作者： Duan, Liming;Jiang, Hao;Zhang, Xu;Li, Guangyao;Cui, Junjia*

期刊： Materials and Manufacturing Processes,2021年36(2):223-234 ISSN：1042-6914

通讯作者： Cui, Junjia

作者机构： [Duan, Liming; Li, Guangyao; Cui, Junjia; Jiang, Hao] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Coll Automobile & Mech Engn, Changsha, Peoples R China.

通讯机构： [Cui, Junjia] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China.

关键词： Carbon fiber reinforced plastics;Cutting tools;Graphite fibers;Infill drilling;Machining;Morphology;Paper laminates;Plastic laminates;Delamination defects;Delamination factor;Experimental investigations;Functional requirement;Machining Accuracy;Macroscopic measurements;Microscopic morphology;Microstructure observation;Quality control

摘要： Electromagnetic punching is an efficient hole-machining process in order to satisfy structural or functional requirements. In this paper, the electromagnetic punching experiments were carried out to investigate hole-punching quality of carbon fiber reinforced plastic laminates with various punches. The quality evaluation such as macroscopic measurement, microstructure observation and delamination analysis was implemented. As a comparison, drilling experiments and corresponding quality tests were also accomplished. The results showed that the cutting tools had significant effects on the quality of the formed holes. For electromagnetic punched holes, the edged punch was superior to flat punch and hollow punch in term of the machining accuracy, microscopic morphology and delamination defect. Comparing with drilling process, the delamination factors of edged punched holes were lower than that of drilled holes on the basic of ultrasonic C-scan technology, implying that delamination of drilled hole was severer than edged punched holes. © 2020 Taylor & Francis.

语种： 英文

作者： Zhang, Xu*;Huang, Yunkai;Meng, Shengfei;Zhu, Congcong;Li, Guangyao;...

期刊： Archives of Civil and Mechanical Engineering,2021年21(1):1-13 ISSN：1644-9665

通讯作者： Zhang, Xu

作者机构： [Zhang, Xu; Huang, Yunkai] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Peoples R China.;[Meng, Shengfei] Changchun Univ Technol, Adv Inst Mat Sci, Changchun 130012, Peoples R China.;[Zhu, Congcong; Li, Guangyao; Cui, Junjia] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China.

通讯机构： [Zhang, Xu] C;Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Peoples R China.

关键词： Electromagnetic loading;Al-4.2%Cu alloys;Adiabatic shearing;Recrystallization

摘要： This paper proposed an electromagnetic loading process with the high-speed impact. Al-4.2% Cu alloy bars were used to employ electromagnetic impact (EI) experiments. Deformation mechanism and microstructure evolution of EI samples were revealed by theoretical model and microstructure characterizations. The EI process had impact force (peak value 40kN) and impact velocity (peak value 6.7m/s) during a short time period (1.25ms). Adiabatic shearing mechanism dominated the whole deformation process, causing that significant microstructure characteristic was adiabatic shear bands (ASBs). The theoretical analysis implied that the formation of ASBs was accounted for the radial velocity gradient. Most plastic deformations concentrated in ASBs, and approximately pure shear deformations resulted in adiabatic temperature rise of 0.33–0.42 Tm inside ASBs. The width of ASBs was about 135μm, in which original equiaxial grains were elongated into laminated sub-structures. TEM observations showed multi-slip systems were simultaneously actuated due to severe shear deformations. High dislocation density and dislocation tangles distributed with the ASBs. Adiabatic temperature rise and distorted energies drove sub-grains rotate into recrystallization grains (70–280nm) with large angle grain boundaries. The needed maximum time (45μs) for rotational dynamic recrystallization was far less than that of plastic deformation, indicating that rotational dynamic recrystallization mechanism contributed to the formation of recrystallization grains. © 2021, Wroclaw University of Science and Technology.

语种： 英文

作者： Wang, Shaoluo;Zhou, Binbin;Zhang, Xu;Sun, Tao;Li, Guangyao;...

期刊： Materials Science and Engineering: A,2020年788:139425 ISSN：0921-5093

通讯作者： Cui, Junjia

作者机构： [Wang, Shaoluo; Li, Guangyao; Zhou, Binbin; Sun, Tao; Cui, Junjia] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Peoples R China.

