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Friction 2024年第3期12卷 375-395页

作者： Xiao YANG Heli LIU Lemeng ZHANG Yiran HU Denis J.POLITIS Mohammad M.GHARBI Liliang WANG Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK Department of Mechanical and Manufacturing Engineering University of CyprusNicosia 1678Cyprus Quaker Houghton Deutschland GmbH Dortmund 44319Germany

The accurate representation of tribological boundary conditions at the tool–workpiece interface is crucial for analysis and optimization of formability,material flow,and surface quality of components during metal forming *** has been found that these tribological conditions vary spatially and historically with process parameters and contact *** time-dependent tribological behaviours are also known as transient tribological phenomena,which are widely observed during forming processes and many other manufacturing application ***,constant friction values are usually assigned to represent complex and dynamic interfacial conditions,which would introduce deviations in the relevant *** this paper,transient tribological phenomena and the contemporary understanding of the interaction between friction and wear are reviewed,and it has been found that these phenomena are induced by the transitions of friction mechanisms and highly dependent on complex loading conditions at the *** modelling techniques for transient behaviours for metal forming applications are also *** accurately describe the evolutionary friction values and corresponding wear during forming,the advanced interactive friction modelling has been established for different application scenarios,including lubricated condition,dry sliding condition(metal-on-metal contact),and coated system.

关键词： transient tribological phenomena interactive friction mechanism modelling techniques metal forming

Galling phenomena in metal forming

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Friction 2021年第4期9卷 665-685页

作者： Kuniaki DOHDA Masahito YAMAMOTO Chengliang HU Laurent DUBAR Kornel F.EHMANN Department of Mechanical Engineering Northwestern UniversityEvanstonIL 60208-3111USA Manufacturing Engineering Center NSKLtd.Fujisawa-Shi 251-8501Japan Institute of forming Technology and Equipment School of Materials and EngineeringShanghai Jiao Tong UniversityShanghai 200240China LAMIH UMR CNRS 8201 Universite Polytechnique Hauts-de-FranceValenciennes Cedex 959313France

Galling phenomena in metal forming not only affect the quality of the engineered surfaces but also the success or failure of the manufacturing operation *** paper reviews the different galling conditions in sheet and bulk metal forming processes along with their evolution and the effects of temperature on galling.A group of anti-galling methods employed to prevent galling defects are also presented in *** techniques for quantitatively measuring galling are introduced,and the related prediction models,including friction,wear,and galling growth models,are presented to better understand the underlying *** phenomena in other processes similar to those occurring in metal forming are also examined to suggest different ways of further studying galling in metal ***,future research directions for the study of galling in metal forming are suggested.

关键词： galling metal forming friction wear adhesion anti-galling

MESHFREE METHOD BASED ON POINT COLLOCATION FOR metal forming SIMULATION

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Acta metallurgica Sinica(English Letters) 2006年第2期19卷 79-84页

作者： H.Y. Wen X.H. Dong X.Y. Ruan Department of Plasticity forming Engineering Shanghai Jiaotong University Shanghai 200030 China

A meshfree method based on reproducing kernel approximation and point collocation is presented for analysis of metal ring compression. The point collocation method is a true meshfree method without the employment of a background mesh. It is shown that, in a point collocation approach, the remesh problem because of the mesh distortion in FEM （finite element method） and the low efficiency in Galerkin-based meshfree method are avoided. The corrected kernel functions are introduced to the stabilization of free-surface boundary conditions. The solution of symmetric ring compression problem is compared with a conventional finite element solution, and reasonable results have been obtained.

