bluuebunny/crossref_metadata_2025 huggingface dataset:
Attendance System Based on Biometric Security
Authors: Danishkumar S. , Sanmathipriya R.S.
Published: November 2012

The goal of Finger Print Based Attendance system is to take attendance of the student in a faster and efficient way. The attendance has been taken by calling out students name in the class which will be time consuming. After taking attendance the list will be sent to the department. Its ability is to uniquely identify each person based on their FINGER PRINT reader. In real time application capability of taking attendances will be more accurate by using Finger Print. Using an USB port or MAX 232 an attendance will be stored inside the database. Using an 8051 microcontroller data can be transferred to MAX 232.Thus the speed and security provided by Finger Print makes it valuable in the education field.
Investigation of Porous Block Porosity on Flow and Entropy Generation inside a T-Micromixer Using Lattice Boltzmann Method
Authors: Delavar Mojtaba Aghajani
Published: November 2012

In this study a two dimensional thermal Lattice Boltzmann model with nine velocities was used to study the flow pattern and thermal field inside a T-micromixer with a porous block. The effects of porosity of porous block and flow Reynolds number were investigated. The results showed that better mixing between hot and cold flows and more heat transfer to horizontal walls in contact with porous block in lower porosities; due to the fact that in lower porosities the effective thermal conductivity of porous block increases. In lower porosities due to higher mixing rates and thermal gradient the entropy generation will increase. According to results it was observed that model with lowest porosity has the maximum mixing rate between two entering hot and cold flows and maximum dimensionless entropy generation.
The Research of the Difference between Small-Strain and Large-Strain Formulations for Shape Memory Alloys
Authors: Yao Jie , Zhu Young Hong , Wu Yun Zhang
Published: November 2012

Based on thermodynamics and phase transformation driving force, we apply a SMA constitutive model to analyze the large and small deformation of SMA materials. Simulations under different loading, uniaxial tension and shear conditions, illustrate the characteristics of the model in large strain deformation and small strain deformation. The results indicate that the difference between the two methods is small under the uniaxial tension case, while the large deformation and the small deformation results are very different under shear deformation case. It lays a foundation for the further studies of the constitutive model of SMA, especially in the multiaxial non-proportional loading aspects.
The Performance Indexes and the Influence Factor of PCP
Authors: Meng Bi Xia , Wen Hou Zhen
Published: November 2012

Confirms the flow area, the minimum value of the comparative slide velocity of the floating contact point, the maximum integration curvature and the radius variation ratio as the performance indexes of PCP, discussed how the PCP’s structure parameters influence the performance indexes. Discovered that the minimum value of the comparative slide velocity of the floating contact point is proportional to the number of rotor’s threads and the coefficient of isometric radius, but is inversely proportional to the radius variation ratio; From the perspective of increasing the minimum value of the comparative slide velocity of the floating contact point, large number of rotor’s threads, big coefficient of isometric radius and little radius variation ratio is needed. But amplify the number of rotor’s threads, the coefficient of isometric radius and decrease the radius variation ratio will reduce the flow area. And amplify the number of rotor’s threads will make the maximum integration curvature greater; decrease the radius variation ratio will reduce the maximum integration curvature too. These four indexes are in contradiction to each other, structure parameters cannot make all performance indexes are optimal.
Friction and Wear Behavior of Textured Al2O3/TiC Ceramic Surface Filled with MoS2 Solid Lubricants
Authors: Xing You Qiang , Deng Jian Xin , Wu Ze , Lian Yun Song
Published: November 2012

Three different textures were produced by Laser Surface Texturing (LST) on Al2O3/TiC ceramic surfaces. MoS2 solid lubricants were filled into the textures. The friction and wear properties of textured and untextured surfaces were investigated by carrying out sliding tests against AISI440C stainless steel balls. Results showed that the textured surfaces filled with MoS2 solid lubricants exhibited lower friction coefficient and excellent anti-wear properties compared with untextured surfaces. At the texture spacing of 100μm, 150μm and 200μm, wavy textured surface had the lowest friction coefficient, while it was the dimpled surface at the texture spacing of 250μm. MoS2 film in the spaces between the textures was formed by mechanical engagement of particles in the rough surfaces and solid lubricants in textures. The friction coefficient and wear rates were reduced by supply of solid lubricants from the textures to the surfaces, bulges around the textures and TiO2 formed after laser texturing.
Rolling Force Prediction Method Based on Fuzzy Identification
Authors: Wang Zhi Yong , Li Yi Geng
Published: November 2012

To improve the precision and efficiency of rolling force prediction on hot rolled strip, a new rolling load prediction of finishing stands method was set up by fuzzy identification. It was based on T-S fuzzy model using clustering subjection functions to calculate the grade of membership for each given pattern, and using recursive least squares method to identify the consequent parameters of fuzzy model. On the basis of the measured data of the 1580 mm, the relation between the main hot strip mill parameters and rolling force was established using fuzzy model. Experimental results show that the prediction precision is higher, responds quickly and steady. The method can satisfy on line control requirements in a hot mill strip rolling process.
Bending Vibration Analysis of Thick Honeycomb Sandwich Panel
Authors: Shen Wei Dong , Wang Sheng Chun , Wang Jian Li , Xu Jia Feng , Song Si Hong
Published: November 2012