通讯机构： [Cui, Junjia] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Aluminum alloys;Aluminum coated steel;Aluminum coatings;Galvanizing;Magnetism;Microstructure;Welding;Zinc coatings;Aluminium-alloy sheets;Comparative analyzes;Galvanized steel sheets;Interfacial microstructure;Magnetic pulse welding;Mechanical behavior;Transition zones;Welding joints;Zinc coated steel sheet;Zinc-coated steel;Steel sheet

摘要： In this study, the relations between interfacial microstructure and mechanical behavior of aluminum alloy sheets and zinc-coated steel sheets magnetic pulse welding (MPW) joints were characterized systematically. MPW joints of aluminum alloy and ungalvanized steel sheets were prepared for comparative analysis. Results showed that some of zinc layer on the galvanized steel was washed away to form metal jet under the high-speed collision. The change of failure mode from interfacial failure to base material fracture due to interfacial microstructure evolution was the fundamental reason for different mechanical behavior of two MPW joints. Because of the difference in element content and the severe plastic shear at the interface, the crystalline grain morphologies and sizes of aluminum and zinc in the transition zone changed. Amorphous structure was also found in the transition zone. The existence of the zinc layer would form brittle and hard phases on the interface, resulting in the generation of welding defects, thereby reducing mechanical properties of the joint. © 2020 Elsevier B.V.

语种： 英文

作者： Deng, Huakun;Yang, Shuaishuai;Li, Guangyao;Zhang, Xu;Cui, Junjia*

期刊： Journal of Materials Processing Technology,2020年280:116601 ISSN：0924-0136

通讯作者： Cui, Junjia

作者机构： [Yang, Shuaishuai; Li, Guangyao; Deng, Huakun; Cui, Junjia] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Sch Automobile & Mech Engn, Changsha 410114, Peoples R China.

通讯机构： [Cui, Junjia] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Deformation;High speed cameras;Speed;Strain rate;Tensile testing;D. digital image correlation (DIC);Dynamic tensile;Electromagnetic;High Speed;High-speed performance;Large-scale applications;Material performance;Tensile deformation;Aluminum alloys

摘要： Aluminum alloy high-speed material behavior should be comprehensively characterized for the application of a high-speed forming process. The current high-speed material testing methods are not conducive to large-scale applications because of their high cost and difficulty. In this paper, a new method for testing the high-speed performance of aluminum alloy based on electromagnetic driving was proposed. A specially designed tool was used to convert bulging deformation to tensile deformation. Two high-speed cameras and a digital image correlation (DIC) system were used to measure the stress–strain relationship of the sample. Based on the stress wave theory, a stress measurement method using two-point measurement was proposed. A numerical model was established, and the model was in good agreement with the experiment. Tests with strain rate ranging from 1000 to 3100 s−1 were conducted, and stress–strain curves were measured. The results matched those obtained with traditional test methods. © 2020 Elsevier B.V.

语种： 英文

作者： Geng, Huihui;Mao, Jingqi;Zhang, Xu;Li, Guangyao;Cui, Junjia*

期刊： Materials Letters,2019年245(Jun.15):151-154 ISSN：0167-577X

通讯作者： Cui, Junjia

作者机构： [Li, Guangyao; Mao, Jingqi; Cui, Junjia; Geng, Huihui] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Sch Automobile & Mech Engn, Changsha 410114, Hunan, Peoples R China.

通讯机构： [Cui, Junjia] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Aluminum alloys;Binary alloys;Iron alloys;Magnetism;Solidification;Thermoanalysis;Welding;Welds;Amorphous layer;Amorphous structures;Formation mechanism;Magnetic pulse;Magnetic pulse welding;Melting layers;Solid-state welding process;Transition zones;Amorphous materials

摘要： Amorphous structure and transition zone were observed in the magnetic pulse welded Al-Fe weld. Simulations and theoretical analysis were carried out to reveal the formation mechanism of the amorphous structure and transition zone. The wave morphology in the Al-Fe interface was well reproduced in simulations, and local melt was found in the weld interface. The cooling rate in the amorphous layer was much higher than that in the transition zone due to the smaller thickness of the melting layer. Materials in the amorphous layer experienced amorphization, while the materials in the transition zone experienced recrystallization. The current work indicated local melt played an important role in the magnetic pulse welding, which was different from the common perception that magnetic pulse welding was a totally solid-state welding process. (C) 2019 Elsevier B.V. All rights reserved.

语种： 英文

作者： Xu, Junrui*;Xie, Xueyun;Wen, Zhisheng;Cui, Junjia;Zhang, Xu;...

期刊： Journal of Manufacturing Processes,2019年37:402-412 ISSN：1526-6125

通讯作者： Xu, Junrui;Liu, Yang

作者机构： [Xie, Xueyun; Wen, Zhisheng; Xu, Junrui; Liu, Yang; Zhu, Daibo] Xiangtan Univ, Minist Educ, Engn Res Ctr Complex Tracks Proc Technol & Equipm, Xiangtan 41105, Peoples R China.;[Xu, Junrui] Xiangtan Univ, Key Lab Welding Robot & Applicat Technol Hunan Pr, Xiangtan 411105, Peoples R China.;[Xu, Junrui] Huazhong Univ Sci & Technol, State Key Lab Mat Proc & Die & Mould Technol, Wuhan, Hubei, Peoples R China.;[Cui, Junjia] Hunan Univ, Coll Mech & Vehicle Engn, State Key Lab Adv Design & Mfg Vehicle Body, Changsha, Hunan, Peoples R China.;[Zhang, Xu] Hunan Univ, Coll Automot & Mech Engn, Changsha Univ Sci & Technol, Changsha, Hunan, Peoples R China.

