Dynamic Stability Analysis for Multi-Flute End Milling

1995 ◽  
Author(s):  
Michael J. Shorr ◽  
Steven Y. Liang
Keyword(s):  
Machine Tool ◽  
Dynamic Stability ◽  
Characteristic Equation ◽  
Cutting Forces ◽  
End Milling ◽  
Machining Process ◽  
Tool Geometry ◽  
Analytical Prediction ◽  
Feedback Model ◽  
Machining System

Abstract This research discusses the methodology of developing a symbolic closed form solution that describes the dynamic stability of multi-flute end milling. A solution of this nature facilitates machine tool design, machining parameter planning, process monitoring, diagnostics, and control. This study establishes a compliance feedback model that describes the dynamic behavior of regenerative chatter for multi-flute tool-work interaction. The model formulates the machining dynamics based upon the interconnecting relationship of the tool geometry convolution and the machining system compliance. The tool geometry convolution characterizes the cutting forces as a function of the process parameters and the material properties, while two independent vibratory modules, the mill tool and the workpiece, represent the machining system compliance. The compliance feedback model allows the development of a corresponding characteristic equation. By investigating the roots of the characteristic equation, this research symbolically expresses the stability of the system as a function of the cutting parameters, the tool geometry, the workpiece geometry, and the vibrational characteristics of the machine tool. Machining experimentation examining the fidelity of the regenerative charter model is discussed. The dynamic cutting forces, cutting vibration, and surface finish of the machining process confirm the validity of the analytical prediction.

Cutting Force Analysis to Determine the Performance of Micro End Milling Process of Silicon Wafer

2007 ◽  
Author(s):  
Rusnaldy ◽  
Tae Jo Ko ◽  
Hee Sool Kim
Keyword(s):  
Cutting Force ◽  
Silicon Wafer ◽  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Tool Material ◽  
Machining Process ◽  
Tool Geometry ◽  
Machined Surface ◽  
Micro End Milling

There is a lack of fundamental understanding of micro-end-milling of silicon wafer, specifically basic understanding of material removal mechanism, cutting forces and machined surface integrity in micro scale machining of silicon. It is necessary to determine the forces generated during the cutting operation due to chip thickness along with tool geometry, tool material properties and workpiece properties because cutting forces will provide vital information for the design, modeling and control of the machining process. In this study, cutting force data can be used to determine cutting regime machining of silicon wafer.

The Study of Cutting Forces About Dynamic Stability of Milling Machine Tools

2008 ◽  
Author(s):  
Petru A. Pop
Keyword(s):  
Machine Tool ◽  
Cutting Force ◽  
Dynamic Stability ◽  
Cutting Forces ◽  
Machine Tools ◽  
Cutting Process ◽  
Depth Of Cut ◽  
Milling Machine ◽  
Dynamic Tests ◽  
Machining System

The paper has presented a study of cutting forces about dynamic stability of milling machine tools. For that has required the analysis of dynamic machining system (DMS), represented by the interaction between elastic structure of machine tool and cutting process. The cutting force occurred during cutting process is dependent by a certain factors as thickness cut, physics-mechanics properties of workpiece, geometry of shaped edge tool, etc. An important factor, which has direct influenced about DMS, is present of vibration, in special at chatter frequency due to real perturbation and damages of DMS. The magnitude of cutting force depends largely on the tool-work engagement and depth of cut. The dynamic installation has used for study of milling cutting process assured the acquisition of vibration and cutting force on each three axes of milling machine tool. The calculus and interpretation of dynamic tests had done by MATLAB R14.v7.01 Program. Dynamic tests have been more that 150 recordings, by variation of cutting depth for each spindle speeds of machine until occurring chatter. It had used for testing four milling cutters with different geometric parameters and differential pitch of cutter. These dynamic tests are emphasizing the direct influences of cutting forces about dynamic machining system. Thus, by reducing, the magnitude of cutting forces due to suppressing the vibrations and implicit enhanced the dynamic stability of milling machine and quality of machining workpiece.

