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Table of Content

    10 October 2014, Volume 25 Issue 19
    Trajectory Planning and Simulation Analysis of Automatic Ultrasonic Testing for Large Rotary Parts
    Zeng Daxing, Shen Erqiang, Hou Yulei, Qiu Xuesong, Liu Jiaqi, Yao Jiantao, Zhao
    2014, 25(19):  2557-2562. 
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    Based on the investigation of the existing problems in traditional manually ultrasonic testing of large rotary parts, trajectory planning and movement law of testing system were researched herein, then the motion simulation of probe inspection trajectory was carried out.This paper discussed the principles of manually testing simulated by automatic testing, set the motion law of the axles and the probe, then planned the probe inspection trajectory. All of the automatic testing process was in line with the standards of non-destructive testing and the efficiency of testing was improved 5.46 times; Based on MATLAB and ADAMS software, the probe inspection trajectory was simulated, and the planning trajectory was realized. The research and results of the simulation demonstrate the feasibility of the automatic testing take the place of manually testing, and possesses theoretical direction significance for the similar trajectory planning in future.

    Flow Pattern and Lubrication Features in Particulate Lubrication Interface
    Meng Fanjing, Liu Kun, Wang Wei
    2014, 25(19):  2562-2567. 
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    The flow pattern and friction coefficient of particulate lubrication between sheared parallel plates (the top plate was fixed, the bottom plate moved with fixed velocity) were studied.The conservation of momentum, slip velocity boundary condition and the conservation of pseudo energy, pseudo temperature boundary conditions were established using the three body friction physical model and the binary collision hypothesis theory. According to the equations, the influences of the three-body parameters on the pseudo temperature, solid volume fraction and friction coefficient were investigated using the numerical methods. The results show that the fluctuation velocity between sheared parallel plates is the direct factor for the change of the pseudo temperature, solid volume fraction and the friction coefficient curves. The change of the three-body parameters can directly influence the fluctuation velocity, thus change the pseudo temperature, solid volume fraction and the friction coefficient curves.

    Study on Distribution of Subsurface Damage on Sapphire Substrate after Two-sided Lapping
    Liu Daobiao, Xu Xiaoming, Zhou Hai, Zhuo Zhiguo, Zang Yue, Gao Xiang,
    2014, 25(19):  2568-2572. 
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    According to prediction theory of subsurface damage layer of hard and brittle materials suggested by other scholars, a model that described the relation between the depth of subsurface damage layer and surface scratch was built. KOH(potassium hydroxide) was used to corrode sapphire substrate processed by two-sided lapping and then monitoring with shape measurement laser microscopy system of VK-X100/X200, thus the distribution of surface scratch could be obtained and the distribution of subsurface damage layer could be predicted. Research results show that the subsurface damage layer decreases as the depth increases and the most of them occurs in the depth of 0~12.9μm below the scratch, the percentage is about 96.7%. The results can help researchers to optimize processing parameters of two-sided lapping to lessen the depth of subsurface damage layer.

    Effects of Clearance Volume on Discharging Characteristics of Reciprocating Oil-gas Multiphase Pump
    Zhang Shengchang, Wang Zhaodong, Deng Hongying, Ma Yi, Yang Lin
    2014, 25(19):  2573-2578. 
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    To study the influences of clearance volume on hydraulic end of reciprocating multiphase pump, fluid field grid was updated by dynamic grid generation technology which was based on the differential equations of movements of the piston and valve, and the three-dimensional numerical simulation of discharging process was conducted. The flow field situation of each moment was obtained by numerical calculation, and pressure boost of cavity, instantaneous flow and delay angle of valve core opening were discussed in different clearance volumes. Results show that under the gas-liquid mixing medium conditions, the presence of the clearance volume extends the compression process. Then it causes the problems such as lag of boost pressure process, imbalance distribution of flow and the increasing of opening delay angle. Therefore clearance volume must be reduced as far as possible in the design and manufacture.

    Numerical Simulation for Ultrasonic Scattering Based on Stress Boundary
    Yan Xiaoling, Dong Shiyun, Xu Binshi,
    2014, 25(19):  2578-2582. 
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    In order to reflect the complex scattered wave field characteristics generated by irregular defects in the process of ultrasonic inspection, a formula for calculation of stress in artificial boundary was given herein. The formula could be applied to all waveforms. When artificial stress boundary was applied in numerical simulation for ultrasonic wave in solid, the size and distribution of stress in media boundary element's surface required to meet the constitutive relation of media and wave equation radiated through the artificial boundaries, the response of boundary nodes and finite element nodes were calculated by the same integral method. Numerical examples demonstrate that the deviation of the proposed boundary is very small, can reflect the the complex scattered wave field characteristics generated by various types of defects in the process of ultrasonic inspection.

