Table of Content

    28 June 2019, Volume 53 Issue 6 Previous Issue    Next Issue
    Composite Adaptive Control for Electro-Hydraulic Servo System Under Interval Excitation Condition
    GUO Qinyang,SHI Guanglin,WANG Dongmei
    2019, 53 (6):  639-646.  doi: 10.16183/j.cnki.jsjtu.2019.06.001
    Abstract ( 1155 )   PDF (1030KB) ( 350 )   Save
    A composite adaptive dynamic surface control method was proposed for high accuracy trajectory tracking of an electro-hydraulic servo system under interval excitation condition. By introducing the first-order command filters to process the virtual control signals during the controller designing process, the complicated calculation of the partial derivatives of the virtual control signals could be avoided. In order to realize the estimation and compensation of the unknown damping coefficient and unknown stiffness coefficient of the hydraulic system, a composite adaptive law was designed, and the stringent persistent excitation condition of the conventional adaptive control method was relaxed. The stability of the closed-loop system was analyzed by using Lyapunov theory, and the comparative simulation results based on MATLAB/Simulink have verified the effectiveness of the proposed control method.
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    Sealing Clearance Optimization of Cam Rotor Vane Motor Based on Heat Property Analysis
    ZHANG Qiang,ZHU Yannan,TAO Jianfeng,WANG Xuyong
    2019, 53 (6):  647-653.  doi: 10.16183/j.cnki.jsjtu.2019.06.002
    Abstract ( 826 )   PDF (3028KB) ( 225 )   Save
    A new kind of cam rotor vane motor(CRVM) is introduced with its operating principle and features. The seal method of CRVM is clearance seal. Under different clearance and working conditions, the local temperature of CRVM seal is obviously different. In this study, pressure-gradient flow temperature rise theory,the parallel-plate clearance flow model and the parallel-disc clearance radial flow model are used to calculate the temperature increase caused by leakage and friction. And the simulation models of two main heating points are established according to the results: One is between cam and stator; The other is between cam and bulkhead. Through the simulation, the influence of sealing clearance, working pressure and rotating speed on the local temperature rise of the seal is analyzed. Moreover, an experimental platform is established to measure the temperature change of CRVM under working conditions, and the results of the simulating calculation are verified. The results show that when the sealing clearance is not selected properly, the local temperature will rise obviously. From the perspective of preventing local oil overheating and improving the working efficiency of CRVM, the optimization sealing clearance index of CRVM is put forward.
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    In-Situ Vision Detection and Compensation of Wheel Profile Error in Profile Grinding
    HU Yixing,XU Liming,FAN Fan,ZHANG Zhe
    2019, 53 (6):  654-659.  doi: 10.16183/j.cnki.jsjtu.2019.06.003
    Abstract ( 952 )   PDF (1880KB) ( 301 )   Save
    This study introduced a method for a rapid vision detection of edge profile of grinding wheel based on a self-developed profile grinding machine. The in-situ vision detection of wheel profile was designed. The accuracy measurement and quantitative assessment of wheel profile were presented. The feasibility and measurement accuracy were experimentally testified. Finally, a segmented quantitative characterization of wheel profile error and error compensation method were proposed for grinding of contour surfaces. Experiments were designed and conducted. The experimental results indicated that the method can online compensate wheel profile error and effectively improve the shape and size precision of profile of machined component.
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    A New Blade-Casing Rubbing Model Based on Hertz Contact Theory
    ZHAO Yang,HUA Yixiong,ZHANG Zhinan,CHAI Xianghai
    2019, 53 (6):  660-664.  doi: 10.16183/j.cnki.jsjtu.2019.06.004
    Abstract ( 1533 )   PDF (1920KB) ( 311 )   Save
    Aiming at the phenomenon of aircraft engine blade-casing rubbing, this paper established a blade-casing Hertz-rubbing model considering the rotation effect and friction thermal effect. The influence factors of rubbing radial deformation were analyzed. The accuracy of the model was verified by comparing with the experiment results of existing normal rubbing force model. Moreover, the influence of rotation speed, stiffness coefficient, friction coefficient on the rubbing radial deformation were also analyzed. The results of the thermo-solid coupling simulation analysis on blade showed that the friction thermal effect had a certain influence on the overall radial deformation.
