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February 30,2011
Volume 4,Issue 4
Pages -
Subject Area:Electrical Engineering,Electric Power System and Automation,Flowing Mechanical Engineering and Hydrodynamic Engineering,Circuit Theory, Electromagnetic Field Theory

Title: Characteristics of dielectric barrier discharge in helium at atmospheric pressure

Authors: HAO Yanpeng, DAI Dong, ZHENG Bin
PP: 373-381
Abstract: Dielectric barrier discharges (DBD) under atmospheric pressure were carried out in helium. Single pulse glow discharge and multi-pulse glow discharge were both observed. The applied voltage, current pulse and Lissajous figures were measured. Characteristics of atmospheric pressure helium glow DBD including the Lissajous figures, the voltage applied to the gas, discharge current through gas gap, electric field strength for breakdown, surface charges on the solid barrier and the voltage-current characteristic curve were investigated. Finally, the formation mechanism of the multi-pulse discharge as well as the potential application of the discharge characteristics to discharge mode diagnosis were discussed.
Keywords: electrical engineering; dielectric barrier discharge; glow discharge; multi-pulse glow discharge; discharge characteristics

Title: Simulation and research on ferroresonance of coal mine power network

Authors: ZHANG Xiaoqing, WANG Chonglin
PP: 366-372
Abstract: The single-phase fault sometimes happens in coal mine power network. Based on the realistic run of a coal mine power network, and combined the accident record, the simulation and analysis was carried out. The arc suppression coil couldn’t launch normally because when grounding fault happened, the part network made up the resonance loop, then resulted in the ferroresonance. Two measures were chosen from some measures of restraining ferroresonance to simulate and find the reasonable and viable restraining method.
Keywords: power supply for coal mine; coal mine power network; ferroresonance; simulation

Title: An approach for estimating head curve of noncavitating inducers

Authors: LI Wenguang
PP: 358-365
Abstract: In this paper, a proposal was suggested where a singularity method was utilized to estimate the head of noncavitating inducers. Initially, the theoretical heads developed by the annular cascades on several cylindrical stream surfaces in an inducer against an ideal fluid through the cascades were calculated by using the singularity method; then an averaged theoretical head was established with those heads. Secondly, a hydraulic loss, which was estimated using an empirical equation, was subtracted from the averaged theoretical head, causing an actual head generated by the inducer. A geometrically dependent correction factor was involved in the empirical equation in the method. The method was validated by using experimental data of head-flow rate curve of the existing 17 inducers found in references. Moreover, the curves showing the relation among the correction factor and the number of blades as well as the mean angle of blade were demonstrated. Compared to the existing empirical equation method, radial equilibrium equation approach and Euler equation of turbomachinery with slip correction, the current method can achieve better agreement with experimental observations. This suggested that the approach proposed in the paper is effective and feasible.
Keywords: fluid machinery and fluid power engineering; inducer; head; prediction; singularity method; hydraulic loss

Title: Study on analog PCB diagnosis method based on neural network and its intelligent testing system

Authors: ZHU Wenji, HE Yigang
PP: 349-357
Abstract: Based on wavelet decomposition, genetic algorithm (GA) and neural networks (NNs), a new testing system for printed circuit board (PCB) is proposed. The proposed method is based on wavelet transformation that allows using the wavelet decomposition as a de-noise tool, the feature information is extracted by wavelet de-noising, multi-resolution, orthogonalization and normalization. And the input patterns are satisfied when the feature information applied to the neural networks. The proposed approach selects GA to optimize the structure and original weight distribution of BP networks. Under considering the characteristics of the printed circuit board, the controlled PCB testing system based on digital signal processing (DSP) is performed. Finally, the realization of the proposed strategy is expounded by using a practical circuit.
Keywords: circuits and systems; back propagation network; printed circuit board testing system; digital signal processing; wavelet transformation; genetic algorithm

Title: Study on fiber laser overlap-welding of automobile dissimilar steels

Authors: MEI Lifang, CHEN Genyu, YI Jiming, LIU Jinwu, LI Shichun
PP: 342-348
Abstract: The high-power fiber laser welding experiments on automotive dissimilar materials such as high-strength galvanized steels, galvanized steels and common cold rolled automotive plates were carried out. The key technologies, the transverse weld topography and the performance of high-power fiber laser lap-welding dissimilar materials were analyzed, so as to control and optimize the craft quality of fiber laser welding automobile body. The test result indicated that the influence of plates space on weld topography was significant when laser welding dual-galvanized plates. On the condition of laser welding lap joint composed of dissimilar materials under the same parameters, the weld width was relatively narrow when the galvanized steel for boarding up. Under this test condition, the cross section of weld joints was similar as “high foot wine glass” when they were welded by CO2 laser, but when lap joints were welded by high power fiber laser, the cross section of joints was similar as “thumb” and the connection width between plates was a bit greater and the joints anti-shearing force was stronger. The anti-tensile ability of lap joint was greater than its anti-shearing ability, and its anti-shearing ability was mainly decided by fusion width between two plates.
Keywords: vehicle engineering; automobile process; fiber laser; overlap welding; cross-section topography; mechanical property

