scholarly journals An Experimentally Aided Operational Virtual Prototyping to Obtain the Best Spindle Speed during Face Milling of Large-Size Structures

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6562
Author(s):  
Krzysztof J. Kaliński ◽  
Marek A. Galewski ◽  
Michał R. Mazur ◽  
Natalia Stawicka-Morawska
Keyword(s):  
Original Method ◽  
Milling Process ◽  
Face Milling ◽  
Spindle Speed ◽  
Experimental Investigations ◽  
Process Data ◽  
Large Size ◽  
Operational Technique ◽  
Production Practice ◽  
Modal Model

The paper presents an original method concerning the problem of vibration reduction in the general case while milling large-size and geometrically complex details with the use of an innovative approach to the selection of spindle speed. A computational model is obtained by applying the so-called operational approach to identify the parameters of the workpiece modal model. Thanks to the experimental modal analysis results, modal subsystem identification was performed and reliable process data for simulation studies were obtained. Next, simulations of the milling process, for successive values of the spindle speed, are repeated until the best vibration state of the workpiece is obtained. For this purpose, the root mean square values of the time plots of vibration displacements are examined. The effectiveness of the approach proposed for reducing vibrations in the process of face milling is verified on the basis of the results of appropriate experimental investigations. The economic profitability of the implementation of the operational technique in the production practice of enterprises dealing with mechanical processing is demonstrated as well.

scholarly journals A method of predicting the best conditions for large-size workpiece clamping to reduce vibration in the face milling process

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Krzysztof J. Kaliński ◽  
Natalia Stawicka-Morawska ◽  
Marek A. Galewski ◽  
Michał R. Mazur
Keyword(s):  
Natural Frequencies ◽  
Vibration Suppression ◽  
Milling Process ◽  
Face Milling ◽  
Modal Identification ◽  
Large Size ◽  
Innovative Method ◽  
The Face ◽  
The Time Domain ◽  
Minimum Work

AbstractThe paper presents an innovative method of solving the problem of vibration suppression during milling of large-size details. It consists in searching for the best conditions for clamping the workpiece based on a rapid modal identification of the dominant natural frequencies only and requires repetitive changes in the tightening torque of the clamping screws. Then, by estimating the minimum work of the cutting forces acting in the direction of the width of the cutting layer, it is possible to predict the best fixing of the workpiece. Application of the method does not require the creation and identification of a computational model of the process or preliminary numerical simulations. The effectiveness of this method was confirmed by the evaluation of the Root Mean Square (RMS) of the vibration level in the time domain observed during the actual face milling process. The worst results were obtained for the configuration of supports tightened with a torque of 90–110 Nm, and the best—with a torque of 50 Nm.

Evaluation of Face Milling Operation Parameters on Surface Roughness of Crankcase Housing by Two Level Factorial Design with Center Points

2018 ◽  
Vol 780 ◽  
pp. 105-110
Author(s):  
Ukrit Thanasuptawee ◽  
Chamrat Thakhamwang ◽  
Somsak Siwadamrongpong
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Milling Process ◽  
Face Milling ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Significance Level ◽  
Machining Center ◽  
Semi Solid

In this study, there are three machining parameters consist of spindle speed, feed rate and depth of cut which were conducted through full factorial with four center points to determine the effect of machining parameters on the surface roughness and verify whether there is curvature in the model for CNC face milling process in an automotive components manufacturer in Thailand. The workpieces used semi-solid die casted ADC12 aluminum alloy crankcase housing which they were performed by the ARES SEIKI model R5630 3-axis CNC vertical machining center and face milling cutter with diameter of 63 millimeters. The surface roughness of face-milled was measured by the surface roughness tester. It was found that the greatest main effect influence to surface roughness was spindle speed, followed by feed rate and depth of cut at significance level of 0.05.

scholarly journals A Method of Predicting The Best Conditions for Clamping a Large-Size Workpiece in Order To Reduce Vibrations in The Milling Process

2021 ◽  
Author(s):  
Krzysztof J. Kaliński ◽  
Natalia Stawicka-Morawska ◽  
Marek A. Galewski ◽  
Michał R. Mazur
Keyword(s):  
Natural Frequencies ◽  
Vibration Suppression ◽  
Milling Process ◽  
Face Milling ◽  
Modal Identification ◽  
Vibration Level ◽  
Large Size ◽  
Innovative Method ◽  
The Time Domain ◽  
Minimum Work

