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tool-wear
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The effect of machining parameters on force signal and tool wear in stone cutting
, Article AIP Conference Proceedings, 24 October 2010 through 27 October 2010, Paris ; Volume 1315 , 2010 , Pages 961-966 ; 0094243X (ISSN) ; 9780735408715 (ISBN) ; Gorjizadeh, A ; Mikaeil, R ; Sharif University of Technology
2010
Abstract
The application of sensor system is becoming more commonplace in improving productivity and reliability. Although measuring force signal have been widely used for monitoring of metal machining process that their application to stone cutting has not been well investigated. In this paper, the effect of machining parameter on force signal and tool wear was investigated. The result indicate that increasing of the depth of cut and spindle speed will increase the force and tool wear while increasing feed rate will increase force and decrease tool wear
Extended Nonlinear Modeling and Stability Analysis of the Peripheral Milling Process
, Ph.D. Dissertation Sharif University of Technology ; Vossoughi, Gholamreza (Supervisor) ; Movahhedy, Mohammad Reza (Supervisor)
Abstract
In this thesis, an extended nonlinear model of peripheral milling process (2D) is presented. For the first time, cutting forces are described through a complete third order polynomial function of the axial depth of cut. Also, cubic nonlinearity is considered for the structural stiffness as a function of tool tip displacement. To complete the model, process damping and tool wear effects are also considered. A set of experiments including modal tests to determine natural frequencies and structural damping ratios; and also cutting force measurements at different feed rates to determine nonlinear cutting force coefficients, are carried out. Also, measurement of critical axial depth of cut at...
Analaysis of Ultrasonic Vibration Assisted Turing of Engineering Ceramics
, M.Sc. Thesis Sharif University of Technology ; Movahhedi, Mohammad Reza (Supervisor) ; Akbari, Javad (Supervisor)
Abstract
Due to high strength, hardness and high resistance to abrasion, ceramics are difficult for machining. Also as the conductivity coefficient of these materials is low, major amount of produced heat during machining process will be absorbed in the cutting tool which causes intensive wear in cutting tool edge. As a result employing traditional machining for these materials because of low machining speed, tool wear, high roughness and large cutting force, has little efficiency in practice. Therefore non-traditional machining method may improve efficacy. In this thesis effect of utilizing ultrasonic vibration in machining process of fused cast silica ceramic has been studied. Aim of this study at...
Bifurcation analysis of nonlinear milling process with tool wear and process damping: Sub-harmonic resonance under regenerative chatter
, Article International Journal of Mechanical Sciences ; Vol. 85, issue , August , 2014 , p. 1-19 ; Vossoughi, G ; Movahhedy, M. R ; Sharif University of Technology
Abstract
In this paper, bifurcation analysis is performed for the nonlinear milling process under sub-harmonic resonance and regenerative chatter, with tool wear and process damping effects. Multiple-scales approach is used to construct analytical approximate solutions for non-autonomous parametrically excited equations of the system with time delay terms. The new bifurcation parameters are the detuning parameter (deviation of the tooth passing frequency from three times of the chatter frequency), damping ratio (affected by process damping) and tool wear width. Jump phenomenon and multi-values responses are observed in the first order solution under sub-harmonic resonance condition. Periodic,...
Tunable vibration absorber for improving milling stability with tool wear and process damping effects
, Article Mechanism and Machine Theory ; Volume 52 , June , 2012 , Pages 59-77 ; 0094114X (ISSN) ; Movahhedy, M. R ; Vossoughi, G ; Sharif University of Technology
2012
Abstract
This paper deals with the problem of chatter suppression in milling process in order to achieve higher precision, better surface quality and larger material removal rate (MRR). The peripheral milling process is modeled as a two degrees of freedom system and the effects of tool wear and process damping are considered. It is shown that when regenerative chatter develops, both tool wear and process damping act as stabilizing factors. For larger values of depth of cut and consequently higher MRR, tunable vibration absorbers (TVA) (in x-y directions) are designed to improve stability. An optimal algorithm is developed which determines the optimum values for absorbers' parameters. The effects of...
