bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Cutting Passes for a Fine-Cut Wire Electro Discharge Machining of Stainless Steel
Authors: Sabudin Sulastri , Lie Iu Ching , Mohamad Eddy Ezwan
Published: December 2011

Work piece surfaces produced by wire EDM can exhibit surface alterations resulting from rapid heating and quenching during machining. The thermally altered layers have tremendous impacts on mechanical properties of machined product. Multi-cutting passes of brass wire into stainless steel sheet SS304 has been suggested in this paper. Three holes was machined at one cutting passes, two cutting passes and three cutting passes respectively and the effect on surface roughness of machined steel was investigated. Visual micro-structure study has been done to explore the existence of white layer and Heat Affected Zone (HAZ) layer. Based upon experimental result, the surface roughness is decreased with the increment of cutting passes. The white layer only formed at first cutting part and did not appear at two and three cutting passes.
Experimental Investigation and Analytical Calculation of the Bending Force for Air Bending of Structured Sheet Metals
Authors: Malikov Viatcheslav , Ossenbrink Ralf , Viehweger Bernd , Michailov Vesselin
Published: December 2011

The increasing interest in structured sheet metals for lightweight constructions and automotive can be seen in recent years. The driving force of this trend is higher stiffness of structured sheet metals in comparison to smooth sheet metals. The structured sheet metal is a sheet metal with a periodical three-dimensional geometry, which is manufactured by hydroforming process. The improved properties of this sheet metal allow the weight reduction of car components and lightweight structures. The purpose of this study is the determination of the force requirements by air bending of structured sheet metal and an analysis of influence factors on the bending force. Moreover an improvement of an analytical calculation of the maximal force for air bending of structured sheet metals is presented. In this work the steels DC04, DX56D-Z and X5CrNi18-10 were investigated. The results have shown that the bending position and the structure location have a big influence on the bending force. All investigated materials have similar behaviour. The largest and smallest bending force can be seen in the bending positions III and II respectively. At the structure location “negative” the maximal bending force is smaller than at the structure location “positive”. The results of the different calculation methods were compared to the experiments. The developed analytical approach provides more precise results than conventional method. In contrast to existing analytical calculation methods it takes into account the influence of the structure location and bending position of structured sheet metals on the bending force
Experimental Investigations of the Machinability of Titanium Alloy TC4 with Different Hydrogen Contents
Authors: Hu Jun , Bao Yong Jie , Gao Hang , Wang Ke Xin
Published: December 2011

The experiments were carried out in the paper to investigate the effect of adding hydrogen in titanium alloy TC4 on its machinability. The hydrogen contents selected were 0, 0.25%, 0.49%, 0.63%, 0.89% and 1.32%, respectively. Experiments with varing hydrogen contents and cutting conditions concurrently. Experimental results showed that the cutting force of the titanium alloy can be obviously reduced and the surface roughness can be improved by adding appropriate hydrogen in the material. In the given cutting condition, the titanium alloy TC4 with 0.49% hydrogen content showed better machinability.
Vibration Analysis of Single Lap Adhesive Joint with Non-Uniform Adhesive Thickness: Experimental and Analytical Investigation
Authors: Li Wei Dong , Gu Jin Xiang , Hu Ping , Wu Kun Yue
Published: December 2011

This paper deals with the analytical and experimental vibration analysis of the single lap adhesive joint with non-uniform adhesive thickness . In the theoretical part, an analytical modal is described and a motion equation is built. A joint consists of two different adherends are bonded over a certain length by a viscoelastic material, epoxy resin. Adherends are modeled as Euler-Bernoulli beams. Both ransverse and axial deformation of adherends are considered in deriving the equations of motion. In the experimental part, the steel use Q235, the aluminium use 6016-T4 and the adhesive use ESP110 and AV138, epoxy resin. Dynamic responses of the joints are investigated using the hammer test technique, natural frequencies and model shapes obtained by using an accelerometer depended on the accelerometer location in the system, which is attributed to its mass contribution to the overall system mass. The investigates are also carried out using the finite element method(FEM) and simulated with ABAQUS. Both results show that resonant frequencies decrease with the slant angle increase.
A Novel Material Preparation of Density Ceramics and Fibre Joining
Authors: Zhao Ying Na , Gao Shui Jing , Hou Gui Qin , Zhang Wen Li
Published: December 2011

The joining materials of density ceramics and woven fibres would be potential value as sealing parts for thermal protection system application in aerospace field. Based on ZrO2-Al2O3-SiO2 phase diagram, the ceramics matrix and interlayer compositions were designed. Using the absorber-microwaves properties of Al-Si alloy, the joining of ZTM ceramics and fibre materials with interlayer was achieved by microwave hybrid heating method. The experiment results indicated that the interlayer ingredients were mullite, zirconia and alumina after microwave sintering. The strength of joint specimens was related with the interlayer compositions and the specimen preserved elasticity property according to the test result of universal testing machine. The joint mechanism of interlayer by microwave sintering was discussed in this paper.
An Automatic Control System Based on Arc Voltage of TIG Welding
Authors: Gu Wang Ping , Xiong Zhen Yu , Wan Wen
Published: December 2011