A simple approach to reduce the governing equations for thick honeycomb sandwich panels to a single equation containing only one displacement function is proposed in this article. The variational equations of motion are derived using Hamilton’s principle and by introducing differential operators. The exact solution of the natural frequencies for rectangular honeycomb sandwich panels with all edges simply-supported is obtained and leading to a satisfied agreement with theoretical results. The influence of the ratio of core thickness to face sheet thickness and aspect ratio on the natural frequencies is studied. The analysis results demonstrate that the presence of inertia of rotation will decrease natural frequencies, and the aspect ration changes not only the value of natural frequencies of the sandwich panel but also the mode order.
A New Mistuning Form Existed in Periodic Structure-Force Mistuning
Authors: Wang Ai Lun , Chen Jie , Wang Qian Jin
Published: November 2012

The mistuning of periodic structure was generally considered to be natural parameter mistuning, such as stiffness mistuning, damping mistuning and mass mistuning. However, in engineering practice, there was another kind of mistuning—force mistuning. Based on a typical concentrated parameter model of periodic structure, the vibration characteristics, such as natural characteristic, vibration mode and vibration localization of periodic structure with different mistuning forms, were compared and analyzed. The results show that, as a new mistuning form, force mistuning won’t bring mode localization, while it could lead to vibration response localization. The results are very important for periodic structure design and manufacture.
The Contrastive Analysis of Several Radiation Cooling Terminal Devices
Authors: Bin Sun , Zhou Yan
Published: November 2012

From three ways of the temperature gradient, the change rate of indoor temperature and heat flux, contrast analysis the cooling effect of three cooling devices on the capillary tube, cooling ceiling and radiant floor, the conclusions could be obtained. The average of vertical temperature gradient in simulated room is equal to 1°C/m, which meets the requirements of human thermal comfort. When the temperature in simulation room falls from 30°C to 26°C, the temperature drop velocity for cooling ceiling is the fastest. The heat flux of the cooling ceiling is maximum, the second one for the capillary tube, and the least one for the radiant floor. Thus, the cooling effect of cooling ceiling is the best.
Mechanism Investigations of Fluid-Solid Conjugate Heat Transfers for Vehicle Exhaust System
Authors: Xiao Guo Quan
Published: November 2012

A conjugate heat transfer study was undertaken using STAR-CD. The boundary conditions are given by vehicle operation and engine operation. All three mechanisms of heat transfer, i.e., convection, conduction, and radiation, were included in the analysis. The vehicle exhaust system components temperatures were analysized at certain several separate variables such as the velocity and temperature of the exhaust gases which depend on the engine operation conditions and the velocity and temperature of the external airflows which depend on vehicle operations. The results showed all three mechanisms of heat transfer and increased quantitative understanding of the flow conditions surrounding vehicle exhaust system.
Mechanical Analysis: Solutions to Instantaneous Acceleration and Cushioning Time of Accelerometer’s Collision
Authors: Zhang Zhong Wei , Chu Xiu Xiang , Ni Yong Zhou
Published: November 2012

A novel and simplified method, which is useful in calibrating instantaneous acceleration and cushioning time of accelerometers after impacted by an object under different parameters’ condition, is proposed in this paper. An investigation on cushioning time, which is usually difficult to be quantified during the process of collision, has also been conducted. Firstly, by mathematical inference on a physical model, we obtained two formula conclusions. Next, numerical simulation suggests that the instantaneous acceleration and cushioning time, to different extent, are sensitive to six factors. Then, influences produced by each of them are studied one by one. By analyzing these influences, the method and results are proved to be correct and practical.
Magnetic Analysis of Ferromagnetic Substance in the Process of Rotation Demagnetization
Authors: Zhu Xian Qiao , Liu Da Ming
Published: November 2012

To solve the problem that is the poor demagnetizing effect and stability issues by the way of demagnetization in the one-dimensional space, a new degaussing method was studied in this paper, based on the analysis of magnetic moment angle distribution during the degaussing deal to iron material. Through the magnetization process analysis to iron material in the rotating magnetic field, the theory has some merits such as good degaussing effect and stability to the iron material after degaussing deal in two-dimensional space. The rotation degaussing enhancing the stability of material magnetic field is tested effectively, comparing to degaussing at one-dimensional space.
Engine Fault Diagnostic System Based on Non-Linear Support Vector Machine
Authors: Xu Gao Huan , Ye Jun Xiang
Published: November 2012

The car engine failures in the course of time and place have many possibilities. The engine fault diagnosis system developed in .NET platform. The core of the system make use of noise wavelet energy features and non-linear support vector machine classification. After the experiment, the system has fairly good results.
Preliminary Research of Crank-Group Driving Mechanism
Authors: Cao Ju Jiang , Wang Yu Qi , Sun Ji Wei
Published: November 2012

