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ISSN 1674-2850
CN 11-9150/N5
 
Current Issue
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October 30,2016
Volume 9,Issue 20
Pages -
Subject Area:Architectural Design Method and Theory,Flowing Mechanical Engineering and Hydrodynamic Engineering,Highvoltage Engineering,Electrical Engineering,Computer Aided Manufacturing
 
Title: Visualization study on public safety and health at home and abroad based on CiteSpace
Authors: WANG Chunxue, LÜ Shuran
PP: 2158-2164
Abstract: In order to know the research hotspots of public safety and health at home and abroad, the articles published from 2000 to 2014 have been searched with the keyword “public safety and health” based on CNKI and Web of Science databases. Knowledge maps of public safety and health were drawn by utilizing CiteSpace. The time distribution, journals, authors, institutions and research hotspots of public safety and health have been reached. The result shows that the research direction of public safety and health at home is comprehensive, and the degree of cooperation between different authors and institutions is low. The research directions of journals of public safety and health study at home are the social security and the safety management while the research directions abroad are the medicine and the public health. The research hotspots of public safety and health are public safety and security, emergency events, emergency management in domestic, and the detection research at home will be more inclined to the road safety. The research hotspots of public safety and health are public health abroad, and the detection research abroad will be more inclined to it.
Keywords: safety engineering; visualization analysis; knowledge map; CiteSpace
 
Title: Image aided instruction of the course of “nonlinear vibration theory and the engineering application”
Authors: LIU Liqin
PP: 2151-2157
Abstract: Nonlinear vibration is one of the most important motion forms of the ship and ocean structures. This course is for the master degree candidates of the ship and ocean engineering major, and it is based on the real problems of the field of ship and ocean engineering. The time histories, phase portraits, fast Fourier transformation (FFT) figures, max Lyapunov exponents, bifurcation figures and Poincare maps are calculated. The nonlinear phenomena which are hard to understand are interpreted by the image showing, such as super harmonic bifurcation, sub harmonic bifurcation and chaos. It will help the students to grasp the application of nonlinear vibration theory in the field of ship and ocean engineering.
Keywords: ocean engineering; nonlinear vibration; numerical simulation; image aided instruction
 
Title: Numerical study of wave impact on the ancient seawall along Qiantang River using CIP-based method
Authors: ZHAO Xizeng
PP: 2141-2150
Abstract: Two dimensional numerical simulation of wave impact on the ancient seawall along Qiantang River is carried out according to the wall’s current condition and local wave conditions. Main attention is paid to the impact pressure and velocity field. The numerical model is developed through the constrained interpolation profile (CIP) based method as the main flow solver of the Navier-Stokes equation, combined with a more accurate volume of fluid (VOF) typed scheme, tangent of hyperbola for interface capturing (THINC), as the free surface capturing method. The multiphase model is used to treat the water-air-solid interactions. Computational results are compared with the experimental data and a good agreement is found. It is concluded that the calculated results are fit for evaluating seawall structure safety.
Keywords: ocean engineering; multi-phase flow; constrained interpolation profile method; impact pressure; tangent of hyperbola for interface capturing method
 
Title: Research on development and regeneration of Zhuangkuo dwellings in Hehuang area of Qinghai province
Authors: ZHOU Linlin, CHEN Jingheng, LEI Zhendong
PP: 2133-2140
Abstract: The research focused on the spontaneous construction development of the traditional Zhuangkuo dwellings in Hehuang aera of Qinghai province. We analysized the variation on construntion material, technology and method in new residences, and summarized the construction problems in house building, such as unsafety, unreasonable and not ecological conditions. In the end, we provide some suggestions in new residences construction, which will offer some help for the professional guidance in modernization transformation of residences in Hehuang area.
Keywords: architectural design and theory; residence construction material variation; construction technological variation; modernization transformation of residence
 
Title: Effects of storage periods for dry-mixed materials on microstructure of ready-mixed shrinkage-compensating concrete
Authors: MA Qinyong, ZHANG Yangyang
PP: 2125-2132
Abstract: In order to study the effect of the storage period for dry-mixed materials on the microstructure of the ready-mixed shrinkage-compensating concrete, microstructure test is carried out with respect to six different kinds of storage periods (3, 7, 10, 15, 20, 30 d), and with the constant expansive agent dosage of 6% and sand moisture content of 1.0%. The results show that when the storage periods of the dry-mixed materials are 3, 7, 10 d, respectively, there exist mass of C-S-H gel and AFt crystal. With the increasing storage period, the diameters of holes are 3.075, 3.979, 5.885 μm, the breadths of micro cracks are 0.364, 0.450, 0.703 μm, and the breadths of micro cracks in the intertacial transition zone (ITZ) are 0.554, 0.949, 1.280 μm. When the storage periods of the dry-mixed materials are 15, 20, 30 d, the diameters of holes are 6.137, 6.335, 7.033 μm, respectively, the breadths of micro cracks are 1.230, 1.352, 1.370 μm, and the increase amplitude is big. The Ca(OH)2 crystals in the oriented arrangement increase, while the C-S-H gel quantity decreases gradually. The intensity of concrete shows a decreasing trend, while there exist new micro cracks nearby the transition zone of the interface, and the size of the micro cracks increases gradually with the increasing storage period.
Keywords: underground engineering; shrinkage-compensating concrete; dry-mixed material; storage periods; microstructure; interfacial transition zone
 
