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Table of Content

    25 January 2017, Volume 28 Issue 02
    Distributed Parameter Model and Experiments of a Broadband Piezoelectric Vibration Energy Harvester
    YANG Binqiang, XU Wentan, LU Guoli, WANG Guangqing
    2017, 28(02):  127-134. 
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    To solve self-power problem of wireless sensor network nodes, a broadband piezoelectric vibration energy harvester with an elastic supporter and amplifier was presented herein. Distributed parameter coupling electromechanical model of piezoelectric vibration energy harvester was established with Hamilton principle and Raleigh-Ritz method by considering the influences of cantilever tip mass. Effects of structural parameters (such as mass ratio, stiffness ratio, and damping ratio) on the vibration performance, the electric output performance of piezoelectric energy harvester were numerically analyzed. Prototype of piezoelectric energy harvester and experimental setup were developed. Some experiments were carried out to testify the validity of the proposed mathematical model. Research results show that the distributed parameter model may obtain higher precision than that of lumped parameter model.
    Evaluation of Metal Plastic Deformation Using Radio-frequency Reflection Features
    YIN Aijun, YAO Wenquan, REN Hongji, DAI Zongxian
    2017, 28(02):  135-138. 
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    This paper proposed a method resulting from electromagnetic properties variation for metal plastic deformation monitoring. Firstly, the influences of electromagnetic parameters (permeability, conductivity) on the radio-frequency reflection features of the metal plate samples were simulated. Energy distribution of radio-frequency varies obviously due to electromagnetic properties variation according to the simulation results. Experiments were conducted to verify simulation results. The results of the experiments indicate that the reflected radio-frequency signal strength decreases with progressive plastic deformation in metal, which has been in conformity with simulations.
    Optimal Design for Regulating Mechanisms of Variable Radial Turbocharger
    XING Shikai, LI Juxia, MA Chaochen, CHEN Lihui, LI Qing
    2017, 28(02):  139-143,149. 
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    A design scheme of turbocharger regulating mechanisms was proposed. In the design scheme, nozzle seat or spacer sleeve structure in traditional turbocharger was replaced by three fixed guide vanes to control the width of the nozzle ring. The design scheme was expected to realize the decrease of the local disturbance in the volute or in the nozzle ring field caused by the special structure, the decrease of the flow loss and the improvement of the turbine stage efficiency. The numerical calculations of the designed model, the nozzle seat structure model and the spacer sleeve structure model were conducted under the same operating conditions. Comparisons among the results of these three types of turbines validated the feasibility of the novel design scheme in theory.
    Test Program Load Spectrum Compilation for Accelerated Life Test of Leaf Springs with Variable Stiffness
    HAN Weiduo, LU Jianwei, LONG Daojiang
    2017, 28(02):  144-149. 
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    Considering characteristics of large deformation and nonlinear stiffness, a method of test program load spectrum compilation suitable for accelerated life test(ALT) of nonlinear leaf springs was presented. Based on the acceleration spectrum exposed to the leaf spring by road test, FEA method was used to obtain stress spectrum at any point. It is found that the amplitudes of stresses obey Weibull distribution,but the mean is not distributed as normal distribution or Weibull distribution. Based on the extrapolated spectrum, method of compilation and realization for bench test was studied. Compared to the results of road test, the compiled ALT program load spectrum is in accordance with the road tests.
    Unified Adaptive Neural Network H∞ Control of Uncertain Wheeled Mobile Robots
    YE Jinhua, WU Haibin
    2017, 28(02):  150-155. 
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    A smooth global unified controller of trajectory tracking and stabilization was proposed for nonholomomic wheeled mobile robots based on adaptive neural network control and H∞ control. Firstly, the system control inputs were expanded by transverse function method, a nonsingular full drive system which was equivalent to original system was established with decoupled input-output. Then an adaptive neural network H∞ controller was designed for the new system, such that the complex system uncertainty was compensated effectively by the adaptive neural network. Disturbances and approximation errors were attenuated with a prescribed disturbance lever by the H∞ control. Adaptability of the controller were further improved, and the control performance was optimized. The effectiveness of the algorithm were verified by simulation results.
