scholarly journals Development and Testing of a High-Frequency Dynamometer for High-Speed Milling Process

Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 11
Author(s):  
Yanlin Lyu ◽  
Muhammad Jamil ◽  
Ning He ◽  
Munish Kumar Gupta ◽  
Danil Yurievich Pimenov
Keyword(s):  
Natural Frequency ◽  
Cutting Forces ◽  
High Frequency ◽  
High Speed ◽  
Milling Process ◽  
Machining Process ◽  
Dynamic Identification ◽  
High Rotational Speed ◽  
Support Plate ◽  
Dynamic Forces

Cutting forces are strongly associated with the mechanics of the cutting process. Hence, machining forces measurements are very important to investigate the machining process, and numerous methods of cutting forces measurements have been applied. Nowadays, a dynamometer is the most popular tool for cutting forces measurements. However, the natural frequency of a dynamometer has a direct impact on the accuracy of measured cutting forces in the machining process. Therefore, few dynamometers are appropriate and reliable to measure the cutting forces at high frequencies. In this work, a new strain-gauge-based dynamometer (SGBD) with a special structure was designed, manufactured, and put to the test to ensure the measurement of high-frequency dynamic forces in the milling process. The main structure of the SGBD is symmetrical and mainly consists of a center quadrangular prism surrounded by four force sensing elastic elements, an upper support plate, and a lower support plate. The dynamic identification test was conducted and indicated that the SGBD′s natural frequency could be stabilized at a high value of 9.15 kHz. To automatically obtain the milling force data with a computer during high rotational speed milling, a data acquisition system was devised for the dynamometer. To reduce the effects of cross-sensitivity and acting point of force, an innovative model based on a conversion matrix was established for the dynamometer. Furthermore, the cutting tests were conducted at high rotational speeds (10,000–18,000 rpm), and it was found that the difference of cutting forces between the SGBD and a Kistler dynamometer are 2.3–5.8% in the X direction and 3.5–8.8% in the Y direction. The experimental findings disclosed that the new kind of dynamometer is reliably for the measurement of high-frequency dynamic forces in milling at high rotational speeds.

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.

scholarly journals Eliminating the Effect of Uncertainties of Cutting Forces by Fuzzy Controller for Robots in Milling Process

2020 ◽  
Vol 10 (5) ◽  
pp. 1685 ◽  
Author(s):  
Khoi Bui Phan ◽  
Hai Thanh Ha ◽  
Sinh Vinh Hoang
Keyword(s):  
Differential Equations ◽  
Dynamic Model ◽  
Cutting Forces ◽  
Fuzzy Controller ◽  
Driving Forces ◽  
Milling Process ◽  
Industrial Robots ◽  
Machining Process ◽  
Depth Of Cut ◽  
Input And Output

This study presents a method of controlling robots based on fuzzy logic to eliminate the effect of uncertainties that are generated by the cutting forces in milling process. The common method to control industrial robots is based on the robot dynamic model and the differential equations of motion to compute the control values. The quantities in the differential equations of the motion of robots are complex and difficult to determine fully and accurately. The interaction forces between the cutting tool and the workpiece are the cutting forces, which are generated during the machining process. It is difficult to calculate the cutting force because it depends on many factors such as material of the machining part, depth of cut, feed rate, etc. This article presents the fuzzy rule system and the selection of the physical value domain of input and output variables of the fuzzy controller. The fuzzy rules are applied in this article to allow us to compute the driving forces based on the errors of input and output signals of the joint positions and velocities, thereby avoiding the calculation of cutting forces. This article shows the simulation results of the fuzzy controller and comparison with the results of the conventional controller when the dynamic model is assumed to be correctly determined. The achieved results are reliable and facilitate the research and application of a fuzzy controller to mechanical processing robots in general and milling machining in particular.

