Generation of Milled Surfaces Including Tool Dynamics and Wear

1993 ◽  
Vol 115 (3) ◽  
pp. 245-252 ◽  
Author(s):  
F. Ismail ◽  
M. A. Elbestawi ◽  
R. Du ◽  
K. Urbasik
Keyword(s):  
Tool Wear ◽  
Flank Wear ◽  
Mechanistic Model ◽  
Surface Profile ◽  
Surface Generation ◽  
Profile Error ◽  
Peripheral Milling ◽  
Characteristic Features ◽  
Tool Dynamics ◽  
Good Agreement

In this paper, a mechanistic model for surface generation in peripheral milling, which includes the effects of cutter vibrations, run out, as well as flank wear is presented. The surface roughness parameters, and characteristic features of the surface profile were examined using computer simulations. The results of the simulation runs were verified experimentally and a good agreement was obtained. The results demonstrated clearly the importance of including tool wear in surface generation predictions. It has been shown that the model is capable of predicting the smearing of the surface generated due to increased tool wear. Also, the ploughing force acting on the wear land considered in the model influenced the resulting profile error significantly.

The RMS Characteristics of Acceleration and Force Signals Depending on Tool Wear in Stable Cutting

1999 ◽  
Author(s):  
Richard Y. Chiou ◽  
Y. K. Kwon ◽  
Steven Y. Liang
Keyword(s):  
Tool Wear ◽  
Random Vibration ◽  
Cutting Tool ◽  
Flank Wear ◽  
Mean Square ◽  
Test Results ◽  
Tool Holder ◽  
Theoretical Predictions ◽  
Acceleration Signals ◽  
Good Agreement

Abstract An analysis of the RMS (Root Mean Square) characteristics of fluctuating force and acceleration signals for a cutting tool engaged in a turning operation in the presence of wear flat on the tool flank is presented in this research. The RMS of acceleration and force signals obtained from experiments in stable cutting is compared with theoretical machining models due to the tool wear effect. The RMS is a measure of the energy, at the tool tip-workpiece interface along the flank, to the random vibration of the cantilever portion of the tool holder. Increasing flank wear results in an increasing stability and decreasing RMS in the thrust direction, dependent upon flank wear-land width. The RMS force and acceleration signals in machining is calculated by frequency band RMS method at the first natural frequency of the cantilever portion of the tool holder in the frequency domain. By reference to experimental evidence, the theoretical predictions show generally good agreement with test results.

scholarly journals Global earthworm distribution and activity windows based on soil hydromechanical constraints

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Siul A. Ruiz ◽  
Samuel Bickel ◽  
Dani Or
Keyword(s):  
Soil Structure ◽  
Mechanistic Model ◽  
Biophysical Model ◽  
Ecosystem Functions ◽  
Soil Conditions ◽  
Agricultural Systems ◽  
Occurrence Patterns ◽  
Additional Constraints ◽  
Earthworm Activity ◽  
Good Agreement

AbstractEarthworm activity modifies soil structure and promotes important hydrological ecosystem functions for agricultural systems. Earthworms use their flexible hydroskeleton to burrow and expand biopores. Hence, their activity is constrained by soil hydromechanical conditions that permit deformation at earthworm’s maximal hydroskeletal pressure (≈200kPa). A mechanistic biophysical model is developed here to link the biomechanical limits of earthworm burrowing with soil moisture and texture to predict soil conditions that permit bioturbation across biomes. We include additional constraints that exclude earthworm activity such as freezing temperatures, low soil pH, and high sand content to develop the first predictive global map of earthworm habitats in good agreement with observed earthworm occurrence patterns. Earthworm activity is strongly constrained by seasonal dynamics that vary across latitudes largely due to soil hydromechanical status. The mechanistic model delineates the potential for earthworm migration via connectivity of hospitable sites and highlights regions sensitive to climate.

Cutting Tool Wear and Mechanisms of Chip Formation During High-Speed Machining of Compacted Graphite Iron

2007 ◽  
Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris
Keyword(s):  
Tool Wear ◽  
Surface Finish ◽  
Failure Criterion ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Tools ◽  
Compacted Graphite Iron ◽  
Crater Wear ◽  
Compacted Graphite ◽  
Cutting Speeds

Cutting tool wear of polycrystalline cubic boron nitride (PcBN) tools was investigated in oblique turning experiments when machining compacted graphite iron at high cutting speeds, with the intention of elucidating the failure mechanisms of the cutting tools and presenting an analysis of the chip formation process. Dry finish turning experiments were conducted in a CNC lathe at cutting speeds in the range of 500–800m/min, at a feed rate of 0.05mm/rev and depth of cut of 0.2mm. Two different tool end-of-life criteria were used: a maximum flank wear scar size of 0.3mm (flank wear failure criterion) or loss of cutting edge due to rapid crater wear to a point where the cutting tool cannot machine with an acceptable surface finish (surface finish criterion). At high cutting speeds, the cutting tools failed prior to reaching the flank wear failure criterion due to rapid crater wear on the rake face of the cutting tools. Chip analysis, using SEM, revealed shear localized chips, with adiabatic shear bands produced in the primary and secondary shear zones.