通讯机构： [Xu, JR; Liu, Y] X;Xiangtan Univ, Minist Educ, Engn Res Ctr Complex Tracks Proc Technol & Equipm, Xiangtan 41105, Peoples R China.

关键词： Deformation;Dynamic recrystallization;Grain refinement;Magnesium alloys;Magnetism;Microstructure;Strain rate;Temperature;AZ31 magnesium alloy sheet;Az31 sheets;Deformation behaviour;Driver sheet;Dynamic recrystallization (DRX);Experimental analysis;Increasing temperatures;Magnetic pulse;Magnesium printing plates

摘要： In this paper, formability of AZ31 sheet in magnetic pulse forming hybrid actuating with driver sheet and temperature were investigated. The effects of discharge parameters, driver sheet and temperature were investigated on bulging by the experimental analysis. Forming height, thickness of AA1060 driver sheet, forming limit curve (FLC), fracture morphology and microstructure were performed to analyze causes of deformation behaviour for driver sheet and temperature. Analysis of driver sheet and temperature effects reveals that the optimum thickness of the driver sheet and temperature are 1 mm and 200 ℃ respectively. The FLC results show increased by increasing temperature from 25 ℃ to 200 ℃ and then decreased by increasing the temperature such as 250 ℃. Compared with quasi-static forming, the temperature effect for formability is unremarkable in magnetic pulse forming with driver sheet. Demonstrating similar drawability and strechability of AZ31 sheet appeared. Microstructure reveals that high strain rate effect, yield strength decreasing (because of temperature effect) and grain refinement are main reasons to affect the formability of AZ31 sheet in magnetic pulse forming with driver sheet and temperature. However, dynamic recrystallization (DRX) is not observed which is usually accompanied at temperatures higher than 150 ℃ in quasi-static forming. © 2018

语种： 英文

作者： Zhang, Xu;Zhu, Congcong;Hu, Lin;Wu, Hequan*;Li, Chunfeng

期刊： Archives of Civil and Mechanical Engineering,2019年19(3):639-647 ISSN：1644-9665

通讯作者： Wu, Hequan

作者机构： [Hu, Lin; Zhang, Xu; Wu, Hequan] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, 960,2nd Sect,Wanjiali South RD, Changsha 410004, Hunan, Peoples R China.;[Zhu, Congcong] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Li, Chunfeng] Harbin Inst Technol, Sch Mat Sci & Engn, Harbin 150001, Heilongjiang, Peoples R China.

通讯机构： [Wu, Hequan] C;Changsha Univ Sci & Technol, Coll Automot & Mech Engn, 960,2nd Sect,Wanjiali South RD, Changsha 410004, Hunan, Peoples R China.

关键词： Electromagnetic impact loading;TA1 titanium alloy;Dynamic recrystallization;Hardness

摘要： In this work, the adiabatic shear band of TA1 titanium alloy subjected to electromagnetic impact loading was investigated. The formation of adiabatic shear band and microstructure evolution within it were revealed by microstructure characterizations. Deformation results showed an adiabatic shear band with the width of 10 μm located in shear deformation zone, and most deformations mainly concentrated in the narrow band. The compressive instability and the hardness difference contributed to the formation of adiabatic shear band. Severe shear deformations led to high location density within the adiabatic shear band. A large amount of dislocations distributed in the form of dislocation cells and random dislocations. The rotational dynamic recrystallization mechanism caused that many dynamic recrystallization grains with the size of 100–200 nm were found inside the adiabatic shear band. Adiabatic temperature rise and distortion energies stored by high dislocation densities provided sub-grain rotations with the driving forces.

语种： 英文

作者： Zhang, Xu;Jiang, Hao;Luo, Tong;Hu, Lin;Li, Guangyao;...