Stability Prediction during Thin-Walled Workpiece High-Speed Milling

2009 ◽  
Vol 69-70 ◽  
pp. 428-432 ◽  
Author(s):  
Qing Hua Song ◽  
Yi Wan ◽  
Shui Qing Yu ◽  
Xing Ai ◽  
J.Y. Pang
Keyword(s):  
High Speed ◽  
Dynamic Properties ◽  
Removal Rate ◽  
Cutting Parameters ◽  
Milling Process ◽  
Machining Process ◽  
High Speed Milling ◽  
Thin Walled ◽  
Optimization Of Cutting Parameters ◽  
Free Material

A method for predicting the stability of thin-walled workpiece milling process is described. The proposed approach takes into account the dynamic characteristics of workpiece changing with tool positions. A dedicated thin-walled workpiece representative of a typical industrial application is designed and modeled by finite element method (FEM). The workpiece frequency response function (FRF) depending on tool positions is obtained. A specific 3D stability chart (SC) for different spindle speeds and different tool positions is then elaborated by scanning the dynamic properties of workpiece along the machined direction throughout the machining process. The dynamic optimization of cutting parameters for increasing the chatter free material removal rate and surface finish is presented through considering the chatter vibration and forced vibration. The investigations are compared and verified by high speed milling experiments with flexible workpiece.

Structure Optimization Design and Application of a Strain Based Dynamometer

2013 ◽  
Vol 770 ◽  
pp. 385-390 ◽  
Author(s):  
Z. Huang ◽  
Wei Zhao ◽  
Ning He ◽  
Liang Li
Keyword(s):  
Natural Frequency ◽  
Cutting Forces ◽  
High Speed ◽  
Optimization Design ◽  
Dynamic Force ◽  
Force Component ◽  
High Speed Cutting ◽  
Milling Operations ◽  
Data Acquisition Software ◽  
Element Theory

A strain based dynamometer used for the prediction and measurement of three-component cutting forces for milling operations has been designed on the basis of the principle of additional elastic element theory. Meanwhile, four Wheatstone bridges, considerable amplifier and data acquisition software based on LabVIEW are also used to compose a whole system acquiring the cutting force signals. In order to obtain higher natural frequency and magnification, this paper focuses on the calculation and optimization of the dimensions of the special structure, and finally its first natural frequency can be stabilized at more than 14kHz, which are high enough to precisely measure the cutting forces, and the magnification can also achieve up to 15. The dynamic characteristics of the dynamometer are studied theoretically and experimentally, the results show that the developed dynamometer is able to measure the dynamic force component in high-speed cutting.

Effect of Surface Roughness and Residual Stress Induced by High Speed Milling Process on Short Crack Growth

2016 ◽  
Author(s):  
B. Zheng ◽  
H. D. Yu ◽  
X. Wang ◽  
X. M. Lai
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Residual Stresses ◽  
Crack Growth ◽  
Damage Evolution ◽  
High Speed ◽  
Milling Process ◽  
Short Crack ◽  
Machining Process ◽  
Effect Of Surface

Surface scratches and residual stresses inevitably appear on the surface of the component as a result of the machining process. The damage evolution of surface scratch due to the combined effect of cyclic loading and residual stresses will be significantly different from the case where only the cyclic loading is considered. In the damage evolution of surface scratch, the short crack growth is of great importance owing to its apparently anomalous behaviors compared with the long-crack growth. In this paper, the effect of the surface roughness and the residual stress on the short crack growth is studied. Firstly, the surface roughness and the residual stress of 7075-T6 aluminum alloy induced by the high speed milling process with various cutting speeds and feed rates are investigated with the experimental method. The maximum height roughness parameter is measured, which is regarded as the surface defect induced by the milling process. The residual stress on the specimen surface is measured with the X-ray diffraction. Results show that the surface roughness becomes higher with the increase of the feed rate. However, the influence of the cutting speed on the surface roughness is not significant. The residual stresses on the specimen surface are all in the compressive state. The residual stress is more compressive as the feed rate increases. The effects of the process parameters on the surface roughness and the residual stress are described by the fitted formulas. Then a modified model is built to characterize short fatigue crack growth behaviors with the consideration of the residual stress. This model is proved to provide a realistic treatment of the short crack growth, as reflected by comparison with experimental fatigue crack growth data of medium carbon steel and 7075-T6 aluminum alloy published in literature. The effect of surface roughness and residual stress caused by the milling process on the short crack growth is also investigated by using the proposed model. The growth of the scratch is nonlinear when it is subjected to the cyclic load. The compressive residual stress reduces the growth rate of the crack. The crack with larger initial surface roughness grows faster than that with smaller roughness. The correlation of surface roughness, residual stress and crack growth length is obtained by the polynomial fitting. The investigations in this paper can help the damage tolerance design of structures and improve the awareness of the effect of the residual stress and surface roughness induced by the machining process on the short crack growth.