    Calculation of Residual Stress Induced by Machining in Internal Surface of TC4 Tubular Parts and Its FEA
    Meng Longhui, He Ning, Li Liang
    2014, 25(19):  2583-2587. 
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    With respect to residual stresses had a strong effect on the usability of the parts and the residual stresses in the material of TC4 were hard to measure with XRD method, this paper briefly presented a method to calculate the residual stresses induced by machining in internal surface of TC4 tubular parts. In order to verify the correctness of the method, the residual stresses varying with depth were applied in internal surface of the model in FEA software, the technology of element birth and death was used to “kill” the elements in internal surface layer by layer to simulate the process of corrosion in experiments. And the residual stresses were calculated based on the changing strains on the external surface of the part and the deduced formulas, and then the calculated residual stresses were contrasted to the stresses that were applied to the model.It can be found that the accuracy of the calculated residual stress is very high, so it can be concluded that this method can be applied to measure the residual stress in practice.

    Parameter Analysis of Influencing Vibration Characteristics of Workbench of CNC Machines
    Wu Qin, Rui Zhiyuan, Yang Jianjun
    2014, 25(19):  2588-2591. 
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    A mathematical model of feed system of an CNC machine was established using Lagrange equation and energy principle, and the influences of parameters on the vibration displacement of workbench were analysed. According to the results of orthogonal tests, it is concluded that the biggest three factors that influence workbench's vibration displacement are the ball screw's lead h, the table mass m and the longitudinal contact stiffness kn in the connection of the table and ball screw. On the feed system test-bed, the longitudinal amplitudes and torsional amplitudes of workbench were measured, they show that the larger the ball screw's lead and  the mass of the workbench the bigger, the greater the axial amplitude of the workbench; and the longitudinal contact stiffness in the connection of workbench and ball screw, the smaller the axial amplitude of the workbench.

    Dynamic Measurement Error Decomposition and Reconstruction Method Based on ICA
    Yang Hongtao, Fang Chuanzhi, Fei Yetai,
    2014, 25(19):  2592-2596,2602. 
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    The method that ICA was used to decompose and reconstruct dynamic measurement errors was researched. The basic algorithm of ICA to decompose and reconstruct dynamic errors was elabrated detailedly. A measuring device for dynamic measurement errors was built by using the coordinate measuring machine and dual-frequency laser interferometer. The dynamic error separating experiments were done. The dynamic error data was processed respectively by using the method of adaptive filtering, wavelet analysis and ICA, which was aimed to separate and reconstruct the systematic errors with linear change and with periodic change and the dynamic random errors. The experimental results prove that the overall sample of the measured dynamic errors must be fully applied for the precise analysis and error component indentification of the measured dynamic errors. Compared with the previous two methods, the systematic error with linear change and with periodic change and the dynamic random error can be separated and reconstructed more effectively and accurately by using ICA.

    Flexible Electromechanical Coupling Dynamic Characteristics Analysis on Permanent Magnet Linear Feed System
    Ning Jianrong, Xia Jiakuan, Yu Ling, Li Tiejun
    2014, 25(19):  2597-2602. 
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    The dynamic characteristics of high-precision CNC machine direct drive linear feed system were affected by mechanical component elastic deformations and the electrical system control parameters susceptibly. From the viewpoint of electromechanical coupling,direct drive linear feed table flexible electromechanical coupling model was established using the finite element method and Lagrange-Maxwell's equations. Combined with the finite element analysis software ANSYS, dynamic simulation software ADAMS, linear feed system flexible electromechanical coupling simulation model was established. Then the system dynamics simulations were analyzed using this simulation model. The analysis shows that the flexibility feed table is up to the real situation, and electrical control parameters have a significant effect on the system dynamics. Linear feed system flexible electromechanical coupling model can provide evidence for direct drive system structure optimization design.