This paper describes an automation welding control system for Tungsten inert gas shielded (TIG) welding to maintain constant arc length. And using this method can replace manual operation. A voltage transducer was used to avoid high-frequency voltage. And dynamic relation between variation of arc length and voltage are described. A digital Proportion-Integration-Differentiation (PID) controller with identified value has been used modulate the rate of electrode feed mechanism. The mechanism, which driven by Servomotor A, can compensated variation of arc length in welding path. By keeping the arc length constant during the welding process, an elegant appearance and higher quality seam is obtained. The experiment result shows that this automatic control system based on digital PID controller is stable, and can working effectively without operator manipulation.
Electrochemical Behavior of Welded Joints with 308L Stainless Welding Wire and Low Temperature Transformation Welding Wire
Authors: Zhao Sen , Jing Hong Yang , Han Yong Dian , Xu Lian Yong
Published: December 2011

The electrochemical behavior of welded joints with 308L stainless solid welding wire and low temperature transformation welding wire using different welding processes was investigated at ambient temperature in 3.5% NaCl solution using potentiodynamic polarisation technique. Welded joints exhibited different corrosion potential due to the dilutions of alloy elements such as Cr, Ni, Ti, Nb and Mo. To reveal the corrosion resistance of welded joints using different welding processes, some significant characterization parameters such as Ecorr, Eb, △E and Icorr in polarisation curves were analyzed and compared. The result shows that the corrosion resistance of welded joints using low temperature transformation welding wire is better than that using 308L stainless solid welding wire.
Principle of the Continuous Variable Cross-Section Recycled Extrusion (CVCE) Process
Authors: Wang Qing Juan , Zhang Ping Ping , Liu Chang Rui
Published: December 2011

A kind of severe deformation method for refined grain materials named continuous variable cross-section recycled extrusion (CVCE) was proposed. The composition structure and working principle of processing were introduced. First, the cylinder specimen was extruded to circular cone and then the circular cone specimen was compressed into columned one. After that, the specimen was rotated by 180° and repeated the forward procedure. All of procedures mentioned above constitute a cycle. The whole process is repeated again and again. The process can introduce ultra-high plastic strain without any geometrical change. The process has been applied to commercial aluminum (1100), Mg alloy. After several cycles of CVCE, bulk materials with sub-micron grain structure were successfully obtained. The average grain size of AZ31 magnesium alloy is refined from 25μm to 3μm after six cycles and the tensile elongation were improved dramatically.
Elastic Deformation Predicting Design and Numerical Simulation for an Asymmetry Multi-Mandrel Aluminum Extrusion Die
Authors: Pan Jian Yi , Zhou Zhao Yao , Dong Shou Bin
Published: December 2011

Detail analysis is presented for the influence of elastic deformation on profile wall thickness, the metal flowing and stress load situation of an asymmetry multi-mandrel die. Through the combination of numerical simulation and traditional experimental design, the method on complex section extrusion dies by quantitative prediction of the elastic deformation situation, can improve the accuracy and success rate effectively. In addition, profiles can be extruded stably when the exit velocity fluctuation is under a corresponding range. Under this range, deformation stress caused by uneven metal flowing is under the critical stress, which relates to the thickness to width ratio t/b.
Mechanical and Electrical Properties of Graphite/Carbon Fiber/Phenolic Resin Composite
Authors: Li Mi Dan , Liu Dong Mei
Published: December 2011

Composites made of phenolic resin filled with natural graphite platelets and carbon fibers are fabricated by mechanical mixing, followed by compression molding. The flexural strength and electrical conductivity of composite are analyzed to determine the influence of phenolic resin and carbon fiber on mechanical and electrical properties. It is found that there is a marked dependence of the electrical conductivity and flexural strength on phenolic resin content. The electrical conductivity decreases and flexural strength increases with the increasing of phenolic resin loading. The presence of carbon fiber helps improve the flexural strength of composite such that 4 wt% CF increases the flexural strength of composite about 90%. However, an excess amount of carbon fiber reduces the flexural strength due to poor dispersion of carbon fiber in composite. The result also shows that the addition of carbon fiber exhibits a slight effect on the electrical conductivity of composite at low carbon fiber loadings.
Hot Forming Behavior and Flow Stress Model of Steel 50A1300
Authors: Zhou Xu Dong , Liu Xiang Ru
Published: December 2011

The researches of non-oriented silicon steel are mainly focused on the effect of main processing parameters on the microstructure and magnetic properties, but there have been few studied about its flow stress until now. In this paper, the non-oriented silicon steel 50A1300 of hot forming is studied by thermal-mechanical simulation method. The hot deformation behavior of the steel is explored and the flow stress model of the steel is established based on the creep mechanism. The model has good accuracy and is feasible.
Research on Pavement Performance with Warm Mix Asphalt Concrete
Authors: Lin Yan Peng , Li Bin
Published: December 2011

