Design and Characterization of a Magnetorheological Damper for Vibration Mitigation during Milling of Thin Components

2016 ◽  
Vol 1812 ◽  
pp. 65-70 ◽  
Author(s):  
S. Puma-Araujo ◽  
D. Olvera-Trejo ◽  
A. Elías-Zuñiga ◽  
O. Martínez-Romero ◽  
C.A. Rodríguez
Keyword(s):  
Degrees Of Freedom ◽  
End Milling ◽  
Experimental Tests ◽  
Milling Process ◽  
Magnetorheological Damper ◽  
Machining Process ◽  
Manufacturing Cost ◽  
Thin Wall ◽  
Integration Model

ABSTRACTThe aerospace and automotive industries demand the development of new manufacturing processes. The productivity during machining of very flexible aerospace and automotive aluminum components is limited for self-excited vibrations. New solutions are needed to suppress vibrations that affect the accuracy and quality of the machined surfaces. Rejection of one piece implies an increase in the manufacturing cost and time. This paper is focused on the design, manufacturing and characterization of a magnetorheological damper. The damper was attached to a thin-floored component and a magnetic field was controlled in order to modify the damping behavior of the system. The dynamics of the machining process was developed by considering a three-degree-of-freedom model. This study was experimentally validated with a bull-nose end milling tool to manufacture monolithic parts with thin wall and thin floor. Experimental tests and characterization of the magnetorheological damper permitted to improve the surface finish and productivity during the machining of thin-floored components. A further aim of this paper was to develop a rheological damper by using magnetorheological fluids (MR) to change the thin floor rigidity with voltage. The stability of the milling process was also analytically described considering one, two or three degrees of freedom, using a mathematical integration model based on the Enhanced Multistage Homotopy Perturbation Method (EMHPM).

Finite Element Analysis of Machining Thin-Wall Parts

2010 ◽  
Vol 458 ◽  
pp. 283-288 ◽  
Author(s):  
R. Izamshah R.A. ◽  
John Mo ◽  
Song Lin Ding
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
End Milling ◽  
Operating Cost ◽  
Weight Ratio ◽  
Milling Process ◽  
Machining Process ◽  
Thin Wall ◽  
Structural Components ◽  
Element Analysis

In an attempt to decrease weight, new commercial and military aircraft are designs with unitised monolithic metal structural components which contains of thinner ribs (i.e., walls) and webs (i.e., floors). Most of the unitised monolithic metal structural components are machined from solid plate or forgings with the start-to-finish weight ratio of 20:1. The resulting thin-walled structure often suffers a deformation which causes a dimensional surface error due to the action of the cutting force generated during the machining process. To alleviate the resulting surface errors, current practices rely on machining through repetitive feeding several times and manual calibration which resulting in long cycle times, low productivity and high operating cost. A finite element analysis (FEA) machining model is developed in this project to specifically predict the distortion or deflection of the part during end milling process. The model aims to provide an input for downstream decision making on error compensation strategy when machining a thin-wall unitised monolithic metal structural components. A set of machining tests have been done in order to validate the accuracy of the model and the results between simulation and experiment are found in a good agreement.

Effects of Radial Immersion and Cutting Direction on Chatter Instability in End-Milling

Manufacturing ◽  
2002 ◽  
Author(s):  
Philip V. Bayly ◽  
Brian P. Mann ◽  
Tony L. Schmitz ◽  
David A. Peters ◽  
Gabor Stepan ◽  
...  
Keyword(s):  
Frequency Domain ◽  
End Milling ◽  
Experimental Tests ◽  
Milling Process ◽  
Element Analysis ◽  
Model Stability ◽  
Interrupted Cutting ◽  
Time Marching ◽  
Variance Estimate ◽  
Low Radial Immersion

Low radial immersion end-milling involves intermittent cutting. If the tool is flexible, its motion in both the x- and y-directions affects the chip load and cutting forces, leading to chatter instability under certain conditions. Interrupted cutting complicates stability analysis by imposing sharp periodic variations in the dynamic model. Stability predictions for the 2-DOF model differ significantly from prior 1-DOF models of interrupted cutting. In this paper stability boundaries of the 2-DOF milling process are determined by three techniques and compared: (1) a frequency-domain technique developed by Altintas and Budak (1995); (2) a method based on time finite element analysis; and (3) the statistical variance of periodic 1/tooth samples in a time-marching simulation. Each method has advantages in different situations. The frequency-domain technique is fastest, and is accurate except at very low radial immersions. The temporal FEA method is significantly more efficient than time-marching simulation, and provides accurate stability predictions at small radial immersions. The variance estimate is a robust and versatile measure of stability for experimental tests as well as simulation. Experimental up-milling and down-milling tests, in a simple model with varying cutting directions, agree well with theory.

