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Improved analytical model for residual stress prediction in orthogonal cutting

null

《机械工程前沿(英文)》 2014年 第9卷 第3期   页码 249-256 doi: 10.1007/s11465-014-0310-1

摘要:

The analytical model of residual stress in orthogonal cutting proposed by Jiann is an important tool for residual stress prediction in orthogonal cutting. In application of the model, a problem of low precision of the surface residual stress prediction is found. By theoretical analysis, several shortages of Jiann’s model are picked out, including: inappropriate boundary conditions, unreasonable calculation method of thermal stress, ignorance of stress constraint and cyclic loading algorithm. These shortages may directly lead to the low precision of the surface residual stress prediction. To eliminate these shortages and make the prediction more accurate, an improved model is proposed. In this model, a new contact boundary condition between tool and workpiece is used to make it in accord with the real cutting process; an improved calculation method of thermal stress is adopted; a stress constraint is added according to the volume-constancy of plastic deformation; and the accumulative effect of the stresses during cyclic loading is considered. At last, an experiment for measuring residual stress in cutting AISI 1045 steel is conducted. Also, Jiann’s model and the improved model are simulated under the same conditions with cutting experiment. The comparisons show that the surface residual stresses predicted by the improved model is closer to the experimental results than the results predicted by Jiann’s model.

关键词: residual stress     analytical model     orthogonal cutting     cutting force     cutting temperature    

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

《机械工程前沿(英文)》 doi: 10.1007/s11465-021-0661-3

摘要: Tool failures in machining processes often cause severe damages of workpieces and lead to large quantities of loss, making tool condition monitoring an important, urgent issue. However, problems such as practicability still remain in actual machining. Here, a real-time tool condition monitoring method integrated in an in situ fiber optic temperature measuring apparatus is proposed. A thermal simulation is conducted to investigate how the fluctuating cutting heats affect the measuring temperatures, and an intermittent cutting experiment is carried out, verifying that the apparatus can capture the rapid but slight temperature undulations. Fourier transform is carried out. The spectrum features are then selected and input into the artificial neural network for classification, and a caution is given if the tool is worn. A learning rate adaption algorithm is introduced, greatly reducing the dependence on initial parameters, making training convenient and flexible. The accuracy stays 90% and higher in variable argument processes. Furthermore, an application program with a graphical user interface is constructed to present real-time results, confirming the practicality.

关键词: tool condition monitoring     cutting temperature     neural network     learning rate adaption    

Cutting heat dissipation in high-speed machining of carbon steel based on the calorimetric method

QUAN Yanming, HE Zhenwei, DOU Yong

《机械工程前沿(英文)》 2008年 第3卷 第2期   页码 175-179 doi: 10.1007/s11465-008-0022-5

摘要: The cutting heat dissipation in chips, workpiece, tool and surroundings during the high-speed machining of carbon steel is quantitatively investigated based on the calorimetric method. Water is used as the medium to absorb the cutting heat; a self-designed container suitable for the high-speed lathe is used to collect the chips, and two other containers are adopted to absorb the cutting heat dissipated in the workpiece and tool, respectively. The temperature variations of the water, chips, workpiece, tool and surroundings during the closed high-speed machining are then measured. Thus, the cutting heat dissipated in each component of the cutting system, total cutting heat and heat flux are calculated. Moreover, the power resulting from the main cutting force is obtained according to the measured cutting force and predetermined cutting speed. The accuracy of cutting heat measurement by the calorimetric method is finally evaluated by comparing the total cutting heat flux with the power resulting from the main cutting force.

关键词: cutting system     medium     temperature     flux     tool    

Crystallographic orientation effect on cutting-based single atomic layer removal

Wenkun XIE, Fengzhou FANG

《机械工程前沿(英文)》 2020年 第15卷 第4期   页码 631-644 doi: 10.1007/s11465-020-0599-x

摘要: The ever-increasing requirements for the scalable manufacturing of atomic-scale devices emphasize the significance of developing atomic-scale manufacturing technology. The mechanism of a single atomic layer removal in cutting is the key basic theoretical foundation for atomic-scale mechanical cutting. Material anisotropy is among the key decisive factors that could not be neglected in cutting at such a scale. In the present study, the crystallographic orientation effect on the cutting-based single atomic layer removal of monocrystalline copper is investigated by molecular dynamics simulation. When undeformed chip thickness is in the atomic scale, two kinds of single atomic layer removal mechanisms exist in cutting-based single atomic layer removal, namely, dislocation motion and extrusion, due to the differing atomic structures on different crystallographic planes. On close-packed crystallographic plane, the material removal is dominated by the shear stress-driven dislocation motion, whereas on non-close packed crystallographic planes, extrusion-dominated material removal dominates. To obtain an atomic, defect-free processed surface, the cutting needs to be conducted on the close-packed crystallographic planes of monocrystalline copper.

