Analytical and experimental stability analysis of AU4G1 thin-walled tubular workpieces in turning process

2020 ◽  
Vol 234 (6-7) ◽  
pp. 1007-1018 ◽  
Author(s):  
Zied Sahraoui ◽  
Kamel Mehdi ◽  
Moez Ben-Jaber
Keyword(s):  
Stability Analysis ◽  
Feed Rate ◽  
Experimental Studies ◽  
Rake Angle ◽  
Machining Process ◽  
Structural Damping ◽  
Turning Process ◽  
Process Stability ◽  
Thin Walled ◽  
The Stability

The development of the manufacturing-based industries is principally due to the improvement of various machining operations. Experimental studies are important in researches, and their results are also considered useful by the manufacturing industries with their aim to increase quality and productivity. Turning is one of the principal machining processes, and it has been studied since the 20th century in order to prevent machining problems. Chatter or self-excited vibrations represent an important problem and generate the most negative effects on the machined workpiece. To study this cutting process problem, various models were developed to predict stable and unstable cutting conditions. Stability analysis using lobes diagrams became useful to classify stable and unstable conditions. The purpose of this study is to analyze a turning process stability using an analytical model, with three degrees of freedoms, supported and validated with experimental tests results during roughing operations conducted on AU4G1 thin-walled tubular workpieces. The effects of the tubular workpiece thickness, the feed rate and the tool rake angle on the machining process stability will be presented. In addition, the effect of an additional structural damping, mounted inside the tubular workpiece, on the machining process stability will be also studied. It is found that the machining stability process is affected by the tubular workpiece thickness, the feed rate and the tool rake angle. The additional structural damping increases the stability of the machining process and reduces considerably the workpiece vibrations amplitudes. The experimental results highlight that the dynamic behavior of turning process is governed by large radial deformations of the thin-walled workpieces. The influence of this behavior on the stability of the machining process is assumed to be preponderant.

Experimental Study of the Dynamic Behavior of Thin-Walled Tubular Workpieces in Turning Cutting Process

2020 ◽  
pp. 1-19
Author(s):  
Zied Sahraoui ◽  
Kamel Mehdi ◽  
Moez Ben Jaber
Keyword(s):  
Dynamic Behavior ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Cutting Process ◽  
Machining Process ◽  
Structural Damping ◽  
Turning Process ◽  
Manufactured Products ◽  
Thin Walled ◽  
The Stability

Nowadays, industrialists, especially those in the automobile and aeronautical transport fields, seek to lighten the weight of different product components by developing new materials lighter than those usually used or by replacing some massive parts with thin-walled hollow parts. This lightening operation is carried out in order to reduce the energy consumption of the manufactured products while guaranteeing optimal mechanical properties of the components and increasing quality and productivity. To achieve these objectives, some research centers have focused their work on the development and characterization of new light materials and some other centers have focused their work on the analysis and understanding of the encountered problems during the machining operation of thin-walled parts. Indeed, various studies have shown that the machining process of thin-walled parts differs from that of rigid parts. This difference comes from the dynamic behavior of the thin-walled parts which is different from that of the massive parts. Therefore, the purpose of this paper is to first highlight some of these problems through the measurement and analysis of the cutting forces and vibrations of tubular parts with different thicknesses in AU4G1T351 aluminum alloy during the turning process. The experimental results highlight that the dynamic behavior of turning process is governed by large radial deformations of the thin-walled workpieces and the influence of this behavior on the variations of the chip thickness and cutting forces is assumed to be preponderant. The second objective is to provide manufacturers with a practical solution to the encountered vibration problems by improving the structural damping of thin-walled parts by additional damping. It is found that the additional structural damping increases the stability of the cutting process and reduces considerably the vibrations amplitudes.

scholarly journals Analytical modeling of a thin-walled cylindrical workpiece during the turning process. Stability analysis of a cutting process

2017 ◽  
Vol 19 (8) ◽  
pp. 5825-5841 ◽  
Author(s):  
Artem Gerasimenko ◽  
Mikhail Guskov ◽  
Alexander Gouskov ◽  
Philippe Lorong ◽  
Alexander Shokhin
Keyword(s):  
Stability Analysis ◽  
Analytical Modeling ◽  
Cutting Process ◽  
Turning Process ◽  
Process Stability ◽  
Cylindrical Workpiece ◽  
Thin Walled

Chatter Suppression via an Oscillating Cutter

1999 ◽  
Vol 121 (1) ◽  
pp. 54-60 ◽  
Author(s):  
F. Yang ◽  
B. Zhang ◽  
J. Yu
Keyword(s):  
Experimental Studies ◽  
Rake Angle ◽  
Transmission Mechanism ◽  
Machining Process ◽  
Chatter Suppression ◽  
Critical Issues ◽  
The Stability ◽  
Cutting System ◽  
Theoretical Analyses

Chatter is one of the critical issues in a machining process since it deteriorates the surface quality of a workpiece and reduces machining efficiency. A new method is developed to suppress chatter in which an oscillating cutter is used to machine the workpiece through a stepping motor and a transmission mechanism so as to vary tool rake angle continuously and periodically in process. Theoretical analyses are performed on the stability of the cutting system, and verified by the experimental studies. Both theoretical analyses and experimental results indicate that the method can suppress chatter in a turning process effectively. With the application of an oscillating cutter, the amplitude can be reduced by 80 percent in cutting a steel workpiece.