scholarly journals Analysis of chip formation and cutting forces in end milling AISI D2 tool steel with different cutting tool geometries

2018 ◽  
Vol 178 ◽  
pp. 01016
Author(s):  
Irina Beşliu ◽  
Dumitru Amarandei ◽  
Delia Cerlincă
Keyword(s):  
Cutting Force ◽  
Tool Steel ◽  
Chip Formation ◽  
Cutting Forces ◽  
Cutting Tool ◽  
End Milling ◽  
Great Influence ◽  
Tool Geometry ◽  
Aisi D2 ◽  
Aisi D2 Tool Steel

The purpose of this study was to investigate and establish the correlations between milling tool geometry, cutting conditions, as input factors and the cutting forces variations and chips formation, as output factors when end milling of AISI D2 tool steel. The experiments were carried out using a Taguchi design array. The chip shape and microstructure and cutting force components were analyzed. The results of the study show that the cutting tool geometry has a great influence over segmented chip formation mechanism and cutting force levels.

scholarly journals Modified Mechanistic Model Based on Gaussian Process Adjusting Technique for Cutting Force Prediction in Micro-End Milling

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Xiaoping Liao ◽  
Zhenkun Zhang ◽  
Kai Chen ◽  
Kang Li ◽  
Junyan Ma ◽  
...  
Keyword(s):  
Gaussian Process ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Mechanistic Model ◽  
Machining Process ◽  
Mechanistic Models ◽  
Machining Processes ◽  
Model Based ◽  
Micro End Milling

Micro-end milling is in common use of machining micro- and mesoscale products and is superior to other micro-machining processes in the manufacture of complex structures. Cutting force is the most direct factor reflecting the processing state, the change of which is related to the workpiece surface quality, tool wear and machine vibration, and so on, which indicates that it is important to analyze and predict cutting forces during machining process. In such problems, mechanistic models are frequently used for predicting machining forces and studying the effects of various process variables. However, these mechanistic models are derived based on various engineering assumptions and approximations (such as the slip-line field theory). As a result, the mechanistic models are generally less accurate. To accurately predict cutting forces, the paper proposes two modified mechanistic models, modified mechanistic models I and II. The modified mechanistic models are the integration of mathematical model based on Gaussian process (GP) adjustment model and mechanical model. Two different models have been validated on micro-end-milling experimental measurement. The mean absolute percentage errors of models I and II are 7.76% and 6.73%, respectively, while the original mechanistic model’s is 15.14%. It is obvious that the modified models are in better agreement with experiment. And model II performs better between the two modified mechanistic models.

FINITE ELEMENT CHIP FORMATION ANALYSIS FOR HIGH SPEED MILLING OPERATIONS

2008 ◽  
Vol 32 (3-4) ◽  
pp. 513-522
Author(s):  
Usama Umer ◽  
Lijing Xie ◽  
Xibin Wang
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
High Speed ◽  
End Milling ◽  
Element Model ◽  
Hardened Steel ◽  
Tool Geometry ◽  
Successful Implementation ◽  
Flat Bottom ◽  
Milling Operations

High speed end milling of hardened steel offers several advantages over EDM in die/molds applications especially due to recent development in machine tools, spindles and controllers. However successful implementation of this technology is limited mainly due to faster tool wear and undesirable surface properties. Finite element modeling and simulation techniques are capable of optimizing the cutting conditions and tool geometry by predicting the temperature and stresses distributions. In this study a finite element model has been developed to predict cutting forces, temperature and stresses distributions in flat end milling processes of hardened steel using PCBN at high cutting speeds. High speed end milling experiments were conducted using flat bottom end mills with single insert having straight cutting edge. Comparison of simulated and experimental cutting forces data shows reasonable agreement at high speed regime using the developed model.