关键词: ACSM     single atomic layer removal mechanism     crystallographic orientation effect     mechanical cutting     Manufacturing III    

and plastic deformation to machined surface temperatures and residual stress patterns in finish dry cutting

Subhash ANURAG, Yuebin GUO,

《机械工程前沿(英文)》 2010年 第5卷 第3期   页码 247-255 doi: 10.1007/s11465-010-0097-7

摘要: Temperature on the machined surface is critical for surface integrity and the performance of a precision component. However, the temperature of a machined surface is challenging for in-situ measurement. Furthermore, the individual contribution of tool/work friction and plastic deformation of work materials to surface temperature is very difficult to quantify because the measured temperature is always the resultant temperature. This lack of understanding on the temperature distribution blocks the design of effective cutting tool geometries and materials to minimize surface temperature. This study provides a finite element method based on a predictive model to decouple the contributions of tool/work friction and material plastic deformation to surface temperature in a dry cutting process. The study shows that the plastic deformation of work material contributes to the majority of surface temperature, whereas the tool/work friction contribution is secondary. High temperatures are produced when more materials are plowed under the cutting edge. A large tool/work friction leads to higher surface temperatures, and the use of a cutting tool with physical properties in process simulation significantly improves the accuracy of predicted surface temperatures. Residual stress reversal from subsurface maximum residual to surface maximum residual stress may occur when tool/work friction increases.

关键词: surface temperature     friction     residual stress     finite element analysis (FEA)     dry cutting     tool property    

Modeling of the minimum cutting thickness in micro cutting with consideration of the friction aroundthe cutting zone

Tianfeng ZHOU, Ying WANG, Benshuai RUAN, Zhiqiang LIANG, Xibin WANG

《机械工程前沿(英文)》 2020年 第15卷 第1期   页码 81-88 doi: 10.1007/s11465-019-0561-y

摘要: Friction modeling between the tool and the workpiece plays an important role in predicting the minimum cutting thickness during TC4 micro machining and finite element method (FEM) cutting simulation. In this study, a new three-region friction modeling is proposed to illustrate the material flow mechanism around the friction zone in micro cutting; estimate the stress distributions on the rake, edge, and clearance faces of the tool; and predict the stagnation point location and the minimum cutting thickness. The friction modeling is established by determining the distribution of normal and shear stress. Then, it is applied to calculate the stagnation point location on the edge face and predict the minimum cutting thickness. The stagnation point and the minimum cutting thickness are also observed and illustrated in the FEM simulation. Micro cutting experiments are conducted to validate the accuracy of the friction and the minimum cutting thickness modeling. Comparison results show that the proposed friction model illustrates the relationship between the normal and sheer stress on the tool surface, thereby validating the modeling method of the minimum cutting thickness in micro cutting.

关键词: tool friction     minimum cutting thickness     finite element method     tool edge radius     micro cutting    

Molecular dynamics modeling of a single diamond abrasive grain in grinding

Angelos P. MARKOPOULOS,Ioannis K. SAVVOPOULOS,Nikolaos E. KARKALOS,Dimitrios E. MANOLAKOS

《机械工程前沿(英文)》 2015年 第10卷 第2期   页码 168-175 doi: 10.1007/s11465-015-0337-y

摘要:

In this paper the nano-metric simulation of grinding of copper with diamond abrasive grains, using the molecular dynamics (MD) method, is considered. An MD model of nano-scale grinding, where a single diamond abrasive grain performs cutting of a copper workpiece, is presented. The Morse potential function is used to simulate the interactions between the atoms involved in the procedure. In the proposed model, the abrasive grain follows a curved path with decreasing depth of cut within the workpiece to simulate the actual material removal process. Three different initial depths of cut, namely 4 ?, 8 ? and 12 ?, are tested, and the influence of the depth of cut on chip formation, cutting forces and workpiece temperatures are thoroughly investigated. The simulation results indicate that with the increase of the initial depth of cut, average cutting forces also increase and therefore the temperatures on the machined surface and within the workpiece increase as well. Furthermore, the effects of the different values of the simulation variables on the chip formation mechanism are studied and discussed. With the appropriate modifications, the proposed model can be used for the simulation of various nano-machining processes and operations, in which continuum mechanics cannot be applied or experimental techniques are subjected to limitations.

