface friction and rake angle on temperature and cutting force and show that results for residual stresses in the workpiece are consistent with experimental data. We hypothesize that by closely coupling simulations to fine scale spatial and temporal experimental measurements of temperature and strain fields, questions related to choice of parameters in FE simulations can be resolved. We have designed and conducted orthogonal cutting experiments to measure temperatures, using IR detectors, with a spatial resolution of 27 × 27 μm and time scale of 200 ns. Experimentally obtained temperature fields are compared with FE results. We also obtain deformation fields with a spatial resolution of 50 × 50 μm.

Multi-Constrained Analysis of Metal Cutting and its Application

2013 ◽  
Vol 589-590 ◽  
pp. 38-44
Author(s):  
Gang Liu ◽  
Ming Chen ◽  
Peng Nan Li ◽  
Qing Zhen Bi ◽  
Bao Cai Guo
Keyword(s):  
Thermal Conductivity ◽  
Stainless Steel ◽  
Metal Cutting ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Cutting Process ◽  
Optimization Strategy ◽  
First Time

The concept of multi-constrained analysis of the cutting process is presented for the first time in the paper. The paper adopts a method to solve an important problem which is how to judge the influence of constrains during the cutting process. The research results are applied for HSS drills for cutting stainless steel. On the basis of the multi-constrained analysis combined with methods of simulations and standard experiments, the optimum methods are provided for structure, coating and cutting parameters of cutting tools. For geometric structure of tools, optimization is to increase thickness of cutting and rake angle. Coating optimization strategy is choosing high temperature hardness and low thermal conductivity coating. Optimization of cutting parameter is to adjust feed fate, then select proper cutting speed. The conclusion of paper is helpful for the cutting optimization.

Effects of Strain Rate and Temperature in Orthogonal Metal Cutting

1966 ◽  
Vol 8 (3) ◽  
pp. 264-275 ◽  
Author(s):  
G. Boothroyd ◽  
J. A. Bailey
Keyword(s):  
Theoretical Analysis ◽  
Strain Rate ◽  
Metal Cutting ◽  
Single Phase ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Rake Angle ◽  
Cutting Process ◽  
Strain Rates ◽  
Continuous Chip

A new theoretical analysis of the orthogonal cutting process is described which is based on the known behaviour of a single phase metal at high strains, strain rates and temperatures. The theoretical analysis applies to the case where a continuous chip is produced under non-lubricated conditions with the absence of a built-up edge on the tool face and indicates the important parameters in the cutting process. The theory is examined experimentally and its validity established. Finally, from a knowledge of the effects of strain rate and temperature on the yield stress of a single phase metal, the theory is used to predict the effects of changes in cutting speed and tool rake angle on the tool forces and geometry of the cutting process. These predictions are compared qualitatively with the results of cutting tests.

Cutting Tool Geometry and Parameters Effects on the Force and Temperature in Turning Steel 1040 Using Finite Element Analysis

2012 ◽  
Vol 548 ◽  
pp. 465-470
Author(s):  
Asaad A. Abdullah ◽  
Usama J. Naeem ◽  
Cai Hua Xiong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Heat Rate ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Tool Geometry ◽  
Element Analysis

In recent years, applications have been proven finite-element method (FEM) in metal-cutting operations to be effective process in the study of cutting and chip formation. In this study, the simulation results are useful for both researchers and machine tool manufacturers for improving the design of cutting parameters. Finite-element analysis (FEA) that used in this study of simulation the cutting parameters and tool geometries effects on the force and temperature in turning AISI 1040. The simulation parameters that used in this study are cutting speed (75 - 300 m/min),feed rate (0.2 mm/rev), cut depth (0.75-1.5 mm), and rake angle (0-20 °). The results of cutting forces were (240 – 520 N), the temperature were (300-420 °C), and the heat rate (14202.3-83772.8 W/mm3) on the cutting edge. The simulation process also show that the increase of cutting speed leads to decrease in the cutting forces, while it has increasing in temperature, and heat rate. Also, the results show that the increase of cutting depth associated increase the cutting force only.

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