Using SBR and epoxy to modified warm-mix asphalt, the penetrability, ductility, softening point of bitumen at different aging times are tested, the comparative analysis of the modified effects of two modified agents to the asphalt mixture is made; Construction temperature of asphalt is determined by using temperature - porosity curve; The results reflect epoxy resin and SBR can improve the high temperature stability and anti moisture infringement capacity, so propose to use warm mix asphalt concrete for the top layer except in special sections layer.
Effects of pH on the Growth of ZnO Nanorod Arrays in Aqueous Solution
Authors: Zhang Chun Mei , Meng Tao , Hao Yan Ping , Chen Qiang
Published: December 2011

Well-aligned crystalline ZnO nanorod arrays were synthesized on the glass substrate via an aqueous solution route, and the effect of the pH value on structural properties and morphology of ZnO nanorod arrays was investigated using XRD and FESEM. FESEM micrographs show the formation of ZnO nanorod arrays at different pH values. XRD patterns confirm that the ZnO nanorods were wurtzite structure preferentially oriented in c-axis direction and the highest quality of nanorod array was formed at high pH value.
Study on Dynamic Mechanical Properties of n-HA/PA66 Composites
Authors: Cheng Lin , Zhang Xiang , Li Yu Bao
Published: December 2011

The dynamic mechanical properties of nano-hydroxyapatite (n-HA) reinforced polyamide 66 (PA66) biocomposites were studied with reference to the effect of n-HA content, frequency and physiological saline. The intrinsic properties of the components, morphology of the system and the nature of interface between the phases determine the dynamic mechanical properties of the composite. The storage modulus (E') values of n-HA/PA66 composites were much higher than those of pure PA66, indicating that the incorporation of n-HA in PA66 matrix induced reinforcing effects obviously. And the E' values of composites increased with increasing of n-HA content. The loss modulus (E") of the composite with 30wt% n-HA was higher that those of pure PA66 and the composite with 40wt% n-HA below 55°C, however, above 55°C, the E" values enhanced with increase of n-HA content. Both frequency and physiological saline had obvious effects on the dynamic mechanical properties for n-HA/PA66 composite. E' and E" values enhanced with increase of frequency, but tanδ values decreased with increasing of frequency. After soaked in physiological saline, the E' and E" values of the composite decreased.
Method of Analyzing the Size of Voids Beneath Rigid Pavement Slabs
Authors: Zhong Yan Hui , Zhang Bei , Ren Ming Ming , Guo Cheng Chao , Xia Chu Chu
Published: December 2011

The size of voids beneath rigid pavement slabs is an important factor which influences the bearing capacity of roads. GPR is an advanced method for detecting voids beneath rigid pavement slabs. Combined with drilling and sampling, equations including parameters of GPR wave amplitude, horizontal size and vertical size of voids are established for analyzing the size of voids. Then, based on the equations, the horizontal size and vertical size of voids can be calculated according to the actual GPR wave amplitude.
Ni3Al-Base Alloy of Laser Welding Behavior Research
Authors: Zhang Dong Yun , Gao Hai Yun , Lu Kun , Luo He Li , Li Shang Ping
Published: December 2011

This text does on research on welding behavior of the Ni3Al alloy casting MX246A of based on laser as heat source. First process parameters have effects on crack sensitive in the study. Laser power decided to heat input and the depth of the weld, which has obvious effects on the hot crack. Crack sensitivity of welding at low speed is quite lower than it at high scanning speed; low scanning speed can reduce the sensitivity of weld cracking. Because of the laser absorption and solidification of weld metal for inheritance of the basic material, grain degree of materials makes a significant impact on crack. Crack sensitivity in the fine grain areas is quite lower than it in the coarse grain areas. It is found in the study that the main reason for the weld crack is Mo elements gathering and caused the oxidation of the partial. Welding of MX246A alloy is realized on the basis of the above research, and performance of welding joint is up to more than 75% of base material.
Passive Laser Assisted Bending of Ultra-High Strength Steels
Authors: Järvenpää Antti , Karjalainen Pentti , Mäntyjärvi Kari
Published: December 2011

Formability of ultra-high strength steels is poor causing problems in bending and stretch forming. The target of this work was to improve the formability of ultra-high strength steel sheets by controlled local laser heat treatments. Three steel grades, a bainitic-martensitic 4 mm DQ960 and two martensitic WR500 with 6 mm and 10 mm thicknesses were heated by controlled thermal cycles using a 4 kW Yb:Yag –laser, followed by self-cooling. Sheets with the thicknesses of 4 and 6 mm were treated on one side only by heating up to the austenitizing temperature. The 10 mm thick WR500 sheet was heat treated separately on the both surfaces by heating to a lower temperature range to produce a shallow tempered layers. The tensile and bendability tests as well as hardness measurements indicated that laser heat treatment can be used to highly improve the bendability locally without significant strength losses.
A Composite Structure Multi-Parameter Sensor Based on an Embedded Fiber Grating
Authors: Zhan Ya Ge , Luo Jun , Wu Hua
Published: December 2011