期刊： International Journal of Mechanical Sciences,2019年156:261-271 ISSN：0020-7403

通讯作者： Cui, Junjia

作者机构： [Hu, Lin; Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Peoples R China.;[Luo, Tong; Li, Guangyao; Cui, Junjia; Jiang, Hao] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

通讯机构： [Cui, Junjia] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Elastic waves;Residual stresses;Engineering applications;Experimental investigations;Experimental values;Interference fit;Joining technology;Stress wave;Theoretical modeling;Thick wall cylinder;Riveting

摘要： As an advanced interference-fit joining technology, electromagnetic riveting (EMR) has wide engineering application prospects in manufacturing and assembly fields. In this paper, a theoretical model on interference fit for EMR process is derived based on the stress wave theory and thick wall cylinder theory. EMR experiments are conducted to verify the analytical model. The compared results show that the analytical solutions agree well with experimental values. The interference-fit model synthetically considers many process parameters factors, not only the material properties and size of rivet, sheets and punch, but also the riveting force. The residual stress distribution, which is an important factor on fatigue life, can be predicted by this model. In addition, this can provide scientific guidance for the process parameter design and riveting setup optimization in engineering application.

语种： 英文

作者： Cui, Junjia;Wang, Qiong;Dong, Dongying;Jiang, Hao;Zhang, Xu;...

期刊： Journal of Materials Research,2019年34(6):1034-1042 ISSN：0884-2914

通讯作者： Li, Guanyao

作者机构： [Li, Guanyao; Wang, Qiong; Cui, Junjia; Dong, Dongying; Jiang, Hao] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.

通讯机构： [Li, Guanyao] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Constitutive models;Finite element method;High strength alloys;Image analysis;Numerical models;Strain measurement;Tensile testing;Digital image correlation technique;Digital image correlations;Finite element simulations;High strain rates;High strength low alloys;Statistical parameters;Strain distributions;Strain rate sensitivity;Strain rate

摘要： In this paper, the influence of strain rate on the mechanical behavior of high-strength low-Alloy (HC420LA) steel were studied. Quasi-static and dynamic tensile experiments were performed with strain rates ranging from 0.001 to 500 s -1 at room temperature. The digital image correlation technique was used to obtain the full-field strain. The experimental results showed that HC420LA steel exhibited positive strain rate sensitivity. Based on experimental results, the modified Johnson-Cook (J-C) model was used to model the constitutive behavior of HC420LA steel. Predictions of the standard and modified J-C models were compared using standard statistical parameters. The modified J-C model showed better agreement with the experimental data. Then, numerical simulation of the representative tensile test at a strain rate of 100 s -1 was performed using the finite element code LS-DYNA. Good correlation between the experimental and numerical simulation results was achieved. Copyright © Materials Research Society 2019.

语种： 英文

作者： Cui, Junjia;Li, Ya;Liu, Quanxiaoxiao;Zhang, Xu;Xu, Zhidan;...

期刊： Journal of Materials Processing Technology,2019年264:273-282 ISSN：0924-0136

通讯作者： Li, Guangyao

作者机构： [Li, Ya; Li, Guangyao; Cui, Junjia; Liu, Quanxiaoxiao] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Cui, Junjia] Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Shaanxi, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changhsa 410114, Peoples R China.;[Xu, Zhidan] SAIC GM Wuling Automobile Co Ltd, Liuzhou 545007, Peoples R China.

通讯机构： [Li, Guangyao] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Aluminum;Aluminum alloys;Fiber reinforced plastics;Joining;Magnetism;Mechanical properties;Reinforced plastics;Reinforcement;Thin walled structures;Welding;Aluminum tubes;Deformation behavior;Joining mechanisms;Magnetic pulse welding;Properties and microstructures;Structural characteristics;Torsional strength;Welding zones;Carbon fiber reinforced plastics

摘要： A structure used for joining thin-walled carbon fiber-reinforced plastic and 5A02 aluminum tubes via the magnetic pulse welding process was proposed. The mechanical properties and microstructure of the MPW joints were investigated. The tensile and torsional strengths of MPW joints were higher than those of the aluminum tube. A peel experiment showed that only two linear welding zones existed. The welding and no-welding areas were caused by the different deformation behaviors of the outer tubes, which was resulted from the inhomogeneous Lorentz force and the certain structural characteristics. Numerical simulations were carried out to reveal the joining mechanism of the joints. © 2018 Elsevier B.V.

语种： 英文

作者： Liang, Jusong;Jiang, Hao;Zhang, Jinsheng;Wu, Xianhe;Zhang, Xu;...

期刊： Archives of Civil and Mechanical Engineering,2019年19(1):240-250 ISSN：1644-9665

通讯作者： Cui, Junjia

作者机构： [Li, Guangyao; Cui, Junjia; Liang, Jusong; Jiang, Hao] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Zhang, Jinsheng; Wu, Xianhe] Chongqing Changan Automobile Co Ltd, Chongqing 401120, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.