    Fluid-structure Coupling Analysis of Hydraulic Cylinder Based on Dynamic Mesh Technology
    ZHANG Rui, JIANG Feng, YANG Jin, HU Tianwei, WANG Weiqiang
    2017, 28(02):  156-162. 
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    Aiming at problems of abrasion of guide sleeve and leakage of hydraulic fluid caused by offset load of hydraulic cylinder, the fluid-structure coupling simulations of hydraulic cylinders under offset load conditions were carried out based on dynamic mesh. Results indicate that, within the radius of friction circle, side thrust of plunger to guide sleeve,the maximum roll displacement of plunger and stress of guide sleeve increase with the increases of offset loads. When the amount of offset load is larger than the radius of friction circle, the three items decrease but still are larger than the results under steady conditions, which indicates that the hydraulic fluid “intensify” the rolls of plunger. Therefore, in the offset loading analyses and design of hydraulic cylinders, fluid-structure coupling technology is strongly recommended, or rationally increase the safety factor of steady structure analysis.
    Characteristics of Power Mechanism for Ultra-high-pressure Hydraulic System with Direct Electric Drive
    XU Hong, DU Zhijiang, SHEN Jiali, WANG Ling
    2017, 28(02):  162-166. 
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    A hyper-pressure control hydraulic system with direct electric drive was introduced to solve the shortages brought by the conventional hydraulic control system, which was based on the isostatic pressing equipment for producing high-quality diamonds and other superhard materials. It was used as a pressure compensation method mainly for the packing stage which was important to high-quality diamonds. The operational principles of this system was introduced, and the mathematical model was built. Main parameters of dynamic mechanisms and frequency charaeteristics of open loop of the system were analysed, and the influences of the main parameters such as effective area of hydraulic cylinder, effective volume of compresstion chamber and elastic stiffness of load on system characteristics were argued.
    Design Tolerance Zone Constrained Registration for Propellers
    MIN Zhuang, PENG Fangyu, ZHENG Yan, YAN Rong
    2017, 28(02):  167-172. 
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    To solve the uneven machining allowance distribution problems of propellers in machining processes, a fast registration method constrained by tolerance was proposed for propeller blank surface and design surface to keep the machining allowance of propeller distribution uniform. First, the influences of propeller radius, the longitudinal oblique, the angle between the blade and the axial position on the spatial position of the design curved surface in the design process were analyzed, and the constraints were established based on changes in the range of propeller design tolerances morphology changes. The mathematical model of the propeller surface with constraints was established, and the optimal solution was found with simulated annealing algorithm quickly. It was vivificated with the registration between propeller blank surface and design surface, and results show that the algorithm may match propeller design surface with blank surfaces quickly.
    Multi-objective Flexible Job Shop Dynamic Scheduling Strategy Aiming at Scheduling Stability and Robustness
    ZHU Chuanjun, QIU Wen, ZHANG Chaoyong, JIN Liangliang
    2017, 28(02):  173-182. 
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    A dynamic FJSP aiming at scheduling stability and robustness was studied. Firstly, an optimization mathematical model was proposed based on scheduling stability and robustness. Secondly, by analyzing characteristics of dynamic FJSP, a job arrival generator and a predictive maintenance generator of machine breakdown were presented. In each rescheduling points, periodic and event driven rescheduling strategies were employed, and a complete rescheduling strategy combined with right-shift rescheduling strategy was proposed. In order to preserve the good characteristics of paternal generations, an improved differential evolution algorithm was designed to solve the dynamic FJSP. The validity of the proposed strategies and algorithm was verified by instances.
    Pareto Artificial Fish Swarm Algorithm for Multi-objective Disassembly Line Balancing Problems
    WANG Kaipu, ZHANG Zeqiang, MAO Lili, LI Liuke
    2017, 28(02):  183-190. 
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    In view of complexity of disassembly line balancing problems, an improved multi-objective artificial fish swarm algorithm was proposed based on Pareto set. In order to improve the searching ability of artificial fish, a random crossover operation of genetic algorithm was introduced to guide the artificial fish to the direction of global optimal disassembly directions. The crowding distance was adopted to filter the non-inferior solutions in the prey, swarm and follow processes of the artificial fish to realize the diversity of each behavior solution results. By employing the strategy of elite reservation, the non-inferior solutions in external file were added to the next iteration of the algorithm, which speeded up the convergence rate of the algorithm. Finally, the proposed algorithm was applied to the disassembly instances of different scales, and the results confirm the effectiveness and superiority of the proposed algorithm by comparing with the existing algorithms. 