Abstract The paper presents an innovative method of solving the problem of vibration suppression during milling of large-size details. It consists in searching for the best conditions for clamping the workpiece based on a rapid modal identification of the dominant natural frequencies only and requires repetitive changes in the tightening torque of the clamping screws. Then, by estimating the minimum work of the cutting forces acting in the direction of the width of the cutting layer, it is possible to predict the best fixing of the workpiece. Application of the method does not require the creation and identification of a computational model of the process or preliminary numerical simulations. The effectiveness of this method was confirmed by the evaluation of the Root Mean Square (RMS) of the vibration level in the time domain observed during the actual face milling process.

Floquet Theory Based Approach for Stability Analysis of the Variable Speed Face-Milling Process

2001 ◽  
Vol 124 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Sridhar Sastry ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor
Keyword(s):  
Stability Analysis ◽  
Floquet Theory ◽  
Milling Process ◽  
Face Milling ◽  
Spindle Speed ◽  
Spindle Speed Variation ◽  
Modes Of Vibration ◽  
Varying Time Delay ◽  
Constant Coefficients ◽  
System Equations

This paper presents a new method for stability analysis of the variable spindle speed face milling process whose dynamics are described by a set of differential-difference equations with periodic coefficients and time varying time delay. Fourier analysis and Floquet theory applied to the system equations result in a characteristic equation of infinite order with constant coefficients. Its truncated version is used to determine the limit of stability by employing standard techniques of control theory. Analytically predicted stability boundaries are compared with lobes generated by time domain simulations. Experimental results are also presented that validate the proposed analytical method for chatter stability analysis. Finally, an example is presented that demonstrates the advantage of using spindle speed variation when machining a workpiece having multiple modes of vibration.

Experimental Investigation on the Rubbing Process of Labyrinth Seals Considering the Material Combination

2020 ◽  
Author(s):  
Lisa Hühn ◽  
Oliver Munz ◽  
Corina Schwitzke ◽  
Hans-Jörg Bauer
Keyword(s):  
Turbine Blades ◽  
Design Guidelines ◽  
Operating Conditions ◽  
Contact Forces ◽  
Experimental Investigations ◽  
Process Data ◽  
Labyrinth Seals ◽  
Material Combination ◽  
Higher Temperature ◽  
And Control

Abstract Labyrinth seals are used to prevent and control the mass flow rate between rotating components. Due to thermally and mechanically induced expansions during operation and transient flight maneuvers, a contact, the so-called rubbing process, between rotor and stator cannot be excluded. A large amount of rubbing process data concerning numerical and experimental investigations is available in public literature as well as at the Institute of Thermal Turbomachinery (ITS). The investigations were carried out for different operating conditions, material combinations, and component geometries. In combination with the experiments presented in this paper, the effects of the different variables on load due to rubbing are compared, and discussed with the focus lying on the material combination. The influence of the material on the loads can be identified as detailed as never before. For example, the contact forces in the current experiments are higher due to a higher temperature resistance of Young’s modulus. The analysis will also be based on the rubbing of turbine blades. Design guidelines are derived for labyrinth seals with improved properties regarding tolerance of rub events. Based on the knowledge obtained, guidelines for designing reliable labyrinth seals for future engines are discussed.

scholarly journals Effect of High Speed Milling Process Parameters on the Milling Force and Surface Topography of AM50A Magnesium Alloy

2018 ◽  
Vol 36 (1) ◽  
pp. 124-131
Author(s):  
Hongji Zhang ◽  
Yuanyuan Ge ◽  
Hong Tang ◽  
Yaoyao Shi ◽  
Zengsheng Li
Keyword(s):  
Magnesium Alloy ◽  
Surface Quality ◽  
High Speed ◽  
Milling Process ◽  
Spindle Speed ◽  
Feed Speed ◽  
Milling Force ◽  
High Speed Milling ◽  
Milling Parameters

