bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Writing Micro/Nano Structures on PZT Wafer by Laser Micromaching
Authors: Li Yi Gui , Liu Jing Quan , Yang Chun Sheng , He Dan Nong , Tanaka Katsuhiko , Sugiyama Susumu
Published: July 2011

The PZT is used for piezoelectric actuators that have high area efﬁciency but no good machinability. A direct writing micro structures on PZT wafer by excimer laser micromaching method has been proposed and confirmed. PZT nano-needle structures have also been fabricated by the direct writing method only by changing the laser micromachiong process parameters. The fabricated nano-needle structures can be very useful because of the need for studies on ferroelectric size effects as well as for potential applications such as ultra-high density memory devices.The relationship of process depth with the excimer laser parameters has been tested.
Influence of Re-Melting Technology on Properties and Microstructures of Ferrous Matrix Composites Reinforced with Tungsten Carbide Particle
Authors: Song Yan Pei , Wang Hui Gai , Feng Zhi Ming , Zhao Zhen Kai
Published: July 2011

The scrap WCP/Fe-C composites were re-melted in a 50 kg medium frequency induction furnace. A regenerated composites ring was manufactured by centrifugal casting process. The microstructure and properties of the composites before and after re-melting were investigated by SEM with energy dispersive spectroscopy and X-ray diffraction. The results showed that the microstructure of the composites after re-melting was composed of un-dissolved WCP, bainite, bone-like crystallites and graphite. The un-dissolved WCPwere uniformly distributed in the outer region of the regenerated composites ring, their volume fraction attained to about 65 vol. %, and size of the un-dissolved WCPwas obviously smaller than that of the WCPbefore re-melting. The impact toughness of the regenerated composites was below those of the composites before re-melting, the hardness and wear resistance of the regenerated composites were almost same as those of the composites before re-melting under the same test conditions.
Development of Porous Scaffolds Using Selective Laser Sintering of Polylactic Acid/ Hydroxyapatite for Bone Tissur Engineering
Authors: Zhang Qiang , Liu Fu Rong , Chen Ji Min
Published: July 2011

In this paper the research focused on the viability of using the selective laser sintering (SLS) technique for creating tissue engineer (TE) scaffolds. A biocomposite blend comprising polylactic acid (PLA) and hydroxyapatite (HA) was used in the research to study the feasibility of the blend to develop scaffolds. The biocomposite blends obtained via physical blending were subjected to laser sintering to fabricate test specimens. The test specimens were characterized using scanning electron microscopy (SEM) and the components before sintering and after sintering were analyzed by infrared spectrophotometry (IR). The results obtained ascertained that SLS-fabricated scaffolds have good potential for TE applications
Study on Thermal Fatigue Resistance of Non-Smooth Cast Iron Treated by Laser Surface Alloying of CrNi Powders
Authors: Xin Tong , Hong Zhou , Min Liu
Published: July 2011

The past studies indicated that thermal fatigue resistance of cast irons could be improved by partly laser melting treatment. However the only disadvantage of this technology is that the enhancement of thermal fatigue resistance would be limited because of the fixed chemical composition of sample matrix. For this purpose, the laser surface alloying of CrNi was selected for changing both the compositions and the microstructures of laser treated zone, and the effects of alloy powder compositions on thermal fatigue behavior were also investigated in this paper. The results indicate that the alloy elements distribute homogeneously, and their contents increase markedly in the non-smooth unit on the alloyed layer. The non-smooth unit is strengthened further compared with laser melting treatment. Thermal fatigue resistance of cast iron is enhanced evidently by laser surface alloying of CrNi powders, and for all samples tested, those treated with 25%Cr-75%Ni powders have the best thermal fatigue resistance.
Tribological Testing Method between Knitted Fabric and Skin in Wet States
Authors: Wang Xu , Wang Fu Mei
Published: July 2011

