SLIP-LINE MODELING OF MACHINING AND DETERMINE THE INFLUENCE OF RAKE ANGLE ON THE CUTTING FORCE

2012 ◽  
Vol 36 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Sabri Ozturk
Keyword(s):  
Cutting Force ◽  
Slip Line ◽  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Uncut Chip Thickness ◽  
Thrust Forces ◽  
Model Approach

In this study, the effects of the rake angle on main cutting force (Fc), and thrust forces (Ft) was investigated. A new slip line model approach for modelling the orthogonal cutting process was proposed. This model was applied at negative rake angles from 0° to –60° and consists of three regions. The main forces were measured with a computer aided quick stop device. Variance Analysis (ANOVA) was utilized to analyze the effects of the cutting parameters on cutting and thrust forces accordingly. Multi-variable regression analysis was also employed to determine the correlations between the factors and the cutting forces. The cutting forces could be calculated by equation parameters which are the rake angle and the uncut chip thickness.

scholarly journals A Slip-Line Field for Ploughing During Orthogonal Cutting

1998 ◽  
Vol 120 (4) ◽  
pp. 693-699 ◽  
Author(s):  
D. J. Waldorf ◽  
R. E. DeVor ◽  
S. G. Kapoor
Keyword(s):  
Slip Line ◽  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Great Promise ◽  
Uncut Chip Thickness ◽  
Workpiece Material ◽  
Line Field ◽  
Slip Line Field ◽  
Edge Radius

Under normal machining conditions, the cutting forces are primarily due to the bulk shearing of the workpiece material in a narrow zone called the shear zone. However, under finishing conditions, when the uncut chip thickness is of the order of the cutting edge radius, a ploughing component of the forces becomes significant as compared to the shear forces. Predicting forces under these conditions requires an estimate of ploughing. A slip-line field is developed to model the ploughing components of the cutting force. The field is based on other slip-line fields developed for a rigid wedge sliding on a half-space and for negative rake angle orthogonal cutting. It incorporates the observed phenomena of a small stable build-up of material adhered to the edge and a raised prow of material formed ahead of the edge. The model shows how ploughing forces are related to cutter edge radius—a larger edge causing larger ploughing forces. A series of experiments were run on 6061-T6 aluminum using tools with different edge radii—including some exaggerated in size—and different levels of uncut chip thickness. Resulting force measurements match well to predictions using the proposed slip-line field. The results show great promise for understanding and quantifying the effects of edge radius and worn tool on cutting forces.

Forces in Green Micromachining of Ceramics: An Experimental Investigation on Micromachining of Aluminum Nitride

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Recep Onler ◽  
Sundar V. Atre ◽  
O. Burak Ozdoganlar
Keyword(s):  
Cutting Forces ◽  
Metal Cutting ◽  
Diamond Tool ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Powder Injection ◽  
Uncut Chip Thickness ◽  
Green State ◽  
Single Crystal Diamond ◽  
Thrust Forces

This paper presents an investigation of green micromachining (GMM) forces during orthogonal micromachining green-state AlN ceramics. Green-state ceramics contain ceramic powders within a binder; processed samples are subsequently debound and sintered to obtain solid ceramic parts. An effective approach to create microscale features on ceramics is to use mechanical micromachining when the ceramics are at their green state. This approach, referred to as GMM, considerably reduces the forces and tool wear with respect to micromachining of sintered ceramics. As such, fundamental understanding on GMM of ceramics is critically needed. To this end, in this work, the force characteristics of powder injection molded AlN ceramics with two different binder states were experimentally investigated via orthogonal cutting. The effects of micromachining parameters on force components and specific energies were experimentally identified for a tungsten carbide (WC) and a single crystal diamond tools. As expected, the thrust forces were seen to be significantly larger than the cutting forces at low uncut chip thicknesses when using the carbide tool with its large edge radius. The cutting forces are found to be more sensitive to uncut chip thickness than the thrust forces are. When a sharp diamond tool is used, cutting forces are significantly larger than the thrust forces even for small uncut chip thicknesses. The specific energies follow an exponential decrease with increasing uncut chip thickness similar to the common trends in metal cutting. However, due to interaction characteristics between cutting edge and ceramic particles in the green body, evidence of plowing and rubbing along the cutting region was observed even with a sharp diamond tool.

