A Feature-Based Approach for Cutter/Workpiece Engagement Calculation in 2-1/2D End Milling

2006 ◽  
Author(s):  
Jue Wang ◽  
Derek Yip-Hoi
Keyword(s):  
Process Modeling ◽  
Cutting Forces ◽  
End Milling ◽  
Process Models ◽  
Machining Process ◽  
Geometric Invariant ◽  
Machining Features ◽  
Virtual Machining ◽  
Feature Based ◽  
Intersection Geometry

Machining process modeling requires cutter/workpiece engagement geometry in order to predict cutting forces. The calculation of these engagements is challenging due to the complicated and changing intersection geometry that occurs between the cutter and the in-process workpiece. Solid modelers can be used to perform these calculations by executing intersection operations between cutter and workpiece surfaces at successive cutter locations. These operations utilize parametric surface/surface intersection (SSI) algorithms. For the large number of engagements that can occur in machining a complicated workpiece this can be a time-consuming and sometimes unreliable process. In this paper, in-process machining features are introduced into machining process modeling for 2 1/2 D end milling, and a feature based approach is presented for addressing the computational complexity and robustness issues in the cutter/workpiece engagement calculations. Geometric Invariant (giF) and Form Invariant Machining Features (fiF) are modeled to help represent engagement conditions analytically. Volume decomposition and composition algorithms are described that extract these two types of machining features from the removal volumes generated at each tool pass. Cutter/workpiece engagements can be analytically extracted from giFs and fiFs without applying repetitive SSI operations. This paper presents one part of ongoing collaborative research into developing Virtual Machining Systems. The engagement conditions that are found are inputs to machining process models that identify cutting forces, predict stability and that optimize the process.

Analysis of Cutting Force in Elastomer End-Milling

2017 ◽  
Vol 11 (6) ◽  
pp. 958-963
Author(s):  
Koji Teramoto ◽  
◽  
Takahiro Kunishima ◽  
Hiroki Matsumoto
Keyword(s):  
Parameter Identification ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Process Models ◽  
Force Model ◽  
Cutting Force Model ◽  
Cutting Force Prediction ◽  
Force Prediction ◽  
The Stability

Elastomer end-milling is attracting attention for its role in the small-lot production of elastomeric parts. In order to apply end-milling to the production of elastomeric parts, it is important that the workpiece be held stably to avoid deformation. To evaluate the stability of workholding, it is necessary to predict cutting forces in elastomer end-milling. Cutting force prediction for metal workpiece end-milling has been investigated for many years, and many process models for end-milling have been proposed. However, the applicability of these models to elastomer end-milling has not been discussed. In this paper, the characteristics of the cutting force in elastomer end-milling are evaluated experimentally. A standard cutting force model and its parameter identification method are introduced. By using this cutting force model, measured cutting forces are compared against the calculated results. The comparison makes it clear that the standard cutting force model for metal end-milling can be applied to down milling for a rough evaluation.

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.

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.

Machining Feature Modeling and Process Intermediate Model Generation in Process Planning

2013 ◽  
Author(s):  
Xu Zhang ◽  
Chao Liang ◽  
Tiedong Si ◽  
Ding Ding
Keyword(s):  
Process Planning ◽  
Feature Recognition ◽  
3D Models ◽  
Machining Process ◽  
Model Generation ◽  
Machining Features ◽  
Intermediate Model ◽  
Machining Feature ◽  
Feature Based ◽  
Solid Modeler

In process planning of machined part, machining feature recognition and representation, feature-based generative process planning, and the process intermediate model generation are the key issues. While many research results have been achieved in recent years, the complete modeling of machining features, process operations, and the 3D models in process planning are still need further research to make the techniques to be applied in practical CAPP systems. In this paper, a machining feature definition and classification method is proposed for the purpose of process planning based on 3D model. Machining features are defined as the surfaces formed by a serious of machining operation. The classification scheme of machining features is proposed for the purpose of feature recognition, feature-based machining operations reasoning, and knowledge representation. Recognized from B-Rep representation of design model, machining features are represented by adjacent graph and organized by feature relations. The machining process plan is modeled as operations and steps, which is the combination and sequencing of machining feature’s process steps. The process intermediate models (PIM) are important for process documentation, analysis and NC programming. An automatic PIM generation approach is proposed using local operations directly on B-Rep model. The proposed data structure and algorithm is adopted in the development of CAPP tool on solid modeler ACIS/HOOPS.

