The Mechanism of Chatter Vibration in a Spindle-Workpiece System: Part 3—Analytical Considerations

1988 ◽  
Vol 110 (3) ◽  
pp. 248-253 ◽  
Author(s):  
E. Marui ◽  
S. Kato ◽  
M. Hashimoto ◽  
T. Yamada
Keyword(s):  
Cutting Force ◽  
Rake Angle ◽  
Velocity Variation ◽  
Damping Capacity ◽  
Phase Lag ◽  
Chatter Vibration ◽  
Dynamic Variations ◽  
Cutting Velocity ◽  
System Part ◽  
Chatter Marks

Chatter vibration occurring in the spindle-workpiece system of a lathe is treated theoretically, considering the phase lag of cutting force and chatter marks, the dynamic variation effects on cutting force of cutting velocity, and the rake angle during vibration. As a result, it is clarified that the chatter vibration is mainly induced by the phase lag of cutting force (primary chatter) and by the phase lag of chatter marks in successive cutting (regenerative chatter). The dynamic variations of the cutting velocity and rake angle make the spindle-workpiece system more unstable under vibration. The effect of cutting velocity variation is more remarkable than that of rake angle in both types of chatter. Chatter vibration can effectively be suppressed by enlarging the damping capacity of the system.

The Mechanism of Chatter Vibration in a Spindle-Workpiece System: Part 2—Characteristics of Dynamic Cutting Force and Vibration Energy

1988 ◽  
Vol 110 (3) ◽  
pp. 242-247 ◽  
Author(s):  
E. Marui ◽  
S. Kato ◽  
M. Hashimoto ◽  
T. Yamada
Keyword(s):  
Cutting Force ◽  
Rake Angle ◽  
Dynamic State ◽  
Phase Lag ◽  
Chatter Vibration ◽  
Vibration Displacement ◽  
Dynamic Variations ◽  
Dynamic Cutting Force ◽  
Cutting Velocity ◽  
System Part

The cutting force acting in the dynamic state of a lathe spindle-workpiece system is affected by the dynamic variations of cutting depth, cutting velocity, and rake angle. In this study, the influences of these parameters on the dynamic cutting force are measured by unique experiments. The phase lag between the dynamic cutting force and vibration displacement is clarified under various cutting conditions. The dynamic cutting force when the cutting velocity and the rake angle are dynamically changed is measured, and the results are represented as the cutting velocity coefficients and the rake angle coefficients. Based on these results, the energy supplied by the dynamic cutting force is obtained and the mechanism by which the chatter vibration occurs is discussed.

The Mechanism of Chatter Vibration in a Spindle-Workpiece System: Part 1—Properties of Self-Excited Chatter Vibration in Spindle-Workpiece System

1988 ◽  
Vol 110 (3) ◽  
pp. 236-241 ◽  
Author(s):  
E. Marui ◽  
S. Kato ◽  
M. Hashimoto ◽  
T. Yamada
Keyword(s):  
Cutting Force ◽  
Energy Supply ◽  
Phase Lag ◽  
Chatter Vibration ◽  
Regenerative Chatter ◽  
Phase Lags ◽  
System Part ◽  
Cutting Operation ◽  
Dynamic Rigidity ◽  
Chatter Marks

The elimination of chatter vibration is important to improve cutting accuracy and to improve productivity of the cutting operation. In this study, the characteristics of the primary and regenerative chatter vibration occurring in the spindle-workpiece system are investigated experimentally using six spindle-workpiece systems having different vibratory properties. The vibratory locus of the spindle-workpiece system is found. The phase lag between the cutting force and chatter displacement and the phase lag between the successive chatter marks are obtained quantitatively. These phase lags are closely related to the energy supply. The chatter vibration hardly grows up in the spindle-workpiece system having large dynamic rigidity.

scholarly journals Accurate Modeling of Working Normal Rake Angles and Working Inclination Angles of Active Cutting Edges and Application in Cutting Force Prediction

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1207
Author(s):  
Peng Li ◽  
Zhiyong Chang
Keyword(s):  
Cutting Force ◽  
High Performance ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Cutting Edge ◽  
Cutting Force Prediction ◽  
Force Prediction ◽  
Inclination Angles ◽  
Cutting Velocity ◽  
Differential Element