Nonlinear oscillation and stability analysis of the turning process with a worn tool
, Article Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference 2009, DETC2009, 30 August 2009 through 2 September 2009 ; Volume 1, Issue PART B , August–September , 2010 , Pages 927-934 ; 9780791848982 (ISBN) ; Ahmadian, M. T ; Bakhtiari Nejad, F ; The Design Engineering Division, ASME; The Computers and Information in Engineering Division, ASME ; Sharif University of Technology
2010
Abstract
Self-excited and forced vibrations are important topics in machining processes because their occurrence results in poor surface finish, increase in tool wear and hampers productivity. In this paper, turning process is modeled as a SDOF dynamic system including quadratic and cubic structural nonlinearities. The effect of tool flank wear, as a contact force between the work-piece and tool, is addressed vigorously. Multiple scale method is used to find the solution of the nonlinear dynamic equation including regenerative chatter, forced excitation and tool wear. It is shown that, width of cut can be considered as the bifurcation parameter of the system. Primary, super-harmonic and sub-harmonic...
Nonlinear oscillation and stability analysis of the turning process with a worn tool
, Article Proceedings of the ASME Design Engineering Technical Conference, 30 August 2009 through 2 September 2009 ; Volume 1, Issue PARTS A AND B , 2009 , Pages 927-934 ; 9780791848982 (ISBN) ; Ahmadian, M. T ; Bakhtiari Nejad, F ; Sharif University of Technology
Abstract
Self-excited and forced vibrations are important topics in machining processes because their occurrence results in poor surface finish, increase in tool wear and hampers productivity. In this paper, turning process is modeled as a SDOF dynamic system including quadratic and cubic structural nonlinearities. The effect of tool flank wear, as a contact force between the work-piece and tool, is addressed vigorously. Multiple scale method is used to find the solution of the nonlinear dynamic equation including regenerative chatter, forced excitation and tool wear. It is shown that, width of cut can be considered as the bifurcation parameter of the system. Primary, super-harmonic and sub-harmonic...
Finite element simulation of ultrasonic-assisted machining: a review
, Article International Journal of Advanced Manufacturing Technology ; Volume 116, Issue 9-10 , 2021 , Pages 2777-2796 ; 02683768 (ISSN) ; Akbari, J ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Ultrasonic-assisted machining is an advanced method which could improve the process of machining. Besides, simulation modeling process is a method to help the researchers analyze different aspects of the process with more details in a shorter time. Simulation of ultrasonic-assisted machining is also a field of research that is of interest to researchers working in the field of machining processes. In recent years, a variety of papers have been published where cutting forces, chip formation, tool wear and temperature, and microstructure changes were simulated. That being the case, a review paper is required to represent the advances implemented by researchers in the simulation of...
Global optimization and design of dynamic absorbers for chatter suppression in milling process with tool wear and process damping
, Article Procedia CIRP ; Volume 21 , 2014 , Pages 360-366 ; ISSN: 22128271 ; Moradi, H ; Vossoughi, G ; Sharif University of Technology
Abstract
Peripheral milling is extensively used in manufacturing processes, especially in aerospace industries where end mills are used for milling of wing parts and engine components. The generation of complex shapes with high quality for various types of materials is the main advantage of milling in contrast to other machining processes. During the milling process, the occurrence of self-excited vibrations or chatter may cause reduction in material removal rate (MRR), damage to the tool and spindle bearing or may result in poor dimensional accuracy and surface finish of the work-piece. In this paper, milling process is modeled as two degrees of freedom (2DOF) system in which the tool wear and...
Tool Life Prediction Using Bayesian Updating
, M.Sc. Thesis Sharif University of Technology ; Akbari, Javad (Supervisor)
Abstract
Traditional tool life models and wear prediction do not take into account the variation inherent in metal cutting processes. These lead to additional manufacturing costs. This research presents a stochastic method for both tool life and tool wear prediction. In the first part, Bayesian inference is applied to estimate the two model constants of Taylor tool life prediction model using a discrete grid method. Tool wear tests are performed using an uncoated M42 HSS tool and AISI 1018 carbon steel work material. Test results are used to update initial beliefs about the constants and the updated beliefs are then used to predict tool life using a probability density function (pdf). Finally, the...