通讯机构： [Cui, Junjia] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Electromagnetic self-piecing riveting;Mechanical properties;Microtopography;Carbon fiber reinforced plastics

摘要： In this paper, the mechanical properties of electromagnetic self-piercing riveted (E-SPR) joints with carbon fiber reinforced plastics (CFRP)/aluminum alloy (Al) 5052 were comprehensively investigated. Microtopography observations, hardness measurements and tensile-shear strength tests were performed by comparing with regular pressure self-piercing riveted (P-SPR) joints. Results showed that the undercut value of E-SPR joints was higher than that of P-SPR joints. The hardness values on rivet legs of E-SPR joints were larger and almost no difference on rivet heads between the E-SPR and P-SPR. In addition, it was found that mechanical properties of E-SPR joints were higher than that of P-SPR joints. The shear fracture appearance indicated that E-SPR joints with higher undercut were more difficult to rupture in the bottom of Al sheet.

语种： 英文

作者： Cui, Junjia;Sun, Tao;Geng, Huihui;Yuan, Wei;Li, Guangyao;...

期刊： International Journal of Advanced Manufacturing Technology,2018年98(5-8):1081-1092 ISSN：0268-3768

通讯作者： Zhang, Xu

作者机构： [Li, Guangyao; Cui, Junjia; Sun, Tao; Geng, Huihui; Yuan, Wei] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Li, Guangyao; Cui, Junjia] Joint Ctr Intelligent New Energy Vehicle, Shanghai 200092, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.

通讯机构： [Zhang, Xu] C;Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.

关键词： Magnetic pulse welding;Grinding directions;Mechanical properties;Interfacial morphology;Element diffusion;Formation mechanism

摘要： Magnetic pulse welding (MPW) has attracted widespread attention due to its advantages on joining dissimilar metals. This paper mainly focused on the effect of surface treatment on the weldability and mechanical properties of Al-Fe joints. Two kinds of surface grinding directions, including parallel to welding direction (P2W) and vertical to welding direction (V2W), were designed to prepare MPW joints. Mechanical properties and interface microstructures were systematically analyzed to establish the corresponding relationship between the two. Results showed V2W welded joints presented a wavy-shape interface and had better mechanical properties. The P2W specimens only showed a straight interface, and the element diffusion in the zone of the wave interface was better than that in the zone of the straight interface. The discharge energies affected mechanical properties by changing the interfacial morphology. In addition, the formed jets could be trapped and led to the formation of interfacial waves when the scratch direction did not coincide with the welding direction, contributing to the formation mechanism of wave interface.

语种： 英文

作者： Cui, Junjia;Dong, Dongying;Zhang, Xu;Huang, Xiaodong;Lu, Guoxing;...

期刊： International Journal of Impact Engineering,2018年115:1-9 ISSN：0734-743X

通讯作者： Li, Guangyao

作者机构： [Li, Guangyao; Cui, Junjia; Dong, Dongying; Jiang, Hao] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Li, Guangyao; Cui, Junjia] Joint Ctr Intelligent New Energy Vehicle, Shanghai 200092, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.;[Huang, Xiaodong; Lu, Guoxing] Swinburne Univ Technol, Fac Sci Engn & Technol, Melbourne, Vic 3122, Australia.

通讯机构： [Li, Guangyao] H;[Li, Guangyao] J;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;Joint Ctr Intelligent New Energy Vehicle, Shanghai 200092, Peoples R China.

关键词： Aluminum;Aluminum alloys;Fiber reinforced plastics;Fracture;Mechanical properties;Microstructure;Reinforced plastics;Reinforcement;Riveting;Rivets;Scanning electron microscopy;Shear stress;Speed;Aluminum alloy sheet;D. digital image correlation (DIC);Failure behaviors;Failure positions;Fracture mechanisms;High Speed;Riveted lap joints;Tensile machines;Carbon fiber reinforced plastics

摘要： Electromagnetic riveting (EMR) has the better riveting quality and more suitable for joining composite materials than traditional riveting. In this work, the failure process of electromagnetic riveted joints was investigated during high speed loading. Mechanical properties of sheet thickness specimens were tested by a high speed tensile machine with a loading speed of 5 m/s. The failure process and fracture mechanism was revealed using digital image correlation (DIC) and scanning electron microscope (SEM). With the increase of CFRP sheet thickness, strain cloud maps demonstrated that the deformation of aluminum alloy plate was more and more severe until the rivet broke from. The failure position of the specimens was transferred from CFRP sheet to aluminum alloy sheet and rivet. The failure modes of specimens were that the carbon fibers were cut off, or forcibly stripped and stratified. The riveted hole of the aluminum alloy plate was turned outward, and the rivet was cut and broken down under the high speed loading. © 2018

语种： 英文

作者： Hu, Lin;Zhong, Yuanxing;Hao, Wei*;Moghimi, Bahman;Huang, Jing;...