scholarly journals Stochastic modeling of the cutting force in turning processes

2020 ◽  
Vol 111 (1-2) ◽  
pp. 213-226
Author(s):  
Gergő Fodor ◽  
Henrik T Sykora ◽  
Dániel Bachrathy
Keyword(s):  
Stochastic Processes ◽  
Cutting Force ◽  
Orthogonal Cutting ◽  
Gaussian White Noise ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Force Model ◽  
Noise Component ◽  
Average Value

Abstract The main goal of this study is to introduce a stochastic extension of the already existing cutting force models. It is shown through orthogonal cutting force measurements how stochastic processes based on Gaussian white noise can be used to describe the cutting force in material removal processes. Based on these measurements, stochastic processes were fitted on the variation of the cutting force signals for different cutting parameters, such as cutting velocity, chip thickness, and rake angle. It is also shown that the variance of the measured force signal is usually around 4–9% of the average value, which is orders of magnitudes larger than the noise originating from the measurement system. Furthermore, the force signals have Gaussian distribution; therefore, the cutting force model can be extended by means of a multiplicative noise component.

Experimental investigation of a slip-line field model for a worn cutting tool

2013 ◽  
Vol 228 (8) ◽  
pp. 1398-1404 ◽  
Author(s):  
Alper Uysal ◽  
Erhan Altan
Keyword(s):  
Wear Rate ◽  
Slip Line ◽  
Field Model ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Rake Angle ◽  
Uncut Chip Thickness ◽  
Line Field

In this study, the slip-line field model developed for orthogonal machining with a worn cutting tool was experimentally investigated. Minimum and maximum values of five slip-line angles ( θ1, θ2, δ2, η and ψ) were calculated. The friction forces that were caused by flank wear land, chip up-curl radii and chip thicknesses were calculated by solving the model. It was specified that the friction force increased with increase in flank wear rate and uncut chip thickness and it decreased a little with increase in cutting speed and rake angle. The chip up-curl radius increased with increase in flank wear rate and it decreased with increase in uncut chip thickness. The chip thickness increased with increase in flank wear rate and uncut chip thickness. Besides, the chip thickness increased with increase in rake angle and it decreased with increase in cutting speed.

Virtual Five-Axis Flank Milling of Jet Engine Impellers: Part 1 — Mechanics of Five-Axis Flank Milling

2007 ◽  
Author(s):  
W. Ferry ◽  
Y. Altintas
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Friction Angle ◽  
Flank Milling ◽  
Cutting Force Prediction ◽  
Jet Engine ◽  
End Mills ◽  
Five Axis

Jet engine impeller blades are flank-milled with tapered, helical, ball-end mills on five-axis machining centers. The impellers are made from difficult-to-cut titanium or nickel alloys, and the blades must be machined within tight tolerances. As a consequence, deflections of the tool and flexible workpiece can jeopardize the precision of the impellers during milling. This work is the first of a two part paper on cutting force prediction and feed optimization for the five-axis flank milling of an impeller. In Part I, a mathematical model for predicting cutting forces is presented for five-axis machining with tapered, helical, ball-end mills with variable pitch and serrated flutes. The cutter is divided axially into a number of differential elements, each with its own feed coordinate system due to five-axis motion. At each element, the total velocity due to translation and rotation is split into horizontal and vertical feed components, which are used to calculate total chip thickness along the cutting edge. The cutting forces for each element are calculated by transforming friction angle, shear stress and shear angle from an orthogonal cutting database to the oblique cutting plane. The distributed cutting load is digitally summed to obtain the total forces acting on the cutter and blade. The model can be used for general five-axis flank milling processes, and supports a variety of cutting tools. Predicted cutting force measurements are shown to be in reasonable agreement with those collected during a roughing operation on a prototype integrally bladed rotor (IBR).

A Study of Relation between Roundness and Cutting Force in CNC Turning Process

2015 ◽  
Vol 799-800 ◽  
pp. 366-371 ◽  
Author(s):  
Deuanphan Chanthana ◽  
Somkiat Tangjitsitcharoen
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Turning Process ◽  
Nose Radius ◽  
Cnc Turning ◽  
Cnc Turning Process ◽  
Tool Nose Radius

The roundness is one of the most important criteria to accept the mechanical parts in the CNC turning process. The relations of the roundness, the cutting conditions and the cutting forces in CNC turning is hence studied in this research. The dynamometer is installed on the turret of the CNC turning machine to measure the in-process cutting force signals. The cutting parameters are investigated to analyze the effects of them on the roundness which are the cutting speed, the feed rate, the depth of cut, the tool nose radius and the rake angle. The experimentally obtained results showed that the better roundness is obtained with an increase in cutting speed, tool nose radius and rake angle. The relation between the cutting parameters and the roundness can be explained by the in-process cutting forces. It is understood that the roundness can be monitored by using the in-process cutting forces.