To drive multiple parallel-axis to rotate synchronously，this paper put forward a kind of new transmission mechanism——crank-group driving mechanism， introduced the concept of it and its working principles，and demonstrated the feasibility of its movement .
Clutch Product Rapid Variant Design Based on Tabular Layouts of Article Characteristics
Authors: Wang Lie , He Yong Rong , Gong You Ping
Published: November 2012

Based on intensive study to variant design method in product parametric technology，the paper put forward to rapid design system which have been successes used in clutch company, The tabular layouts of article characteristics describe standardization and regularization information of product , can expediently implement the product variant design and variant response of downstream process. The method firstly computes clutch parameters according to outside requirement, then inquired if there is existed product, then decided whether to design a new product or get original product. After this process, then acquire the product main model, which can abstain geometric model and realize some other analysis and virtual simulation, at last, generated satisfying product. The method in this paper have been successful used in clutch company’s design process, and highly improve it’s products creation ability and products competition in market.
The Research of Mechanical Automated Stereo Garage of Automobile
Authors: Song Zhi Lan , Ran Wen Xue , Wu Jun Shuai
Published: November 2012

With the rapid development of modern automotive industry and people's living standards improvement, more and more families have private cars; As the agricultural people migrate to the cities, the urban population expand rapidly .Because of the non-renewable land resources, many cultivated lands are used for building residence communities in many cities. As a populous and agricultural country like China, the decrease of long-term cultivated land can result in severe food shortages. Combining the objective reality of China's automobile hot and the difficulty of parking, this paper studies the necessity and importance of mechanical automated stereo garage of automobile, and discusses the various forms and structures of mechanical automated stereo garage of automobile.
Study of Diagnosis Algorithm for Coherence of Fuel Injection of High-Pressure Common Rail Fuel System
Authors: Sang Hai Lang , Yue Guang Zhao , Lv Zhi Hua , Li Shi Zhen , Zhang Zhan Teng , Qiu Tao , Lei Yan , Peng Jing
Published: November 2012

This paper analyzes the relationship between fuel rail pressure and fuel injection amount and presents a diagnosis algorithm for coherence of injection in cylinders based on the fuel rail pressure. A simplified model of common-rail fuel system in multi-cylinder diesel engine was built and basic analysis was completed based on this model. The analysis induced that the rail pressure drop dp/dt is mainly relevant with QInj. The experimental investigation of common-rail fuel system shows the pressure drop happens during the fuel injection period, which is induced by fuel injection. Both model analysis and experimental investigation show that the rail pressure may be used as the basis of diagnosis for coherence of fuel injection.
Dynamics of Joints with Clearance for a Cantilever Beam Subjected to a Moving Mass
Authors: Yang Guo Lai , Dong Wei
Published: November 2012

This paper presents theoretical analysis, numeric calculation and experimental test for a cantilever beam subjected to a moving mass with clearance. Coupled transverse vibration equations of cantilever beam subjected to a moving rigid body with clearance were formulated by discretizing Euler beam based on assumption mode method. Numeric computation code was developed. A test bed for measuring joint clearance was constructed. Dynamic clearance tests were carried out under different work conditions. The accuracy of theoretical analysis was verified by comparison between experimental data and simulated results.
The Design of Surfactant Multiplex System for Lowering Threshold Pressure
Authors: Yin Dai Yin , Zhou Ya Zhou , Zhang Cheng Li
Published: November 2012

In order to increase surfactant compound system injection in low permeability reservoir of Chaoyanggou oilfield, we do research into formula of surfactant compound system according to reservoir condition. By contrasting to interfacial tension of different kinds of surfactants, we choose petroleum sulfonate surfactant T720-40# as main agent. As equilibrium interfacial tension of this surfactant cannot meet the requirements, so we add Na2CO3 as auxiliary agent to decrease interfacial tension. The results of laboratory experiment research show that equilibrium interfacial tension of this multiplex surfactant system can reach 2×10-2mN/m. It has good thermal endurance, salt resistance, and also has good compatibility with Chaoyanggou injection water and formation water. It can make rock wettability reverse, reduce threshold pressure and displacement pressure and it can improve recovery by 5% contrasting to water flooding.
Shear Ram Height Characterization for Copper Wire Bond Shear Test
Authors: Sauli Z. , Retnasamy V. , Shapri A. H. M. , Rahman N. A. Z. , Norhaimi W.M.W. , Taniselass S. , Vairavan R.
Published: November 2012

The work here investigates the height effect during a shearing process of a copper ball bond in a wire bond. Finite element analysis was used to investigate this analysis.The effects of the shear ram height on the stress and strain response of the copper ball bond were investigated. The results obtained hows there is a significant effect of the shear height to the Von Mises stress and equivalent strain response to the copper ball bond during the shearing simulation.
Effect of High Swirl Velocity on Mixture Formation and Combustion Process of Diesel Spray
Authors: Khalid Amir , Manshoor Bukhari
Published: November 2012