Title: Online detection method of EMU bogie hunting and instability
Authors: ZHANG Bing
PP: 2113-2124
Abstract: Based on TB10761—2013 and hunting and instability data of EMU, a method for identifying hunting and instability of bogie was proposed. FPGA and DSP were used for algorithm of high-speed EMU’s hunting instability, and a real-time high speed train bogie hunting and instability monitoring system was designed. The entire system was classified into two components, the dominated control system and sub-measurement system respectively. The dominated control system communicates and controls the sub-measurement system via the CAN bus. The dominated control system is responsible for analysis of instability information, giving accurate temporal and spatial information of instability according to the combination of the GPS module and train speed module, sending alarm signals and saving fault information. The real-time lateral accelerations of bogies are monitored by sub-measurement system, which determines whether instability occurs and sends instability data to the dominated control system via the CAN bus. Through the line tests and simulation verification, the monitoring system can accurately detect the hunting and instability of the high-speed train bogie and has the advantages of stability and easy installation.
Keywords: vehicle engineering; hunting and instability; FPGA; DSP; real-time monitoring
 
Title: A cellular automaton model of traffic considering the variable acceleration mode
Authors: DING Jianxun, ZHENG Yangbianmu
PP: 2106-2112
Abstract: Most of cellular automaton (CA) models of traffic have taken the relationship between the acceleration and the specific value of current velocity into account. On the base of Nagel-Schrechenberg (NS) model, this paper presents a modified CA model in which the variable acceleration mode and the slowdown in the rate from the randomization behavior were investigated. Numerical simulation results show that the proposed model can reveal the influence of driver’s variable acceleration mode on traffic and generate metastable states or hysteresis in traffic flow under the same level of randomization probability and different rates from the slowdown behaviors.
Keywords: transportation systems engineering; traffic flow; cellular automaton model; variable acceleration mode
 
Title: Micro-radar-based pedestrian detection and trajectory reconstruction
Authors: NI Ying, LI Xuhong
PP: 2099-2105
Abstract: Micro-radar detector is a kind of new paved-in detector that can detect pedestrians at crosswalks, which compensates the disadvantages of other detectors, for example, video-based detectors are easily handicapped due to light and weather conditions and low accuracy of microwave detectors. Based on data collected at a demonstration crosswalk with micro-radar detectors installed in Danville, CA, a methodology that reconstruct pedestrian/bicyclist trajectories is proposed. On the basis of information collected by micro-radar detection, we could gain space-time scatter diagram. Given by different characteristics between pedestrians and bicyclists, standard trajectory curves can be generated, by comparing the shifted standard trajectories and data collected, trajectories can be reconstructed. Further, analysis of the impact of pedestrian flow on the detection algorithm by VISSIM is demonstrated. The research shows that the detection precision is reduced in the range of less than 10%, with the increase of crossing pedestrian flow, the overall accuracy is above 75%.
Keywords: transportation systems engineering; pedestrian detection; micro-radar detector; trajectory reconstruction; simulation
 
Title: Numerical simulation and experimental study of cavitation performance on double-suction centrifugal used in ships
Authors: KUANG Haiyun, ZHANG Shishuai, ZHI Bowen, WANG Yu
PP: 2092-2098
Abstract: The cavitation performance of a double-suction centrifugal pump used in ships with specific speed of 81.8 is numerically simulated by ANSYS-CFX software. The distribution law of bubble volume fraction on the blade surface in pump at the cavitation occurrence was obtained. In addition, the distribution law of bubble inside impeller was discussed and the reason of the head decreased on the critical NPSH was analyzed. Meanwhile, the experimental study of cavitation performance is made for the centrifugal pump used in ships. The experimental results validate the accuracy of numerical simulation.
Keywords: flow mechanical engineering and fluid power engineering; double-suction centrifugal pump; cavitation performance; numerical simulation; experimental measurement
 