期刊： IEEE ACCESS,2018年6:59695-59704 ISSN：2169-3536

通讯作者： Hao, Wei

作者机构： [Zhong, Yuanxing; Zhang, Xin; Hu, Lin; Du, Ronghua] Changsha Univ Sci & Technol, Sch Automot & Mech Engn, Changsha 410205, Hunan, Peoples R China.;[Hao, Wei] Changsha Univ Sci & Technol, Hunan Key Lab Smart Roadway & Cooperat Vehicle In, Changsha 410205, Hunan, Peoples R China.;[Moghimi, Bahman] CUNY, Dept Civil Engn, New York, NY 10031 USA.;[Huang, Jing] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

通讯机构： [Hao, Wei] C;Changsha Univ Sci & Technol, Hunan Key Lab Smart Roadway & Cooperat Vehicle In, Changsha 410205, Hunan, Peoples R China.

关键词： energy-saving algorithm;Optimal path algorithm;real-time speed;signalized intersection;vehicle infrastructure cooperative systems

摘要： Vehicle speed trajectory and traffic signals significantly impact vehicle's fuel consumption and travel time in the urban road network. In this paper, we proposed an optimal vehicle routing algorithm that takes the waiting time at signalized intersections and eco-driving model into consideration. First, the data of the floating car collected by the GPS are matched with the electronic map, and the average traveling speed of the vehicle in each road segment is calculated in real time. The position and timing information of the signal lights at each intersection are pre-acquired to establish an eco-driving model at signalized intersections with the support of cooperative vehicle infrastructure system technologies. The vehicle accelerates through the signalized intersection to reduce the waiting time in the case, where the headway is allowed, while the vehicle decelerates to the minimum speed to avoid idling. Based on the traffic lights red light, green light conversion probability, and vehicle energy-saving driving model, the signal light cycle duration is divided into four parts: the green light pass section, the red-light acceleration section, the red light idle section, and the red-light deceleration section. Combining the probability distribution and the fuel consumption model, the average fuel consumption at the intersection area can be calculated. Taking the optimal energy consumption as the goal, combined with the A∗ algorithm, an optimal path algorithm that considers the influence of traffic lights and energy consumption is proposed. Finally, two examples are tested, including a real-world road map in Changsha city to demonstrate the effectiveness of the proposed algorithm. And the results show that the proposed model has good performance on energy consumption reduction. © 2013 IEEE.

语种： 英文

作者： Jiang, Hao;Cong, Yanjun;Zhang, Xu;Li, Guangyao;Cui, Junjia*

期刊： Materials & Design,2018年142:297-307 ISSN：0264-1275

通讯作者： Cui, Junjia

作者机构： [Cong, Yanjun; Li, Guangyao; Zhang, Xu; Cui, Junjia; Jiang, Hao] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.;[Li, Guangyao; Cui, Junjia] Joint Ctr Intelligent New Energy Vehicle, Shanghai 200092, Peoples R China.

通讯机构： [Cui, Junjia] H;[Cui, Junjia] J;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;Joint Ctr Intelligent New Energy Vehicle, Shanghai 200092, Peoples R China.

关键词： Aluminum;Concrete beams and girders;Cracks;Elastomers;Fatigue of materials;Fatigue testing;Fiber reinforced plastics;Joints (structural components);Plastics applications;Reinforced plastics;Reinforcement;Carbon fiber reinforced plastics (CFRP);Engineering applications;Fatigue behavior;Fatigue degradation;Mechanical performance;Overlapping regions;Property degradation;Salt spray;Carbon fiber reinforced plastics

摘要： The durability of hybrid carbon fiber reinforced plastics (CFRP)/aluminum alloy (Al) structures is receiving increasing attentions in engineering applications. In this paper, the mechanical performance of CFRP/Al electromagnetically riveted lap joints after exposure in neutral salt spray environment for various ageing time was studied. The shear and fatigue tests were conducted. The mechanical property degradation laws and failure mode evolution were obtained. The results showed that the shear and fatigue properties of the CFRP/Al electromagnetically riveted lap joints linearly decreased with the increase of ageing time. In addition, the fatigue test results showed that three weeks was the critical ageing time for failure mode changing. Fatigue crack initiated from the riveted hole (below 3 weeks) and the edge of the overlapping region (over 3 weeks) of Al sheet, respectively. Meanwhile, the fracture analysis showed that the cracks of specimens after long-time ageing (over 3 weeks) were initiated from the several corrosion pits simultaneously. © 2018 Elsevier Ltd

语种： 英文

作者： Geng, Huihui;Mao, Jingqi;Zhang, Xu;Li, Guangyao;Cui, Junjia*

期刊： Journal of Materials Processing Technology,2018年262:1-10 ISSN：0924-0136

通讯作者： Cui, Junjia

作者机构： [Li, Guangyao; Mao, Jingqi; Cui, Junjia; Geng, Huihui] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Li, Guangyao; Mao, Jingqi; Cui, Junjia; Geng, Huihui] Joint Ctr Intelligent New Energy Vehicle, Shanghai 200092, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Sch Automobile & Mech Engn, Changsha 410114, Hunan, Peoples R China.