关键词: molecular dynamics     abrasive process     chip formation     cutting force     temperature    

A review on ductile mode cutting of brittle materials

Elijah Kwabena ANTWI, Kui LIU, Hao WANG

《机械工程前沿(英文)》 2018年 第13卷 第2期   页码 251-263 doi: 10.1007/s11465-018-0504-z

摘要:

Brittle materials have been widely employed for industrial applications due to their excellent mecha-nical, optical, physical and chemical properties. But obtaining smooth and damage-free surface on brittle materials by traditional machining methods like grinding, lapping and polishing is very costly and extremely time consuming. Ductile mode cutting is a very promising way to achieve high quality and crack-free surfaces of brittle materials. Thus the study of ductile mode cutting of brittle materials has been attracting more and more efforts. This paper provides an overview of ductile mode cutting of brittle materials including ductile nature and plasticity of brittle materials, cutting mechanism, cutting characteristics, molecular dynamic simulation, critical undeformed chip thickness, brittle-ductile transition, subsurface damage, as well as a detailed discussion of ductile mode cutting enhancement. It is believed that ductile mode cutting of brittle materials could be achieved when both crack-free and no subsurface damage are obtained simultaneously.

关键词: ductile mode cutting     brittle materials     critical undeformed chip thickness     brittle-ductile transition     subsurface damage     molecular dynamic simulation    

Cutting performance of surgical electrodes by constructing bionic microstriped structures

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0728-9

摘要: Surgical electrodes rely on thermal effect of high-frequency current and are a widely used medical tool for cutting and coagulating biological tissue. However, tissue adhesion on the electrode surface and thermal injury to adjacent tissue are serious problems in surgery that can affect cutting performance. A bionic microstriped structure mimicking a banana leaf was constructed on the electrode via nanosecond laser surface texturing, followed by silanization treatment, to enhance lyophobicity. The effect of initial, simple grid-textured, and bionic electrodes with different wettabilities on tissue adhesion and thermal injury were investigated using horizontal and vertical cutting modes. Results showed that the bionic electrode with high lyophobicity can effectively reduce tissue adhesion mass and thermal injury depth/area compared with the initial electrode. The formation mechanism of adhered tissue was discussed in terms of morphological features, and the potential mechanism for antiadhesion and heat dissipation of the bionic electrode was revealed. Furthermore, we evaluated the influence of groove depth on tissue adhesion and thermal injury and then verified the antiadhesion stability of the bionic electrode. This study demonstrates a promising approach for improving the cutting performance of surgical electrodes.

关键词: surgical electrodes     tissue adhesion     thermal injury     bionic structures     cutting performance     medical tools    

Edge preparation methods for cutting tools: a review

《机械工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11465-023-0766-y

摘要: Edge preparation can remove cutting edge defects, such as burrs, chippings, and grinding marks, generated in the grinding process and improve the cutting performance and service life of tools. Various edge preparation methods have been proposed for different tool matrix materials, geometries, and application requirements. This study presents a scientific and systematic review of the development of tool edge preparation technology and provides ideas for its future development. First, typical edge characterization methods, which associate the microgeometric characteristics of the cutting edge with cutting performance, are briefly introduced. Then, edge preparation methods for cutting tools, in which materials at the cutting edge area are removed to decrease defects and obtain a suitable microgeometry of the cutting edge for machining, are discussed. New edge preparation methods are explored on the basis of existing processing technologies, and the principles, advantages, and limitations of these methods are systematically summarized and analyzed. Edge preparation methods are classified into two categories: mechanical processing methods and nontraditional processing methods. These methods are compared from the aspects of edge consistency, surface quality, efficiency, processing difficulty, machining cost, and general availability. In this manner, a more intuitive understanding of the characteristics can be gained. Finally, the future development direction of tool edge preparation technology is prospected.