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    Dynamic Behavior of Coupled Flexible Plate Structure with Piezoelectric Actuator via Absolute Nodal Coordinate Formulation
    YI Canming,YU Haidong,WANG Hao
    2019, 53 (6):  665-672.  doi: 10.16183/j.cnki.jsjtu.2019.06.005
    Abstract ( 995 )   PDF (1150KB) ( 411 )   Save
    Coupled flexible structures are widely applied on soft robots as actuators, which are combined with hard electric actuating material and flexible medium. The accurate description for the rigid-flexible coupling and large deformation is of great importance for the structure design and accurate control of the actuators and soft robots. In this paper, a flexible beam-plate coupled structure is established based on the deformation compatibility condition, the deformation of the structure is described with absolute nodal coordinate formulation, and the dynamic equations are developed based on Hamilton’s principle. To investigate the influence of actuation, piezoelectric material constitutive equations are imposed to the beam element as a piezoelectric actuator of the structure. The results indicate that the deformations of the coupled flexible structure under piezoelectric actuation increase linearly with the increase of input voltage. The structure conducts periodical vibrations under actuation, the amplitude and the period of the vibration increase nonlinearly with the decrease of Young’s modulus.
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    Blade Force Characteristics and Tonal Noise Prediction of Axial Fans with Uneven-Spaced Blades
    PAN Dinghao,WU Yadong,PENG Zhigang,OUYANG Hua,DU Zhaohui
    2019, 53 (6):  673-680.  doi: 10.16183/j.cnki.jsjtu.2019.06.006
    Abstract ( 1269 )   PDF (4926KB) ( 297 )   Save
    In this paper, the numerical simulation method is used to investigate the even-spaced and uneven-spaced automotive cooling fans. The relationship between blade force and uneven-spaced blade distribution angle is analyzed through blade striping treatment, and the model between blade force and blade phase angle of uneven-spaced fan is established. Based on the characteristics of uneven-spaced fan blade force, a noise prediction method for uneven-spaced fan is proposed by using Lowson point force model, and a peak noise prediction model for low-speed non-uniformly distributed fan based on fan blade force model is established. The prediction model is verified by comparing with the prediction results of Lowson model based on computational fluid dynamics (CFD), experimental data and other uneven-spaced fan blade noise prediction models.
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    An Explicit Parallel Successive Over-Relaxation Method for Simulation of 2-Dimensional Incompressible Flows
    ZHANG Xiaohui,BAI Junli,GU Xiechong,MA Ning
    2019, 53 (6):  681-687.  doi: 10.16183/j.cnki.jsjtu.2019.06.007
    Abstract ( 1024 )   PDF (1169KB) ( 200 )   Save
    An explicit finite volume parallel successive over-relaxation (FV-pSOR) iterative method is proposed to improve the efficiency of successive over-relaxation (SOR) iterative method in solving the algebraic equations obtained by discretizing the governing equations of 2-dimensional incompressible flows. Based on the domain decomposition technique, computation domain is separated into four sub-domains, and group explicit SOR schemes are constructed for the algebraic equations with general coefficients in flow problems. Furthermore, the iterative route has been discussed in detail. To confirm availability of this algorithm, a series of calculations for a typical lid-driven cavity flow are performed. It demonstrates that comparing to the SOR iterative method, current FV-pSOR iterative method improves the computation efficiency several folds while the accuracy is not degraded.
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    Field Test and Numerical Analysis of a New Water-Proof System for a Shield Tunnel
    ZHANG Zixin,XIAO Shihui,LIU Tongwei,HUANG Xin,HE Ren
    2019, 53 (6):  688-695.  doi: 10.16183/j.cnki.jsjtu.2019.06.008
    Abstract ( 1003 )   PDF (11905KB) ( 275 )   Save
    The practical application effect of the new waterproof system is investigated by the design and field test in Maliuzhou traffic tunnel project in Hengqin New District, Zhuhai. Extend finite element method (XFEM) is used to analyze the effect of the inducing joint waterproofing system on the crack development, and the effect of the new reactive butyl rubber plate water stop in different spacing layouts is calculated by using the numerical simulation and is used to optimize the applications in projects. The test results show that the new waterproof system is effective in controlling the crack development and leakage of water, compared with the traditional method of self-waterproofing concrete, the new system proves the rationality and feasibility of the new waterproof system design. Besides, the numerical simulation results are in good agreement with the field test results. By means of the analysis of the crack development results under different spacing of induced joints, it is determined that the optimal arrangement space is 4—5 m. In addition, the design process should focus on the role of temperature and shrinkage of concrete that may cause cracks.