A composite structure multi-parameter sensor based on an embedded polarization maintaining fiber grating (PMFG) has been studied theoretically and experimentally. A fiber Bragg grating (FBG, for comparison with the PMFG) and a PMFG are embedded in glass fiber reinforced polymer (GFRP) laminates in the experiment. The temperature and stress response characteristics of the fiber gratings embedded in corresponding GFRP are studied. The temperature sensitivity of the FBG improves from 10.64pm/°C to 21.66pm/°C. The temperature sensitivity of the PMFG improves from 10.22m/°C to15.7pm/°C (x-axis) and from 9.56 pm/°C to15.1 pm/°C (y-axis). The peak wavelengths in the reflection spectra of the two gratings all shift linearly with the temperature and/or the stress of GFRP. The two temperature-wavelength sensitivities and the two stress-wavelength sensitivities of the PMFG are all different with each other. The temperature and the stress of the GFRP can be calculated according to the two peak wavelength (in x-axis and in y-axis) shifts of a PMFG. Therefore, one PMFG is component for monitoring the temperature and the stress of a composite structure simultaneously according to the experimental results.
Theoretical Investigation on Prestress during the Manufactural Process of Integrated Multilayer Wrapped Pressure Vessel
Authors: Zhu Xiao Qin , Li Nan Jing , Wang Zhong , Yang Yong , Yang Hai Bin , Zhao Hui Yuan
Published: December 2011

Integrated multilayer wrapped pressure vessel is widely used in process industrial production. In allusion to its manufactural process and structural characteristics as well as considering the frictional force between the laminates in the relative displacement of the laminates, the calculation formulae in the laminate or the inner cylinder prestressed by the wrapping force of the hydraulic manipulator were derived by principles of mechanics. The investigative results of the prestress distribution in the integrated multilayer wrapped vessel structure have a certain direct significance for its actual manufacture and insuring its manufactural quality.
Investigation of Crack Initiation and Propagation during Rolling Contact Fatigue of SUJ2 Steel Bearings Using a Newly Developed One-Point Testing Machine
Authors: Rozwadowska Justyna , Kida Katsuyuki , Costa Santos Edson , Honda Takashi , Koike Hitonobu , Kanemasu Kenji
Published: December 2011

An innovative type of one-point rolling contact fatigue (RCF) machine was developed in order to investigate crack initiation and propagation in metals. The microstructural changes and propagation of subsurface cracks during rolling contact in specimens tested by using the new device were studied by laser confocal microscope and X-ray diffraction. It was shown that this new method presents several important advantages compared to the conventional thrust type RCF machines.
Influence of Vibration on the Heat Transfer of Lost Foam Casting Filling
Authors: Zhao Zhong , Fan Zi Tian
Published: December 2011

The vibration is superimposed to the filling process of aluminum and magnesium alloy in lost foam casting, and the flow lengths and the molten metal temperatures of the flow front are collected, and they compared with no-vibration. The results show that the vibration can significantly improve the filling capacity of the aluminum alloy, magnesium alloy in lost foam casting. Compared to the samples without vibration, the flow lengths of A356 alloy with vibration in lost foam casting increased by 33% and that of AZ91D alloy increased by 15%.The heat transfer of molten metal on the flow front was analyzed, and it indicates that the vibration energy extends the filling time of the molten metal on the flow front in lost foam casting.
Numerical Simulation on Electron Beam Welding Temperature Field of Al-Li Alloy
Authors: Wang Shao Gang , Yu Kuang , Xing Li
Published: December 2011

The numerical simulation of electron beam welding temperature field for 2090 Al-Li alloy sheet of 2 mm thickness is conducted by using the ANSYS software. The combined model of Gauss surface heat source with cylindrical body heat source in linear attenuation is used according to the unique nail-shaped weld of electron beam welding joint, and the distribution cloud image of temperature field and the instantaneous weld thermal cycle curves of Al-Li alloy electron beam welding are obtained through calculation. The effect of welding parameters such as electron beam power and welding speed on the distribution of temperature field and weld width is investigated. Results show that electron beam welding has a very high rate of both temperature ascending and descending, and the rate of temperature ascending is higher than that of descending. With the increase of electron beam power or decrease of welding speed, the temperature of fusion zone elevates, and the weld width increases. The appearance of weld obtained through numerical simulation is greatly consistent with the practical welding.
The Effect of Percentage of Primary α on Mechanical Properties of Bimodal Microstructure of TC4
Authors: Yang Jing Min , Wang Yang Wei , Gao Ju Bin , Xiong Pan
Published: December 2011

In order to discuss the effect of content of primary α on properties of bimodal microstructure, the TC4 sheet in rolling state was heat treated at different temperatures of 10~50°Cbelow the β-transus temperature, then a series of bimodal microstructures with different content of primary α were obtained by air-cooled procedure. Quasi-static and dynamic compress tests were carried out with universal material testing machine and Split Hopkinson Pressure Bar (SHPB) respectively. The results indicated that the relationship between mechanical properties and primary α is irregular, and that bimodal microstructure with 25% primary α shows a better combination of strength and ductility.
Hardness and Impact Toughness of Niobium Alloyed Austempered Ductile Iron
Authors: Abdullah Bulan , Alias Siti Khadijah , Jaffar Ahmed , Freddawati Rashiddy  Wong , Ramli A.
Published: December 2011