In order to measure the friction force between skin and varied wet knitted fabrics, it was proposed that the complete wetting fabrics could be hung on the line for different time to get the testing fabrics with different water content (wet state). The relative hanging time was innovatively used to characterize the water content in the knitted fabric. Then the friction curves between knitted fabrics and skin could be measured on the new lab developed fabric-skin friction tester in 6 different wet states. It was found that there were other three kinds of friction-sliding displacement curves except normal friction curve. According to the characteristic of various friction curves, 4 kinds of friction indexes were added to characterize the friction properties between knitted fabric and skin in different wet state.
The Effect of Rail Material on Wear Behavior of Wheel and Rail
Authors: Jiang Wen Juan , Zhang Xiang Long , Zhong Wen , Liu Qi Yue
Published: July 2011

This study investigates the effect of rail material on their wear behavior of rail-wheel system by using MMS-2A twin-disc abrasion tester. When one type of wheel matches with different types of steel rail, the worn lose of the steel rail decreases with the increasing hardness, and the abrade wear of wheel increases. The trend showed by the SEM micrograph of the wear scar was consistent with the results of the worn lose.
Inhibition Behaviour of a Mixed Additive upon Zinc Electrowinning from Sulphate Solutions Containing Germanium
Authors: Liu Chun Xia , Shen Qing Feng , Xiong Min , Shan Yun , He Su Fang , He Yu Ping
Published: July 2011

A detailed investigation has been carried out to determine the inhibition behavior of a mixed additive gelatin+thiourea+cresol (GTC) on zinc electrowinning from sulphate solutions containing germanium. The results indicate that zinc redissolution is inhibited because of germanium in existence, current efficiency is increased and surface morphology of cathode zinc is improved using proper GTC in the electrolyte. Cathode polarization curves were traced and analyzed to indicate that additive GTC may inhibit the depolarization and stimulating hydrogen evolution effects of germanium on zinc deposition.
House Renovations and Extensions in Malaysia: An Investigation of Mechanical Changes and Modification of House in Klang Valey, Malaysia
Authors: Jamel Muhammad Afiq , Utaberta Nangkula
Published: July 2011

House, is a valuable asset in human’s life and is one critical and important setting in developing lives of human being. Therefore, as time goes by, people develop and wanting to improve the state and quality of their house so that they can live their lives towards better meaning parallel to their up growth. But, easy said than done, renovation is some work that needs thinking about. In fact, most of houses which are dwelled by modern Malay people in Malaysia nowadays did not evolve in synchronize to the Malay people’s needs. We could see lots of houses being renovated or extended by owners after the houses get dwelled in especially of those terrace housing in Malaysia. The renovations scenario upon these terrace houses is indeed one of the serious housing issues and problems in Malaysia. This writing thus will focus its investigation towards the phenomena of renovations upon selected double-storey terrace housing within Klang Valley, Malaysia. Investigations will be carried out by questionnaires, statistic analysis of findings from site visits, and interviews with the owners of the houses. Among those things that will be investigated are about the type of renovations that have been done and the factors which influence the act of renovating. Results show that the type of renovations varies, be it on a major or minor scale. Those renovations of houses involving numerous parts or sections of houses such as the kitchen, rooms, bathrooms, and so forth and were done because of many different factors or reasons.
Simulation of Inclusions Removal Influenced by Snorkel and Blowing Parameters in RH Refining
Authors: Ai Xin Gang , Li Sheng Li , Wang Ning , Lv Nan
Published: July 2011

In this paper the influence of snorkel length and snorkel inner diameter and lifting gas flow rate on inclusion removal rate are discussed. It is found that inclusion removal rate varies greatly with snorkel length and snorkel inner diameter. Prolonging the snorkel length is benefited for inclusions removal in RH and inclusion remove time is enhanced, but inclusion remove rate is decreased when snorkel inner diameter is reduced. There is a best lifting gas flow rate for inclusion removal.
The Modal Analysis of Roller Chain Drives
Authors: Li Bao Lin , Fan Shuai , Zhang Yan
Published: July 2011