关键词: edge preparation method     preparation principle     cutting edge geometry     edge characterization     tool performance    

Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0729-8

摘要: When ultrasonically cutting honeycomb core curved parts, the tool face of the straight blade must be along the curved surface’s tangent direction at all times to ensure high-quality machining of the curved surface. However, given that the straight blade is a nonstandard tool, the existing computer-aided manufacturing technology cannot directly realize the above action requirement. To solve this problem, this paper proposed an algorithm for extracting a straight blade real-time tool face vector from a 5-axis milling automatically programmed tool location file, which can realize the tool location point and tool axis vector conversion from the flat end mill to the straight blade. At the same time, for the multi-solution problem of the rotation axis, the dependent axis rotation minimization algorithm was introduced, and the spindle rotation algorithm was proposed for the tool edge orientation problem when the straight blade is used to machine the curved part. Finally, on the basis of the MATLAB platform, the dependent axis rotation minimization algorithm and spindle rotation algorithm were integrated and compiled, and the straight blade ultrasonic cutting honeycomb core postprocessor was then developed. The model of the machine tool and the definition of the straight blade were conducted in the VERICUT simulation software, and the simulation machining of the equivalent entity of the honeycomb core can then be realized. The correctness of the numerical control program generated by the postprocessor was verified by machining and accuracy testing of the two designed features. Observation and analysis of the simulation and experiment indicate that the tool pose is the same under each working condition, and the workpieces obtained by machining also meet the corresponding accuracy requirements. Therefore, the postprocessor developed in this paper can be well adapted to the honeycomb core ultrasonic cutting machine tool and realize high-quality and high-efficient machining of honeycomb core composites.

关键词: honeycomb core     straight blade     ultrasonic cutting     tool pose     postprocessor    

Design of ultrasonic elliptical vibration cutting system for tungsten heavy alloy

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0715-1

摘要: Nanoscale surface roughness of tungsten heavy alloy components is required in the nuclear industry and precision instruments. In this study, a high-performance ultrasonic elliptical vibration cutting (UEVC) system is developed to solve the precision machining problem of tungsten heavy alloy. A new design method of stepped bending vibration horn based on Timoshenko’s theory is first proposed, and its design process is greatly simplified. The arrangement and working principle of piezoelectric transducers on the ultrasonic vibrator using the fifth resonant mode of bending are analyzed to realize the dual-bending vibration modes. A cutting tool is installed at the end of the ultrasonic vibration unit to output the ultrasonic elliptical vibration locus, which is verified by finite element method. The vibration unit can display different three-degree-of-freedom (3-DOF) UEVC characteristics by adjusting the corresponding position of the unit and workpiece. A dual-channel ultrasonic power supply is developed to excite the ultrasonic vibration unit, which makes the UEVC system present the resonant frequency of 41 kHz and the maximum amplitude of 14.2 μm. Different microtopography and surface roughness are obtained by the cutting experiments of tungsten heavy alloy hemispherical workpiece with the UEVC system, which validates the proposed design’s technical capability and provides optimization basis for further improving the machining quality of the curved surface components of tungsten heavy alloy.

关键词: tungsten heavy alloy     ultrasonic elliptical vibration cutting     Timoshenko’s theory     resonant mode of bending     finite element method    

Depth of cut models for multipass abrasive waterjet cutting of alumina ceramics with nozzle oscillation

Jun WANG

《机械工程前沿(英文)》 2010年 第5卷 第1期   页码 19-32 doi: 10.1007/s11465-009-0082-1

摘要: An experimental study of the depth of cut in multipass abrasive waterjet (AWJ) cutting of alumina ceramics with controlled nozzle oscillation is presented. It is found that this cutting technique can significantly increase the depth of cut by an average of 50.8% as compared to single pass cutting without nozzle oscillation under the corresponding cutting conditions and within the same cutting time. Predictive models for the depth of cut are then developed. The modelling process starts with single pass cutting using a dimensional analysis technique and the particle erosion theories applied to alumina ceramics, before progressing to the development of the models for multipass cutting. The models are finally assessed both qualitatively and quantitatively with experimental data. It is shown that the model predictions are in good agreement with the experimental data with the average deviations of about 1%.

关键词: abrasive waterjet     engineering ceramics     depth of cut     cutting performance     nozzle oscillation     machining    

Analysis and comparison of laser cutting performance of solar float glass with different scanning modes