The effect of different austempering holding times on the hardness and impact toughness of 0.254% niobium alloyed austempered ductile iron was investigated in this study. Molten ductile iron was prepared in an induction furnace with capacity of 60kg. Samples with dimension of 300m x Ø25mm in form of Y block double cylinder was constituted and solidified samples were then machined in accordance to ASTM E23 for impact test specimens. Samples were ground and polished before Rockwell hardness test was conducted. Austempering heat treatment process with austenitizing temperature of 900°C for 1 hour and austempering temperature of 350°C for 1 hour, 2 hours and 3 hour holding times were then carried out. The results from this research indicated that austempering the sample for 1 hour resulted in significant improvement of the impact toughness values but increasing the austempering holding time deficiently reduced the values. On the contrary, the hardness of niobium alloyed austempered ductile iron continues to increase with respect to longer austempering holding times.
Experimental Study on Improved Phase-Shift Control Soft-Switching Converter
Authors: Yu Yan , Ma Chao , Ma Wen Bin
Published: December 2011

A novel phase-shifted Soft-switching converter is presented in this thesis，which is based on the Tou structural, groundwork of summarization of the development of lower Electronics in recent years and lucubration in theoretical basis of modern high frequency soft switching power convert technique and analysis of operation principle, characteristic of the circuit and inherent drawbacks of traditional phase-shifted Soft-switching converter. Explicit description of main circuit topology, operation principle, characteristic of the circuit of the novel phase-shifted Soft-switching converter as well as the simulation analysis with the PSPICE software is proposed. The main works that I did: The design involves calculation of transformer, inductor and capacitance in main circuit, parameter selection of each element and realization of control circuit. Electric circuit Tou structural is verified by emulation experiment. The electric circuit reduces availably switch exhaust of traditional soft switch transformation electric circuit. The experiment proved to the possibility of the reformed prefect. The experiment has important reference value to improved soft switch transformation.
Kinematics Analysis and Precision Design for a 2-DOF Spatial Mechanism
Authors: Xie Zhi Jiang , Liu Xiang Hui , Song Dai Ping
Published: December 2011

A 2-DOF spatial mechanism was designed for pointing requirement. It can meet the requirement by adjusting the length of bipod. The kinematics analysis result which was made by Pro/Mechanism shows that this mechanism meets the design requirements; meanwhile, the main factors that have an impact on mechanism precision were analyzed by Pro/e Behavioral Modeling. The result shows the bipod is the key point to achieve mechanism precision. This study provides theoretical foundation for the follow-up manufacture and assembly.
Numerical Study on Ventilated Supercavitation Reaction to Gas Supply Rate
Authors: Gao Guo Hua , Zhao Jing , Ma Fei , Luo Wei Dong
Published: December 2011

In the present investigation, a computational fluid dynamics technique is used to investigate the ventilated supercavitation reaction to the change of gas supply rate. Detached eddy simulation, a hybrid RANS-LES method is used for turbulence modeling, and improved Singhal’s model is used to simulate cavitation process. Simulation results show that the change of cavity shape is lagging behind that of gas supply. When gas supply is shut, cavities experience a series fluctuation before reaching equilibrium state, if natural cavitation numbers are large; in contrast, they are monotone decreasing under small natural cavitation numbers.
Analysis and Simulation of Strong Earthquake Ground Motions Using ARMA Models
Authors: Menasri Abderrazak , Brahimi Malek , Bali Abderrahmane
Published: December 2011

The acceleration record of an earthquake ground motion is a nonstationary process with both amplitude and frequency content varying in time. The paper presents a general procedure for the analysis and simulation of strong earthquake ground motions based on parametric ARMA models. Structural design spectra are based on smoothed linear response spectra obtained from different events scaled by their peak values. Such an approach does not incorporate other characteristics of the excitation represented by measured data. This study investigate the use of non-stationary models which can be considered characteristic and representative of specific historical earthquakes. An earthquake record is regarded as a sample realization from a population of such samples, which could have been generated by the stochastic process characterized by an Autoregressive Moving Average (ARMA) model. This model is capable of reproducing the nonstationary amplitude as well as the frequency content of the earthquake ground accelerations. The moving time-window technique is applied to synthesize the near field earthquakes, Boumerdes-1, Boumerdes -2, and Boumerdes -3 2003 recorded on dense soils in Algeria. This model, is based on a low-order, time-invariant ARMA process excited by Gaussian white noise and amplitude modulated using a simple envelope function to account for the non-stationary characteristics. This simple model gives a reasonable fit to the observed ground motion. It is shown that the selected ARMA (2,1) model and the algorithm used for generating the accelerograms are able to preserve the features of the real earthquake records with different frequency content. In this evaluation, the linear and non linear responses of a given soil layer have been adopted. This study suggests the ability to characterize the earthquake by a minimum number of parameters.
Effect of Polyurethane with Different Elastic Modulus on the Response of Aircraft Windshield against Bird Strike
Authors: Liu Li Zhong , Ma Zhen Zhu , Pang Shi Hong , Zang Shu Guang , Ou Ying Chun , Zuo Yan
Published: December 2011