Finite Element Analysis of a Frictionally Damped Slender Endmill

2012 ◽  
Author(s):  
Reza Madoliat ◽  
Sajad Hayati
Keyword(s):  
Finite Element ◽  
End Milling ◽  
Friction Stress ◽  
Milling Process ◽  
Machining Process ◽  
Depth Of Cut ◽  
Parameter Study ◽  
Bending Vibration ◽  
Element Analysis ◽  
Tool Axis

This paper primarily deals with suppression of chatter in end-milling process. Improving the damping is one way to achieve higher stability for machining process. For this purpose a damper is proposed that is composed of a core and a multi fingered hollow cylinder which are shrink fitted in each other and their combination is shrink fitted inside an axial hole along the tool axis. This structure causes a resisting friction stress during bending vibration. Using FEA-ANSYS the structure is simulated. Then a parameter study is carried out where the frequency response and the depth of cut are calculated and tabulated to obtain the most effective configuration. The optimal configuration of tool is fabricated and finite element results are validated using modal test. The results show a high improvement in performance of the tool with proposed damper. Good agreement between experiments and modeling is obtained.

Optimization of Process Parameters for Cutting Force for Aluminium 7010 in CNC End Milling Process

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
M. Kishanth ◽  
P. Rajkamal ◽  
D. Karthikeyan ◽  
K. Anand
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Process Parameters ◽  
End Milling ◽  
Milling Process ◽  
Machining Process ◽  
Depth Of Cut ◽  
Optimization Of Process Parameters ◽  
Cnc End Milling ◽  
End Milling Process

In this paper CNC end milling process have been optimized in cutting force and surface roughness based on the three process parameters (i.e.) speed, feed rate and depth of cut. Since the end milling process is used for abrading the wear caused is very high, in order to reduce the wear caused by high cutting force and to decrease the surface roughness, the optimization is much needed for this process. Especially for materials like aluminium 7010, this kind of study is important for further improvement in machining process and also it will improve the stability of the machine.

Modeling & Analysis of End Milling Process Parameters Using Artificial Neural Networks

2014 ◽  
Vol 592-594 ◽  
pp. 2733-2737 ◽  
Author(s):  
G. Harinath Gowd ◽  
K. Divya Theja ◽  
Peyyala Rayudu ◽  
M. Venugopal Goud ◽  
M .Subba Roa
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Process Parameters ◽  
End Milling ◽  
Milling Process ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Artificial Neural ◽  
End Milling Process

For modeling and optimizing the process parameters of manufacturing problems in the present days, numerical and Artificial Neural Networks (ANN) methods are widely using. In manufacturing environments, main focus is given to the finding of Optimum machining parameters. Therefore the present research is aimed at finding the optimal process parameters for End milling process. The End milling process is a widely used machining process because it is used for the rough and finish machining of many features such as slots, pockets, peripheries and faces of components. The present work involves the estimation of optimal values of the process variables like, speed, feed and depth of cut, whereas the metal removal rate (MRR) and tool wear resistance were taken as the output .Experimental design is planned using DOE. Optimum machining parameters for End milling process were found out using ANN and compared to the experimental results. The obtained results provβed the ability of ANN method for End milling process modeling and optimization.