Wenyuan LI, Yu HUANG, Youmin RONG, Long CHEN, Guojun ZHANG, Zhangrui GAO

《机械工程前沿(英文)》 2021年 第16卷 第1期   页码 97-110 doi: 10.1007/s11465-020-0600-8

摘要: Cutting quality and efficiency have always been important indicators of glass laser cutting. Laser scanning modes have two kinds, namely, the spiral and concentric circle scanning modes. These modes can achieve high-performance hole cutting of thick solar float glass using a 532-nm nanosecond laser. The mechanism of the glass laser cutting under these two different scanning modes has been described. Several experiments are conducted to explore the effect of machining parameters on cutting efficiency and quality under these two scanning modes. Results indicate that compared with the spiral scanning mode, the minimum area of edge chipping (218340 µm ) and the minimum Ra (3.01 µm) in the concentric circle scanning mode are reduced by 9.4% and 16.4% respectively. Moreover, the best cutting efficiency scanning mode is 14.2% faster than that in the spiral scanning mode. The best parameter combination for the concentric circle scanning mode is as follows: Scanning speed: 2200 mm/s, number of inner circles: 6, and circle spacing: 0.05 mm. This parameter combination reduces the chipping area and sidewall surface roughness by 8.8% and 9.6% respectively at the same cutting efficiency compared with the best spiral processing parameters. The range of glass processing that can be achieved in the concentric circle scanning mode is wider than that in the spiral counterpart. The analyses of surface topography, white spots, microstructures, and sidewall surface element composition are also performed. The study concluded that the concentric circle scanning mode shows evident advantages in the performance of solar float glass hole cutting.

关键词: laser cutting     solar float glass     scanning mode     surface quality     cutting efficiency    

Energy efficient cutting parameter optimization

Xingzheng CHEN, Congbo LI, Ying TANG, Li LI, Hongcheng LI

《机械工程前沿(英文)》 2021年 第16卷 第2期   页码 221-248 doi: 10.1007/s11465-020-0627-x

摘要: Mechanical manufacturing industry consumes substantial energy with low energy efficiency. Increasing pressures from energy price and environmental directive force mechanical manufacturing industries to implement energy efficient technologies for reducing energy consumption and improving energy efficiency of their machining processes. In a practical machining process, cutting parameters are vital variables set by manufacturers in accordance with machining requirements of workpiece and machining condition. Proper selection of cutting parameters with energy consideration can effectively reduce energy consumption and improve energy efficiency of the machining process. Over the past 10 years, many researchers have been engaged in energy efficient cutting parameter optimization, and a large amount of literature have been published. This paper conducts a comprehensive literature review of current studies on energy efficient cutting parameter optimization to fully understand the recent advances in this research area. The energy consumption characteristics of machining process are analyzed by decomposing total energy consumption into electrical energy consumption of machine tool and embodied energy of cutting tool and cutting fluid. Current studies on energy efficient cutting parameter optimization by using experimental design method and energy models are reviewed in a comprehensive manner. Combined with the current status, future research directions of energy efficient cutting parameter optimization are presented.

关键词: energy efficiency     cutting parameter     optimization     machining process    

标题 作者 时间 类型 操作

Improved analytical model for residual stress prediction in orthogonal cutting

null

期刊论文

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

期刊论文

Cutting heat dissipation in high-speed machining of carbon steel based on the calorimetric method

QUAN Yanming, HE Zhenwei, DOU Yong

期刊论文

Crystallographic orientation effect on cutting-based single atomic layer removal

Wenkun XIE, Fengzhou FANG

期刊论文

and plastic deformation to machined surface temperatures and residual stress patterns in finish dry cutting

Subhash ANURAG, Yuebin GUO,

期刊论文

Modeling of the minimum cutting thickness in micro cutting with consideration of the friction aroundthe cutting zone

Tianfeng ZHOU, Ying WANG, Benshuai RUAN, Zhiqiang LIANG, Xibin WANG

期刊论文

Molecular dynamics modeling of a single diamond abrasive grain in grinding

Angelos P. MARKOPOULOS,Ioannis K. SAVVOPOULOS,Nikolaos E. KARKALOS,Dimitrios E. MANOLAKOS

期刊论文

A review on ductile mode cutting of brittle materials

Elijah Kwabena ANTWI, Kui LIU, Hao WANG

期刊论文

Cutting performance of surgical electrodes by constructing bionic microstriped structures

期刊论文

Edge preparation methods for cutting tools: a review

期刊论文

Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

期刊论文

Design of ultrasonic elliptical vibration cutting system for tungsten heavy alloy

期刊论文

Depth of cut models for multipass abrasive waterjet cutting of alumina ceramics with nozzle oscillation

Jun WANG

期刊论文

Analysis and comparison of laser cutting performance of solar float glass with different scanning modes

Wenyuan LI, Yu HUANG, Youmin RONG, Long CHEN, Guojun ZHANG, Zhangrui GAO

期刊论文

Energy efficient cutting parameter optimization

Xingzheng CHEN, Congbo LI, Ying TANG, Li LI, Hongcheng LI

期刊论文