通讯机构： [Cui, Junjia] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Aluminum alloys;Binary alloys;Ductile fracture;Fracture mechanics;High speed cameras;Image analysis;Iron alloys;Magnetism;Speed;Strain measurement;Tensile strength;Tensile testing;Welds;Digital image correlation methods;Digital image correlations;Dissimilar joints;Dynamic tensile test;Interfacial fracture;Magnetic pulse welding;Non-uniform distribution;Strain rate sensitivity;Strain rate

摘要： To investigate the mechanical properties and fracture behavior of Al-Fe magnetic pulse welds, quasi-static and dynamic tensile tests were performed under five tensile speeds (2 mm/min, 1, 5, 10 and 15 m/s). High-speed cameras were employed to record the tensile process, and the strain maps of the joints were obtained using digital image correlation method. The morphology and microstructures of the fracture surfaces under these tensile speeds were investigated. The Al-Fe joints showed positive strain rate sensitivity in terms of the maximum shear load as it increased by 22% when the tensile speed rose from 2 mm/min to 15 m/s. The strain rate sensitivity also led to the change of failure mode from base metal fracture to interfacial fracture. Strain rate in the weld zone showed sharply nonuniform distribution when the joints suffered high-speed loading. The strain rate sensitivity of intermetallic layer revealed the coexistence reason of cleavage and ductile fracture in the interfacial failure. © 2018 Elsevier B.V.

语种： 英文

作者： 胡林;钟远兴;黄晶;杜荣华;张新

期刊： 汽车工程,2018年40(10):1223-1229,1253 ISSN：1000-680X

通讯作者： Hu, L.

作者机构： 长沙理工大学汽车与机械工程学院, 长沙, 410114;长沙理工大学, 工程车辆安全性设计与可靠性技术湖南省重点实验室, 长沙, 410114;湖南大学, 汽车车身先进设计制造国家重点实验室, 长沙, 410082;[胡林; 钟远兴; 杜荣华; 张新] 长沙理工大学汽车与机械工程学院, 长沙, 410114 长沙理工大学, 工程车辆安全性设计与可靠性技术湖南省重点实验室, 长沙, 410114;[黄晶] 湖南大学, 汽车车身先进设计制造国家重点实验室, 长沙, 410082

通讯机构： School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha, China

关键词： 最优路径算法;车路协同;信号交叉口;等待时间

摘要： 本文中提出了一种考虑信号交叉口等待时间的车辆最优路径规划算法。通过GPS采集的浮动车数据与电子地图进行匹配,实时计算出各路段的车辆平均行驶速度和通行时间。基于马尔科夫链构建信号交叉口红绿灯的概率模型,通过车路协同技术预先获取各路段交叉口信号灯的位置和相位配时信息,并在车辆接近交叉口时对车辆速度进行优化,将车辆加速通过交叉口视为绿灯时间的延长,并以此构建车辆快速通过交叉口的等待时间模型。在此基础上,结合A*算法,提出一种考虑快速通过信号交叉口的改进A*算法。最后选取长沙市区某路网为算例进行仿真分析,结果表明改进A*算法所得路径的通行时间明显短于传统A*算法。

语种： 中文

作者： Zhang, Xu*;Zhang, Maoyun;Sun, Liqiang;Li, Chunfeng

期刊： Archives of Civil and Mechanical Engineering,2018年18(3):887-901 ISSN：1644-9665

通讯作者： Zhang, Xu

作者机构： [Zhang, Xu] Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.;[Sun, Liqiang; Zhang, Maoyun] Capital Aerosp Engn Machinery Co, Beijing 100076, Peoples R China.;[Li, Chunfeng] Harbin Inst Technol, Sch Mat Sci & Engn, Harbin 150001, Heilongjiang, Peoples R China.

通讯机构： [Zhang, Xu] C;Changsha Univ Sci & Technol, Coll Automot & Mech Engn, Changsha 410114, Hunan, Peoples R China.