Aiming at calculating the natural frequency of roller chain drives, the software Catia was used for modeling the roller chain drives accurately and Ansys Workbench was applied to analyze the modal and harmonic response of the tension side chains, comparing the natural frequency and the theoretical calculation results of simplified model. The results showed that the deviation increased with the increase of the order of natural frequency and modal numerical simulation provides certain reference for engineering application.
Review and Prospect on Dynamic FE Model Updating Methods of Footbridge Structures Based on Ambient Excitation
Authors: Zhao Rui , Zhang Yi Gang
Published: July 2011

The discrete finite element (FE) model often cannot reflect structure characteristics accurately due to imply more idealistic assumptions and simplifications. Therefore, it is necessary to update FE model for structural damage identification, response calculation, safety evaluation, optimization design, and so on. This article will illustrate respectively three key steps of updating parameters selection, target function selection and optimization method in process of dynamic FE model updating of footbridge structures based on ambient excitation, and put forward a feasible updating method: combine empirical method with sensitivity analysis method to select updating parameters; joint natural frequencies, MAC and modal flexibility as target function; adopt optimization algorithm based on the optimization theory.
Non-Linear Finite Element Analysis of Contact-Impact between Drill String and Wellbore under Air Drilling
Authors: Yu Ben Fu , Yan Xiang Zhen , Yang Xiu Juan , Li Gen Sheng
Published: July 2011

The dynamic mechanics model was built up to analyze the contact-impact between drill string and wellbore according to the characteristics of contact-impact, based on non-linear finite element method and Lagrange method. The dynamic mechanics equations were deduced by the dynamic mechanics model. The stress and deformation field of drill string with different parameters of bottom hole were obtained and tested by experiments and numerical simulation respectively. And also, the propagation laws of stress wave generated by contact-impact in drill pipe were studied. The comprehensive results indicate that the numerical results agree well with the actual dynamic process of contact-impact. The stress waves generated by contact-impact cause the change of stress. The contact-impact between drill string and wellbore under air drilling is the main reason for early drill string failure.
Dynamic Stiffness Identification of Bolted Joints
Authors: Guo Tie Neng , Song Bin , Guo Dong Liang , Chen Zhong Qing
Published: July 2011

The joint has a significant effect on the dynamic characteristic of the mechanism, and the identification of the stiffness of the joints has become a key problem. In this paper, a method is presented for identifying the dynamic characteristic of joints. An experiment is designed to test the dynamic parameter of the bolted joints specimen; the identification method, based on experiment, has a high accuracy result. By taking a specimen to experiment and identify the dynamic characteristic of joints, the relationship between the preload on the bolts and the joints stiffness is acquired. In order to validate the accuracy of the result, the FEM software is used to simulate. There are only a small discrepancy between the results of identification and simulation.
Surface Characteristics and Water Absorption of Sol-Gel Coated Impregnated Paper Pressed onto Plywood
Authors: Wang Shaoxia , Jämsä Saila , Mahlberg Riitta , Nikkola Juha , Mannila Juha , Ritschkoff Anne Christine , Peltonen Jouko
Published: July 2011

Two silane-based hybrid coatings were developed to modify the surface energy of phenolic resin impregnated paper. The coated paper samples were further pressed onto surfaces of plywood. The surface properties and water repellence of coated paper were investigated by AFM, XPS and water contact angle measurements. The water absorption of plywood with pressed paper was studied by water uptake tests. It was found that the sol-gel coatings had slightly improved the water repellence of the impregnated paper. The water absorption of plywood was also slightly decreased.
Optimization of Concrete Open-Loop Pumping Displacement Control Parameters under Variable Loads
Authors: Wang An Lin , Shi Zhong Qiu , Yuan Cai Xing , Hu Yu Qin , Jiang Tao , Zhang Qi
Published: July 2011