scholarly journals Mechanistic modeling of cutting forces in high-speed microturning of titanium alloy with consideration of nose radius

2021 ◽  
Author(s):  
Kubilay Aslantas ◽  
Şükrü Ülker ◽  
Ömer Şahan ◽  
Danil Yu Pimenov ◽  
Khaled Giasin
Keyword(s):  
Cutting Forces ◽  
High Speed ◽  
Mechanistic Model ◽  
Cutting Speed ◽  
Mechanistic Modeling ◽  
Machining Process ◽  
Depth Of Cut ◽  
Nose Radius ◽  
Multilinear Regression Analysis ◽  
Edge Radius

AbstractMicroturning is a micromechanical machining process used to produce microcylindrical or axially symmetrical parts. Microcylindrical parts are mainly used in microfluidic systems, intravenous micromotors, microsurgical applications, optical lens applications, and microinjection systems. The workpiece diameter is very small in microturning and therefore is greatly affected by the cutting forces. For this reason, it is important to predict the cutting forces when machining miniature parts. In this study, an analytical mechanistic model of microturning is used to predict the cutting forces considering the tool nose radius. In the semi-empirically developed mechanistic model, the tool radius was considered. A series of semi-orthogonal microturning cutting tests were carried out to determine the cutting and edge force coefficients. The mechanistic model was generalized depending on the cutting speed and depth of cut by performing multilinear regression analysis. In the study, the depth of cut (ap = 30–90 µm) and feed values (f = 0.5–20 µm/rev) were selected considering the nose radius and edge radius of the cutting tool. The experiments were carried out under high-cutting speeds (Vc = 150–500 m/min) and microcutting conditions. Ti6Al4V alloy was used as the workpiece material and the tests were carried out under dry cutting conditions. Validation tests for different cutting parameters were carried out to validate the accuracy of the developed mechanistic model. The results showed that the difference between the mechanistic model and the experimental data was a minimum of 3% and a maximum of 24%. The maximum difference between the experimental and the model usually occurs in forces in the tangential direction. It has been observed that the developed model gives accurate results even at a depth of cut smaller than the nose radius and at feed values smaller than the edge radius.

3D Finite Element Assisted Numerical Simulation of Orbital Drilling Process of Ti6Al4V

2019 ◽  
Author(s):  
Salman Pervaiz ◽  
Ali Daneji ◽  
Sathish Kannan
Keyword(s):  
Finite Element ◽  
Rotational Speed ◽  
Cutting Forces ◽  
Threshold Value ◽  
Machining Process ◽  
Burr Formation ◽  
Drilling Process ◽  
Low Thrust ◽  
High Rotational Speed ◽  
Orbital Drilling