关键词： meshfree method RKPM (reproducing kernel particle method) point collocation metal forming frictional contact

THE ADAPTIVE FINITE ELEMENT REMESHING IN LARGE DEFORMATION OF metal forming

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Acta metallurgica Sinica(English Letters) 2004年第3期17卷 323-326页

作者： X.X.Guo J.S.Liu Advanced Manufacturing Technology and Engineering Department Shenzhen Polytechnic Shenzhen 518055ChinaSchool of Material Science and Engineering Taiyuan Heavy Machinery Institute Taiyuan 030024 China

The adaptive remeshing technique for quadrilateral elements consists of modules thetrigger of remeshing, the new mesh generation, adaptive refinement and interpolationof field variables. The new adaptive mesh genemtion is the key problem. First, acoarse mesh is created by using 'loop algorithm'. Subsequent local mesh adaptiverefinement is performed based on effective strain. Finally, a typical example of upset-ting is given to test efficient of techniques, from which it is verified that the remeshingalgorithm developed here exhibits good performance and has high accuracy.

关键词： adaptive remeshing quadrilateral elements metal forming

Test of Friction Parameters in Bulk metal forming Based on Forward Extrusion Processes

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Journal of Shanghai Jiaotong university(Science) 2020年第3期25卷 333-339页

作者： CHEN Xia WEN Tong LIU Kefan HONG Yifei College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

Existing methods for examining the friction parameters in metal forming all have advantages and *** on the theory of plasticity,the current study established quantitative correlations among friction coefficient/factor,yield stress of the workpiece material,load and die geometry in the forward extrusion with a conical die,and then designed a procedure for testing the friction parameters in forming processes using the correlations.A series of extrusion experiments along with the numerical simulations,using AA 7050 specimens under various lubricating conditions,were carried *** results proved that the method can obtain the friction coefficient/factor with an acceptable ***,since the effects of material properties,forming velocity,temperature and surficial condition,etc.,on the deformation can be directly considered in the operation,this method is applicable to a wide range of material types and forming *** avoid the occurrence of "barreling phenomenon" under large load which may lead to failure of the operation,it is recommended that half angle of the conical die ranges from 5 to 10 degrees.

关键词： metal forming tribo-testing forward extrusion friction coefficient friction factor

Development and Prospect on Optimum Design of metal forming Process

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Journal of Materials Science & Technology 1992年第6期8卷 461-464页

作者：韩静涛 Dept.of Mechanical Engineering Tsinghua UnversityBeijing100084China

*** research of metal forming theoryand technology always takes an importantplace in materials science and ***,in a long period,the developmentof technology goes ahead of the *** design principles used in prac-

关键词： metal forming optimization numerical simulation quality predication

Thermal-mechanical analysis of metal forming based on meshfree method

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Thermal-mechanical analysis of metal forming based on meshfr...

Inhibiting plastic tensile instability of non-symmetric thin-walled shell component via increasing regional metal inflow based on heterogeneous pressure-carrying medium

第五届国际材料与热加工物理模拟及数值模拟学术会议

作者： Guang-ru HUA1 a* Hong-yu WEN2 b Li-qiang AN1 c (1 School of Mechanical Engineering North China Electric Power University 619 Yonghua North Road Baoding Hebei Province 071003 China) (2 National Die & Mold CAD Engineering Research Center Shanghai Jiao Tong University 1954 Huashan Road Shanghai 200030 China)

A thermal-mechanical analysis of metal forming based on meshfree method is performed. During the coupled analysis, two independent sub-systems, i.e. the velocity field and temperature field are considered. The effect of deformation on temperature field is added into the temperature solution by the vector of heat flux generated by internal energy, and the effect of temperature on plastic deformation is considered by the flow stress at that temperature. The unknown function of temperature distribution is constructed using reproducing kernel approximation. Contours of the temperature field of a metal ring under compression are obtained. Using the thermal-mechanical coupling method, the results are compared with those obtained by FEM and experiment to verify the accuracy of the proposed method.