To solve the problem of piston striking cylinder and pumping insufficiency, an optimization method of concrete open-loop pumping displacement control is derived and presented. In order to control piston stroke effectively, the optimization model of concrete open-loop pumping displacement control parameters is built based on considering the system’s open-loop characteristics. Satisfying the physical constraint of preventing piston striking cylinder and maximizing piston’s effective stroke are taking as the evaluation criterion during the modeling process. Using this method, simulation and experimental research has been proceeded in a type of concrete pump. The result shows that concrete pumping piston can not only meet the noninterference physical constraint, but also increase the pumping efficiency significantly under variable loads. The optimization model provides a new method that can be used in engineering practice for solving the design problem of concrete pumping open-loop control system under variable loads.
Nonlinear Primary Vibration of Circular Sandwich Plates and Modal Analysis
Authors: Liu Xiao Man , Du Guo Jun , Hu Yu Da , Niu Xiao Xia
Published: July 2011

The nonlinear forced vibration of damped circular sandwich plates is studied. From the movement equations of circular sandwich plate expressed in displacement components, got the relevant nonlinear vibration equation by Galerkin method. The changing of initial deflection, stiffness and a harmonic force which can affect kinetic characteristic of configuration was researched. The FRF of primary resonance periodical solutions were obtained, synchronously modal analysis experiment for composite material plates were tested.
Enhancement of Acid Resistance for Ultramarine Blue by Silica Coatings
Authors: Liu Miao , Li Si Fang , Umereweneza Daniel
Published: July 2011

The acid resistance of ultramarine blue was greatly enhanced by silica coatings. Sodium metasilicate nonahydrate was used as silica precursor and ammonium chloride was used to react with it. Fourier transform infrared (FT-IR) spectroscopy was used to characterize surface structure on the coating layer. The effects of coating conditions on acid resistances of the coated ultramarine blue were investigated. The acid resistance was evaluated by immersing the pigment in 10 wt% hydrochloric acid. The results showed the optimal mass ratio of silicate to ultramarine was 3.75 and the proper solid content was 60 g/L. Under above conditions, the silica coated ultramarine blue exhibited an acid resistance of 8, while the uncoated ultramarine blue only showed an acid resistance of 1.
The Analysis on Circulating Fluidized Bed Boiler Heat Tube Failure
Authors: Zhao Bin , Li Jun Hao , Shen Jing Quan , Wang Guo Zhong
Published: July 2011

Boiler heat tube failure is a long-term technical problem plaguing the production of electricity. The research on how to prevent failure of boiler heat tubes has practical significance. In this paper, select the type of the Tangshan Dong fang power plant SG-490/13.8-M572 CFB boiler as the research object, part by pressure, failure type, and run-time statistics on the heat tubes failure of two boilers throught the collation and analysis on records, the basic rules of the failure are found out, statistics show that the water wall and super heater tubes explosion causes boiler shutdown time accounted for unplanned boiler shutdown time about 82%, small power generating capacity of about 11% of the total time. Finally, relevant technical strategies including improving maintenance quality and strengthening boilers regular inspection are proposed, the unplanned outage of units is radically reduced, and the safety and reliability of boiler operation is comprehensively improved.
Design of Vacuum System of Steam Jet Bursting Unit for Chestnut Shell
Authors: Dang Xi Nan , Chen Qiao Fu , Yang Li Jun
Published: July 2011

According to the vacuum bursting process for fresh chestnut shell and requirements for relevant vacuum system, a vacuum system of steam jet pump was designed with a start-up jet pump attached to it. Of which the waste gas from ejector was used for reheating in the bursting process to lead the vacuum bursting unit to run more reliably and stably with efficiency improved and energy consumption reduced. The rate of bursting came up to 95% in the process test.
Optimization of the Cooling Channels in a Journal Bearing Based on Thermohydrodynamic Analysis
Authors: Guo Jia , Huang Bin , Chen Zhi Lan , Wang Le Qin
Published: July 2011