Manufacturing error compensation based on cutting tool location correction in machining processes
, Article International Journal of Computer Integrated Manufacturing ; Vol. 27, Issue. 11 , 29 Oct , 2014 , pp. 969-978 ; ISSN: 0951192X ; Sharif University of Technology
Abstract
Inaccuracies in workpiece location lead to errors in position and orientation of machined features on the workpiece, and strongly affect the assemblability and the quality of the product. The accurate positioning of workpiece on a fixture is influenced by rigid body displacements and rotations of the workpiece due to several errors (e.g. geometric radial and position errors in locators and manufacturing tolerances of the workpiece). In this paper, an efficient approach is introduced for analysis and compensation errors in the workpiece-fixture-cutting tool system. A new mathematical formulation of workpiece-fixture modelling is proposed to establish the relationship between the locating...
Sliding mode control of the turning process for eliminating regenerative chatter in the presence of parametric uncertainties
, Article ASME 2007 International Mechanical Engineering Congress and Exposition, IMECE 2007, 11 November 2007 through 15 November 2007 ; Volume 3 , 2007 , Pages 449-456 ; 0791842975 (ISBN) ; Movahhedy, M. R ; Vossoughi, G. R ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2007
Abstract
Chatter suppression is an important topic in any type of machining process. In this paper, orthogonal cutting process is modeled as a single degree of freedom dynamic system. A nonlinear delay differential equation is presented that models flank wear of the tool. Uncertainties in cutting velocity, tool wear size and parameters of the dynamic model are included in the model of cutting process. The force provided by a piezo-actuator is taken as the control input of the system. A sliding mode control scheme is used and an effective control law is derived which suppresses the chatter vibration. Results for two distinct cases of a sharp tool and a worn tool are presented and compared which shows...
Adaptive control of regenerative chatter in turning process with tool wear effect
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings ; Vol. 10, Issue PART B , 2010 , pp. 1023-1030 ; ISBN: 9780791843833 ; Moradi, H ; Vossoughi, G. R ; Alasty, A ; Movahhedi, M. R ; Sharif University of Technology
Abstract
Chatter suppression is of great importance for achieving high precision and surface quality in machining processes. A single degree of freedom model of orthogonal turning process is used to set up the nonlinear delay differential equation of motion. Tool wear effect is considered as the contact force between the workpiece and tool flank surfaces. Uncertainties in parameters of dynamic model and machining conditions are included in the model. An adaptive control strategy is applied for chatter suppression in cutting process. The force provided by a piezoactuator is the control input of the system. Results of stability analysis and adaptive control for two distinct cases of sharp and worn...
Adaptive control of regenerative chatter in turning process with tool wear effect
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings ; Volume 10, Issue PART B , 2010 , Pages 1023-1030 ; 9780791843833 (ISBN) ; Moradi, H ; Vossoughi, G. R ; Alasty, A ; Movahhedi, M. R
Abstract
Chatter suppression is of great importance for achieving high precision and surface quality in machining processes. A single degree of freedom model of orthogonal turning process is used to set up the nonlinear delay differential equation of motion. Tool wear effect is considered as the contact force between the workpiece and tool flank surfaces. Uncertainties in parameters of dynamic model and machining conditions are included in the model. An adaptive control strategy is applied for chatter suppression in cutting process. The force provided by a piezoactuator is the control input of the system. Results of stability analysis and adaptive control for two distinct cases of sharp and worn...
Tool condition monitoring based on sound and vibration analysis and wavelet packet decomposition
, Article 2012 8th International Symposium on Mechatronics and its Applications, ISMA ; April , 2012 ; 9781467308625 (ISBN) ; Akbari, J ; Behzad, M ; EMAL(Emirates Aluminium) ; Sharif University of Technology
2012
Abstract
Tool Condition Monitoring (TCM) is a vital demand of advanced manufacturing in order to develop automated unmanned production. Continuing the machining operation with a worn or damaged tool will result in damages to the workpiece. This problem becomes more important in supplementary machining processes like drilling which the workpiece usually has passed a lot of machining processes and any damage to workpiece at this stage results in high production losses. In this research features of sound pressure and vibration signals in drilling process are recorded and analyzed in order to detect tool wear. Signal statistical features are extracted in time domain, and the features trends as the tool...