Within the scope of high speed milling process parameters, analyzed and discussed the effects of spindle speed, feed rate, milling depth and milling width on milling forces in the process of high speed milling of AM50A magnesium alloy. At the same time, the influence of milling parameters on the surface roughness of AM50A magnesium alloy has been revealed by means of the measurement of surface roughness and surface micro topography. High speed milling experiments of AM50A magnesium alloy were carried out by factorial design. Form the analysis of experimental results, The milling parameters, which have significant influence on milling force in high speed milling of AM50A magnesium alloy, are milling depth, milling width and feed speed, and the nonlinear characteristics of milling force and milling parameters. The milling force decreases with the increase of spindle in the given mill parameters. For the effects of milling parameters on surface quality of the performance, in the milling depth and feeding speed under certain conditions with the spindle speed increases the surface quality of AM50A magnesium alloy becomes better with the feed speed increases the surface quality becomes poor. When the spindle speed is greater than 12000r/min, the milling depth is less than 0.2mm, and the feed speed is less than 400mm/min, the milling surface quality can be obtained easily.

High Definition Metrology-Based Quality Improvement of Surface Texture in Face Milling of Workpieces with Discontinuous Surfaces

2021 ◽  
pp. 1-38
Author(s):  
Guilong Li ◽  
Shichang Du ◽  
Bo Wang ◽  
Jun Lv ◽  
Yafei Deng
Keyword(s):  
Quality Improvement ◽  
Surface Texture ◽  
Mechanical Performance ◽  
Processing Parameters ◽  
Milling Process ◽  
Face Milling ◽  
Measurement Instruments ◽  
High Definition ◽  
Tool Marks

Abstract In face milling process, the quality of surface texture is vital for mechanical performance of workpieces. The quality of surface texture, especially for waviness, is directly affected by tool marks, a commonly observed phenomenon in face milling. However, appropriate approaches for evaluation and modeling of tool marks are absent to date. Limited to the resolution as well as the efficiency of conventional measurement instruments, the height data of tool marks is hard to be entirely obtained, leading to valuable information omission. Besides, most existing models of tool marks are established for general workpieces with regular geometry and continuous surfaces. Since the cutter-workpiece engagement mode has a significant impact on the generation of tool marks, current models could be inaccurate or invalid when dealing with workpieces with discontinuous surfaces. To overcome this shortage, a novel approach is proposed in this paper, aimed at quality improvement of surface texture in face milling of workpieces with discontinuous surfaces. Firstly, the evaluation indexes for tool marks are defined based on the recently developed high definition metrology (HDM). Secondly, the physical modeling of tool marks is presented, taking the face milling mechanism into account. Thirdly, the physical-informed optimization model is developed to search for the optimal processing parameters for surface quality improvement. At last, the effectiveness of the proposed approach is verified by a face milling experiment on the engine blocks.

scholarly journals Automatic Identification of Tool Wear Based on Convolutional Neural Network in Face Milling Process

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3817 ◽  
Author(s):  
Xuefeng Wu ◽  
Yahui Liu ◽  
Xianliang Zhou ◽  
Aolei Mou
Keyword(s):  
Neural Network ◽  
Tool Wear ◽  
Machine Tool ◽  
Convolutional Neural Network ◽  
Network Model ◽  
Automatic Detection ◽  
Milling Process ◽  
Face Milling ◽  
Machining Process ◽  
Model Parameters

Monitoring of tool wear in machining process has found its importance to predict tool life, reduce equipment downtime, and tool costs. Traditional visual methods require expert experience and human resources to obtain accurate tool wear information. With the development of charge-coupled device (CCD) image sensor and the deep learning algorithms, it has become possible to use the convolutional neural network (CNN) model to automatically identify the wear types of high-temperature alloy tools in the face milling process. In this paper, the CNN model is developed based on our image dataset. The convolutional automatic encoder (CAE) is used to pre-train the network model, and the model parameters are fine-tuned by back propagation (BP) algorithm combined with stochastic gradient descent (SGD) algorithm. The established ToolWearnet network model has the function of identifying the tool wear types. The experimental results show that the average recognition precision rate of the model can reach 96.20%. At the same time, the automatic detection algorithm of tool wear value is improved by combining the identified tool wear types. In order to verify the feasibility of the method, an experimental system is built on the machine tool. By matching the frame rate of the industrial camera and the machine tool spindle speed, the wear image information of all the inserts can be obtained in the machining gap. The automatic detection method of tool wear value is compared with the result of manual detection by high precision digital optical microscope, the mean absolute percentage error is 4.76%, which effectively verifies the effectiveness and practicality of the method.

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