    Cloud Manufacturing-oriented Mixed-model Hybrid Shop-Scheduling Problem
    LU Jiansha, HU Qinghui, DONG Qiaoying, TANG Hongtao
    2017, 28(02):  191-198,205. 
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    To solve the scheduling problems for cloud manufacturing-oriented mixed-model hybrid shop, considering the integrated optimization of mixed flow assembly and part processing, and collaborative scheduling of cloud service tasks and self-made tasks, the model was presented based on three objectives: minimizing the makespan, production smoothing of parts, and maximizing the utilization rate of the job shop. Then, a hybrid BBO algorithm with two level hierarchical structures was proposed to solve the model. In the hybrid algorithm, batching strategy was put forward in the first level and hybrid shop scheduling was designed in the second level. Moreover, a mutation strategy of differential evolution algorithm was introduced to the transport operator of BBO to improve the searching efficiency. Finally, an example was given to test the model and algorithm, and the results demonstrat the feasibility and effectiveness of the method.
    Main Parameter Design and Workspace Analysis of a Novel 3-RRR+(S-P) Humanoid Robotic Bionic Shoulder
    YANG Long, CHU Hongpeng, SUN Tongshuai, QIU Xuesong, ZHOU Yulin
    2017, 28(02):  199-205. 
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    The moving spaces of human shoulder were obtained by experiments. Based on the principles of structural bionic, the output offset angles of 3-RRR+(S-P) humanoid robotic bionic shoulder were designed as 45° referring to the structure of humerus. And then, the secure workspaces of the bionic shoulder were obtained by coordinate transformation. Based on the principles of space consistency, the installation orientations of the bionic shoulder relative to “human body” were determined referring to the moving spaces of human shoulder. The center positions(symmetry axes) of the secure workspaces of the bionic shoulder relative to “human body” and the moving spaces of human shoulder were coincident. Thereby, the 3-RRR+(S-P) humanoid robotic bionic shoulder was proposed. Finally, the workspace mapping relation between 3-RRR+(S-P) humanoid robotic bionic shoulder and human shoulder was obtained.
    Method and Device for Material Odor Evaluation and Selection of Automobile Interior Design Based on User's Olfactory Sensation Experiences
    TANG Bangbei, GUO Gang, XIA Jinjun
    2017, 28(02):  206-214. 
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    To improve the pleasure of user's olfactory sensation experiences in automobile interior design,an automobile interior industrial material odor evaluation and selection method and device were proposed based on user smell perception experience. Firstly,the principles of user smell perception experiences were analysed. Then,the evaluation index system was constructed based on user's smell experiences. The triangular fuzzy comprehensive evaluation model of user's smell perception experiences was established. The automobile seat material odor user experience testing was used as an example, and 20 subjects were recruited for the user smell experience test experiments of four car seat leather materials from different manufacturers. The experimental data was calculated by the evaluation model to select the optimal car interior smell of leather material,and inspection and analysis were carried out on the model.
    Tribology Performance of High Speed Arc Spraying Al-Ni-Mm-Co Coating under Lubrication Conditions of Different Greases
    XI Xiang, XIA Yanqiu, CAO Zhengfeng, WANG Junyao, LIANG Xiubin, QIAO Yulin
    2017, 28(02):  215-222. 
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    Aluminum coating and Al-Ni-Mm-Co coating were formed on the surface of 6061 aluminum alloy by arc spraying to overcome deficients of hardness and anti-wear of aluminum alloy. Micro hardness, microstructure and components of the coatings were analyzed by micro hardness tester, scanning electron microscopy and X-ray diffraction, respectively. The tribology performances of two coatings lubricated by two types of greases were investigated by a ball-on-disk tribometer. The results show that the tribology performance of Al-Ni-Mm-Co coating is better than that of the 6061 aluminum alloy and aluminum coating, and the reason is attributed to the protective oxide film which is formed by Al2O3, NiO and CoO on the wear scar. The principal wearing form of the Al-Ni-Mm-Co coating is fatigue wear.
