Analytical predictions and experimental validation of cutting force ratio, chip thickness, and chip back-flow angle in restricted contact machining using the universal slip-line model

2002 ◽  
Vol 42 (6) ◽  
pp. 681-694 ◽  
Author(s):  
N. Fang ◽  
I.S. Jawahir
Keyword(s):  
Cutting Force ◽  
Slip Line ◽  
Experimental Validation ◽  
Chip Thickness ◽  
Line Model ◽  
Flow Angle ◽  
Back Flow ◽  
Force Ratio

Analytical Prediction of the Chip Back-Flow Angle in Machining With Restricted Contact Grooved Tools

2003 ◽  
Vol 125 (2) ◽  
pp. 210-219 ◽  
Author(s):  
N. Fang ◽  
I. S. Jawahir
Keyword(s):  
High Speed ◽  
Experimental Validation ◽  
Chip Thickness ◽  
Interfacial Stress ◽  
Tool Geometry ◽  
Analytical Prediction ◽  
Flow Angle ◽  
Back Flow ◽  
Definition Of ◽  
The Given

This paper develops a new analytical model to predict the chip back-flow angle in machining with restricted contact grooved tools. The model is derived from a recently established universal slip-line model for machining with restricted contact cutaway tools. A comprehensive definition of the chip back-flow angle is presented first, and based on this, a quantitative analysis of the chip back-flow effect is established for a given set of cutting conditions, tool geometry, and variable tool-chip interfacial stress state. The model also predicts the cutting forces, the chip thickness, and the chip up-curl radius. A full experimental validation of the analytical predictive model involving the use of high speed filming technique is then presented for the chip back-flow angle. This validation provides a range of feasible/prevalent tool-chip interfacial frictional conditions for the given set of input conditions.

Prediction of Chip Back-Flow Angle in Machining With Restricted Contact Grooved Tools

2000 ◽  
Author(s):  
N. Fang ◽  
I. S. Jawahir
Keyword(s):  
Predictive Model ◽  
High Speed ◽  
Experimental Validation ◽  
Chip Thickness ◽  
Interfacial Stress ◽  
Tool Geometry ◽  
Flow Angle ◽  
Back Flow ◽  
Definition Of ◽  
The Given

Abstract This paper presents a new predictive model for chip back-flow angle in machining with restricted contact grooved tools. This model is derived from the recently established universal slip-line model for machining with restricted contact cut-away tools. A comprehensive definition of the chip back-flow angle is first developed, and based on this, a quantitative analysis of the effect of chip back-flow is presented for the given set of cutting conditions, tool geometry and variable tool-chip interfacial stress state. This model also predicts cutting forces, chip thickness ratio and chip up-curl radius. A full experimental validation of the predictive model involving the use of high speed filming techniques is then presented for chip back-flow angle and this validation provides a range of feasible/prevalent tool-chip interfacial frictional conditions for a given set of input conditions.

A Quantitative Sensitivity Analysis of Cutting Performances in Orthogonal Machining with Restricted Contact and Flat-Faced Tools

2004 ◽  
Vol 126 (2) ◽  
pp. 408-411
Author(s):  
Ning Fang
Keyword(s):  
Sensitivity Analysis ◽  
Slip Line ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Contact Length ◽  
Machining Parameters ◽  
Flow Angle ◽  
Orthogonal Machining ◽  
Different Types ◽  
Machining Operations

This paper presents a new quantitative sensitivity analysis of cutting performances in orthogonal machining with restricted contact and flat-faced tools, based on a recently developed slip-line model. Cutting performances are comprehensively measured by five machining parameters, i.e., the cutting forces, the chip back-flow angle, the chip up-curl radius, the chip thickness, and the tool-chip contact length. It is demonstrated that the percentage of contribution of tool-chip friction to the variation of cutting performances depends on different types of machining operations. No general conclusion about the effect of tool-chip friction should be made before specifying a particular type of machining operation and cutting conditions.

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.

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.

scholarly journals Correction and accuracy improvement of non-parallel shear zone model

2018 ◽  
Vol 207 ◽  
pp. 02002
Author(s):  
Yaoke Wang ◽  
Meng Kou ◽  
Wei Ding ◽  
Huan Ma ◽  
Liangshan Xiong
Keyword(s):  
Experimental Data ◽  
Cutting Force ◽  
Shear Zone ◽  
Coordinate Transformation ◽  
Chip Thickness ◽  
Zone Model ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
Experimental Values ◽  
1045 Steel

When applying the non-parallel shear zone model to predict the cutting process parameters of carbon steel workpiece, it is found that there is a big error between the prediction results and the experimental values. And also, the former approach to obtain the relevant cutting parameters of the non-parallel shear zone model by applying coordinate transformation to the parallel shear zone model has a theoretical error – it erroneously regards the determinant (|J|) of the Jacobian matrix (J) in the coordinate transformation as a constant. The shape of the shear zone obtained when |J| is not constant is drew and it is found that the two boundaries of the shear zone are two slightly curved surfaces rather than two inclined planes. Also, the error between predicted values and experimental values of cutting force and cutting thrust is slightly smaller than that of constant |J|. A corrected model where |J| is a variable is proposed. Since the specific values of inclination of the shear zone (α, β), the thickness coefficient of the shear zone (as) and the constants related to the material (f0, p) are not given in the former work, a method to obtain the above-mentioned five constants by solving multivariable constrained optimization problem based on experimental data was also proposed; based on the obtained experimental data of AISI 1045 steel workpiece cutting force, cutting thrust, chip thickness, the results of five above-mentioned model constants are obtained. It is found that, compared with prediction from uncorrected model, the cutting force and cutting thrust of AISI 1045 steel predicted by the corrected model with the obtained constants has a better agreement with the experimental values obtained by Ivester.