关键词： Thermal-mechanical Meshfree method metal forming Reproducing kernel approximation

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Chinese Journal of Aeronautics 2024年第1期37卷 391-413页

作者： Nan XIANG Yiquan SHU Pengyi WANG Menghan YANG Haoran WANG Tao HUANG Junqing GUO Fuxiao CHEN School of Materials Science and Engineering Henan University of Science and TechnologyLuoyang 471023China National Key Laboratory for Precision Heat Processing of metals School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China College of Mechanical&Electrical Engineering Shaanxi University of Science&TechnologyXi’an 710021China Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous metal new Materials and Advanced Processing Technology Luoyang 471023China

Heterogeneous pressure-carrying medium was employed to establish a differentiated pressure field on sheet metal in flexible die forming process in this work,which aimed at matching the non-symmetric shape of target component and improving metal inflow to avoid local tensile ***,metal inflow corresponding to the differentiated pressure field was analytically *** of a typical non-symmetric shell component was experimentally and numerically studied based on the proposed *** with forming processes based on the uniform pressure,difference of metal inflow in two sides of the non-symmetric component increased from 2.16 mm to 3.36 mm and metal inflow in critical region increased by 11.9%when differentiated pressure field(taking heterogeneous elastomer#4–3 for example)was *** resultant maximum thinning ratio decreased by 4.2% and the uniformity of shell thickness increased by 16.9%.With the decrease of Shore hardness of elastomer in the formed region,stress path in the ready-to-form region transferred towards the bi-axial tension stress state,i.e.,stress ratio(a)***,stress triaxiality(η)in characteristic regions were regulated appropriately,which decreased the risk of tensile *** was attributed to the decreased normal pressure and frictional resistance at sheet/elastomer interface in the formed region.

关键词： Aluminum alloys Finite element method metal forming Plastic deformation Sheet metal

A data-driven approach to RUL prediction of tools

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Advances in Manufacturing 2024年第1期12卷 6-18页

作者： Wei Li Liang-Chi Zhang Chu-Han Wu Yan Wang Zhen-Xiang Cui Chao Niu Department of Mechanical Engineering University College LondonLondonWC1E 7JEUK Shenzhen Key Laboratory of Cross-Scale Manufacturing Mechanics Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China SUSTech Institute for Manufacturing Innovation Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China School of Mechanical and Manufacturing Engineering The University of New South WalesKensingtonNSW2052Australia Baoshan Iron&Steel Co. Ltd.Shanghai200941People’s Republic of China

An effective and reliable prediction of the remaining useful life(RUL)of a tool is important to a metal forming process because it can significantly reduce unexpected maintenance,avoid machine shutdowns and increase system *** study proposes a new data-driven approach to the RUL prediction for metal forming processes under multiple contact sliding *** data-driven approach took advantage of bidirectional long short-term memory(BLSTM)and convolutional neural networks(CNN).A pre-trained lightweight CNN-based network,WearNet,was re-trained to classify the wear states of workpiece surfaces with a high accuracy,then the classification results were passed into a BLSTM-based regression model as inputs for RUL *** experimental results demonstrated that this approach was able to predict the RUL values with a small error(below 5%)and a low root mean square error(RMSE)(around 1.5),which was more superior and robust than the other state-of-the-art methods.

关键词： Remaining useful life(RUL) Bidirectional long short-term memory(BLSTM) Data-driven approach metal forming

Characteristic of energy input for laser forming sheet metal

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Chinese Optics Letters 2003年第10期1卷 606-608页

作者：李俐群陈彦宾封小松 State Key Laboratory of Advanced Welding Production and Technology Harbin Institute of Technology Harbin 150001

Laser forming is a process in which laser-induced thermal deformation is used to form sheet metal without a hard forming tool or external forces. The energy input of laser beam is the key factor for the temperature and stress distribution of sheet metal. The purpose of this work is to investigate the influence of energy input condition on heat input and deformation angle for two-dimension laser forming. Variations in heat input resulting from material deformation was calculated and discussed in this paper at first. Furthermore, in laser forming under the condition of constant laser energy input, the effects of energy input mode on deformation angle and temperature field were investigated.

关键词： Laser beams metal forming Sheet metal