Identification of Cutting Shear Stress, Shear and Friction Angles Using Flat End Milling Tests

2016 ◽  
Vol 836-837 ◽  
pp. 112-116 ◽  
Author(s):  
Min Wan ◽  
Wen Jie Pan ◽  
Wei Hong Zhang
Keyword(s):  
Shear Stress ◽  
Cutting Forces ◽  
High Speed ◽  
End Milling ◽  
Local System ◽  
Milling Process ◽  
Transformation Model ◽  
Machining Process ◽  
Flat End Milling ◽  
Cartesian Coordinate

Orthogonal-to-oblique transformation model, which is formulated based on the cutting database including shear stress, shear and friction angles, can be used to predict cutting forces in high speed milling process and any other machining process. The involved shear stress, shear and friction angles are traditionally identified from abundant number of turning experiments. For the purpose of saving experimental cost, this paper presents a novel method to identify these parameters directly from flat end milling processes. Identification procedures are established by transforming the cutting forces measured in Cartesian coordinate system into a local system. The advantage lies in that in spite of the cutter geometries and cutting conditions, only a few tests are required to develop the model, which is experimentally validated to be effective for predicting the cutting force in terms of magnitude and shape in other machining cases.

Study on Virtual Machining Process of Peripheral Milling of Thin-Walled Workpiece

2014 ◽  
Vol 941-944 ◽  
pp. 1937-1942
Author(s):  
Yuan Xiang Liu ◽  
Feng Chen ◽  
Chu Jun Liang
Keyword(s):  
Milling Process ◽  
Process Models ◽  
Machining Process ◽  
Peripheral Milling ◽  
Machined Surface ◽  
Element Analysis ◽  
Dimensional Error ◽  
Virtual Machining ◽  
Thin Walled ◽  
Time Required

Thin-walled workpiece is easy to deform in machining. In order to predict the dimensional error of machined surface of thin-walled workpiece, computer simulation technology is studied, which is called virtual machining process. For the simulation of workpiece deformation, much numerical analysis should be done. Research indicates using FEA (Finite Element Analysis) in each step of simulation process needs too much time to meet the requirements of industrial application. Therefore it is important to decrease the simulation time. In this paper, a new method is proposed to realize rapid analysis of workpiece deflection in virtual machining process, which combines rapid analytical solution method with a few times of accurate FEA, thus greatly decreases the time required for whole simulation. For the simulation, several peripheral milling process models are presented with increasing order of sophistication and accuracy, which can be applied to simulate cutting process with the effect of workpiece deformation caused by cutting force. In the final section, the comparison between simulation results and experiments shows the proposed methods and models can closely predict dimensional error and texture of machined surface of flexible workpiece.

Investigation of experimental study of end milling of CFRP composite

2015 ◽  
Vol 22 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Erol Kiliçkap ◽  
Ahmet Yardimeden ◽  
Yahya Hışman Çelik
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Feed Rate ◽  
Cutting Forces ◽  
End Milling ◽  
Cutting Speed ◽  
Machining Process ◽  
Cnc Milling ◽  
End Mill ◽  
Cfrp Composite

AbstractCarbon fiber-reinforced plastic (CFRP) composites are materials that are difficult to machine due to the anisotropic and heterogeneous properties of the material and poor surface quality, which can be seen during the machining process. The machining of these materials causes delamination and surface roughness owing to excessive cutting forces. This causes the material not to be used. The reduction of damage and surface roughness is an important aspect for product quality. Therefore, the experimental study carried out on milling of CFRP composite material is of great importance. End milling tests were performed at CNC milling vertical machining center. In the experiments, parameters considered for the end milling of CFRP were cutting speed, feed rate, and flute number of end mill. The results showed that damage, surface roughness, and cutting forces were affected by cutting parameters and flute number of end mill. The best machining conditions were achieved at low feed rate and four-flute end mill.

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.

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