The normal Rake angle is an important geometric parameter of a turning tool, and it directly affects the accuracy of the cutting force prediction. In this study, an accurate model of the working normal rake angle (WNRA) and working inclination angle (WIA) is presented, including variation in the cutting velocity direction. The active cutting edge of the turning tool is discretized into differential elements. Based on the geometric size of the workpiece and the position of the differential elements, the cutting velocity direction of each differential element is calculated, and analytical expressions for the WNRA, WIA, and working side cutting edge angle are obtained for each differential element. The size of the workpiece is found to exert an effect on the WNRA and WIA of the turning tool. The WNRA and WIA are used to predict the cutting force. A good agreement between the predicted and experimental results from a series of turning experiments on GH4169 with different cutting parameters (cutting depth and feed rate) demonstrates that the proposed model is accurate and effective. This research provides theoretical guidelines for high-performance machining.

Effect of Machining Parameters on Deformation Field in Machining by Finite Element Method

2011 ◽  
Vol 80-81 ◽  
pp. 942-945
Author(s):  
C.L. Wu ◽  
Z.R. Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cutting Force ◽  
Large Strain ◽  
Effective Strain ◽  
High Hardness ◽  
Rake Angle ◽  
Machining Parameters ◽  
Cutting Velocity ◽  
Element Method

Formation of chip is a typical severe plastic deformation progress in machining which is only single deformation stage. The large strain, low temperature and deformation force are the major premises to create significant microstructure refinement in metals and alloys. A finite element method was developed to characterize the distribution of strain, temperature and cutting force. Effects of rake angle, cutting velocity and friction on effective strain, cutting force imposed in the chip are researched and the conditions which lead to the large stain deformation in machining are highlighted. The results of simulation have shown that chip materials with ultrafine grained and high hardness can be produced with negative tool rake angle at some lower cutting velocity.

scholarly journals Experiments in the Machining of Ice at Negative Rake Angles

1984 ◽  
Vol 30 (104) ◽  
pp. 77-81 ◽  
Author(s):  
D.K. Lieu ◽  
C.D. Mote
Keyword(s):  
Cutting Force ◽  
Chip Formation ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Rake Angle ◽  
Cutting Depth ◽  
Orthogonal Machining ◽  
Cutting Force Components ◽  
Force Components

AbstractThe cutting force components and the cutting moment on the cutting tool were measured during the orthogonal machining of ice with cutting tools inclined at negative rake angles. The variables included the cutting depth (< 1 mm), the cutting speed (0.01 ms−1to 1 ms−1), and the rake angles (–15° to –60°). Results of the experiments showed that the cutting force components were approximately independent of cutting speed. The resultant cutting force on the tool was in a direction approximately normal to the cutting face of the tool. The magnitude of the resultant force increased with the negative rake angle. Photographs of ice-chip formation revealed continuous and segmented chips at different cutting depths.

Effect of the Cutting Velocity and Heat Treatment on Turning Cutting Forces of an SMA Cu-Al-Be Alloys

2013 ◽  
Vol 758 ◽  
pp. 157-164
Author(s):  
Francisco Valdenor Pereira da Silva ◽  
José Paulo Vogel ◽  
Rodinei Medeiros Gomes ◽  
Tadeu Antonio de Azevedo Melo ◽  
Anna Carla Araujo ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Cutting Force ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Chip Formation ◽  
Cutting Forces ◽  
Cutting Velocity ◽  
Resultant Forces

This work studies the effect of heat treatment and cutting velocities on machining cutting forces in turning of a Cu-11.8%Al-0.55%Be shape memory alloys. The heat treatment was performed to obtain samples with austenite and martensite microstructures. Cutting force was investigated using a 3-component dynamometer in several revolutions and data were analyzed using statistic tools. It was found that the resultant forces were higher in quenched alloy due to the presence of Shape Memory Effect. Chip formation occurred in a shorter time in the sample without the Shape Memory Effect.