Abstract Drilling is one of most executed manufacturing operations to assist the assembling of different engineering components. In orbital drilling process, a milling tool is rotating along its own axis in combination with the spiral rotational movement. The rotation of tool about its own axis is with high rotational speed, but the spiral movement of tool is at low rotational speed. These rotational movements generate a hollow geometry when moved in combination. Orbital drilling process is emerging as a viable drilling process when burr formation has to be reduced from the metallic workpiece. It is gaining more popularity in the aerospace industry due to its ability to machine holes in difficult to cut alloys, composites and composite stacks. Major advantages of orbital drilling are linked with efficient chip evacuation, reduction in heat build-up and low thrust forces due to its intermittent cutting nature. The cutting forces generated during the process can be taken as a significant output parameter that play a vital role towards the overall performance of the cutting process. Controlling the cutting forces under threshold value can improve the overall machining efficiency by limiting associated deflections, tool wear and energy consumption. The current paper aims to study the orbital drilling process using finite element (FE) assisted numerical methodology. The study will utilize different orbital drilling parameters such as spindle speed, orbit speed and axial feed rate, and explore their influence on the over all machining process.

scholarly journals Cutting Forces Measurement for Milling Process by Using Working Tables with Integrated PVDF Thin-Film Sensors

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4031 ◽  
Author(s):  
Ming Luo ◽  
Zenghui Chong ◽  
Dongsheng Liu
Keyword(s):  
Thin Film ◽  
Cutting Force ◽  
Cutting Forces ◽  
Polyvinylidene Fluoride ◽  
Force Measurement ◽  
Milling Process ◽  
Machining Process ◽  
Signal Spectrum ◽  
Milling Force ◽  
Thin Film Sensors

In the milling process, cutting forces contain key information about the machining process status in terms of workpiece quality and tool condition. On-line cutting force measurement is key for machining condition monitoring and machined surface quality assurance. This paper presents a novel instrumented working table with integrated polyvinylidene fluoride (PVDF) thin-film sensors, thus enabling the dynamic milling force measurement with compact structures. To achieve this, PVDF thin-film sensors are integrated into the working table to sense forces in different directions and the dedicated cutting force decoupling model is derived. A prototype instrumented working table is developed and validated. The validation demonstrates that profiles of the forces measured from the developed instrumented working table prototype and the dynamometer match well. Furthermore, the milling experiment results convey that the instrumented working table prototype could also identify the tool runout due to tool manufacturing or assembly errors, and the force signal spectrum analysis indicates that the developed working table can capture the tool passing frequency correctly, therefore, is suitable for the milling force measurement.

Cutting forces analysis of micro-milling process on Inconel 718 – a finite element approach

2020 ◽  
Vol 11 (02) ◽  
pp. 2050011
Author(s):  
Padmaja Tripathy ◽  
Kalipada Maity
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Inconel 718 ◽  
Cutting Speed ◽  
Fem Analysis ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Parameters

This paper presents a modeling and simulation of micro-milling process with finite element modeling (FEM) analysis to predict cutting forces. The micro-milling of Inconel 718 is conducted using high-speed steel (HSS) micro-end mill cutter of 1mm diameter. The machining parameters considered for simulation are feed rate, cutting speed and depth of cut which are varied at three levels. The FEM analysis of machining process is divided into three parts, i.e., pre-processer, simulation and post-processor. In pre-processor, the input data are provided for simulation. The machining process is further simulated with the pre-processor data. For data extraction and viewing the simulated results, post-processor is used. A set of experiments are conducted for validation of simulated process. The simulated and experimental results are compared and the results are found to be having a good agreement.

Inverse dynamic analysis of milling machining robot, application in calibration of cutting force

2019 ◽  
Vol 57 (6) ◽  
pp. 773 ◽  
Author(s):  
Hai Ha Thanh
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Inverse Dynamics ◽  
Milling Process ◽  
Machining Process ◽  
Empirical Formulas ◽  
Inverse Dynamic ◽  
Serial Manipulators ◽  
Machining Robot ◽  
Dynamics Problems

This article presents analysis of inverse dynamics of serial manipulators in milling process. Cutting forces and complicated motion involve to difficulties in solving dynamics problems of robots. In general, cutting forces are determined by using empirical formulas that lead to errors of cutting force values. Moreover, the cutting forces are changing and causing vibration during machining process. Errors of cutting force values affect to the accuracy of the dynamic model. This paper proposes an algorithm to compute the cutting forces based on the feedback values of the robot's motion.    

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