The analysis of windshield against bird strike is necessary for reducing the disastrous consequences. The flat windshield which involves two pieces of glass together with a polyurethane interlayer is often used in the aircraft. The mechanical property of the polyurethane interlayer is an important factor of affecting the response of windshield against bird strike. This effect is investigated in this work by simulating the bird impacting the flat windshields with the polyurethane of different elastic modulus. The bird is modeled with SPH method. The calculation results indicate that the elastic modulus of polyurethane affect the response of windshields in many points. For the elastic modulus of 5 MPa, the thickness of polyurethane interlayer is compressed by 16% during the striking. The compressive effects decrease the contact force and the displacement of windshield to some extent. Especially, the major principle stresses in the inner and outer glass are decreased by the compressive effects significantly. It is found that the major principle stresses in the outer glass are 103 MPa lower than those of the case with the elastic modulus of 600 MPa. The relatively small stress in the glass means that the windshield can afford more serious impact and has the better impact resistance.
New Method for Measuring Liquid Level in WFGD System
Authors: Li Li , Tan Zheng Hui , Liu Jia Wen
Published: December 2011

Traditional method for measuring liquid level of absorption tower in wet flue gas desulfurization (WFGD) system is introduced in this paper, and it's found that measuring accuracy of the method exists in large deviation. A new method is proposed to measure liquid level of absorption tower for this situation. The local test results show that not only measurement result of new method is more close to the actual liquid level than traditional method, but also using new method can save operation cost and ensure the safety, stability, and economic operation of WFGD system.
Microstructure and Properties of Roller Surface Alloyed by Laser
Authors: Feng Liang , Liu Qi Bin
Published: December 2011

To improve the service performance of roller. The surface of roller was alloyed by a 5kW CO2 laser. The microstructure, hardness and wear resistance were investigated by means of OM, XRD, Micro-hardness Testing Machine and MMS-2A screen display friction tester. The experimental results indicate that excellent metallurgical bonding is obtained between alloying layer and substrate, the main microstructure of laser alloying coating is composed of phases such as γ-Fe, Fe(Ni,Cr), (Fe,Cr)7C3, MoC, Fe2MoC, WC and SiC etc. The strengthening mode is particle-reinforced mechanism. The corrosion resistance of connection zone is better than that of alloying zone. The average of microhardness value is as high as 718 HV, which is more two times than that of substrate, and the average of wear resistance value of alloying layer is approximately three times larger than that of substrate
Simulation and Application of Fuzzy Control System with Integrator
Authors: Li Ping , Yan Chang Feng , Zeng Ling Ke , Cheng Xiao Su
Published: December 2011

This article simulated fuzzy control system by using MATLAB and compared the normal fuzzy control system with the fuzzy control system which has an integrator. Further more, the influence of quantize factors, proportional factors and integral constants on system was studied. The simulation results show that static error always exists in normal fuzzy control systems and proportional factors influence the stability of the system greatly. Put an integrator into a fuzzy control system, and static error can be eliminated and the system stability can be improved. The conclusion of simulation and practical experience, use fuzzy control system with integrator in reality. It can get good results.
Application of Desulfurization Additive in Desulphurization System for 600MW Units
Authors: Li Li , Zeng Bin
Published: December 2011

This paper studies the application of desulfurization additives in the desulfurization system for 600MW units, Results show that desulfurization additives have a positive effect on the desulphurization efficiency, and it can gain notable economic benefits when it guarantees the effective concentration of the desulfurization additives and the quantity of limestone
Noise Suppression of Optical Voltage Transducer by a Robust Control
Authors: Li Li Jing , Li Bing Jun , Bi Lan , Zhang Xi , Zhang Chun Xi
Published: December 2011

This paper investigates an H∞ robust controller for improving the measurement accuracy of the Optical Voltage Transducer with noise and parameter uncertainty. Firstly, the optical voltage transducer based on closed-loop detection is analyzed, and the model of the system is established concerning noise and uncertainty. Secondly, according to the model, this paper is theoretically devoted to the study of the Robust control for meeting the design target, while guarantees that the closed-loop system is asymptotically stable. Furthermore, we give a design criterion in terms of linear matrix inequality for the Robust control in the presence of noise and uncertainty. Finally, the experimental results demonstrate the effectiveness and feasibility of the robust controller.
Research on Porous Sprayer for Refining of Aluminium Melt
Authors: Hao Cheng Gang , Li De Zhi , Zeng Jian Min
Published: December 2011

The relationship among the transfer coefficient of hydrogen, the size and the moving velocity of bubbles has been obtained according to the transfer model of hydrogen in aluminum melt. The experiments were carried out to invetstigate the degassing efficiency of a porous sprayer immersed in the molten aluminum. The results indicate that refining of molten aluminum can be conducted with a porous sprayer that was immersed in the melt at one end and was connected with inert gas at another end through a pipe. The refining efficiency is affected by number of bubbles or size of bubbles and by floating speed of bubbles. The hydrogen concentration in aluminium melt decreases with the increasing of the spraying time. In the condition of 0.6 m3/h flowing rate and spraying time of 10 minutes, the removal rates of hydrogen and impurities are about 60 percent and 68 percent，respectively for A357 casting aluminium alloy.
Responses and Optimization of a PID-Based Speed Regulating System of the Planetary Mixer
Authors: Yang Ming Jin , Li Xi Wen , Wang Zhi Gang , Shi Tie Lin
Published: December 2011