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    Bonding and Load Bearing Characteristics of Grouting Layer in Prefabricated Cement Concrete Pavement
    ZHU Maojiang,WENG Xingzhong,ZHANG Jun,YANG Bohan,LIU Junzhong
    2019, 53 (6):  696-703.  doi: 10.16183/j.cnki.jsjtu.2019.06.009
    Abstract ( 1173 )   PDF (1218KB) ( 304 )   Save
    In order to solve the optimization problem of grouting layer in the application of prefabricated cement concrete pavement, an orthogonal test scheme with four factors (grouting type, bottom roughness, grouting thickness and base structure) and three levels was designed. The vertical static and fatigue loading tests and lateral loading test were carried out. Results show that the bottom roughness has the greatest influence on the bonding characteristics between the grouting layer and the surface layer. The grouting type has the greatest influence on the bonding characteristics between the grouting layer and the base layer, as well as the bearing capacity of pavement structure. After fatigue loading, the neutral plane of the surface layer exhibits upper shifts in different degrees. The relationship between deflection, pressure and fatigue loading times has three stages: dramatic change, linear change and stable stage. Under lateral load, high strength non-shrink grouting material (CGM) has the best bond with the base. The relationship between lateral load and superstructure displacement meet the quadratic polynomial pattern. When the grouting material is CGM, the slab bottom is smooth, the grouting thickness is 2.0cm, the base structure is 12% cement stabilized soil, the pavement grouting layer achieves the best bonding characteristics.
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    Morphology and Distribution of the Liquid Metal Embrittlement Crack in the Resistance Spot Welded Joint of the Galvanized Q&P980 Steel
    KONG Liang,LING Zhanxiang,WANG Ze,WANG Min,PAN Hua,LEI Ming
    2019, 53 (6):  704-707.  doi: 10.16183/j.cnki.jsjtu.2019.06.010
    Abstract ( 1346 )   PDF (8265KB) ( 299 )   Save
    When some solid metals or alloys are to directly contact with specific liquid metals or alloys in tensile stress, their strength and ductility will drop and early fracture will occur, such a phenomenon is known as liquid metal embrittlement (LME). Iron can be embrittled by liquid zinc. After carrying out resistance spot welding experiment on the galvanized high strength Q&P980 steel plates, cracks were detected on the surface of joint, those cracks were found to be filled with zinc, thus it could be assumed that the cracks were caused by LME phenomenon, as zinc coating was melted and stress existed during welding process. LME cracks mainly distribute on the step and periphery of the indentation, and they showed different depth and forms.
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    Influence of the Electrode Shape on Service Life in 5052 Aluminum Alloy Resistance Spot Welding
    DU Huimin,LUO Zhen,AO Sansan,ZHANG Yu,HAO Zhizhuang
    2019, 53 (6):  708-712.  doi: 10.16183/j.cnki.jsjtu.2019.06.011
    Abstract ( 1105 )   PDF (7537KB) ( 249 )   Save
    Numerical simulations of resistance spot welding with different electrode (?6mm, ?8mm cone electrodes, and ?16mm ball electrode) were performed by ANSYS to examine the effect of the nugget shape on the weld properties and the service life of the electrodes under the same parameters. Continuous spot welding is carried to verify the correctness of the finite model. The results indicate that as for the cone electrode, the smaller the diameter of the electrode is, the larger the size of the nugget, and the weld joint has good performance. The contact area between the ball electrode and the work piece is too small and the joule heat generated is large. So, the ignition loss of electrodes is a crucial problem for the ball electrode. The simulation results are in good agreement with the metallographic results. The service life is improved by 20% compared with the ball electrode when the 5052 thin plate is welded by ?6mm cone electrode, which provides the theoretical basis for selecting the electrode shape.