    Error Analysis Based on Non-metric Lens in Industrial Close-range Photogrammetry
    Ran Xiansheng, Zhu Caichao, Huang Zehao
    2014, 25(19):  2603-2607. 
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    Based on the researches of len distortions,this paper presented an opinion that it was applicable to directly replace the industrial tailor-made lens with normal prime lens. The comparison tests were performed between photos of tailor-made lens and photos of normal lens by examination methodology requested by VDI/VED2634 Part I, and the calculation was performed by TRITOP within the comparison photos in order to obtain the data cloud.  The research displays that the measurement results, root mean square error is less than 0.125mm and range is less than 0.323mm. In addition, the parameters ENIKmeet the qualification requirements too. Furthermore, during the on-field testing, the normal prime lens is sufficient to meet the requirements of measurement and qualification in the industrial applications.

    Kinematics Analysis of Self-reconfigurable Robot during Deformation Process and Simulation of Obstacle Climbing
    Ge Weimin, Zhang Huajin, Wang Xiaofeng, Lei Yinglin
    2014, 25(19):  2608-2613,2619. 
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    Self-reconfigurable robot could change its configuration depending on the task environments. This paper discussed the transforming process of snake-like configuration changing into circular configuration, defined the junction surface of modular units and coordinate transform matrix, and got the universal formula based on the D-H method. Then The motion trail,velocity and acceleration during the transformation were simulated by RecurDyn and MATLAB. With the result, the correctness and the validity of the universal formula were proved; trajectory modification and reconfiguration space were judged; the stability of the robotic system was estimated; the awareness level of control algorithm was improved. Finally, two kinds of ring rolling gait were analyzed, and through the simulation, the ability of obstacle climbing was proved.

    Knowledge Representation Method for Aircraft Tooling Design Based on Ontology
    Li Changjie, Ming Xinguo, Qiu Kunhua, Xu Genhong
    2014, 25(19):  2614-2619. 
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    Firstly the tooling design knowledge was analyzed to extract the main concepts, relationships among concepts and attributes. A tooling design ontology model including design objects, design process, designers and design knowledge was created, and then Protégé was used to build the design ontology instance of assembly tooling for the horizontal tail beam, and the OWL language was used to represent the design knowledge ontology, and finally the tooling design knowledge management prototype system was developed. The demonstrating applications were carried out in a large aviation manufacturing enterprise.

    Ontology Reasoning Technology Application for Product Design Knowledge Service
    Chen Si, Yan Yan, Wang Zhao, Wang Guoxin
    2014, 25(19):  2620-2627. 
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    Aiming at existing problems in the process design-knowledge service such as incorrect service solution architecture and incomplete service matching model, a framework of product design knowledge service with reasoning technology was proposed. To ensure the correctness of service solution architecture, a method of consistency check for service requirement hierarchy was proposed based on ontology axiom. In addition, the SWRL rule base and reasoning engine were designed to find the implied relationship and semantics in the requirement model, and the semantics of service matching model was enriched. Finally, this approach was used in a knowledge service system for military-vehicle validating its effectiveness and feasibility.

    Time Synchronization in Multi-parameter Telemetry for Rotary Part
    Ma Jiangang, Sun Jianguo, Zhang Tianhong
    2014, 25(19):  2628-2633. 
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    According to the strict synchronization requirements of parameter measurement for rotary machine and the concentrated distribution characteristics of telemetry nodes, a RNBS technology was provided. By the wired communication among reference nodes, the broadcast news arrived at each node simultaneously, and then the time message and the moment of message arrival time were used for time synchronization. RNBS has advantages of high accuracy, high efficiency, easy realization in whole net and easy application in engineering. At last, RNBS was tested on the self-developed platform. The results show that the synchronization error is less than 1ms inside 30 minutes, and different precisions can be achieved by setting the synchronous cycle, which meets the requirements of time synchronization in multi-parameter telemetry for rotary machine.

    Fault Diagnosis of Rolling Bearings Based on DLMD Sample Entropy and Fuzzy Clustering
    Meng Zong, Wang Yachao, Wang Xiaoyan,
    2014, 25(19):  2634-2641. 
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    In view of the problem that the traditional local mean decomposition (LMD) was difficult to effectively extract the weak high frequency signal components,a method of DLMD was put forward. A new approach for rolling bearing fault diagnosis based on the combination of DLMD, sample entropy and fuzzy clustering was proposed. Firstly, rolling bearing vibration signals were decomposed with DLMD to obtain a certain number of product function(PF)components which had physical meaning. Then the sample entropies of the PF components were calculated and used as the eigenvectors. Finally, the eigenvectors were recognized and classified through the fuzzy clustering. The experimental results show that the method based on the combination of DLMD, sample entropy and fuzzy clustering can be used to recognize and classify rolling bearing fault signals accurately and effectively.