Title: Investigation on damage effect of fragment kill element on cruise missile

Authors: HU Bo, LIU Rongzhong
PP: 336-341
Abstract: This paper analyzed the basic form, the structure, the dimension and the mechanism of the cruise missile, and then set up the damage model of the missile. The equivalent model of the cruise missile warhead section was established according to the equivalent target principle. Taking the tungsten ball as the example, based on the AUTODYN software, the damage effect value simulation to the equivalent target goal was carried on. The simulation result indicated that when the speed increases to 900 m/s, the tungsten ball with the diameter of 7.6 mm may penetrate effectively to the 8 mm equivalent target, and broken piece after the penetration still has certain speed, thus realizes destruction to missile.
Keywords: other disciplines of special-use machinery engineering; damage effect; cruise missiles; warheads; fragment

Title: Analysis on the deformation of core rod in the melting quartz drawing machine with the software of ANSYS

Authors: MENG Hu, HE Rongkai
PP: 330-335
Abstract: In this paper, the phenomenon of the deformation of core rod in the quartz drawing machine is analyzed and the reason is summarized theoretically, which is used in the practical production. When the rod is moved, the moving speed must be selected properly, which can eliminate the deformation. Therefore, the software of ANSYS is used to analyze the relationship between resistance and deformation of the core rod. At the same time, it is verified that the micro-deformation caused by moving the rod does not affect its function.
Keywords: mechanical-electronic engineering; quartz drawing machine; core rod; software of ANSYS; deformation

Title: Finite element analysis of piston based on SolidWorks Simulation

Authors: ZHANG Zhongtao, WANG Jing, ZHANG Zhongliang, GAO Jihong
PP: 324-329
Abstract: The paper applies finite element analysis to a type of diesel engine piston with finite element analysis software of SolidWorks Simulation, separately analyzes its stress distribution in the mechanical load and its temperature field distribution in the thermal load, and analyzes its strength and comprehensive deformation with the combined effect of mechanical load, thermal load and inertia force, and on this basis finds the reason of piston failure, finally optimizes the design.
Keywords: mechanical manufacturing and automation; piston; finite element analysis; temperature field; strength analysis; comprehensive deformation

Title: Study on finite element analysis system for cable-strut structure of point-supported curtain walls

Authors: JIANG Guanying, YAN Chunping
PP: 316-323
Abstract: The analysis procedure of cable-strut structure in point-supported curtain walls has its special characteristics In allusion to it, the finite element analysis (FEA) basic flow of cable-strut structure of point-supported curtain walls was introduced, and a four-layer system structure including interface layer, control layer, the FEA layer and data layer was proposed, as well as the function structure. A global FEA solution using initial state analysis with twice singular value decomposition combined with load-up condition analysis with CR formation method was proposed. Finally, a finite element analysis system for cable-strut structure of point-supported curtain walls was developed, and the example indicated that the calculated results of the system were precise and valid.
Keywords: mechanical manufacturing and automation; cable-strut structure; finite element analysis; four-layer system structure; initial state analysis; load-up condition analysis

Title: Optimization of shx fonts based on NURBS curve fitting

Authors: MEI Shiwei, LI Shuiping
PP: 311-315
Abstract: According to features of computer numerical control (CNC) engraving and the problem of shx vector Chinese characters discovered in CNC engraving, this paper presents a method to fit and optimize the shx fonts with nonuniform rational B-spline (NURBS) curves. During the process of fitting, firstly the choice of data points has been discussed, and then it puts forward the method of virtual data pointing to avoid the first and last data points oscillated during the process of NURBS curves reversing combining with the features of vector Chinese characters. Finally, the program diagram was developed and the contrast of shx regular script before and after fitting has been provided was given. The results show that the aesthetics and smoothness of fitted shx Chinese characters are greatly improved, which is suitable for CNC engraving.
Keywords: mechanical manufacturing and automation; computer numerical control engraving; shx fonts; nonuniform rational B-spline; virtual data points