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    Constructions of Intermediate Configuration in Sheet Forming Simulation
    LIU Yongcai,BAO Yidong,QIN Xuejiao,LIU Yulin,CHEN Wenliang
    2019, 53 (6):  713-718.  doi: 10.16183/j.cnki.jsjtu.2019.06.012
    Abstract ( 1044 )   PDF (2959KB) ( 312 )   Save
    The large time step static implicit finite element method (FEM) for sheet metal forming simulation is presented to alleviate the convergence problem of the traditional implicit incremental FEM, and the simulation process of sheet metal forming is divided into bending deformation and tensile deformation. According to constraints of positions between the blank and mold, the shape of bending deformation which is called intermediate configuration is calculated. Meanwhile, a method based on pre-stress membrane element for constructing an intermediate configuration is also proposed in this paper. In this method, the contact states of the blank nodes are determined by the contact algorithm. The contact zone of blank is determined by the shape of mold, the non-contact zone is calculated with iterations for equilibrium equations by the pre-stress membrane element. The result shows that the proposed algorithm could obtain the appropriate intermediate configurations quickly and provide precise surface sliding constraint for tensile deformation.
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    Finite Element Analysis and Test Study on Shovel Spinning
    LI Ping,DAI Guangxu,YANG Weizheng,HU Chuanpeng,WU Chao,XUE Kemin
    2019, 53 (6):  719-725.  doi: 10.16183/j.cnki.jsjtu.2019.06.013
    Abstract ( 1091 )   PDF (3703KB) ( 357 )   Save
    By introducing a double-spinning rollers and its semi-enclosed structure of shovel spinning, a 3D rigid-plastic finite element method model of the spinning process of the inner cylinder on double cylindrical parts with flange was established on the platform of Simufact, and was used to validate the forming effect. The material in the major deformation zone has the displacement toward the axial, radial and tangential directions due to the compressive stress with nonuniform distribution during shovel spinning processing, therefore the inner cylinder exhibits an increasing effect in the axial length and the radial thickness. At the later stage of forming, the metal at the bottom is easier to be subjected to the compressive stress from the metal in the small deformation zone, which results in the difficulty of radial thickness and the lack of material on the inside of the barrel wall appeared. The greater the feed distance is, the more obvious the thickening effect and the lack of material are. The spinning process was tested on the spinning machine of CDC-60, and the results show that the effective height and the effective thickness can reach to 35.0mm and 6.9mm, respectively, which are over 15 times and 3 times of the thickness of shovel spinning, the errors of simulated and test results were less than 10%. The feasibility of numerical simulation analysis and semi-closed spinning roller structure is verified.
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    Finite Element Analysis of Weld Nugget Formation in Weld-Bonding of Three Stacks of Steel Sheets
    SHEN Jie,ZHANG Yansong
    2019, 53 (6):  726-733.  doi: 10.16183/j.cnki.jsjtu.2019.06.014
    Abstract ( 1052 )   PDF (8998KB) ( 203 )   Save
    Based on the ANSYS software, a multi-physics finite element model was established to research the weld nugget formation during the weld-bonding process of three stacks of steel sheets. The contact resistance between the steel sheets with the adhesive was parameterized in this model to illustrate the effect of the adhesive on the weld-bonding process. The calculation results in the structure, electric and thermal field during the weld nugget formation were investigated and validated by the experiment. The research results show that the weld nugget formation in the weld-bonding joint with 0.8mm DC04, 1.4mm DP600 and 1.8mm DP780 is about 40ms earlier than that in the resistance spot welding joint under the same welding condition. The weld nugget formation between DP600 and DP780 is 80 ms earlier than that between DC04 and DP600 during the weld-bonding process.
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    High-Rank Matrix Completion Method for Autism Spectrum Disorders
    LI Yuanchao,CHEN Feng
    2019, 53 (6):  734-740.  doi: 10.16183/j.cnki.jsjtu.2019.06.015
    Abstract ( 1138 )   PDF (714KB) ( 145 )   Save
    To solve the clinical data recover problem of autism spectrum disorders (ASDs), a high-rank matrix completion (HRMC) algorithm based on alternating direction method of multipliers (ADMM) was proposed. Under consideration of different parameters with different significance, the important parameters and unimportant ones were attached with various weights. In a case study, test data were generated to find the optimal parameters. Furthermore, the algorithm was applied on practical ASD clinical data. The results show that the algorithm performs better in comparison with other parameterized algorithms and normal matrix completion algorithm, which indicates that it can be applied in practical data cleaning and processing.
