scholarly journals Effect of Vibration Direction of Ultrasonic Vibrating Cutting Edge on Internal Stress Fluctuation of Workpiece

2021 ◽  
Vol 15 (4) ◽  
pp. 457-465
Author(s):  
Hiromi Isobe ◽  
Masatoshi Okuda ◽  
Keisuke Hara ◽  
Jun Ishimatsu ◽  
◽  
...  
Keyword(s):  
Stress Distribution ◽  
Cutting Force ◽  
Ultrasonic Vibration ◽  
Rake Angle ◽  
Cutting Edge ◽  
Force Vector ◽  
Vibration Direction ◽  
Vibration Period ◽  
Tool Vibration ◽  
Intermittent Cutting

The aim of this study is to investigate the dynamic phenomenon of ultrasonic vibration-assisted cutting by utilizing a stress distribution visualization system. The vibrating cutting-edge is considered to be a cause of dynamic changes in the cutting force at ultrasonic frequencies. However, many researchers have explained the effect of ultrasonic vibration-assisted cutting by evaluating the time-averaged cutting force, because existing dynamometers are unable to measure the dynamically changing cutting force at ultrasonic frequencies. There are some reports that the vibration direction of cutting edge strongly affects tool wear. However, in practical ultrasonic cutting, the vibration of the cutting edge has yet to be measured in a production environment. In this study, the instantaneous stress distribution on the workpiece was visualized by a photoelastic method that combines a pulsed laser emission synchronized with tool vibration. The developed photographic system can capture 360 frames in one ultrasonic vibration period. The dynamic cutting force was calculated by Flamant’s stress distribution theory. It was experimentally confirmed that the stress distribution under vibration-assisted conditions showed periodical changes synchronized with vibration. Because these results are compatible with well-known vibration-cutting theories, the imaging system was able to show the periodic changes in stress distribution in the ultrasonic frequency band. This indicates that the dynamic change in cutting force during the ultrasonic vibration period affects intermittent cutting conditions. In this report, the vibration direction was adjusted from −9.5° to +9.5° along the cutting direction. When the tool moved in upwards for the cutting phase and downwards for withdrawal phase, the stress distribution was continuously observed over one tool vibration period; no intermittent cutting was observed. The locus of the cutting force vector was affected by the ultrasonic vibration direction and rake angle of the cutting tool. A negative rake angle showed that the direction of the cutting force vector shifted toward the workpiece side near the most advanced position of the cutting edge.

Visualization of Dynamically Changing Cutting Force Under Ultrasonic Cutting Condition

2020 ◽  
Author(s):  
Hiromi Isobe ◽  
Masataka Okuda ◽  
Keisuke Hara ◽  
Akira Sakurada ◽  
Jun Ishimatsu
Keyword(s):  
Stress Distribution ◽  
Cutting Force ◽  
Ultrasonic Vibration ◽  
Dynamic Change ◽  
Rake Angle ◽  
Cutting Condition ◽  
Ultrasonic Frequency ◽  
Vibration Direction ◽  
Vibration Period ◽  
Intermittent Cutting

Abstract The aim of this study is to investigate the dynamic phenomenon of ultrasonic vibration-assisted cutting condition by utilizing visualization system of stress distribution. The vibrating cutting edge is considered to be cause of dynamic change of cutting force at ultrasonic frequency. However, many researchers have explained the effect of ultrasonic vibration-assisted cutting by evaluating the time-averaged cutting force, because the dynamometers have insufficient frequency characteristics to measure the dynamically changing cutting force in ultrasonic frequency. In this study, the instantaneous stress distribution on workpiece was visualized by photoelastic method in combination of pulse laser emission synchronized with tool vibration. A constructed photographic system is able to capture 360 flames for one ultrasonic vibration period. Dynamic cutting force is calculated by stress distribution by Flamant theory. It was experimentally confirmed that the stress distribution under vibration-assisted condition showed the periodical change synchronized with insert vibration. Because these results are compatible with well-known vibration cutting theories, the imaging system is able to show the periodic change of stress distribution in ultrasonic frequency band. It is considered that the dynamic change of cutting force for ultrasonic vibration period affects intermittent cutting condition. In this report, the vibration direction was adjusted from −9.54° to +9.5° to the cutting direction. When the tool moved in upward for the cutting phase and downward for withdrawal phase, the stress distribution continued to be observed over one period of tool vibration and intermittent cutting did not occurred. The locus of cutting force vector was affected by the ultrasonic vibration direction and rake angle of cutting tool. Negative rake angle showed that the direction of the cutting force vector shifted to the workpiece side near the most advanced position of the cutting edge.