Predictive Modeling of Nonlinear Regenerative Chatter via Measurement, Analysis, and Simulation

1999 ◽  
Author(s):  
J. R. Pratt ◽  
M. A. Davies ◽  
M. D. Kennedy ◽  
T. Kalmár-Nagy
Keyword(s):  
Cutting Force ◽  
Initial Conditions ◽  
Stability Boundary ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Computational Techniques ◽  
Regenerative Chatter ◽  
Stability Lobe ◽  
Measurement Analysis ◽  
On Chip

Abstract A single-degree-of-freedom active cutting fixture is employed to reveal and analyse the hysteretic nature of the lobed stability boundary in a simple machining experiment. Specifically, the seventh stability lobe of a regenerative cutting process is mapped using experimental, analytical, and computational techniques. Then, taking width of cut as a control parameter, the transition from stable cutting to chatter is observed experimentally. The cutting stability is found to possess a substantial hysteresis so that either stable or chattering tool motions can exist at the same nominal cutting parameters, depending on initial conditions. This behavior is predicted by applying nonlinear regenerative chatter theory to an empirical characterization of the cutting force dependence on chip thickness. Time-domain simulations that incorporate both the nonlinear cutting force dependence on chip thickness and the multiple-regenerative effect due to the tool leaving the cut are shown to agree both qualitatively and quantitatively with experiment.

Analysis of the effect of tool posture on stability considering the nonlinear dynamic cutting force coefficient

2021 ◽  
pp. 1-19
Author(s):  
Zepeng Li ◽  
Rong Yan ◽  
Xiaowei Tang ◽  
Fang Yu Peng ◽  
Shihao Xin ◽  
...  
Keyword(s):  
Cutting Force ◽  
Nonlinear Dynamic ◽  
Chip Thickness ◽  
Cutting Depth ◽  
Force Coefficient ◽  
Critical Cutting Depth ◽  
Dynamic Cutting Force ◽  
Cutting Force Coefficient ◽  
Tool Posture ◽  
Instantaneous Uncut Chip Thickness

Abstract In aviation and navigation, complicated parts are milled with high-speed low-feed-per-tooth milling to decrease tool vibration for high quality. Because the nonlinearity of the cutting force coefficient (CFC) is more evident with the relatively smaller instantaneous uncut chip thickness, the stable critical cutting depth and its distribution against different tool postures are affected. Considering the nonlinearity, a nonlinear dynamic CFC model that reveals the effect of the dynamic instantaneous uncut chip thickness on the dynamic cutting force is derived based on the Taylor expansion. A five-axis bull-nose end milling dynamics model is established with the nonlinear dynamic CFC model. The stable critical cutting depth distribution with respect to tool posture is analyzed. The stability results predicted with the dynamic CFC model are compared with those from the static CFC model and the constant CFC model. The effects of tool posture and feed per tooth on stable critical cutting depth were also analyzed, and the proposed model was validated by cutting experiments. The maximal stable critical cutting depths that can be achieved under different tool postures by feed per tooth adjustment were calculated, and corresponding distribution diagrams are proposed for milling parameter optimization.

In-Process Prediction of Surface Roughness in Grinding Process by Monitoring of Cutting Force Ratio

2014 ◽  
Vol 627 ◽  
pp. 29-34 ◽  
Author(s):  
Vichaya Thammasing ◽  
Somkiat Tangjitsitcharoen
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Spindle Speed ◽  
Least Square ◽  
Depth Of Cut ◽  
Grinding Process ◽  
Average Surface Roughness ◽  
Average Surface ◽  
Developed Surface ◽  
Force Ratio

The purpose of this research is to develop the models to predict the average surface roughness and the surface roughness during the in-process grinding by monitoring the cutting force ratio. The proposed models are developed based on the experimentally obtained results by employing the exponential function with four factors, which are the spindle speed, the feed rate, the depth of cut, and the cutting force ratio. The experimentally obtained results showed that the dimensionless cutting force ratio is usable to predict the surface roughness during the grinding process, which can be calculated and obtained by taking the ratio of the corresponding time records of the cutting force Fy in the spindle speed direction to that of the cutting force Fz in the radial wheel direction. The multiple regression analysis is utilized to calculate the regression coefficients with the use of the least square method at 95% confident level. The experimentally obtained models have been verified by the new cutting tests. It is proved that the developed surface roughness models can be used to predict the in-process surface roughness with the high accuracy of 93.9% for the average surface roughness and 92.8% for the surface roughness.

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