Special Issue on Machining of CFRP Composites

2016 ◽  
Vol 10 (3) ◽  
pp. 299-299
Author(s):  
Akira Hosokawa
Keyword(s):  
Carbon Fiber ◽  
Cooling System ◽  
End Milling ◽  
High Strength ◽  
Machining Process ◽  
Abrasive Waterjet ◽  
Tool Geometry ◽  
Fiber Reinforced ◽  
Special Issue ◽  
Cfrp Composites

There is a growing need for carbon-fiber-reinforced plastics (CFRP/CFRTP/GFRP) inthe aircraft, aerospace, and automotive industries due to their high strength-to-weightratio, high rigidity, and other features. Using these outstanding composites as machinecomponents requires machining with the desired configuration, accuracy, and surfaceintegrity. However, due to the composite structure of high-strength carbon fiber and theadhesive plastics, CFRP is difficult to machine without causing spalling or delamination,fluffing, fiber pullout, thermal degradation of the matrix resin, or other kinds of surfaceor subsurface damage. Rapid tool wear is also a serious problem that varies with thefiber orientation of the CFRP. In order to avoid these problems, various innovative or careful approaches have beentaken in drilling, trimming by milling, sawing, and grinding CFRP. Non-traditional machiningtechniques, including the use of abrasive waterjets, have been employed. Inthese techniques, the machining process, tool geometry, cooling system, and other machiningparameters are optimized. In addition, the influence of surface integrity on thetensile and/or fatigue strength or on other mechanical properties of CFRP has also drawninterest. In addition, regarded as a “machining process” in a broad sense, the press formingof continuous fiber reinforced thermoplastic (CFRTP) sheets is a promising techniqueused in the manufacture of structural components. In CFRTP forming, the effects thatfiber layout naturally have on the deformation mechanisms must be understood, andtemperature, pressure, speed, and stroke control should be optimized. This special issue consists of twelve recent, high-quality research articles related to themachining of CFRP composite materials. These articles include one review and eleventechnical papers on the topics of drilling, end milling, abrasive waterjet machining, andforming. The editors would like to express our deep appreciation to all the authors fortheir invaluable submissions and to the anonymous reviewers for their earnest efforts.Without these, this special issue could not have been published. We hope that furtherresearch on the machining of CFRP composites will make advances inspired by thisspecial issue.

COMPLEXITY-BASED ANALYSIS OF THE INFLUENCE OF TOOL GEOMETRY ON CUTTING FORCES IN ROUGH END MILLING

Fractals ◽  
2018 ◽  
Vol 26 (05) ◽  
pp. 1850078 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Fractal Structure ◽  
End Milling ◽  
Complex Structure ◽  
Tool Geometry ◽  
Machining Parameters ◽  
End Mill ◽  
Force Signal ◽  
Machining Operations

It is known that geometry of cutting tool affects the cutting forces in machining operations. In addition, the value of cutting forces changes during machining operations and creates a chaotic time series (signal). In this paper, we analyze the variations of the complex structure of cutting force signal in rough end milling operation using fractal theory. In fact, we analyze the variations of cutting force signal due to variations of tool geometry (square end mill versus serrated end mill). In case of each type of end mill, we did the machining operation in wet and dry conditions. Based on the results, the fractal structure of cutting force signal changes based on the type of milling tool. We also did the complexity analysis using approximate entropy to check the variations of the complexity of cutting force signal, where the similar behavior of variations between different conditions was obtained. The method of analysis that was used in this research can be applied to other machining operations to study the influence of different machining parameters on variations of fractal structure of cutting force.