Diesel engines generate undesirable exhaust emissions during combustion process and identified as major source pollution in the worldwide ecosystem. To reduce emissions, the improvements throughout the premixing of fuel and air have been considered especially at early stage of ignition process. Purpose of this study is to clarify the effects of swirl velocity on flow fuel-air premixing mechanism and burning process in diesel combustion that strongly affects the exhaust emissions. The effects of physical factors on mixture formation and combustion process to improve exhaust emissions are discussed in detail. This study investigated diesel combustion fundamentally using a rapid compression machine (RCM) together with the schlieren photography and direct photography methods. RCM was used to simulate actual phenomenon inside the combustion chamber with changing design parameter such as swirl velocity, injection strategies and variable nozzle concept. The detail behavior of mixture formation during ignition delay period was investigated using the schlieren photography system with a high speed digital video camera. This method can capture spray evaporation, spray interference and mixture formation clearly with real images. Ignition process and flame development were investigated by direct photography method using a light sensitive high-speed color digital video camera. Moreover, the mechanism and behavior of mixture formation were analyzed by newly developed image analysis technique. Under high swirl condition, the ignition delay is extended, the higher heat losses and unutilized high-density oxygen associated with slower initial heat recovery begins might be the explanation for the longer combustion duration, reductions of pick heat release and promote combustion and soot oxidation. The real images of mixture formation and flame development reveal that the spray tip penetration is bended by the high swirl motion, fuel is mainly distributed at the center of combustion chamber, resulting that flame is only formed at the center region of the combustion chamber. It is necessary for high swirl condition to improve fuel-air premixing.
Numerical Investigation of the Circle Grids Fractal Flow Conditioner for Orifice Plate Flowmeters
Authors: Manshoor Bukhari , Khalid Amir
Published: November 2012

Flow rate measurements are among the most important operations in modern industries dealing with increasingly expensive fluids such as petroleum, natural gas and water. The accuracy of flow meters depends mainly on their position in a pipe network and their operating conditions. Pipe fittings such as valves and bends generate turbulence and swirl and distort the flow distribution in the pipe, leading to a substantial amount of measuring error. For accurate flow rate measurements, the standards ISO 5167 specify either a sufficient straight piping lengths or the inclusion of a flow conditioner between the flow distortion and the flow meter. Flow conditioners serve to reduce the developing length between pipe fittings and flow meters and to create fully developed flow condition within short distances. In the present study, numerical modeling of the flow development upstream and downstream of the orifice plate which used circle grid fractal flow conditioner has been made. Computational Flow Dynamics techniques have been used to predict the flow development downstream the flow conditioners.
Thermo Mechanical Analysis of SS304 Circular Grid Plate Hard Faced with Colmonoy
Authors: Balaguru S. , Shashi Kumar , Vela Murali , Chellapandi P.
Published: November 2012

In this paper, plasma transfer arc welding using hard faced material Colmonoy which is deposited on a annular groove of a circular grid plate made up of SS 304 was studied. Hard face deposition made by Plasma Transferred Arc Welding (PTAW) on a annular groove of a grid plate at relatively high temperature, generates residual stresses due to differential shrinkage of the molten deposit, process-induced thermal gradients and difference in coefficients of thermal expansion between the colmonoy deposit and base material SS 304. However, the magnitude and distribution of the residual stresses vary depending on the heat input, deposition process, and the geometry of the component. Finite element analysis of residual stress is performed with commercial FEA package of ANSYS 12.0 which includes moving heat source, material deposit, temperature dependent material properties, metal plasticity and elasticity. Coupled thermo-mechanical analysis is done for welding simulation and the element birth and death technique is employed for simulation of filler metal deposition. Finally residual stress is evaluated so that annealing is performed accordingly to relieve residual stresses in order to carry out fracture analyses thereafter.
Evaluation of Cutting Force and Surface Temperature for Round and Square Member in Laser Assisted Turn-Mill
Authors: Choi Jun Young , Lee Choon man
Published: November 2012

LAT (Laser Assisted Turning) is an effective machining method for difficult to cut materials. Especially, because of the characteristics of a significant reduction in machining costs and flexibility in its machining, the applications of LAT have been largely extended to various machining fields. However, Studies on LAT are still staying at the beginning of research and represent a limitation in which a LAT process was applied to round members only. According to increases in customized production of special purpose parts, the researches on LAT for clover or polygon section members are necessary. In this paper, a LATM (laser assisted turn-mill) process was proposed to complement LAT.
Numerical Investigation on Laser Ablation Characteristics of PTFE in Advanced Propulsion Systems
Authors: Zhang Dai Xian , Zhang Rui , He Zhen , Wu Jian Jun , Zhang Fan
Published: November 2012