The performance of speed regulating is very important to the mixing process with safe, efficient operation and high quality of production. Strategies and practices of responses and optimization of a PID-based speed regulating system of a planetary mixer were presented in this paper. Research results show that: by means of the signal constraint function presented by Simulink Response Optimization, optimization PID parameters of the 2-DOF-PID controller can be obtained, and the response of close-loop control system has quite good performance of overshoot, response time, and stability compared with an open-loop control system.
Effect of Vortex Generators on Aerodynamic Characteristics of a Car
Authors: Yan Xu , Ye Jian , Zhao Zhi Ming , Hu Xing Jun , Liao Lei
Published: December 2011

In order to reduce the aerodynamic drag, a domestic car was selected as study object to research the size and the layout of the vortex generator with the method numerical stimulation. By comparing the values of drag coefficient (Cd) the cars with vortex generators (VGs) and the original and then analyzing the mechanism of drag reduction, a final optimized strategy was achieved. It was concluded that VGs can lower the Cd of a car but the effect depends on the size and the layout. Our research achievements can serve as reference for automobile aerodynamic drag reduction, and are also significant to energy saving and emission reduction.
Suppression of Chatter Vibration by Fuzzy Sliding Mode Control in Machining Processes
Authors: Ostad-Ahmad-Ghorabi Mohamad Jafar , Zahery Morteza Mohamad , Abbasy Saeed
Published: December 2011

Chattering elimination of machining processes is an important issue in turning operation, due to the damages caused by this phenomenon. Limited productivity rate, decrease in tool life, poor surface quality and noisy workplace are some adverse effects of the chatter vibration. In this paper two control strategies are developed to suppress chatter vibration in turning process including a worn tool. A single degree of freedom model of the turning process including tool wear is briefly described. In the first stage, sliding mode approach used to control the system, and in the second stage fuzzy sliding mode approach is used. The simulation results indicate that the fuzzy sliding mode performs better than the direct sliding mode controller.
The Modeling Study of Active Power Filter Based on Adaptive Notch Filter
Authors: Zheng Min Ying , Yu Wan Neng , Xu Yi Qun
Published: December 2011

Aiming at small power grid’s influencing on the frequency stabilization of the power grid when load’s large change, the basic development present situation and work principle of active power filter are analyzed at first. Then combining active filter’s control strategy based on instantaneous reactive power and hysteresis current, the active filter simulation model about grid frequency’s change is established according to studying the method of using adaptive notch filter to measure power frequency. Finally, the simulation results prove that the active power filter model could track the changing frequency quickly and compensate harmonic current accurately, and enhance power quality and reliability of the small power grid.
Interval Granules in Incomplete Information Systems
Authors: Chen Xiao Hui , Li Ren Pu , Zhang Zhi Wang
Published: December 2011

Rough set theory is an efficient mathematical theory for data reduction and knowledge discovery of various fields. However, classical rough set theory is not applicable for knowledge induction of incomplete information systems. In this paper, a concept of interval granule is presented. Based on this concept, the hierachical structure of knowledge granularity and approximation of rough sets in incomplete information systems are studied, and related properties are given. An example show that the interval granule have better results than existing models for knowledge induction and approximation.
Study on Refining Technology of Low-Sulfur Steel
Authors: Zhang Min , Zeng Jian Hua
Published: December 2011

In order to bring on the producing of low & ultra-low sulfur steel and optimal control of refining slag composition and property converter tapping, slag oxidability and oxygen activity have been analyzed. In addition, optimal refining slag composition and adding process, adding system of modifying agent and bottom argon-blowing in ladle were researched as well. On this basis, refining process of low-sulfur steel has been optimized. The results show that sulfur content in steel is as low as 6.6×10-6~40×10-6，which achieved the production of low sulfur steel.
Research on Boom-Type Roadheader Vibration Testing Based on the LabVIEW
Authors: Zhao Li Juan , Lv Xiu Mei , Tong Wei
Published: December 2011

This develops the roadheader vibration characteristics test system according to the structural characteristics and working principle of the cantilevered roadheader. Using the piezoelectric acceleration sensor detects vibration signal, and passing by signal processing and A/D conversion， vibration signals are sent to the PC with wireless transmission mode, vibration signals detected by the LabVIEW is realized real-time data acquisition, time-frequency analysis and digital processing. Based on this system testing results can effectively master roadheader operation state, identify the vibration characteristics, look for vibration source and put forward reasonable damping vibration measure, which provide the basis for roadheader in the best running condition. The development of roadheader vibration detection system uses the method that combines theory and simulation experiment , which realizes the real-time detection of roadheader vibration behavior, rational signal analysis of roadheader vibration and accurate processing of data results, it provides an important method to ensure the reliability of roadheader.
Impact of JIT and TQM Strategies on Searching for Health Information and Ensuring Service Quality in Hospitals
Authors: Kuo Tung Sheng , Lan Chun Hsiung , Chen Shu Hui , Lin Shih Hsien
Published: December 2011