关键词： Electromagnetic riveting;TA1 titanium alloy;Mechanical properties;Joining qualities

摘要： In this work, an electromagnetic-mechanical-thermal coupling numerical model was proposed and electromagnetic riveting (EMR) experiments were performed using Phi 6 mm TA1 titanium alloy rivets. Experimental verification showed that the proposed model could be suitable for predicting the EMR process, and the corresponding relationships among magnetic pressures, deformations of rivet tails and discharge voltages were revealed. In addition, simulation results presented that most deformations occurred in the locally upsetting stage of rivet tail. The maximum temperature rise reached up to 426 degrees C within the shear deformation zone of rivet tail. The rivet tails with high speed deformations could bear 9.9 kN shear loads and 12.5 kN pull-out loads, respectively. The EMR joining structures with multi-layered sheets had very high interference-fit qualities, and the average relative interferences were 2.5-3.0% for as-received multi-layered structures. Consequently, the EMR process can be used for difficult-to-deformation material rivets under the high efficiency, high quality and ambient temperature. (C) 2018 Politechnika Wroclawska. Published by Elsevier Sp. z o.o. All rights reserved.

语种： 英文

作者： 胡林;程启寅;黄晶;陈强;张新

期刊： 汽车工程,2018年40(11):1294-1301 ISSN：1000-680X

通讯作者： Hu, L.

作者机构： 长沙理工大学汽车与机械工程学院, 长沙, 410114;长沙理工大学, 工程车辆安全性设计与可靠性技术湖南省重点实验室, 长沙, 410114;湖南大学, 汽车车身先进设计制造国家重点实验室, 长沙, 410082;中国汽车技术研究中心, 天津, 300162;[胡林; 程启寅; 张新] 长沙理工大学汽车与机械工程学院, 长沙, 410114 长沙理工大学, 工程车辆安全性设计与可靠性技术湖南省重点实验室, 长沙, 410114

通讯机构： School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha, China

关键词： 轿车-自行车碰撞;骑车人;头部损伤;骑行姿态

摘要： 为探究轿车-自行车事故中骑车人的骑行姿态对其头部损伤的影响规律,首先采用PC-Crash软件建立自行车、骑车人和轿车模型,进行4组不同背角范围的仿真并分析骑车人骑行姿态对头部损伤的影响。接着,从中国交通事故深入研究( CIDAS)数据库中挑选出79例轿车-自行车事故,用于分析实际案例中坐姿对头部动力学响应的影响。最后,通过多项式拟合,建立了在4个姿态分组下,头部碰撞速度、绕转距离和损伤程度与车速之间关系的数学模型。结果表明:骑车人头部的损伤程度随轿车碰撞速度的升高而增大,但随骑车人的背角的增大而减小。

语种： 中文

作者： Geng, Huihui;Xia, Zehua;Zhang, Xu;Li, Guangyao;Cui, Junjia*

期刊： Materials Characterization,2018年138:229-237 ISSN：1044-5803

通讯作者： Cui, Junjia

作者机构： [Li, Guangyao; Xia, Zehua; Cui, Junjia; Geng, Huihui] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Li, Guangyao; Cui, Junjia] Joint Ctr Intelligent New Energy Vehicle, Shanghai 200092, Peoples R China.;[Zhang, Xu] Changsha Univ Sci & Technol, Sch Automobile & Mech Engn, Changsha 410114, Hunan, Peoples R China.

通讯机构： [Cui, Junjia] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.

关键词： Alloy steel;Aluminum;Dissimilar materials;High resolution transmission electron microscopy;High strength alloys;High strength steel;Intermetallics;Iron alloys;Joining;Magnetism;Mechanical properties;Microstructure;Scanning electron microscopy;Tensile testing;Welding;High strength low alloy steel (HSLA);Intermediate layers;Joining technology;Magnetic pulse welding;Micro-structure evolutions;Microstructures and mechanical properties;Properties and microstructures;Quasi-static tensile test;Aluminum alloys

摘要： Magnetic pulse welding (MPW) is an innovative joining technology for dissimilar materials. The MPW with high joining qualities could be realized between high strength steel and 5× aluminum alloys. In this work, the MPW joints between aluminum alloy (AA 5182) sheet and high-strength low alloy steel (HC340LA) sheet were prepared under various discharge energies. The mechanical properties and microstructure observations were employed to evaluate the joint performance. Results showed that a lower discharge voltage tended to cause joints with poor quality. When the discharge energy increased, the failure position gradually changed from the weld zone to the weaker base metal (Al) during quasi-static tensile tests. In addition, the effect of discharge energies on microstructure evolution in the intermediate layer was revealed by high-resolution transmission electron microscopy (HRTEM) and scanning electron microscope (SEM). Atomic-scale diffusion was found to be the mainly welding mechanism of the Al/Fe joint. The intermetallic compound (IMC) FeAl2 and ultra-fine grains (UFG) were found in the intermediate layer under high discharge energy. © 2018 Elsevier Inc.

语种： 英文