The Polytetrafluoroethylene (PTFE or Teflon) based propellants may be used in Pulsed Plasma Thruster, laser ablation thruster and other advanced propulsion systems. Because of the complex behaviors and phenomena of PTFE in ablation process, the study on thrusters’ operation process becomes complicated. Thermal and mechanical events are investigated, including phase transition, thermo-chemical and optical property variations, and multi-pulses laser ablation of PTFE. Considering more details including internal absorption of radiation, reflectivity of material, surface emission, a one-dimensional ablation model is developed and implemented numerically using a non-uniform grid, and implicit finite-volume method to gain greater insight into the process of laser ablation. The model is validated against analytical solutions and is in accordance with previous experimental results. The parameters of optical transmittance, reflectance and absorption coefficients are measured in experiments and are used in the numerical simulation. The laser ablation characteristics of PTFE are investigated, including the effects of wavelength and multipulses. It’s indicated that the laser ablation processes are influenced intensively by changing the laser wavelength and the effects of multiple pulses are also significant. The above numerical simulation provides insight into physical mechanisms of laser ablation, and suggests potential ways of improving thruster’s efficiency
Mechanical Behavior of Composite Plate under Combined Impact and Internal Pressure
Authors: Teshnizi S. Sharifi , Sharifishourabi G. , Yazid Yahya Mohd , Ayob Amran
Published: November 2012

This research presents results obtained from numerical analysis of a circular composite plate under impact of drop hammer and internal pressure load simultaneously. Influence of reinforced orientationangles of the multi-layer composite plate with fixed boundary conditions on displacements and axial stresses along the radius direction was studied. Employing ABAQUS software results for reinforcedorientation angles of [0/90/0]s, [0/45/60]s, [0/45/90]s, [0/30/60]s, [0/30/75]s, [0/15/30/60/75/90],[0/45/90/90/-45/0] are compared. Finding indicated that the reinforcedorientation angles have considerable effect on the axial stresses changing from compressive to tensile stresses. [0/45/90/90/-45/0]s showed the minimum displacements and axial stresses.
Linear Analysis of Crack Propagation in a Solid Rocket Propellant
Authors: Gulzar Mubashir
Published: November 2012

The Solid Rocket Propellant in its crude form is a rubber like material. This rubber like material performs very interestingly when used to study crack propagation. Blunting of crack tips occurred in the composite when the load is applied, which is generally non-linear phenomenon. The crack propagation analysis for such case is generally taken for double edge cracks but the presence of central cracks in the composites cannot be ignored. This trend is nonlinear and complex. In order to simplify things, optical grade polyurethane material is used instead. The polyurethane material we used for our experimental work was PSM-4. In this research work, an extensive study is made regarding crack propagation analysis using the basic principles of fracture mechanics and its different techniques for finding out the parameter necessary for tracing crack propagation. Mode 1 (Opening Mode) is considered for the central crack propagation analysis. The objectives set in this context are the determination of Stress Intensity Factor of central crack in the specimen using photoelastic experimental data and simulation of central crack in softwares (ANSYS, Pro-e). For this purpose a rectangular plate with Central Crack was used to be experimented upon using the techniques of Photoelasticity. A comparative analysis technique is adopted to compare the effectiveness of results from experiments as well as software simulations.
Finite Element Analysis of Curvature Precast Polymer Panel for Temporary Support of Tunnels
Authors: Khalajmasoumi M. , Koloor S.S.R. , Arefnia A. , Ibrahim I.S. , Yatim J. Mohd
Published: November 2012

In the past few decades, underground railway systems as one of the accepted transportation system have become an integral part of populated cities, and consequently developing advanced structure to speed up the tunnels construction process become vital. Ceiling collapse is defined as the major failure in construction of tunnels that need to be concerned to prevent any hazardous on workers. Sprayed Concrete (SC) is the traditional structure that has been used for temporary support of tunnels under construction process. The disadvantages of SC such as tough preparation and installation process that is also time consuming procedure, is caused a necessary need to design new structure to be replaced by traditional cases. This study is concentrated on design and mechanical analysis of curvature polymer panel to be replaced by SC in tunnels. For this reason, Hard Density Polyethylene (HDPE) Polymer is selected due to its specific mechanical features such as high strength and stiffness to weight ratio. The tests of compression and tension are performed to extract the material properties and mechanical behaviour of HDPE polymer. A good study is done on mechanics of polymer materials to select an appropriate model accurate enough to model HDPE polymer. YEOH model is selected and utilized in Finite Element Analysis (FEA) using ABAQUS 6.9EF. Explicit Dynamic (ED) Procedure is used to simulate the hyperelastic deformation of HDPE polymer structures. The mathematical model and computational procedure are validated using simulation results of a three-dimensional (3D) model of a cubic HDPE polymer under compression load that compared well with experimental data. The established simulation procedure has applied on the proposed model of curvature HDPE polymer structure for temporary supports of tunnels. The actual loading and boundary condition in tunnels are tried to apply on the structure and the model is ran using FEM and ED procedure. The flexural strength response of structure is plotted as load-deflection curve to show the stiffness that can be tolerated with the curvature structure. A complete discussion is given on stress and hyperelastic deformation of the structure. The results are illustrating the advantage and disadvantage of designed structure and the possibility of utilize polymer materials in tunnelling process. The computational procedure is strongly recommended for design and analysis of polymer structures for different engineering application.
Numerical Simulation of the Effect of Ethanol on Diesel HCCI Combustion Using Multi-Zone Model
Authors: Zhu Su Wei , Wang Chun Mei , Qian Ye Jian , Ou Li Jun , Wang Hui Chun
Published: November 2012