The Analysis of Tool Wear in Milling CFRP with Different Diamond Coated Tool

2015 ◽  
Vol 667 ◽  
pp. 231-236 ◽  
Author(s):  
Xiao Fan Yang ◽  
You Sheng Li ◽  
Guo Hong Yan ◽  
Ju Dong Liu ◽  
Dong Min Yu
Keyword(s):  
Tool Wear ◽  
Flank Wear ◽  
Milling Process ◽  
Cutting Condition ◽  
End Mill ◽  
Reinforced Plastics ◽  
Right Hand ◽  
Coated Tool ◽  
New Type ◽  
Fiber Reinforced Plastics

Carbon fiber-reinforced plastics (CFRP) are typical difficult-to-machine materials, which is easy to produce many defects such as burrs, dilacerations, layering in milling process. And selecting the appropriate cutting tool has become the key to machining CFRP with high quality and efficiency. In the paper, the machining principle of milling CFRP with new type end mill was analyzed. The diamond coating of general right-hand end mill, cross-flute router and fine-cross-nick router were used to cutting CFRP under the same cutting condition. Through the comparative analysis of the workpiece’s surface quality and tool wear, it concluded that: compared with right-hand diamond coated end mill, cross-flute diamond coated router or fine-cross-nick diamond coated router could effectively suppress the appearance of burrs and dilacerations; abnormal coating peeling appeared in the flank face of right-hand diamond coated end mill, forming the boundary wear, which accelerated wear failure; the flank wear of diamond coated cross-flute router and fine-cross-nick router were both abrasive wear. Due to having more cutting edge than cross-flute router in cutting process, the flank wear of fine-cross-nick router was slower, and the tool life was longer. So it was more suitable for cutting CFRP.

Tool Life Analysis when Turning Ti-6Al-4V Using Vegetable Oil-Based Cutting Fluid

2017 ◽  
Vol 882 ◽  
pp. 36-40
Author(s):  
Salah Gariani ◽  
Islam Shyha ◽  
Connor Jackson ◽  
Fawad Inam
Keyword(s):  
Tool Wear ◽  
Tool Life ◽  
Vegetable Oil ◽  
Flank Wear ◽  
Cutting Speed ◽  
Fractional Factorial ◽  
Cutting Fluid ◽  
Depth Of Cut ◽  
Tool Flank Wear ◽  
Fluid Concentration

This paper details experimental results when turning Ti-6Al-4V using water-miscible vegetable oil-based cutting fluid. The effects of coolant concentration and working conditions on tool flank wear and tool life were evaluated. L27 fractional factorial Taguchi array was employed. Tool wear (VBB) ranged between 28.8 and 110 µm. The study concluded that a combination of VOs based cutting fluid concentration (10%), low cutting speed (58 m/min), feed rate (0.1mm/rev) and depth of cut (0.75mm) is necessary to minimise VBB. Additionally, it is noted that tool wear was significantly affected by cutting speeds. ANOVA results showed that the cutting fluid concentration is statistically insignificant on tool flank wear. A notable increase in tool life (TL) was recorded when a lower cutting speed was used.

Generalized Mechanistic Force System Model of Ball-End Milling for Sculpture Surface Machining

2001 ◽  
Author(s):  
Ismail Lazoglu
Keyword(s):  
End Milling ◽  
Mechanistic Model ◽  
Milling Process ◽  
Force System ◽  
Workpiece Surface ◽  
Surface Machining ◽  
Ball End Milling ◽  
End Milling Process ◽  
Validation Experiments ◽  
Good Agreement

Abstract In this paper, a new mechanistic model is developed for the prediction of cutting force system in ball-end milling process. The key feature of the model includes the ability to calculate the workpiece / cutter intersection domain automatically for a given cutter location (CL) file, cutter and workpiece geometries. Moreover, an analytical approach is used to determine the instantaneous chip load and cutting forces. The model also employs a Boolean approach for given cutter, workpiece geometries, and the CL file in order to determine the surface topography and scallop height variations along the workpiece surface which can be visualized in 3-D. Some of the typical results from the model validation experiments performed on Ti-6A1-4V are also reported in the paper. Comparisons of the predicted and measured forces as well as the surface topographies show good agreement.

scholarly journals Predicting the Tool Wear of a Drilling Process Using Novel Machine Learning XGBoost-SDA

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4952
Author(s):  
Mahdi S. Alajmi ◽  
Abdullah M. Almeshal
Keyword(s):  
Machine Learning ◽  
Cast Iron ◽  
Tool Wear ◽  
Flank Wear ◽  
Accurate Prediction ◽  
Superior Performance ◽  
Gradient Boosting ◽  
Support Vector ◽  
Drilling Process ◽  
Extreme Gradient Boosting