According to the optimization problem of the cooling channels a conventional journal bearing, the thermohydrodynamic(THD) mathematical model of the journal bearing was set up and the numerical solution was done combined with ANSYS. Considering the effects of the internal cooling channels in the pad on controlling the working temperature effectively by convection, the narrow space in the pad was made full use to form network type internal cooling channels in the pad. The calculation model set up in this paper was then applied to the THD analysis of the original and the improved journal bearing models. The obtained results show that the working temperature of the pad is obviously improved by the internal cooling channels. And then the working temperature of the pad under different convective heat transfer coefficients were studied. It was found that the overall working temperature on the inside surface of the pad decline significantly with an average decline 2 ~ 3°C, as the convective heat transfer coefficient of the internal cooling channels is strengthened from 200W/m2·K to 500W/m2·K.
SABER-Based Simulation for Compact Dynamic Electro-Thermal Modeling Analysis of Power Electronic Devices
Authors: Chen Ming , Hu An , Tang Yong , Wang Bo
Published: July 2011

Power electronic modules including insulated gate bipolar transistor (IGBT) are widely used in the field of power converter application. The temperature distribution inside these modules becomes more important for electrical characteristics, reliability and lifetime of integrated power electronic modules. In this paper, a seven-layer compact RC thermal component network model based on the physical structure is presented. A dynamic electro-thermal model, which is composed of electrical model, compact RC thermal component network model and electro-thermal interface is developed for the IGBT. These models interact with each other to calculate the temperature of each layer of module and parameters of each model. The thermal model determines the evolution of the temperature distribution within the thermal network and thus determines the instantaneous junction temperature used by the electrical model. Such built dynamic electro-thermal simulation methodology is implemented in the Saber circuit simulator, and the simulation result is validated by the experimental study, which adopted with infrared thermal imaging camera. The built dynamic electro-thermal model could be helpful for the research on operation performance and heat sink design for such power electronic devices.
Relation between Concave Cone 3 Dimension Topography and Residual Stress in Thermal Barrier Coatings
Authors: Han Zhi Yong , Wang Huan
Published: July 2011

Considering the concave cone 3 dimension interface topography unit, the distribution of residual stress in thermal barrier coating was calculated using ABAQUS soft by finite element method. The calculating result shows that the residual stress is affected by interface topography unit obviously. Compressive stress exists in concave cone topography unit. Stress concentrates in boundary of topography unit and reaches maximal value at the lowest place of the topography. Compressive stress changes with the size of topography unit and the space between two topography units distinctly.
Study on Dynamic Minimum Thickness of Cut by Nanoscratch Testing
Authors: Zhang Hua Li , Kuai Ji Cai , Zhang Fei Hu
Published: July 2011

Nanoscratch tests showing clear ploughing behavior and stable chip formation was conducted to investigate the influence of friction coefficient on the minimum thickness of cut. A theoretical model accounting for the minimum thickness of cut is used to analyze the effects of the friction coefficient and force ratio. Results show that the minimum thickness of cut is strongly dependent on both friction coefficient and force ratio. Theoretical minimum thickness of cut can be obtained when adhesion friction plays a dominant role in the cutting process. Appropriate adjustments of processing parameters are hereby suggested to result in stable micro-machining process without ploughing, not only forming fine-thin continuous chip, but also achieving high surface quality. The role of friction coefficient on the minimum thickness of cut with δ (cutting depth/edge radius) is also discussed.
Research on Progress of Micro Processing Technology
Authors: Wang Yan Feng , Zhang Hui Xia
Published: July 2011

Miniaturization of all kinds of industrial product is a direction of development. Micro processing is the foundation of making the product miniaturization. This paper introduces the basic concept, technology level and main using ways of micro processing.
Marine Authigenic Deposits Mineral - New Fields for the Development of Rare Earth Resources
Authors: Zhang Ying , Liu Chang Shui , Gao Lian Feng , Zhang Zhen Guo , Zhang Peng
Published: July 2011