This study investigates the potential of controlling diesel homogenous charge compression ignition (HCCI) combustion by blending ethanol, which inhibits low temperature oxidation offering the possibility to control ignition in HCCI combustion. The simulation results from a multi-zone model show that the ethanol reduces the key active intermediate radicals OH, CH2O, H2O2, delays the low temperature oxidation reaction (LTR), reduces the heat released during LTR stage. As a result, it retards the main combustion stage.
Research on a STM32F Based Digital Integral Technology for Rogowski Current Transformer
Authors: Li Yin , Xie Yue
Published: November 2012

In this paper, a STM32F based on digital integral technology for Rogowski current transformer is studied. An analog integrator is used as an original model, and this model is discretized so that a digital integral formula is obtained. By using 32-bit microprocessor STM32F103C8T6, the integration of Rogowski coil output signal is realized. The experimental results show that the accuracy of the output by using this digital integral technology can reach 5P class defined IEC60044-8.
An Improved Dynamic Surface Control Approach and Applications to the Control of DC-DC Power Converter
Authors: Li Wen Lei
Published: November 2012

This article presents an improved dynamic surface control (IDSC) approach for DC-DC Buck converter with parameter uncertainties and external disturbances. For IDSC method, the parameters update laws are designed based on uncertainty equivalence criterion, the requirements to the controlled systems are reduced, and the problem of explosion of complexity can be overcome. The features of the derived controller are discussed and illustrated by the Simulation study. The analysis and simulation show that the obtained controller possesses good adaptability and robustness to system uncertainties.
Analysis on Electric Field Distribution of ±1000kV DC Wall Bushing with Considering Space Charge
Authors: Zhang Li , Li Qing Min , Zhang Li Na , Cao Lei
Published: November 2012

Based on space charge theory, electric field and potential distribution of ±1000kV DC wall bushing under DC and AC work condition is analyzed in this paper. The position and amount of space charge can be deduced from space charge theory and surface charge theory. By analyzing electric field and potential distribution under DC and AC voltage work condition with and without space charge, valuable conclusions are drawn, which provides valuable reference for insulation design.
New Method to Identify Sympathetic Inrush in Transformer Based on Hilbert Huang Transform
Authors: Gong Mao Fa , Xia Wen Hua , Li Guo Liang , Bai Xing Zhen , Li Lan Bing
Published: November 2012

Sympathetic inrush may cause the mal-operation of differential protection. Aiming at this problem, based on the characteristic that sympathetic inrush contains a lot of aperiodic component and high harmonics, this paper proposes to use Hilbert Huang transform to identify sympathetic inrush. Firstly, the mathematical model of sympathetic inrush is established to analyze its characteristic. Then Hilbert transform is used to obtain harmonic contents of sympathetic inrush and internal fault current. According to the proportion of fundamental to current, sympathetic current can be identified and differential protection can be blocked. The simulation results show that this method has better reliability and sensitivity than the second harmonic restraint scheme. Besides, it has a good ability against TA saturation.
An Analytical Method to Calculate the Eddy Current Losses of Transformer Shielding Coil
Authors: Bai Bao Dong , Gao Ying Ying , Wang Jia Yin
Published: November 2012

This paper mainly researches the eddy current losses of transformer shielding coil by adopting for analytical method. This method calculates the conductor’s boundary conditions directly by using the analytical solution of the leakage magnetic field, which is generated into the conductor eddy current equation for the analytical formula, then compared the analytical method with the finite element method to fix the analytical formula, the relevant theories are applied to analyze the results of using two different shielding to reduce the losses and find the effectively measures.
Three-Dimensional Magnetic Field Analysis of Poly-Magnet Line-Start Permanent Magnet Synchronous Motor
Authors: An Yue Jun , Pei Dong Xu , Xue Li Ping , Li Yong
Published: November 2012

In order to solve the existing permanent magnet synchronous motor starting from starting performance and energy target fight between rotor and limited space of conflict. The line-start permanent magnet synchronous motor with the special structure of the disk magnet polyed magnetic type has been proposed. Motor rotor punching trough, size, and cast aluminum material can give full consideration to the requirements of line-start function in the new type of permanent magnet synchronous motor. polymer magnets which is formed from alternating magnetic yokes and permanent magnetic ring is set between the hinge and the rotor part; Interval set on the outer circle of magnetic yoke take the magnetic flux to pole. Air-gap flux density can be achieved highly by utilized to set up the starting winding after the rest of the limited space in the poly magnet structure. By finite electromagnetic field analysis software Ansoft, Three-dimensional magnetic field can be analyzed in Poly-Magnet Line-start Permanent Magnet Synchronous Motor. The result show that poly magnet structure improves the air gap magnetic field strength; Under the premise of better starting capability, it can improve the power index of motor.
Study and Analysis the Facture Mechanism for Fine-Blanking with Negative Clearance on 60Mn
Authors: Zhang Z.M. , Li F. , Zhang H.
Published: November 2012