Title: Optical sensor for ice monitoring of transmission lines
Authors: MAO Naiqiang, LI Yabo, JIANG Jun, ZHOU Hongyang, MA Guoming
PP: 2086-2091
Abstract: The icing on transmission lines leads insulator flashover and tower failure. The optical sensor, which adopted the fiber bragg grating (FBG) as sensing element, is not susceptible to electromagnetic interference, and works steadily in harsh temperature and humidity environment. Compared with traditional electronic sensor, the developed load sensor is suitable for the transmission lines ice monitoring. The load sensor adopts S shear type structure and overload protection. Then, an H beam is applied to reduce the eccentric load influence on the sensor. At last, the mechanical compensation structure is designed to eliminate the temperature influence on the strain measurement.
Keywords: high voltage engineering; ice monitoring; fiber bragg grating; tension sensor; overload protection
 
Title: Application and design of AD7606 in electric machine control system
Authors: LIN Mingyao, HE Chunxiao, GU Weigang
PP: 2079-2085
Abstract: In order to realize the real-time control and stability of the system which is based on DSP, the voltage and current of the main circuit required would be sampled by sensor which has the effect of isolation, and then the signals would be sent into the A/D pins on the DSP through matching conditioning circuits. For the DSP’s on-chip A/D module has its disadvantages in designing range and immunity ability, in this paper, the hardware circuit of AD7606 was designed for TI’s TMS320F28335. In order to verify the rationality and efficiency of the sampling chip, three different experiments are designed for the comparison between these two signal processing methods in the following aspects: the accuracy of sampling data, the RSD of sampling data and the genres of sampling signal. According to the consequences, analysis has been given.
Keywords: electrical engineering; motor control system; TMS320F28335; AD7606; hardware design
 
Title: A new wear testing apparatus for orthopedic implant materials
Authors: TANG Fei, HUA Zikai, CHEN Jiajia, HONG Yue
PP: 2074-2078
Abstract: Wear has been recognized as the key factor affecting the long-term performance of orthopedic implants such as hip, knee and spine prostheses. In this paper, a new wear testing apparatus for orthopedic implant materials was designed and developed. Via this apparatus, according to the characteristics and requirements of orthopedic implant material wear tests, the wear of ultra-high molecular weight polyethylene (UHMWPE) and cross-linked UHMWPE counter with cobalt chromium alloy (CoCrMo) was investigated. Moreover, the debris generated by the experiment was extracted, and the particle morphology and distribution were analyzed and an effective testing method for the wear evaluation of orthopedic implants can be achieved.
Keywords: mechanical friction, wear and lubrication; orthopedic implant; materials; wear; test; apparatus
 
Title: Effect of atomization parameters on oil droplets characteristics in oil-air flow field of CMQL
Authors: ZHANG Chengliang, ZHANG Song, LÜ Ying, ZHANG Tao
PP: 2066-2073
Abstract: The effect of atomization parameters on oil droplets characteristics in cryogenic minium quantity lubrication (CMQL) cutting condition was studied by means of computational fluid dynamics (CFD) method, and the optimization of atomization parameters was carried out. Firstly, the dimensions of the atomizer were measured to establish the model of computational domain, and the grid was partitioned. Secondly, the governing equations were determined, and the boundary conditions were applied. Finally, an orthogonal simulating experimental method was designed to investigate the oil droplets characteristics with different atomization parameters. The simulating results indicate that oil mist with low temperature, high velocity and small size can be obtained from cryogenic air, large air flow rate and cutting oil flow rate, which is beneficial to improving the cooling and lubrication function of cryogenic oil-air cutting medium.
Keywords: computer aided manufacturing; computational fluid dynamics; cryogenic minimum quantity lubrication; atomization parameters; oil droplets characteristics
 
Title: Development and technological test of special high frequency pulse power supply for tiny hole electrolysis processing
Authors: CHEN Yuanlong, YANG Kun, CHANG Weijie, WAN Chenguang, OUYANG Junhao
PP: 2060-2065
Abstract: Aiming at a study of small holes for a new type of medical syringe needle in electrochemical machining process, high frequency pulse power is developed. The output mode of this power is direct current with insulated gate bipolar transistor (IGBT) chopper, and the pulse frequency is 1-100 kHz. The output voltage is adjustable in 0-50 V, and the maximum of output current is 50 A. The pulse frequency and duty ratio are adjustable independently. The pulse drive signal of IGBT power module is produced by high-frequency timer array unit in the NEC micro controller unit, and the output waveform is good which has a steep rise along with the falling edge. According to the characteristics of small holes in electrochemical machining process, we set the rapid protection circuit to ensure the safety of the machining process and reliability of the workpiece and the pulse power. Through the process tests of small holes in electrochemical machining, the feasibility and effectiveness of the power prototype are verified.
Keywords: non-conventional machining; electrochemical machining; high frequency pulse power; tiny hole; insulated gate bipolar transistor