Tool wear negatively impacts the quality of workpieces produced by the drilling process. Accurate prediction of tool wear enables the operator to maintain the machine at the required level of performance. This research presents a novel hybrid machine learning approach for predicting the tool wear in a drilling process. The proposed approach is based on optimizing the extreme gradient boosting algorithm’s hyperparameters by a spiral dynamic optimization algorithm (XGBoost-SDA). Simulations were carried out on copper and cast-iron datasets with a high degree of accuracy. Further comparative analyses were performed with support vector machines (SVM) and multilayer perceptron artificial neural networks (MLP-ANN), where XGBoost-SDA showed superior performance with regard to the method. Simulations revealed that XGBoost-SDA results in the accurate prediction of flank wear in the drilling process with mean absolute error (MAE) = 4.67%, MAE = 5.32%, and coefficient of determination R2 = 0.9973 for the copper workpiece. Similarly, for the cast iron workpiece, XGBoost-SDA resulted in surface roughness predictions with MAE = 5.25%, root mean square error (RMSE) = 6.49%, and R2 = 0.975, which closely agree with the measured values. Performance comparisons between SVM, MLP-ANN, and XGBoost-SDA show that XGBoost-SDA is an effective method that can ensure high predictive accuracy about flank wear values in a drilling process.

scholarly journals Simulation and Experimental Study on the Surface Generation Mechanism of Cu Alloys in Ultra-Precision Diamond Turning

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 573
Author(s):  
Zhang ◽  
Guo ◽  
Chen ◽  
Fu ◽  
Zhao
Keyword(s):  
Tool Wear ◽  
Diamond Tool ◽  
Surface Characteristics ◽  
Diamond Turning ◽  
Generation Mechanism ◽  
Surface Generation ◽  
Machining Parameters ◽  
Nose Radius ◽  
Cu Alloys ◽  
Ultra Precision

The surface generation mechanism of the Cu alloys in ultra-precision diamond turning is investigated by both simulation and experimental methods, where the effects of the cutting parameters on the surface characteristics are explored, including the workpiece spindle speed, the cutting depth, the feed rate and the nose radius of the diamond tool. To verify the built model, the cutting experiments are conducted at selected parameters, where the causes of the error between the simulation and the machining results are analyzed, including the effects of the materials microstructure and the diamond tool wear. In addition, the nanometric surface characteristics of the Cu alloys after the diamond turning are identified, including the finer scratching grooves caused by the tool wear, the formation of the surface burs and the adhesion of graphite. The results show that the built model can be basically used to predict the surface topography for the selection of the appropriate machining parameters in the ultra-precision diamond turning process.

scholarly journals Online Tool Wear Monitoring by the Analysis of Cutting Forces in Transient State for Dry Machining of Ti6Al4V Alloy

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1014 ◽  
Author(s):  
Sánchez Hernández ◽  
Trujillo Vilches ◽  
Bermudo Gamboa ◽  
Sevilla Hurtado
Keyword(s):  
Tool Wear ◽  
Feed Rate ◽  
Cutting Forces ◽  
Flank Wear ◽  
Cutting Speed ◽  
Transient State ◽  
Cutting Parameters ◽  
Dry Machining ◽  
Crater Wear ◽  
Force Amplitude

In this work, the analysis of the cutting speed and feed rate influence on tool wear and cutting forces in Ti6Al4V alloy dry machining is presented. The study has been focused on the machining in a transient state. The tool wear mechanisms, tool wear intensity and cutting forces evolution have been analyzed as a function of the cutting parameters. Experimental results show that the main cutting force amplitude exhibits a general trend to increase with both cutting parameters. Crater wear was more evident at high cutting speeds, whereas flank wear was present on the whole interval of the cutting parameters analyzed. Furthermore, the cutting speed shows a slightly higher influence on crater wear and the feed rate shows a higher influence on flank wear. Finally, several experimental parametric models have been obtained. These models allow predicting the evolution of crater and flank tool wear, as well as the cutting forces, as a function of the cutting parameters. Additionally, a model that allows monitoring the tool wear on the machining transient state as a function of the main cutting force amplitude has been developed.

Analysis of Tool Wear: Part II: Applications of Flank Wear Models

1970 ◽  
Vol 92 (1) ◽  
pp. 109-114 ◽  
Author(s):  
A. Bhattacharyya ◽  
A. Ghosh ◽  
Inyong Ham
Keyword(s):  
Tool Wear ◽  
Critical Points ◽  
Quantitative Assessment ◽  
Inflection Point ◽  
Flank Wear ◽  
Cemented Carbides ◽  
Temperature Sensitive ◽  
Tool Failure ◽  
Cutting Speeds ◽  
Asme Paper

For machining with cemented carbides and ceramics, a quantitative assessment of tool failure at the flank for establishing “limit criterion” is necessary. The arbitrarily chosen flank wear limit for all cutting speeds is not valid at higher cutting speeds because of the earlier appearance of the “inflection point” which is often taken as criterion of flank-failure. In this paper, proceeding from the basic physical model of flank wear described in Part I of the paper (ASME Paper No. 68—WA/Prod-5), tool-life relations in the form of Taylor’s equations have been theoretically developed, the parameters of which have been compared with, experimental results. Further, the critical points of inflexion where the flank-wear characteristic enters temperature sensitive region resulting in accelerated wear have been uniquely defined. The location of these critical points have also been verified experimentally.

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