Title: Research on implicit coordination mechanism of manufacturing system based on pheromone

Authors: TANG Dunbing, WANG Lei, ZHENG Kun, GU Wenbin, YUAN Weidong
PP: 304-310
Abstract: Aiming at the shortages existing in traditional contract net protocol (CNP) coordination mechanism in manufacturing system, a pheromone-based implicit coordination approach is proposed by referring to biological behavior coordination approach. The pheromone-based coordination principle is analyzed. A pheromone-based coordination algorithm is presented for task allocation. An experimental simulation platform for pheromone-based implicit coordination mechanism is developed. A specific experiment proves the validity and feasibility of this proposed implicit coordination approach.
Keywords: mechanical manufacturing and automation; manufacturing system; pheromone; implicit coordination;coordination algorithm

Title: Multi-domain unified modeling language Modelica and its simulation platform

Authors: TIAN Yongli, YAN Yunhui, ZHANG Ziqian
PP: 298-303
Abstract: Modelica can describe complex physical system that contains multi-domain constituents include mechanical, electronic, hydraulic, thermal, biologic and control using unified format. The language has been widely used in many demanded industrial sectors. In this paper, a new Modelica language based modeling and simulation platform includes the main function modules and the methods for implementation was introduced. That is, improve the simulation efficiency of Modelica language by the application of parallel computing and distributed parallel computing, and realize the co-simulation implementation of Modelica simulation platform with other simulation software through shared memory and the high level architecture (HLA)/run time infrastructure (RTI) implementation. The research provides a more comprehensive reference to promote the application of Modelica language in our country.
Keywords: mechanics; multi-domain modeling; Modelica; parallel computation; co-simulation

Title: Research and application on design and calculation software of pumping units

Authors: LIU Yalei, GUO Dengming
PP: 293-297
Abstract: The paper provides design and calculation software of pumping units, owing to many types of the pumping units and the complexity of the calculation. The software contains many types of the pumping units, and can calculate the geometric parameters, the technological parameters, the movement parameters, and the torque parameters. Furthermore, the software can draw the movement curve and the torque curve. The application indicates that the software has accurate calculation results and easy operation easily, so it is widely used.
Keywords: mechanical design principles and methods; pumping units; calculation; software

Title: Preliminary study on re-safety function of fuze’s safety system

Authors: ZHU Shan, LI Haojie
PP: 287-292
Abstract: For the needs of higher safety and less misdamage, the re-safety function that makes the fuzes change from armed state into safety state through the slider interrupter mechanism under abnormal conditions is studied. The re-safety function and its principle are discussed, and the implement scheme is proposed, too. The slider interrupter mechanism is used in the design; it is an integrated structural design. Finally，the feasibility analysis is conducted on the proposals, and theoretical analysis shows that it’s feasible.
Keywords: mechanical design principles and methods; fuze; safety system; re-safety function; slider interrupter mechanism

Title: Kinematics simulation of crankshaft-link-piston mechanism in a type of engine with UG software

Authors: FENG Yuanjie, LI Bei
PP: 282-286
Abstract: The paqer takes the crankshaft-link-piston mechanism of a type of four cylinder engine as the object for studying, uses the entity modeling function of Unigraphics (UG) software to accomplish the modeling of three elements. Then it establishes the assembly model through the assembly function. Finally, it uses the motion simulation function to complete the process of motion, and obtains the law of motion of the crankshaft-link-piston mechanism, in order to provide a reliable theory for design and optimization of the mechanism.
Keywords: mechanical design and theory; crankshaft; link; piston; UG; kinematics simulation

Title: Mechanical design of stacking crane used in automated high-rise warehouse

Authors: LI Ning, LIN Zhong
PP: 275-281
Abstract: In this paper, by study of the features of the packet sorting system and the environment of the automated warehouse where the stacking crane works, an optimal design approach to the structure of the stacking crane and the optimal structural parameters were obtained. Firstly, the classical dynamic method was used to comprehensively analyze the machine, including stationary and dynamic inflexibility, intension, stability, etc. Secondly, the structural parameters were elementarily chosen and checked by the rationality of structural design. The parameters were improved time after time during checking process in order to meet the demand of the design. Thirdly, 3D model of the stacking crane was made by using of the UGNX software and the rationality of the parameters was observed by the vivid visual effects. According to the reality of the sizes and weights applied in postal packets logistics industry, the outcomes of the checking parameters can meet the practical needs.
Keywords: mechanical design and theory; stacking crane; dynamic analysis; computer aided design

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