Experimental Investigations of Cutting Parameters Influence on Cutting Forces and Surface Roughness of Quartz Glass

2013 ◽  
Vol 641-642 ◽  
pp. 367-370
Author(s):  
Gui Qiang Liang ◽  
Fei Fei Zhao
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Diamond Wheel ◽  
Experimental Investigations ◽  
Depth Of Cut ◽  
Feed Force

Abstract In the present study, an attempt has been made to investigate the effect of cutting parameters (cutting speed, feed rate and depth of cut) on cutting forces (feed force, thrust force and cutting force) and surface roughness in milling of Quartz glas using diamond wheel. The cutting process in the up-cut milling of glass is discussed and the cutting force measured. The cutting force gradually increases with the cutter rotation at the beginning of the cut, and oscillates about a constant mean value after a certain undeformed chip thickness. The results show that cutting forces and surface roughness do not vary much with experimental cutting speed in the range of 55–93 m/min. The suggested models of cutting forces and surface roughness and adequately map within the limits of the cutting parameters considered.

The Constant Force Component due to Material Separation and Its Contribution to the Size Effect in Specific Cutting Energy

2005 ◽  
Vol 128 (3) ◽  
pp. 811-815 ◽  
Author(s):  
Sathyan Subbiah ◽  
Shreyes N. Melkote
Keyword(s):  
Size Effect ◽  
Cutting Force ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Constant Force ◽  
Specific Cutting Energy ◽  
Force Component ◽  
Uncut Chip Thickness ◽  
Cutting Energy ◽  
Material Separation

The contribution of material separation in cutting ductile metals to the constant force component, and, hence, to the size effect in specific cutting energy is explored in this paper. A force-decomposition-based framework is proposed to reconcile the varied reasons given in literature for the size effect. In this framework, the cutting force is broken down into three components: one that is decreasing, another that is increasing, and the third that remains constant, with decreasing uncut chip thickness. The last component is investigated by performing orthogonal cutting experiments on OFHC copper at high rake angles of up to 70deg in an attempt to isolate it. As the rake angle is increased, the resulting experimental data show a trend toward a constant cutting-force component independent of the uncut chip thickness. Visual evidence of ductile tearing ahead of the tool associated with material separation leading to chip formation is shown. The measured constant force and the force needed for ductile crack extension are then compared.

On Tool Instability During Machining

1991 ◽  
Author(s):  
C. Sahay ◽  
R. N. Dubey
Keyword(s):  
Cutting Force ◽  
Shear Deformation ◽  
Static Analysis ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Uncut Chip Thickness ◽  
Frictional Interaction ◽  
Machining System ◽  
The Relationship

Abstract The present paper describes the role of the tool in vibrations of a machining system. The cutting force has been assumed to be constant. The shear deformation of the tool is considered. The quasi-static analysis of the situation yields a maximum allowable uncut chip thickness, which shows how the frictional interaction at the tool face and the ratio of the components of cutting forces alter this value. The relationship also expresses the effect of tool dimensions and work material on the vibration of the tool.

Determination of Cutting Forces for Micro Milling

2008 ◽  
Author(s):  
Shih-Ming Wang ◽  
Zou-Sung Chiang ◽  
Da-Fun Chen
Keyword(s):  
Cutting Force ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Micro Milling ◽  
Force Model ◽  
Machining Parameters ◽  
Cutting Force Model ◽  
Optimal Cutting Parameters

To enhance the implementation of micro milling, it is necessary to clearly understand the dynamic characteristics of micro milling so that proper machining parameters can be used to meet the requirements of application. By taking the effect of minimum chip thickness and rake angle into account, a new cutting force model of micro-milling which is function the instantaneous cutting area and machining coefficients was developed. According to the instantaneous rotation trajectory of cutting edge, the cutting area projected to xy-plane was determined by rectangular integral method, and used to solve the instantaneous cutting area. After the machining coefficients were solved, the cutting force of micro-milling for different radial depths of cut and different axial depths of cut can be predicted. The results of micro-milling experimental have shown that the force model can predict the cutting force accurately by which the optimal cutting parameters can be selected for micro-milling application.

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