Investigation of Chatter Vibration in End-Milling Process by Considering Coupled System Model

2014 ◽  
Vol 939 ◽  
pp. 201-208
Author(s):  
Kosuke Hattori ◽  
Hiroyuki Kodama ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Cutting Tool ◽  
End Milling ◽  
Milling Process ◽  
Work Piece ◽  
Vibration Modes ◽  
Test Results ◽  
Chatter Vibration ◽  
Simple Method ◽  
Excited Vibration ◽  
End Milling Process

Chatter vibration in cutting processes usually leads to surface finish degradation, tool damage, cutting noise, energy loss, etc. Self-excited vibration particularly seems to be a problem that is easily increased to large vibration. The regenerative effect is considered as one of the causes of chatter vibration. Although the chatter vibration occurs in various types of processing, the end-milling is a typical process that seems to cause the chatter vibration due to a lack of rigidity of one or more parts of the machine tools, cutting tool, and work-piece. The aim of our research is to propose a simple method to control chatter vibration of the end-milling process on the basis of a coupling model integrating the related various elements. In this study, hammering tests were carried out to measure the transfer function of a machine tool and cutting tool system, which seems to cause vibration. By comparing these results, finite elemental method (FEM) analysis models were constructed. Additionally, cutting experiments were carried out to confirm the chatter vibration frequencies in end-milling with a machining center. In the hammering tests, impulse hammer and multiple acceleration pick-ups are connected to a multi-channel FFT analyzer and estimate the natural frequencies and natural vibration modes. A simplified FEM model is proposed by circular section stepped beam elements on the basis of the hammering test results, considering a coupling effect. In comparisons of the calculated results and hammering test results, the vibration modes are in good agreement. As a result, the proposed model accurately predicts the chatter vibration considering several effects among the relating elements in end-milling. Moreover, it can be seen that the chatter vibration is investigated from a viewpoint of the integrating model of the end-milling process.

Mode Coupling Behavior in End Milling

2009 ◽  
Author(s):  
C. Y. Huang ◽  
J.-J. Junz Wang
Keyword(s):  
Mode Coupling ◽  
End Milling ◽  
Milling Process ◽  
Chatter Vibration ◽  
Rotation Direction ◽  
Coupling Behavior ◽  
Structure Vibration ◽  
The Stability ◽  
Milling Dynamics ◽  
End Milling Process

Chatter is caused by two main mechanisms: the regenerative waviness and the mode coupling. Both of these two chatter mechanisms always exist simultaneously, but most studies only discuss the regenerative chatter behavior. The purpose of this paper is to investigate the mode coupling behavior in end milling process. A mechanical model considering both of the regenerative and mode coupling effects is then constructed to simulate the milling dynamics. It is shown that the stability of milling is dominated by the eigenvalues of the process matrix and the structure vibration trajectories are affected by the eigenvectors of the process matrix. The rotation direction of chatter vibration is an important feature to determine whether mode coupling chatter occurs or not. By analyzing vibration trajectories, this paper then shows that chatter vibration will rotate in the direction which periodically accumulates the vibration energy. Finally, some methods for adjusting the cutting conditions to avoid the mode coupling chatter are proposed.

Machinability of Aluminum Nitride Ceramic Using TiAlN and TiN Coated Carbide Tool Insert

2013 ◽  
Vol 773-774 ◽  
pp. 437-447
Author(s):  
Moola Mohan Reddy ◽  
Alexander Gorin ◽  
Abou Ei Hossein A. Khaled ◽  
D. Sujan
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
End Milling ◽  
Cutting Speed ◽  
Milling Process ◽  
Work Piece ◽  
Carbide Tool ◽  
Coated Carbide ◽  
Cnc End Milling ◽  
End Milling Process

This research presents the performance of Aluminum nitride ceramic in end milling using using TiAlN and TiN coated carbide tool insert under dry machining. The surface roughness of the work piece and tool wear was analyzed in this. The design of experiments (DOE) approach using Response surface methodology was implemented to optimize the cutting parameters of a computer numerical control (CNC) end milling machine. The analysis of variance (ANOVA) was adapted to identify the most influential factors on the CNC end milling process. The mathematical predictive model developed for surface roughness and tool wear in terms of cutting speed, feed rate, and depth of cut. The cutting speed is found to be the most significant factor affecting the surface roughness of work piece and tool wear in end milling process.

scholarly journals Investigation on Effect of Material Hardness in High Speed CNC End Milling Process

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
N. V. Dhandapani ◽  
V. S. Thangarasu ◽  
G. Sureshkannan
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Cutting Tool ◽  
End Milling ◽  
Removal Rate ◽  
Milling Process ◽  
Depth Of Cut ◽  
Study Results ◽  
Cnc End Milling ◽  
End Milling Process

This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results.

Investigation of Control Methods of Chatter Vibration Based on Analysis of End-Milling Chatter Mark

2016 ◽  
Vol 1136 ◽  
pp. 639-644 ◽  
Author(s):  
Ryosuke Shiota ◽  
Tatsuya Furuki ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Machine Tools ◽  
Cutting Tool ◽  
Natural Frequencies ◽  
End Milling ◽  
Relative Displacement ◽  
Surface Pattern ◽  
Work Piece ◽  
Chatter Vibration ◽  
Machined Surface ◽  
Milling Chatter

Chatter vibration generated by coupling a work-piece, machine tools, and cutting tool is a serious problem for engineers. A regular pattern forms the machined surface when chatter vibration occurs. There must be a direct relationship between the relative displacement and machined surface. We propose a method for controlling chatter vibration of end-milling from a machined surface. Hammering tests were first carried out to determine the natural frequencies of machine tools and the tool system, which are likely to be the cause of vibration. We also propose a technique of applying reverse analysis to end-milling surfaces. The machined surface is assumed to include an essential index to easily control chatter vibration at the factory. We found that chatter vibration occurs near the frequency of the cutting tool, tool holder, and their coupling, not at the natural frequency, and the chatter vibration frequency can be calculated by analyzing the surface pattern and cutting conditions. Moreover, the proposed method was effective in analyzing chatter vibrations including more than two kinds of natural frequencies at the same time.

scholarly journals Chatter Vibration Comparison Between Normal Helix Angle and Variable Helix Angle in End Milling Process Based on Spectrum Analysis

2020 ◽  
Vol 11 (3) ◽  
pp. 531-536
Author(s):  
Achmad As'ad Sonief ◽  
◽  
Arda Nur Fauzan ◽  
Fachry Azlan ◽  
Muhammad Aziz Bashori
Keyword(s):  
Spectrum Analysis ◽  
Cutting Tool ◽  
End Milling ◽  
Helix Angle ◽  
Depth Of Cut ◽  
Chatter Vibration ◽  
Machining Processes ◽  
Chatter Vibrations ◽  
Excited Vibration ◽  
Variable Helix

Chatter vibration in machining processes is often found in cutting processes which will decrease the machining efficiency and the surface quality of the products. Chatter is a relative vibration of the cutting tool and workpiece caused by the fluctuation of cutting force that is concerned to be a self-excited vibration. The variable Helix Angle Cutting tool which has pitch angle variation will also inflict different tooth passing frequencies on the flute that stand contiguous and trim the resonance frequency. This research aims to compare chatter vibrations that occurred between Normal Helix Angle and Variable Helix Angle cutting tool based on spectrum analysis on cutting parameter variety (depth of cut; rotation speed; feed rate milling). The outcome is spectrum analysis can detect the chatter phenomenon, measure the natural frequency (38-42 Hz), and also compare chatter vibrations between two tools appropriately.

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