    Parametric Modeling and Characteristic Analysis of Co-rotating Conjugate Tooth Profiles
    Wei Weifeng, Ren Lijuan, Zhang Guangpeng, Han Xuzhao
    2014, 25(19):  2641-2646. 
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    Aiming at the co-rotating conjugate tooth profile, a meshing line equation was established based on parameters such as: center distance, diameters of screw tip and screw groove and the screw edge coefficient. A mathematical model of the conjugate tooth profiles was built based on the meshing line reversal method. The characteristics of the co-rotating conjugate tooth profiles are obtained that the self-cleaning wedge angle changes along with the meshing location, the tangent line of instantaneous meshing point of the tooth profile is perpendicular to the center line and the instantaneous relative motion velocity of the meshing point is the highest and is always equal to the value of the rotation speed multiplying the center distance. This research proves a foundation for the systematic study of the co-rotating conjugate tooth profiles design theory.

    Dynamic Integration Scheduling Methods of Ultra-thin Aluminum Foil Processing
    Chen Jin, Deng Yufeng, Liu Qin, Cui Junhua
    2014, 25(19):  2647-2652. 
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    Ultra-thin aluminum foil manufacturing is the production with some characteristics of flow processing, discrete processing, assembly. Based on these features, a mathematical model was established based on minimax algebra, which could derive the state iterative formula and summarize the multi-objective evaluation index. The model used heuristic method to make the orders in accordance with rules to optimize schedule and generated heat treatment plan, which made the orders timely-delivered and energy saving. This approach integrated schedule and loading furnace production plan, and the production could be controlled online when it was adjusted dynamically or changed for order input.

    Optimization Design on AGV Frame Structure
    Wu Bin, Qian Xiaoming, Wu Xing, Shen Ke
    2014, 25(19):  2653-2657,2664. 
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    With the objective of same intensity and lighter weight, an optimization design method was proposed to reduce self weight coefficient of AGV. On the basis of mechanics analysis on AGV frame structure, load position and wheel position were worked out with mathematical programming, which were important constraint conditions for AGV frame structure optimization. A kind of multi-criteria formulation was proposed for AGV frame structure based on variable density method and optimality criteria and calculated by finite element software. A 3D optimization model was constructed and analyzed. The results show that the optimization method is effective and reasonable.

    Analysis on Aerodynamic Noise Characteristics of Multi-blade Centrifugal
    Xie Chao, Gu Zhengqi, Yang Zhendong, Yang Xiaotao, Zong Yiqi, Luo Zemin
    2014, 25(19):  2658-2664. 
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    Created a simple geometric model, two-way fluid-structure interaction calculation was more accurate though experimental verification. Then, multi-blade centrifugal fan of a vehicle air conditioning system was taken as an research object, effects of the volute FSI on the fan aerodynamic noise were analyzed. Flow field calculation was carried out using CFX software and structure calculation was carried out using ANSYS software, respectively. Based on MFX-ANSYS/CFX data coupling platform, two-way synchronization solution method was used to solve the ventilator airflow field and the response of volute structure. The results show that, FSI effects enhance the flow field pressure pulsation; after considering FSI effects,the sound power level of the centrifugal fan impeller outlet and volute airway surface increases significantly, and the noise value of the fan outlet increases 5.24dB.

    A Method for Modulating Cam Curve and Optimization Using Particle Swarm Technique
    Wang Wenge, Rao Xinghua, Tan Shiwei
    2014, 25(19):  2665-2668,2673. 
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    The theory of modulation was applied to the existing cam curve. With the adjustment and control effect of modulation function on the shape of cam curve, the mathematical model of cam curve modulated with the multi-objectives  optimization was established, which consisted of characteristic values of the cam curve. In addition, the solving procedure of the model using particle swarm optimization technique was present. A new method that modulated and optimized cam curve was proposed. To illustrate the method, a corrected sine acceleration movement cam profile was modulated and optimized. The optimization example illustrates that the presented new method can adjust the shape of cam curve, improve dynamics characteristic of cam profile and achieve cam profile with good synthetic performances.