Rare earth metals are an important strategic resource. Due to scarce reserves, and large consumer demand, it is facing the crisis of resource depletion. Marine are the largest deposits sites in the world. In the long growth history, marine autogenic sedimentary mineral, such as polymetallic nodules, crusts with large quantities, not only contain the enrichment of Mn, Fe, Co, Cu, Ni and other valuable metals, but also contain extremely rare earth elements (REE) in the crust. Thus, in the process of developing marine mineral resources, Mn, Fe, Co, Cu, Ni and other metals are used, while it is possible for the development and utilization of the associated rare earth mineral. Marine may become a new field of rare earth resources development.
Ultra-Precision Shaping and Polishing Experiments in Nanoparticle Colloid Jet Machining
Authors: Song Xiao Zong , Zhang Yong , Zhang Fei Hu
Published: July 2011

In this paper, ultra-precision shaping and polishing experiments have been done to research the shaping and polishing characters of nanoparticle colloid jet machining. A high-purity quartz glass sample with aspheric surface profile was employed as workpiece and polished by nanoparticle colloid jet machining. We utilized surface profilometer to measure the surface profiles of workpiece before and after shaping by nanoparticle colloid jet machining. The measurement results indicate that the nanoparticle colloid jet machining has good shaping ability to satisfy the demands for surface shape correction in ultra-precision machining. Atomic force microscopy (AFM) was utilized to observe the surface microscopic morphological characteristics of the workpiece surface polished by nanoparticle colloid jet machining. The observation results show that the roughness of the workpiece surface has been reduced from 1.919 nm RMS to 0.784 nm RMS by nanoparticle colloid jet machining. Based on the atomic force microscopy observation results, power spectral density analyses have been done to evaluate the polishing performance of the nanoparticle colloid jet machining.
A Watershed’s Environmental-Economic Optimization and Management Framework Based on Environmental Carrying Capacity
Authors: Huang Kai , Tang Hai Ping , Guo Hong Li
Published: July 2011

This paper introduced the idea of environmental carrying capacity (ECC) to the planning of watershed’s environmental-economic optimization. And a case study in Lake Fuxianhu is utilized from year 2008 to 2028. The results are: based on the water environment carrying capacity of lakes, with the adjustment of industrial internal structure, distribution and development speed of three major industries, the water quality of the basin will be I class. This adjustment will not only keep a rapid development of economy, but also can make sure the improvement of Lake Fuxianhu Basin environment. Thus, the development of society and environment will be coordinated. The application of water environment carrying capacity of lakes to instruct the scale of social development is very significant to the sustainable development among economy, society and environment.
Electrochemical Behavior of Fe-Cr-Mo-C-B Amorphous Alloy Coating in HCl Solution
Authors: Chen Qing Jun , Hu Lin Li , Zhou Xian Liang , Hua Xiao Zhen
Published: July 2011

The corrosion behavior of Fe44Cr16Mo16C18B6amorphous alloy coating was studied by electrochemical polarization curves and electrochemical impedance spectroscopy (EIS) in different HCl concentration solution at room temperature. Experimental results show that the polarization curves of the coating present a wide passivation range under open circuit potential and icorrincrease from 1.049×10-5A/cm2to 1.487×10-5A/cm2with HCl solution from 0.5M to 2.0M. The EIS of coating are composed of high-frequency inductive loop and low-frequency capacitance arc, which is different from the EIS of other amorphous alloys, the Rt is up to 5789Ω·cm2in 2M HCl solution. The especial equivalent circuit model R(RL)(Q(R(QRW))) can better interpret the corrosion behavior of the amorphous alloy coating.
Study of Modification of High Temperature Melting Compound Steel Slag-Fly Ash
Authors: Long Yue , Shi Yan , Lei Yun Bo , Xing Hong Wei , Li Jie , Zhang Yu Zhu
Published: July 2011