Calibration of a Milling Force Model Using Feed and Spindle Power Sensors

2008 ◽  
Author(s):  
Bryan Javorek ◽  
Barry K. Fussell ◽  
Robert B. Jerard
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Machining Process ◽  
Force Model ◽  
Cutting Force Model ◽  
Drive Power ◽  
Average Force ◽  
Force Monitoring ◽  
Milling Force Model

Changes in cutting forces during a milling operation can be associated with tool wear and breakage. Accurate monitoring of these cutting forces is an important step towards the automation of the machining process. However, direct force sensors, such as dynamometers, are not practical for industry application due to high costs, unwanted compliance, and workspace limitations. This paper describes a method in which power sensors on the feed and spindle motors are used to generate coefficients for a cutting force model. The resulting model accurately predicts the X and Y cutting forces observed in several simple end-milling tests, and should be capable of estimating both the peak and average force for a given cut geometry. In this work, a dynamometer is used to calibrate the feed drive power sensor and to measure experimental cutting forces for verification of the cutting force model. Measurement of the average x-axis cutting forces is currently presented as an off-line procedure performed on a sacrificial block of material. The potential development of a continuous, real-time force monitoring system is discussed.

Cutting Force and Friction Modelling in High Speed End-Milling

2015 ◽  
Author(s):  
Sunday J. Ojolo ◽  
Olumuwiya Agunsoye ◽  
Oluwole Adesina ◽  
Gbeminiyi M. Sobamowo
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Cutting Forces ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Tool ◽  
End Milling ◽  
Cutting Process ◽  
Machining Process ◽  
Work Piece

Temperature field in metal cutting process is one of the most important phenomena in machining process. Temperature rise in machining directly or indirectly determines other cutting parameters such as tool life, tool wear, thermal deformation, surface quality and mechanics of chip formation. The variation in temperature of a cutting tool in end milling is more complicated than any other machining operation especially in high speed machining. It is therefore very important to investigate the temperature distribution on the cutting tool–work piece interface in end milling operation. The determination of the temperature field is carried out by the analysis of heat transfer in metal cutting zone. Most studies previously carried out on the temperature distribution model analysis were based on analytical model and with the used of conventional machining that is continuous cutting in nature. The limitations discovered in the models and validated experiments include the oversimplified assumptions which affect the accuracy of the models. In metal cutting process, thermo-mechanical coupling is required and to carry out any temperature field determination successfully, there is need to address the issue of various forces acting during cutting and the frictional effect on the tool-work piece interface. Most previous studies on the temperature field either neglected the effect of friction or assumed it to be constant. The friction model at the tool-work interface and tool-chip interface in metal cutting play a vital role in influencing the modelling process and the accuracy of predicted cutting forces, stress, and temperature distribution. In this work, mechanistic model was adopted to establish the cutting forces and also a new coefficient of friction was also established. This can be used to simulate the cutting process in order to enhance the machining quality especially surface finish and monitor the wear of tool.

Real-Time Cutting Force Prediction and Cutting Force Coefficient Determination during Machining Processes

2011 ◽  
Vol 223 ◽  
pp. 85-92 ◽  
Author(s):  
Balázs Tukora ◽  
Tibor Szalay
Keyword(s):  
Cutting Force ◽  
Real Time ◽  
Cutting Forces ◽  
End Milling ◽  
Orthogonal Cutting ◽  
Machining Process ◽  
Work Piece ◽  
Processing Unit ◽  
Cutting Force Prediction ◽  
Force Prediction

In this paper a new method for instantaneous cutting force prediction is presented, in case of sculptured surface milling. The method is executed in a highly parallel manner by the general purpose graphics processing unit (GPGPU). As opposed to the accustomed way, the geometric information of the work piece-cutter touching area is gained directly from the multi-dexel representation of the work-piece, which lets us compute the forces in real-time. Furthermore a new procedure is introduced for the determination of the cutting force coefficients on the basis of measured instantaneous or average orthogonal cutting forces. This method can determine the shear and ploughing coefficients even while the cutting geometry is continuously altering, e.g. in the course of multi-axis machining. In this way the cutting forces can be predicted during the machining process without a priori knowledge of the coefficients. The proposed methods are detailed and verified in case of ball-end milling, but the model also enables the applying of general-end cutters.

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