Influence of Cutting Conditions on the Width of Adiabatic Shear Bands: An Investigation Using Finite Element Simulation

2013 ◽  
Vol 820 ◽  
pp. 194-199
Author(s):  
Tao Cui ◽  
Hong Wei Zhao ◽  
Ye Tian ◽  
Chuang Liu
Keyword(s):  
High Speed ◽  
Shear Bands ◽  
Chip Thickness ◽  
Rake Angle ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
High Speed Cutting ◽  
Model Combining ◽  
Cutting Velocity ◽  
Microstructure Prediction

In this paper, a novel model combining the microstructure prediction model and a modified constitutive model of the Johnson-Cook (JC) model was developed and embedded into FEM software via the user subroutine. The chip formation and microstructure evolution in high speed cutting of Ti-6Al-4V alloy were simulated. The results indicated that dynamic recrystallization mainly happened in adiabatic shear bands (ASBs), where the grain size had a big decline. Then FEM simulations were carried out to investigate the effect of cutting velocity, uncut chip thickness, and the rake angle on the ASBs width of the serrated chips. It can be concluded that the width of ASB increases with the increasing of cutting depth and cutting velocity, and decreases with the increasing of rake angle of the tool.

scholarly journals Study of Shear-Cutting Mechanisms on Wood Veneer

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 703
Author(s):  
Vicky Reichel ◽  
Werner Berlin ◽  
Felix Rothe ◽  
Jan Beuscher ◽  
Klaus Dröder
Keyword(s):  
Cutting Force ◽  
Cutting Process ◽  
Polymer Materials ◽  
Manufacturing Processes ◽  
Renewable Materials ◽  
Wood Material ◽  
Target Values ◽  
Tool Shape ◽  
Cutting Velocity ◽  
Cutting Mechanisms

Multi-material structures made from renewable materials are increasingly being addressed in research and industry. Especially lightweight applications based on wood and polymer materials offer an important opportunity to reduce weight and CO2 emissions, and thus create a sustainable economy. When establishing new material combinations, it is necessary to take economical and efficient manufacturing processes into count to enable the market entry. Therefore, the existing manufacturing processes needed to be adapted and improved in terms of the specific machining characteristic of the wood material. This study targets a combined process where a forming and shear-cutting process is also integrated in an injection-molding tool. The findings on the shear-cutting process of wood veneers are not widely investigated yet. Therefore, process and material-related dependences like cutting velocity, tool shape design, and preconditioning of wood veneers were examined. The target values cutting force and cutting-edge quality were used to describe the relations. The results showed specific damage and fiber fractions of the wood material compared to the isotropic materials (e.g., metal). In addition, low cutting forces appeared by realizing a drawing cut and high cutting speeds. A decrease in the cutting force with a higher moisture content could not be shown for the used wood types.

Research of Formation Mechanics on Nanostructured Chips by Multi-Deformations Based on Finite Element Method

2014 ◽  
Vol 989-994 ◽  
pp. 352-355
Author(s):  
C.L. Wu ◽  
Z.R. Wang ◽  
Wen Zhang
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Large Strain ◽  
Effective Strain ◽  
Longitudinal Section ◽  
Rake Angle ◽  
Governing Parameter ◽  
Cutting Velocity ◽  
Mean Strain

Formation of chip is a typical severe plastic deformation progress in machining which is only single deformation stage. The rake angle of tool is governing parameter to create large strain imposed in the chip. Effect of rake angle and deformation times on effective strain, mean strain, strain variety and strain rate imposed in the chip are researched respectively. The result of simulation have shown that the chip with large strain and better uniform of strain along the longitudinal section of chip can be produced with negative rake angle at some lower cutting velocity by multi-deformations in large strain machining.

On the Cause of Regenerative Chatter Due to Workpiece Deflection

1974 ◽  
Vol 96 (1) ◽  
pp. 179-186 ◽  
Author(s):  
S. Kato ◽  
E. Marui
Keyword(s):  
Differential Equation ◽  
Experimental Results ◽  
Phase Lag ◽  
Chatter Vibration ◽  
Transient Vibration ◽  
Regenerative Chatter ◽  
Work Surface ◽  
Chatter Vibrations

The cause and the mechanism of regenerative chatter vibrations due to the deflection of workpiece occurring in machining metals are investigated experimentally. The regenerative chatter vibration is induced by the phase lag of the undulations in successive cutting. This means that small undulations initially produced on a work surface by the transient vibration of the workpiece become larger and the undulations extend over the whole work surface because a given amount of energy is available for exciting or maintaining the vibration owing to the phase lag of successive undulations. Then, a differential equation of chatter vibration is introduced based on the experimental results, and some remarks on the properties of chatter vibration are given.

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