In order to improve the punching process, further enhance the blanking section quality. This paper studied the common blanking of 60Mn and the fine blanking with negative clearance of 60Mn blanking work piece metallographic structure by using scanning electron microscope. The results show that the fine blanking with negative clearance process can increase the work-hardening degree and further thin the punching surface tissue, inhibit the crack, and make the blanking surface smooth. The tensile and tear result in the generation of cracks and burrs, and the extrusion forming of fine blanking with negative clearance inhibit the generation of cracks, and eliminate the conditions of the burrs. As the extrusion process, the degree of work hardening in fine blanking with negative clearance is higher than the common blanking, the organizations are more closed.
Power Transmission Analysis between Two Flexible Subsystems Coupled by a Stiff Junction
Authors: Lin Ji
Published: November 2012

This paper concerns the power transmissions between two flexible subsystems (i.e., with short-wavelength deformations) coupled by a stiff junction (i.e., with long-wavelength deformations). Typical examples of such built-up models are flexible plates connected via stiff beams, for instance. Research shows that, in general, the power flow exchanged between the two flexible subsystems decreases as the stiffness of their junction part increases. Conditions are then derived under which the power transmission between the two flexible subsystems can be neglected such that the statistical energy response of each individual subsystem can be predicted independently. It thus allows the mid-frequency vibration behavior of whole built-up model to be predicted in a very simple manner. A numerical example consisting of two short-wavelength plates connected via a long-wavelength beam is given to illustrate the validity of the present theory.
Modal Analysis of 160KVA Dry-Type Transformer Based on ANSYS
Authors: Bai Bao Dong , Yang Guo Hui , Qu Bing Yin , Zhang Jian
Published: November 2012

In this paper, the modal analysis was carried out on the core and cavity of a 160KVA dry-type transformer based on the finite element analysis software of ANSYS. And the simulation results of the natural frequencies and modal shapes were obtained, which provided a theoretical guidance to the design of the transformer structure, and were meaningful to reduce the vibration and noise level of the transformer.
Static and Dynamics Analysis of 2.0MW Generator Frame
Authors: Ding Chao Yi , Dai Lu Ping , Guo Hong Che
Published: November 2012

ANSYS12.1 software is applied to the generator frame modeling and the static and dynamics performance analysis of the frame. The frame is calculated to find the max stress and the first six frequency, and based on the results, some suggestions is put forward for the optimization design.
Reflection of Conductive Plane Covered by Double Inhomogeneous Plasma Slab
Authors: Yan Fei , Yuan Zhong Cai , Wang Yong , Gong Shi Lian , Li Zheng
Published: November 2012

This paper presents numerical results in the form of graphs of the power reflection coefficients for electromagnetic signals normally incident upon a conductive plane covered with two layers of inhomogeneous plasma slabs. The plasma electron density varies only in the direction perpendicular to the plane. Parameters considered in the computation cover a relatively wide range and the functional dependence of the power reflection coefficients on these parameters is studied. The results indicate that in a rather broad frequency range, the electromagnetic attenuations by the double slabs obviously excel the sum of attenuations resulted from two plasma layers when each layer exits respectively. The structure presented is easy to set up, which is instructive for plasma stealth.
Multi-Peaked Velocity Spectrum of a AC-Electric-Field-Induced Electrolytic Flow with Microelectrodes
Authors: Sethi Astha , Parikh Pritesh , Benedict Samatha , Deb Subimal , Banerjee Souri
Published: November 2012

We study the electrolytic flow in a system of coplanar parallel electrodes subjected to an AC field. The model system has been thoroughly examined numerically for a large range of frequencies of the applied potential where we find a peak in the spectrum of the velocity magnitude at high frequencies along with exhibition of a pronounced peak at lower frequencies. Interestingly the first peak in the velocity spectrum shifts to lower frequencies while the second peak to higher frequencies with increasing distance from the electrode edge which suggests a formation of a non-planar electric double layer structure at higher frequencies.
State Recognition for Main Bearing of Wind Turbines Based on Multi-Fractal Theory
Authors: Sun Zi Qiang , Chen Chang Zheng , Zhou Bo
Published: November 2012

The main bearing dynamic characteristics of megawatt wind turbines are complex system with strong non-linearity, strong coupling and time-varying. The vibration signals are mixed with background noise, so it is difficult to extract the characteristics of week signals. Based on the dynamic characteristics, multi-fractal theory is put forward to detect and recognize the working status of the main bearing of megawatt wind turbines. Different working states are recognized intuitively by different dimensions of multi-fractural which are sensitive to variety of working state. The paper justifies the method can detect and recognize different working states of main bearings quickly and accurately through the experiments on the main bearings of 3 WM wind turbines.
Conditioning Circuit of Energy Harvesting Device in Substations
Authors: Cheng Yan , Yu Chun Hui , Huang Jin Xin , Zhang Li
Published: November 2012