    Study on Clinch Joining for Cu/Al Alloy Sheets and Mechanical Properties of Joints
    Yang Huiyan, He Xiaocong, Deng Chengjiang, Zeng Kai, Ding Yanfang
    2014, 25(19):  2669-2673. 
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    Clinch was adopted to join Cu and Al alloy sheets. Mechanical performance of the joints was studied based on the lap-shear tests, and the effects of sequence of sheets on the lap-shear load of clinched joint were analyzed at the same time. It can be seen from the experimental results that the clinched joints present higher lap-shear load when the upper sheet is Cu alloy rather than Al alloy. The lap-shear load is about 3kN, which is 4.6 times of the other one. The optimization for composite joints based on the joint failure modes was carried out. Results show that when the lower sheet thickness increases, the energy absorption increases obviously but the lap-shear load slightly. If the lower sheet is displaced by a sheet with higher material strength, lap-shear load of joints increases distinctly. A conclusion can be drawn from the joint failure modes that a high joint lap-shear load corresponds to the neck fracture mode.

    Investigation of Rigid Particle Flow Method in Simulating Free Forging Processes
    Liu Min, Zhu Ming, Ma Qingxian, Ai Jing
    2014, 25(19):  2674-2680. 
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    When grid-based numerical methods dealt with large plastic deformation problems such as free forging,stamping forming, high speed impact and dynamic crack propagation,there was  frequently loss of calculation accuracy due to mesh distortion and remeshing difficulties, or even the calculation could not be conducted. Aiming at these problems, a numerical simulation method for large metal plastic deformation-RPF method was proposed based on theory of continuum mechanics and the basic principles of molecular dynamics. A mathematical model for RPF method was established and critical numerical techniques such as initial particle configuration, particle search algorithm, numerical integration and boundary conditions were studied. When RPF method was applied to high temperature upsetting of nuclear power disk forgings and finish forging of heavy nuclear power head, the calculation results show that for simulating large plastic deformation problems, the results of RPF method are in good agreement with the experimental ones, and RPF method can effectively explain the formation mechanism of laminated cracks in heavy disk forgings and lamellar tearing in head forgings. This research lays the foundation for further simulating more complex free forging processes using RPF method.

    Reverse and Optimization of Sheet Forming Parameters Based on PSO-RBF Surrogate Model
    Qiao Liang, Song Xiaoxin, Xie Yanmin, Wang Jie, Wang Xinbao
    2014, 25(19):  2680-2685. 
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    In order to obtain the forming parameters of materials under the conditions of complex states of stress and strain accurately and improve the accuracy of finite element numerical simulation of sheet metal forming, a new method based on the advanced RBF surrogate model was  presented. By introducing a radial correction coefficient into the radial basis kernel function of the RBF surrogate model, and using PSO to optimize the radial correction coefficient, the approximation accuracy of the model could be improved. Applying the PSO-RBF model to a nonlinear function, it shows that this method can improve the accuracy of the model effectively. At the same time,the PSO-RBF model was applied into the parameter reverse of sheet forming. The results show that the material parameters based on the PSO-RBF model can reflect the sheet forming materials flow trend and strain distribution more accurately.

    Research on Steering Wheel Shake of Vehicle during High-speed Driving Based on Chassis Incentive
    Hu Zhaohui, Shao Hui, He Zhicheng, Cheng Aiguo
    2014, 25(19):  2686-2691. 
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    A whole FE-model of steering system was built including steering joints,steering column and steering system, and exerted the frequency spectrum of acceleration obtained by test to steering joint to simulate frequency response functions, then optimized the results based on the thickness or structures of major plates,at last tested and verified the optimization results.The example indicates that the analysis method can analyze and solve the problem of steering wheel shake successfully during the vehicle high-speed driving.Thus, the method provides an significant idea of vehicle's research and development, and shortens vehicle's development period greatly.

    Model Predictive Control for Hybrid Electric Vehicle Based on Markov Chain Approach
    Meng Fanbo, Huang Kaisheng, Zeng Xiangrui, Zhang Yao
    2014, 25(19):  2692-2697. 
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    This paper used model predictive control method and choosed three different torque prediction models such as the acceleration pedal invariability, exponential decay and Markov stochastic process. Based on different prediction models, the dynamic optimization method could be used to optimize the toque ratio with comparison of the hybrid control strategy based on rules. The simulation results indicate that model predictive control for hybrid electric vehicle energy distribution has potential to improve the fuel economy. At last, this paper gives out the advanced research direction for the application of model predictive control on hybrid electric vehicle energy distribution.