High-Speed Capturing of Stress Distribution of Workpiece under Ultrasonically Assisted Cutting Condition

2014 ◽  
Vol 1017 ◽  
pp. 747-752
Author(s):  
Hiromi Isobe ◽  
Keisuke Hara
Keyword(s):  
Stress Distribution ◽  
Cutting Force ◽  
High Speed ◽  
Cutting Tool ◽  
Light Emission ◽  
Cutting Speed ◽  
Cutting Condition ◽  
Photoelastic Method ◽  
Intermittent Cutting ◽  
Ultrasonic Vibration Cutting

This paper reports the stress distribution inside the workpiece under ultrasonic vibration cutting (UVC) condition. Many researchers have reported the improvement of tool wear, burr generation and surface integrity by reduction of time-averaged cutting force under UVC condition. However general dynamometers have an insufficient frequency band to observe the processing phenomena caused by UVC. In this paper, stress distribution inside the workpiece during UVC was observed by combining the flash light emission synchronized with ultrasonically vibrating cutting tool and the photoelastic method. Instantaneous stress distribution during UVC condition was observed. Because UVC induced an intermittent cutting condition, the stress distribution changed periodically and disappeared when the tool leaved from the workpiece. It was found that instantaneous maximum cutting force during UVC condition was smaller than quasi-static cutting force during conventional cutting when the cutting speed was less than 500 mm/min.

Correlation of Cutting Force and Power Consumption for Ultrasonic-Vibration-Assisted Cutting of Label Paper Stacks

2012 ◽  
Author(s):  
Karl-Robert Deibel ◽  
Jens Boos ◽  
Sascha Weikert ◽  
Konrad Wegener
Keyword(s):  
Cutting Force ◽  
Ultrasonic Vibration ◽  
Quality Parameters ◽  
Cutting Edge ◽  
Pull Out ◽  
Edge Quality ◽  
Force Reduction ◽  
Cutting Speeds ◽  
Guillotine Cutting

Experiments comparing conventional and ultrasonic vibration assisted guillotine cutting of paper stacks have been performed on plain and aluminum coated label paper. It is shown that ultrasonic vibration assisted cutting reduces the cutting force for both paper species. Reduction of the cutting force allows the down holder force to be decreased and lowers the compression of the paper stack necessary to prevent pull-out of the top sheets of paper. Using a higher amplitude setting on the ultrasonic generator further decreases the cutting force for the paper stack. For three different cutting speeds, it is shown that ultrasonic vibration assisted cutting force reduction depends on the average speed of the tool for both paper species. A linear regression with present experimental data is done to obtain an equation for the relation between input generator power and resulting cutting force. Finally, the quality of the cutting edge is examined, quality parameters are defined, and according to these the cutting edge quality is assessed.

scholarly journals Precise Design of Drill Structure Based on Cutting Force Distribution Alone Cutting Edge in CFRP Drilling

2021 ◽  
Author(s):  
Xin-Yi Qiu ◽  
Peng-Nan Li ◽  
Chang-Ping Li ◽  
Qiu-Lin Niu ◽  
Shu-Jian Li ◽  
...  
Keyword(s):  
Cutting Force ◽  
Thrust Force ◽  
Rake Angle ◽  
Cutting Edge ◽  
Distribution Model ◽  
Force Distribution ◽  
Force Coefficient ◽  
Cutting Force Prediction ◽  
Drilling Performance ◽  
Step Drill