The influence of SiC particles on tool wear in machining of Al/SiC metal matrix composites produced by powder extrusion
, Article Advanced Materials Research, 18 September 2011 through 21 September 2011, Stuttgart ; Volume 325 , 2011 , Pages 393-399 ; 10226680 (ISSN) ; 9783037852316 (ISBN) ; Kouchakzadeh, M. A ; Rahiminasab, J ; Kadivar, M. A ; Sharif University of Technology
2011
Abstract
Metal matrix composites (MMCs) have received considerable attention due to their excellent engineering properties. However, poor machinability has been the main deterrent to their substitution for metal parts. The hardness and abrasive nature of reinforcement phase causes rapid tool wear during machining which results in high machining costs. In this study, the effect of SiC particles (5, 15 & 20 percent) on tool wear in turning process is experimentally investigated. Continuous dry turning of Al/SiC particulate metal matrix composite produced by powder metallurgy and utilizing titanium carbide inserts has been achieved as the test method. The influence of machining parameters, e.g. cutting...
Spindle speed variation for regenerative chatter suppression in turning process with tool wear effect
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010 ; Volume 4 , 2010 , Pages 619-626 ; 9780791849187 (ISBN) ; Vossoughi, G ; Rahaeifard, M ; Movahhedy, M ; ASME Turkey Section ; Sharif University of Technology
Abstract
Chatter suppression in machining processes results in more material removal rate, high precision and surface quality. In this paper, a single degree of freedom model of orthogonal turning process is used to set up the delay differential equation of motion with considering the tool wear effect as a contact force between the workpiece and tool flank surfaces. Sinusoidal spindle speed variations with different frequencies around the mean speed are modulated to disturb the regenerative mechanism. The optimal amplitudes of the speed modulations are found based on a genetic algorithm such that the input energy to the turning process is minimized. Results of the stability analysis and the...
Using a vibration absorber to suppress chatter vibration in turning process with a worn tool
, Article Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference 2009, DETC2009, 30 August 2009 through 2 September 2009 ; Volume 1, Issue PART B , August-September , 2010 , Pages 1335-1341 ; 9780791848982 (ISBN) ; Bakhtiari Nejad, F ; Movahhedi, M. R ; Sharif University of Technology
2010
Abstract
Dynamic vibration absorbers are used as semi-active controllers to reduce the undesirable vibrations in many applications such as electrical transmission lines, helicopters, gas turbines, engines, bridges and etc. One type of these absorbers is tunable vibration absorber (TVA). In this paper, regenerative chatter in an orthogonal turning process is suppressed using a (TVA). It is shown that TVA can modify the frequency response function of the cutting tool so as to improve cutting stability in turning process. In addition, tool wear is an important factor which works as a positive damping and helps the chatter suppression beside exertion of the TVA. Finally, using the SIMULINK Toolbox of...
Using a vibration absorber to suppress chatter vibration in turning process with a worn tool
, Article Proceedings of the ASME Design Engineering Technical Conference, 30 August 2009 through 2 September 2009, San Diego, CA ; Volume 1, Issue PARTS A AND B , 2009 , Pages 1335-1341 ; 9780791848982 (ISBN) ; Bakhtiari Nejad, F ; Movahhedi, M. R ; Sharif University of Technology
Abstract
Dynamic vibration absorbers are used as semi-active controllers to reduce the undesirable vibrations in many applications such as electrical transmission lines, helicopters, gas turbines, engines, bridges and etc. One type of these absorbers is tunable vibration absorber (TVA). In this paper, regenerative chatter in an orthogonal turning process is suppressed using a (TVA). It is shown that TVA can modify the frequency response function of the cutting tool so as to improve cutting stability in turning process. In addition, tool wear is an important factor which works as a positive damping and helps the chatter suppression beside exertion of the TVA. Finally, using the SIMULINK Toolbox of...
Experimental modeling and optimizing process parameters in the laser assisted machining of silicon carbide particle-reinforced aluminum matrix composites
, Article Materials Research Express ; Volume 6, Issue 8 , 2019 ; 20531591 (ISSN) ; Movahhedy, M. R ; Khodaygan, S ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
The process of laser assisted machining (LAM) of metal matrix composites (MMC) is experimentally studied. The effects of process parameters (cutting speed, feed rate and depth of cut), laser parameters (laser power, laser frequency and laser beam angle), and the percentage of reinforcing particles on the tool wear and the surface roughness are investigated. Furthermore, the effects of the mentioned parameters on the built-up edge (BUE), chip shape, and workpiece temperature are explored. The experiments were performed using uncoated tungsten carbide and PCD tools under dry conditions. In order to analyze the sensitivity of the process parameters, the Plackett-Burman method was used for...