A capacitive energy harvesting device is proposed to harvest energy from electric field in substations. It can achieve electric energy from electromagnetic environment for wireless smart sensors. It’s obvious that the surface of it can generate charge when it’s put in the electric field. However, the output voltage of it is unstable and it cannot power directly the wireless sensors. So a conditioning circuit is essential for the device. With the purpose of designing and analyzing conditioning circuit, a simple model is used to equal the energy harvesting unit. In order to power the sensors steadily, the conditioning circuit should consist of some subcircuits such as AC-DC rectifier and DC-DC converter. At last, a simple digital temperature sensor is used to study the operating characteristics of the conditioning circuit in the stage of experiment.
Analysis on the Friction Performance of the Bionic Surface with the Convex Domes for Increasing Friction
Authors: Sun Hui , Xiao Lin Jing , Sun Chuan Yu
Published: November 2012

The surface micro textures on the feet of the animals such as flies, geckos and tree frogs have been studied. According to the research result and the science of the bionic tribology, the bionic surfaces with the convex domes which possess the certain structural features are obtained. They can increase the friction coefficient. The increasing friction mechanism of the bionic surface with the convex domes is analyzed using the methods of theory analysis, simulation and experimental verification. The friction force between the bionic surface with the convex domes and the belt consists of the sliding friction force and the additional resistance resulting from the inlaying meshing effect. The contact transformation of the bionic surface with cylindrical convex domes and the belt is simulated by the software ANSYS. The increasing friction effect of the bionic surface with the cylindrical convex domes is verified by the experiments.
Design of a Microstrip Antenna Based on the Magnetoelectric Composite Material
Authors: Yang Hong , Lei Yu
Published: November 2012

Based on the transmission line mode theory, designed one kind of small and dual band microstrip antenna on the magnetoelectric composite material. Then do the simulation by HFSS11.0 which based on the finite element method. The simulation results show that, when the return loss less than -10dB, antenna working in band 2360MHz~2500MHz and 3900MHz ~4200MHz, Compared with ordinary antenna, this antenna not only realizes the multi band, but also in the working frequency bandwidth compared to common antenna slightly raised, antenna size is reduced nearly 85%. Good impedance matching. This microstrip antenna has some value on the mobile device miniaturization for the miniaturization and dual band.
Architectural Application of Smart Materials for Non-Flexible Structures Made by Flexible Formworks
Authors: Bemanian Mohammadreza , Mahdavinejad Mohammad Javad , Karam Ali , Ashtiani Sima Rezaei
Published: November 2012

Flexible formworks are dominantly used for concrete constructions. These constructions become rigid after curing and their form cannot be changed, also their color or translucency is stable during usage period; i.e. these constructions are not flexible. On the other hand, in order to satisfy new architectural requirements the necessity of flexibility and smartness is undeniable for the construction.The questions of this paper are: How smartness can be added to rigid structures What are the roles of nano-flexible formworks to turn non-flexible structures into flexible ones To answer the research questions, descriptive - analytical research method has been adopted and empirical data gathered to feed inference mechanism. Our investigation shows that if the flexible formwork has been made by smart materials which are changeable in nano-scale, and the formwork is left on the structure even after curing, it would act as a nano-flexible skin for the structure and would satisfy some architectural requirements in nano-scale.
Effects of Atmospheric Conditions on the Mechanical Properties of Tires
Authors: Olszewski Zbigniew , Waluś Konrad J.
Published: November 2012

Safe driving requires from the driver several visual-mental activities (perception, Proper selection of the tires depending on the season allows for optimizing the level of risk associated with driving in varying weather conditions. Properties tires used in the vehicle operational parameters show variability of depending on temperature, leading consequently to change the characteristics of the traction of the vehicle. Understanding the nature of these relationships is essential to determine the nature interaction. tires and road surface This paper presents experimental results hardness of tires under normal traffic using a mobile measuring equipment.
Investigating the Effect of Gripping on Upper Limbs Muscles by Modeling and Electromyography Test
Authors: Azizpour Ghazaleh , Sadeghimehr Mohsen , Sharifi Mesbahoreza
Published: November 2012

These days most of the workers use hand controller tools. Because of this it is useful to know the relations between hand and these kinds of tools. One of these relations is cylindrical power grip. For this reason first of all a device is prepared for measuring the torque value. After that by creating a model in ANYBODY software for gripping motion for forces and muscular activities have been calculated. In this case for solving the inverse kinetic problem several cost functions are defined and the results are compared. On the other hand, by using Electromyography tests in gripping motion the activity of 3 surface muscles are investigated and finally the modeling and Electromyography’s results are compared.