Abstract At present, the problems that need to be solved urgently in CFRP drilling are delamination and tool wear, which are closely related to the distribution of cutting force on the cutting edge. The aim of this paper is to present a method to analyze the cutting force distribution on the main cutting edge of the drill. This method applies to the analysis of the drilling performance of double point angle (DPA) drill and to optimize the step drill structure for CFRP drilling. Both of these applications prove the correctness of the analysis method. According to the calculation model of the rake angle of the main cutting edge of the twist drill and the cutting force prediction model, the distribution model of the cutting force on the main cutting edge is established. This method reveals the basic reason why the thrust force increases linearly when a single main cutting edge cuts into the workpiece. In the process of analyzing the drilling performance of the DPA drill, the edge force coefficient is used to represent the thrust force, and the application environment of the drill with a different structure is analyzed. Based on the distribution characteristics of the axial force on the main cutting edge, the step ratio of the step drill is optimized. This method can optimize the step ratio of the step drill. This method can be employed to optimize the step ratio of any structure step drill.

Mechanistic Model Based on the Actual Removal Volume during Simultaneous Five-Axis Milling

2011 ◽  
Vol 223 ◽  
pp. 713-722 ◽  
Author(s):  
Seok Won Lee ◽  
Andreas Nestler
Keyword(s):  
Cutting Force ◽  
Process Model ◽  
Tool Path ◽  
Mechanistic Model ◽  
Cutting Tools ◽  
Rake Angle ◽  
Milling Process ◽  
Cutting Edge ◽  
Nc Code ◽  
Five Axis

In this paper we present a novel mechanistic model of cutting process of the cylindrical tool by using the actual removal volume per tooth via NC simulation. The simulation kernel enables “virtually” cutting the workpiece in milling process per NC code, as well as calculating the removal volume per tooth which leads to predict the actual cutting force during simultaneous five-axis machining. Combined with the material removal simulation, the advanced mechanistic process model, which can enable the prediction of the cutting force and adjust the trajectory velocity of the cylindrical tools undergoing five-axis movement, is presented by applying the line integral along the cutting edge and taking the rake angle and cutting edge roundness into consideration. The novel methodology to adjust the cutting force by prevailing cutting tools undergoing multi-axis motion is to be validated by experiment and integrated into tool path planning systems.

Cutting Force of Hollow Needle Insertion in Soft Tissue

2013 ◽  
Author(s):  
Bruce L. Tai ◽  
Yancheng Wang ◽  
Albert J. Shih
Keyword(s):  
Finite Element ◽  
Cutting Force ◽  
Cohesive Zone ◽  
Element Model ◽  
Rake Angle ◽  
Needle Insertion ◽  
Cutting Edge ◽  
Analysis Tool ◽  
Phantom Tissue ◽  
Hollow Needle

This paper presents a 3-D finite element model (FEM) using cohesive zone (CZ) concept to simulate the hollow needle insertion and identify the change in cutting force. CZ is a FEM technique that integrates the fracture mechanics based on surface energy and has often used in analysis of crack propagation. Experiments of needle insertion into the soft polyvinyl chloride (PVC) phantom tissue were conducted using two types of needle (bias bevel and lancet) under a constant speed to identify friction and cutting forces. Using the CZ concept, a thin layer of FEM is built to observe the tissue flow and cutting force along the needle cutting edge during insertion. Both experimental observation and modeling results show higher cutting force for the lancet tip due to smaller rake angle along the cutting edge. This FEM approach has demonstrated the potential as being an analysis tool for hollow needle insertion.

Lubrication Effect of Smeared Oil on Workpiece Surface in Intermittent Cutting With Very Short Cutting Duration

2020 ◽  
Author(s):  
Yoshiki Nakamura ◽  
Fumihiro Itoigawa ◽  
Shinya Hayakawa ◽  
Satoru Maegawa ◽  
Xiaoxu Liu
Keyword(s):  
Cutting Force ◽  
Temperature Rise ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Temperature ◽  
Cutting Edge ◽  
Frictional Heat ◽  
Low Viscosity ◽  
Ti Alloys ◽  
Intermittent Cutting