This investigation analytically and empirically the effects of just-in-time (JIT) and total quality management (TQM ) strategies on searching for health information and the quality of hospital service, and analyzes the steps that are involved in knowledge management that are required to improve the quality of service in a hospital. The final section of this investigation proposes that effectively promoting total quality management activities requires managers to evaluate, and to improve the convenience of systems for searching health information. The results also indicate that the JIT strategy is directly positively related to the effectiveness of searches for health information and the quality of service at a hospital, and that a positive relationship exists between the TQM strategy, searching for information and quality of service in all instances.
Ergonomic Analysis of the Master of Minimally Invasive Surgical Robot
Authors: Zhang Qing Bo , Zhao Chen , Luo Xiao Ming
Published: December 2011

How to well design the master console is one of the key techniques of master-slave surgical robot system. Related to the slave arms, to the surgeon and to the other components of the console the two master arms need to satisfy all requirements of different aspect. In this paper the ergonomic problem is treated. Operated by the surgeon the master arm should be placed in a suitable position. In addition, it should also have good back-drivability. Some analyses and rationales are made to solve these problems.
A Combined Modeling Method Based on Multiple-Sensor Integrated Measuring System for Reverse Engineering
Authors: Liu Peng Xin , Liu Xuan , Li Min
Published: December 2011

In this paper a combined modeling method using digitized points measured by multiple-sensor integrated measuring system with a touch probe and a optical scanning probe is presented. The optical scanning data in the form of triangulated mesh and the high precision data captured by a touch probe on an integrated measuring system are transformed into a common coordinate system by the worktable for registration and improved ICP algorithm. A data merging method is used to keep the high precision of feature surfaces.The merging data is unified into a precise 3D model in CAD software environment based on the strategy for optimization reconstruction. Experimental results demonstrate the efficiency of the proposed method, which enhances the flexibility of digitizing while maintaining the accuracy of feature surfaces.
Simulation on Anode Electric Field Intensity about Electrochemical Jet Machining
Authors: Zhang Cheng Guang , Zhang Fei Hu , Zhang Cheng Guang
Published: December 2011

The theory of electrochemical jet machining was introduced, and effect of different parameters on anodic electric field intensity is finite element analyzed by ANSYS software. The Simulation results show that, the electric field shares the same distribution under different electrolysis voltage, which generally contains three parts, uniform distribution area, gradually weakened area, scattered area. In the uniform distribution area, electric field shows comparative uniformity. The anode electric field generated by different jet distance is also obvious distribution areas, the electric field intensity shows decreasing trend. Electric field intensity is found to have a close relationship with electro jet nozzle diameter, in which a faster jet velocity would bring more concentrated distribution of the electric field as well as a smaller size of electric field.
Potential of Energy Saving and Technical Measures in Sintering in China
Authors: Yin Xiu Fu , Hao Su Ju , Jiang Wu Feng , Zhang Yu Zhu
Published: December 2011

Compared to Japan sintering process, there is a large potential in energy saving in China. In order to reduce the sintering energy consumption, some effective measures such as reducing the solid fuel consumption, the gas consumption and the electricity consumption should be taken, meanwhile new characteristic technology of energy saving should be developed. Recycling the secondary energy is the other way of energy saving for sustainable development. And most especially, waste heat recovery has a great significance for saving energy.
Influencing Factors on Dynamic Response of Hydrostatic Guideways
Authors: Wang Zhi Wei , Zhao Wan Hua , Lu Bing Heng
Published: December 2011

Stiffness and damping of hydrostatic guideways are calculated by small perturbation method based on Reynolds equation in dynamic regime. The hydrostatic guideway is considered as a system which consists of the mass, the spring and the damper. The effects of some main parameters on stiffness, damping and damping ratio are analyzed which include the supply pressure, the film thickness, the pad dimension, the pressure ratio, the lubricating oil volume and the lubricating oil viscosity. The relationships between the settling time of the hydrostatic guideways and these parameters are investigated under a step load. It is shown that the slide block returns to equilibrium without overshooting under a step load, and the amplitude of the block vibration has not a maximum value under a cyclic load, due to the large damping effect( ξ>1). In addition, the settling time can be shorten with the increase of the supply pressure, the film thickness and the lubricating oil volume, and also with the decrease of the pressure ratio and the lubricating oil viscosity. The settling time get the shortest value when recess parameter( α) is 0.55.
Coupling Control and Analytical Model of the Shaker on a Centrifuge
Authors: Wang Yong Zhi , Yuan Xiao Ming , Sun Rui
Published: December 2011

With the unique function of simulating a combined environment of high static fields and shaking load, centrifugal shakers can provide an effective and advanced testing method to dynamic characteristics and failure mechanism of reduced scale structure models and materials. Their construction has begun both at home and abroad, whereas waveform distortion and instability often happen to the perfect shakers after installed on a centrifuge in the process of their construction. The knowledge about this phenomenon is difficult to find and systems theory is absolutely blank. Practically the construction of centrifugal shakers is still in an exploratory stage. This paper analyses coupling control of shakers on a centrifuge in three aspects of installation method, bucket deformation and arm deformation. Simultaneously corresponding analytical models is also established, aim to guide theory study and equipment design.