Stability analysis in machining process by using adaptive closed-loop feedback control system in turning process

2020 ◽  
pp. 107754632095261
Author(s):  
Kashfull Orra ◽  
Sounak K Choudhury
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Closed Loop ◽  
Machining Process ◽  
Feedback Control System ◽  
Turning Process ◽  
Tool Vibration ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
The Stability

The study presents model-based mechanism of nonlinear cutting tool vibration in turning process and the strategy of improving cutting process stability by suppressing machine tool vibration. The approach used is based on the closed-loop feedback control system with the help of electro–magneto–rheological damper. A machine tool vibration signal generated by an accelerometer is fed back to the coil of a damper after suitable amplification. The damper, attached under the tool holder, generates counter forces to suppress the vibration after being excited by the signal in terms of current. The study also discusses the use of transfer function approach for the development of a mathematical model and adaptively controlling the process dynamics of the turning process. The purpose of developing such mechanism is to stabilize the machining process with respect to the dynamic uncut chip thickness responsible for the type-II regenerative effect. The state-space model used in this study successfully checked the adequacy of the model through controllability and observability matrices. The eigenvalue and eigenvector have confirmed the stability of the system more accurately. The characteristic of the stability lobe chart is discussed for the present model-based mechanism.

A numerical approach for the stability analysis of open thin-walled beams

2013 ◽  
Vol 48 ◽  
pp. 76-86 ◽  
Author(s):  
Egidio Lofrano ◽  
Achille Paolone ◽  
Giuseppe Ruta
Keyword(s):  
Stability Analysis ◽  
Numerical Approach ◽  
Thin Walled ◽  
The Stability

Stall Nonlinear Flutter of Wind Turbine Blade Modeled as Thin-Walled Composite Beam Integrated with Structural Damping

2013 ◽  
Vol 291-294 ◽  
pp. 496-500
Author(s):  
Yong Sheng Ren ◽  
Ting Rui Liu
Keyword(s):  
Structural Model ◽  
Structural Damping ◽  
Aeroelastic Stability ◽  
Damping Matrix ◽  
Modal Damping ◽  
Strip Theory ◽  
Analytical Formulas ◽  
Thin Walled ◽  
The Stability ◽  
Domain Integration

The effects of structural damping on the aeroelastic stability have been investigated for composite thin-walled blade. Structural model of the composite thin-walled blade exhibits bending-bending-twist coupling, with accounting for the presence of pretwist angle. The aerodynamic model used in the present paper is the differential dynamic stall model developed at ONERA. The structural damping of the blade is predicted based on the analytical formulas of the modal damping of thin-walled composite structure. The effect of structural damping on aeroelastic stability is taken into account by using proportional damping matrix. By means of Galerkin method, the nonlinear aeroelastic equations are reduced to ordinary equations. The general aerodynamic forces are obtained from strip theory. The resulting equations are then linearized for small perturbation about the equilibrium point and the stability characteristics are investigated through eigenvalue analysis and time domain integration.

Chatter in Turning Process Incorporating the Effect of Ploughing Force

1999 ◽  
Author(s):  
Z. C. Wang ◽  
W. L. Cleghorn ◽  
S. D. Yu
Keyword(s):  
Stability Analysis ◽  
Cutting Force ◽  
Force Model ◽  
Turning Process ◽  
Cutting Force Model ◽  
Stability Curve ◽  
Characteristic Roots ◽  
The Laplace Transform ◽  
Machining System ◽  
The Stability

Abstract In this paper, the stability analysis of turning process is performed based on a new cutting force model which includes the effect of ploughing force. This approach utilized the Laplace transform to identify the characteristic roots of the examined machining system. The stability of the machining system can then be determined by examining the locations of the characteristic roots. The stability curve for a specific turning process can then be plotted. The effect of different cutting force models on the stability is also investigated. The results clearly demonstrate some chatter phenomena observed by other researchers.

Preliminary Study on the Effect of Mass-Induced Damping on Machining Delicate Workpiece Geometry

2013 ◽  
Vol 764 ◽  
pp. 83-89
Author(s):  
A. Kamaruddin ◽  
W.C. Pan ◽  
S.L. Ding ◽  
J. Mo
Keyword(s):  
Machining Process ◽  
Depth Of Cut ◽  
Machining Processes ◽  
Stability Lobe ◽  
Mechanical Factors ◽  
Preliminary Study ◽  
Thin Walled ◽  
Enhance Efficiency ◽  
The Stability ◽  
Minor Increment

Study of predicting chatter has been around for many years. These studies are crucial for our understanding of machining processes and to enhance efficiency in manufacturing. This paper presents a new mechanism affecting the stability of machining process called mass induced damping. This effect is simulated numerically with tested values of initial parameters taken for impact tests of a thin-walled workpiece. Results from the simulation shows minor increment in allowable depth of cut by numerically calculated using stability lobe theory. This effect will open a new understanding how certain mechanical factors would affect the value of damping of a system.

Nonlinear Stability Analysis of Thin-Walled Pier

2013 ◽  
Vol 361-363 ◽  
pp. 1251-1254
Author(s):  
Xiao Mei Dong
Keyword(s):  
Stability Analysis ◽  
Nonlinear Stability ◽  
Shell Element ◽  
Nonlinear Stability Analysis ◽  
Nonlinearity Effect ◽  
Updated Lagrangian Formulation ◽  
Thin Walled ◽  
Displacement Theory ◽  
The Stability ◽  
Updated Lagrangian

Shell element was used to simulate thin-walled piers. Mander constitutive model was adopted for analysis about the material nonlinearity. By finite displacement theory the geometric nonlinearity effect was reckoned in stability analysis based on Updated Lagrangian formulation. Nonlinear stability analysis during different construction stages indicates that the stability of pier in cantilever stage is weakest. Considered the dual non-linearity, the stability coefficient descends distinctly.

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