Chatter Investigation in Titanium Milling

2014 ◽  
Vol 1019 ◽  
pp. 318-324
Author(s):  
Jean Claude Fwamba ◽  
Lerato Crescelda Tshabalala ◽  
Cebo Philani Ntuli ◽  
Isaac Tlhabadira
Keyword(s):  
Feed Rate ◽  
End Milling ◽  
Processing Condition ◽  
Weight Ratio ◽  
Dimensional Accuracy ◽  
Milling Process ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Performance ◽  
Chatter Vibrations

<span><p align="LEFT"><span><span style="font-family: Times New Roman;" face="Times New Roman">Titanium and its alloys have been experiencing extensive development over the past few decades. They have found wide applications in the aerospace, biomedical and automotive industries owing to their good strength-to-weight ratio and high corrosion resistance. Machining performance is often limited by chatter vibrations at the tool-workpiece interface. Chatter is an abnormal tool behaviour which is one of the most critical problems in the machining process and must be avoided to improve the dimensional accuracy and surface quality of the finished product. This research aims at investigating chatter trends in the end milling process and to identify machine parameters that have effects on chatter during machining. The machine parameters investigated include axial feed rate, spindle revolute speed and depth of cut. In this research, experimental data was collected using sensors to analyze the existence of chatter vibrations on each processing condition. This research showed that the combination of the machine parameters, feed rate and spindle speed within certain proportions has an influence on machine vibrations during end milling and if not managed properly, may lead to chatter. </span></span></p> <p align="LEFT"></p>

Machining: Quality, Cost and Environmental Estimation and Tradeoffs

2000 ◽  
Author(s):  
Panicos A. Nicolaou ◽  
Deborah L. Thurston
Keyword(s):  
End Milling ◽  
Machining Process ◽  
Manufacturing Cost ◽  
Cutting Fluids ◽  
Activity Based Costing ◽  
Estimation Model ◽  
Quality Estimation ◽  
Quality Cost ◽  
Milling Quality ◽  
Drilling Quality

Abstract The machining process affects manufacturing cost, product quality and the environment. This paper presents a method for formulating a mathematical model for first estimating quality, cost and environmental impacts of two machining operations (end milling and drilling), and then for tradeoff decision making. The milling quality estimation model is developed through virtual experimentation on a simulation model and the drilling quality estimation model through physical experimentation. Cost is estimated through an activity based costing approach. Environmental BOD and FOG impacts are estimated through stoichiometric analysis of cutting fluids. Inputs include material choice, feed rate, speed and cutting fluids. A case study of an automotive steering knuckle is presented.

scholarly journals Modeling of the Feed-Motor Transient Current in End Milling by Using Varying-Coefficient Model

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Mi Xiao ◽  
Long Wen ◽  
Xi Li ◽  
Liang Gao
Keyword(s):  
Predictive Model ◽  
End Milling ◽  
Milling Process ◽  
Current Amplitude ◽  
Transient Current ◽  
Machining Process ◽  
Varying Coefficient Model ◽  
Varying Coefficient ◽  
Motor Current ◽  
The Stability

In order to ensure the stability of the machining process, it is vital to control the machining condition during the milling process. While the feed-motor current is related to many physical variables, such as the cutting force and tool wear, we can indicate it as the key variables to monitoring the conditions of the milling process. A predictive model of the feed-motor current amplitude is established in this paper. The change regulation of the transient current amplitude during the milling process is investigated, and the effect of the spindle speed on the transient current amplitude is studied as well. Since the transient current amplitude is time-varying, the predictive model is a typical panel data type. In this case, the varying-coefficient model (VCM), a potential soft computing method, is applied to solve this predictive model. Then several experiments are conducted to evaluate the performance of VCM method. Results show that the predicted values match the experimental value well, and the correctness of the predictive model for transient current amplitude is also validated.

scholarly journals Non-Invasive Estimation of Machining Parameters during End-Milling Operations Based on Acoustic Emission

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5326
Author(s):  
Andrés Sio-Sever ◽  
Erardo Leal-Muñoz ◽  
Juan Manuel Lopez-Navarro ◽  
Ricardo Alzugaray-Franz ◽  
Antonio Vizan-Idoipe ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
End Milling ◽  
Low Cost ◽  
Milling Process ◽  
Machining Process ◽  
Measuring System ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machining Processes ◽  
Non Invasive

This work presents a non-invasive and low-cost alternative to traditional methods for measuring the performance of machining processes directly on existing machine tools. A prototype measuring system has been developed based on non-contact microphones, a custom designed signal conditioning board and signal processing techniques that take advantage of the underlying physics of the machining process. Experiments have been conducted to estimate the depth of cut during end-milling process by means of the measurement of the acoustic emission energy generated during operation. Moreover, the predicted values have been compared with well established methods based on cutting forces measured by dynamometers.

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.

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