Abstract In the metal cutting, generally, application of lubricant to a cutting edge is one of the methods in order to suppress temperature rise of the cutting edge by reducing frictional heat. However, the reduction in friction with lubricant disappears at higher temperature environment because of the loss of lubricant oiliness associated with temperature rise. Conversely, this reduction effect might work only in the initial stage immediately after cutting edge /work engagement because the temperature is not so high. Therefore, if the cutting duration of each blade of end-mill is shorten by limiting the cutting length per once, the cutting temperature can be suppressed to be lower than the moderate magnitude for lubrication. On the other hand, Ti-alloys with low thermal conductivity would experience quite high temperature increase during the high-speed cutting process. Therefore, it is thought that lubricant cannot be used properly with conventional cutting methods. In this study, the high-speed milling method mentioned above was used to implement the machining of Ti-alloys, and the lubricant effects of different types oils were compared from two aspects as tool wear and cutting force. As a result, when using low-viscosity synthetic ester oil, the damage to the cutting edge was suppressed most. At the same time, there was no fluctuation in cutting force by repeated machining. From this result, it was suggested that the lubricant performance, in intermittent cutting with very short cutting duration, depends on the heat resistance and permeability of the oil.

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.

Longitudinal–torsional ultrasonic vibration-assisted side milling process

2019 ◽  
Vol 233 (10) ◽  
pp. 3356-3363 ◽  
Author(s):  
Chenjun Wu ◽  
Shijin Chen ◽  
Caiwei Xiao ◽  
Kai Cheng ◽  
Hui Ding
Keyword(s):  
Cutting Force ◽  
Ultrasonic Vibration ◽  
High Frequency ◽  
Milling Process ◽  
Cutting Process ◽  
Side Milling ◽  
Milling Tool ◽  
Helical Angle ◽  
Vibration Milling ◽  
Intermittent Cutting

In this paper, a longitudinal–torsional ultrasonic vibration-assisted side milling is investigated. Different from the continuous cutting process in conventional side milling, the longitudinal–torsional ultrasonic vibration milling process is high-frequency intermittent. The intermittent cutting process is caused by the helical trajectory of the cutting edge. A mathematical model is established to simulate the trajectory and then the high-frequency intermittent cutting process is analyzed based on the model. Spindle speed, helix angle of milling tool, and ultrasonic vibration amplitudes are found to be the factors that are responsible for the ultrasonic cutting effect. When the spindle speed is 1500 r/min and the helical angle of milling tool is 30°, ultrasonic vibration milling experiments have shown that the cutting force can be reduced by 45.8% in the x direction at the most, 27.6% in the y direction, and 48% in the z direction compared to conventional milling. The experimental results also show that the decrement of the cutting force decreases along with the increasing of the cutting speed and helical angle of milling tool due to the decrease of the uncutting time. However, the increasing of the vibration amplitude can increase the decrement.

scholarly journals Z-Map Based Cutting Force Prediction for Elliptical Ultrasonic Vibration-Assisted Milling Process

2021 ◽  
Author(s):  
Zhongqun Li ◽  
Jiandong Xiao Xiao ◽  
Xiong HAN ◽  
Weifeng ZHANG
Keyword(s):  
Cutting Force ◽  
Ultrasonic Vibration ◽  
High Frequency ◽  
Cutting Speed ◽  
Milling Process ◽  
Force Model ◽  
Cutting Force Prediction ◽  
Hard And Brittle Materials ◽  
The Impact ◽  
Intermittent Cutting

Abstract Elliptical ultrasonic vibration-assisted milling (EUVAM) adds high-frequency vibration to conventional milling (CM) to realize high-frequency intermittent milling. It has broad application prospects in the processing of difficult-to-cut materials such as titanium alloys, superalloys and hard and brittle materials. To reveal the mechanism of the highly intermittent cutting nature in EUVAM, according to the motion relationship between cutting edge and workpiece and the Z-map model of the workpiece, a method and its algorithm for calculating undeformed cutting thickness and thus the cutting force in EUVAM are proposed. The simulation results show that EUVAM can improve the actual cutting speed when compared with CM, and the proportion of idle cutting time will directly determine the intermittent degree of the milling process. The experiment of EUVAM is performed to verify the correctness of the proposed cutting force model, and the impact of spindle speed on the cutting force in EUVAM is also analyzed.

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