    Study on Surface Roughness of Nickel-based Supperalloy during Honing
    GAO Shaowu, YANG Changyong, , XU Jiuhua, FU Yucan, ZHOU Xiaowei, YAN Wen, ZUO Peng
    2017, 28(02):  223-227,232. 
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    To explore the honing processes of nickel-based supperalloy and achieve the high efficient machining of nickel-based supperalloy precision bores, feed-controlled honing tests of GH4169 were conducted. Then the surface roughness after honing was analyzed. The results show that, grain size and feed per stroke are significant factors affecting the surface roughness at 95% and 99.5% confidence level, but tangential speed and axial speed are not significant. Reducing grain size and feed per stroke, the average undeformed chip thickness decreases, resulting in better surface roughness,and narrower scratching grooves of the honing surface.
    Analysis on Balance Type Double-stator Axial Piston Pump and Its Flow Fluctuation
    LIU Qiaoyan, WEN Desheng, GAO Junfeng
    2017, 28(02):  228-232. 
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    A new type of axial piston pump with double stator was designed to make multi-level flow output and work in different pressures without a reducing valve in one shall. After demonstrating its operating principles and structure features, the expressions of theoretic displacement, the theoretic instantaneous flow, and total discharge coefficient of inequality were launched, which were under different conditions of the pump. The influences of different piston numbers on output characteristics, the influences of lag angel on output flow were analyzed. The results show that the pump may achieve two different pressures, and the pulsation of the pump decreases with the growing of pistons, and the flow pulsation of even pistons with odd pistons of the two signal pump is smaller than the others. At last, reasonable control the lag angle may improve the volatility of the pump effectively.
    Multi-field Coupling Numerical Model and Its Applications of Piezoelectric Actuated Diaphragm-driven Microjet
    WANG Kun, XI Juntong,
    2017, 28(02):  233-240. 
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    A multi-field coupling numerical model was presented based on an actual structure of a piezoelectric actuated diaphragm-driven microjet printhead that designed and manufactured by the authors. The effects of each parameters were studied in the model. Some important problems of the model such as the judgement of turbulent flow and the effects of the surface force were considered. The relations among the driving wave forms and the droplet properties and the pressure changes in the chamber during a working period were studied with this model.
    Effects of Inclusions of Complex Shape on Cracks of Wheel Rim
    CHEN Huanguo, CAI Li, CHEN Wenhua, CHEN Pei, YI Yongyu, LI Yajie
    2017, 28(02):  240-245. 
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    Influences of inclusion shapes on local stresses and crack nucleation in CRH5 wheel rim were analyzed. Results show that the sharper of inclusion, the greater stress level of inclusion. Meanwhile, the local stress increases with the decrease of inclusion thickness and the increase of inclusion radius. And it leads to increase of local stress concentration factor. It indicates that fatigue cracks are produced easier and the reliability of the wheels is reduced. The critical inclusion sizes in different operating conditions were calculated by using FEM and curve fitting method. Results also show that the critical inclusion size changes followed by changes of the operating conditions. And the critical size is relative smaller when it is the curved track. Wheel rim fatigue cracking may be initiated once the inclusion size is bigger than the critical inclusion size.
    Influences of High Speed Vehicle Wheel Flat on Bogie's Vibration Characteristics
    WANG Chen, WANG Xu, LUO Shihui, MA Weihua
    2017, 28(02):  246-251. 
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     In order to predict the influences of wheel flat on vehicle performance, based on vehicle/track coupling dynamics theory and non-Hertz contact theory, a high-speed train dynamics model was established. The geometric shape of the worn and new wheel flats were described with mathematical method. The effects of wheel flat dynamic impact on dynamics performance of vehicle running gear were investigated. The results show that: the impacts of worn wheel flats are larger than that of the new ones. With the increase of wheel flat's length, there is a gradual increase in wheel/rail impact and vibration acceleration of running gear. When the length of the wheel flat is as 10mm and the speed is as 100km/h, the wheel-rail vertical force reaches maximum value. The differences of vibration characteristic between sprung and unsprung parts vary obviously with the changes of the speed. Default stting the wheel rail vertical force as the standard, wheel flat size should be limited to 30mm.