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    Evaluation Method of Equipment’s Contribution Rate to System-of- Systems Based on Operation Loop and Self-Information Quantity
    LUO Chengkun,CHEN Yunxiang,HU Xu,XUE Dingyuan
    2019, 53 (6):  741-748.  doi: 10.16183/j.cnki.jsjtu.2019.06.016
    Abstract ( 1360 )   PDF (1214KB) ( 511 )   Save
    Aiming at the problem of various equipment and complicated correlations in operation system-of-systems under the information conditions, an evaluation method of equipment’s contribution rate to system-of-systems based on operation loop and self-information quantity is proposed from the perspective of system-of-systems effectiveness. The equipment and correlations are abstracted as nodes and edges. The edges’ metrics are determined according to the tactical and technical indexes of the nodes, and the network model of operation system-of-systems based on operation loop is constructed. According to the number and effectiveness of the operation loop involved in each target node, the method for evaluating the effectiveness of operation system-of-systems based on self-information quantity is proposed. And the corresponding evaluation model is built. Taking an anti-aircraft carrier operation system-of-systems as an example, the results show that the proposed method has fully taken the heterogeneity and uncertainty of each equipment and correlation into consideration to evaluate the equipment’s contribution rate to system-of-systems comprehensively and objectively. The proposed method can provide methodological support for equipment demonstration and operation system-of-systems optimization.
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    Power System Transient Stability Assessment Based on Extreme Learning Machine
    ZHANG Linlin,HU Xiongwei,LI Peng,SHI Fang,YU Zhihong
    2019, 53 (6):  749-756.  doi: 10.16183/j.cnki.jsjtu.2019.06.017
    Abstract ( 935 )   PDF (1033KB) ( 785 )   Save
    With the enhanced trend of alternative clean energy and power electronics in power system, the traditional numerical simulation methods based on theoretical model will face new challenges, while the self-adaptive data-driven power system stability assessment method is gaining more and more attention. Based on the theory of extreme learning machine (ELM), a transient stability assessment method suitable for online application is proposed. Firstly, the samples are screened by adjusting the ratio of stable and unstable simulation samples, to reduce the sample imbalance in which unstable samples are far less than stable ones in the sample set, and the recursive feature elimination is used to further process the sample set. Then, the cross-validation is used to optimize the ELM network structure, and the processed sample set is used to train the ELM. Finally, the system stability based on the output of the neural network is predicted, and the reliability of the results with the improved evaluation criteria is evaluated. Test results show that the recursive feature elimination can significantly reduce the feature redundancy and improve the performance of the model, and the proposed algorithm has a shorter training time while can provide more accurate results.
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    Arterial Injury Assessment by Computational Interaction Model of Shear Thinning Blood with Expanded Stenotic Vascular
    JIANG Xudong,LI Pengfei,LIU Zheng,TENG Xiaoyan
    2019, 53 (6):  757-764.  doi: 10.16183/j.cnki.jsjtu.2019.06.018
    Abstract ( 1166 )   PDF (8526KB) ( 244 )   Save
    The interaction of intravascular stent, stenotic artery and blood characterized with shear thinning is analyzed to investigate the induced arterial injury during implantation of a stent into a curved artery. Computational fluid-structure interaction model with S-type and N-type stents is presented to anticipate the plaque vulnerability based on three indices including the peak plaque stress, highest wall shear stress and wall equivalent stress, and the resultant arterial restenosis based on lowest wall shear stress. The numerical results show that the developed peak plaque stress, peak wall shear stress and peak wall equivalent stress for the N-type stent is less than the counterparts for the S-type stent, which suggest that the former takes a lower risk of plaque rupture than the latter. Compared with the S-type stent, the less areas with the lowest wall shear stress and more flow cross-section are observed in the expanded stenotic artery for the N-type stent, which suggests that the risk of arterial restenosis is lower for the N-type stent.
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