Reconstruction of high temperature melting compound steel slag-fly ash can be effectively digest f-CaO in steel slag. The experimental result shows that the f-CaO contents in modified slag is greatly affected by fly ash addition(respectively 5%, 7%, 14%) when the temperature is 1580°C and constant temperature is 30min, the digestion rates are respectively 56.99%,63.69%,68.55%. Modified mineral content of the steel slag changes greatly, mainly reflects at enormous increase in magnetite, dicalcium silicate, tricalcium silicate, wustite and vitreous. By micro-structure analysis of several kinds of modified slag mineral, tricalcium silicate mainly shape for branch of tree, dicalcium silicate is in the form of a circular, wustite and vitreous mainly distribute in aggregation state. The above minerals can increase cementitious activity for modified slag becoming cement.
Study on Papermaking Processes Wastewater Treatment
Authors: Wang Sen , Li Xin Ping , Zhang An Long , Wang Zhao Rong
Published: July 2011

In this paper, Cost-effectiveness of various straw pulp wastewater treatment technologies were compared in detail, moreover the separate and combined process of Coagulation Sedimentation, Anaerobic Baffled Reactor, Sequencing Batch Reactor and Biological Aerated Filter processes were researched. The test result has showed that when addition dosage of PAM and PAC is 4mg/L and 80mg/L in Coagulation Sedimentation separately, and ABR HRT is 10h, the biodegradability of the straw wastewater increased from 0.25 after pretreatment to about 0.45. As the best SBR HRT is 8h, the CODcr removal rate was about 62%, the BOD5 removal rate was 70.7% averagely, and the treatment effectiveness is steady correspondingly. But in combined process, the CODcr removal rate of SBR unit is significantly increased to 78%, the CODcr removal rate of whole system is higher than 90%. Finally, the BAF has been applied to the advanced treatment on outwater of two biological treatment. The experimental results show that there is a good efficiency on the advanced treatment of the using the method, the CODcr of outwater is 78 mg/L, the BOD5 is 28 mg/L, the chroma is 32 times, the SS is 38 mg/L, and the treated water not only meets the state's new discharge standards (GB3544-2008), but also satisfies the requirements of reuse water, and the cost of whole treatment is only RMB 1.80 yuan / m3 wastewater.
Study on Parameter Optimize of High-Speed Mobile and Matlab Simulate
Authors: Li Kong Zhao , Zhang Cheng Hong , Zhang Cheng Guang
Published: July 2011

Parameters optimization design of high-speed moving object is a very complex question. It involves many other subjects both in theoretical research and engineering application. Therefore, it is very significant to research on motion parameter optimization design of high-speed moving object. Firstly, in the known initial moment, the entering depth of moving object is; the initial velocity is; the length of moving object is L; the angle into the water is; and the average relative density of object is. It researches on the optimization of the best slenderness ratio, cavitation number and cavitator radius of high-speed objects. And then it specifically deduces the best motion displacement under the known initial momentum. Finally, it takes computer simulation and imitation to all optimized parameters and gives specific numerical examples by applying MATLAB, which provides theoretical basis for actual experiments.
The Influence of Cutting Conditions on Friction and Wear Properties of PEEK, CF/PEEK and GF/PEEK Composites Using PCD Tools
Authors: Wang Wen Xia
Published: July 2011

The present study establishes the relationships between the cutting conditions (cutting speed and feed rate) on trbological properties. Three types of PEEK composites such as unreinforced PEEK, reinforced PEEK with 20% of carbon fibres and 20% of glass fibres were used for the tribological tests. The parametric analysis reveals that, wear increases with increase in feed rate and cutting velocity while the friction coefficient decreases for all the materials tested. The investigation illustrates that the addition of reinforcements to PEEK improve the tribological properties relation with the cutting conditions.
Hull Design and Structural Analysis of an Underwater Robotic Vehicle
Authors: Negahdaripour Shahriar , Bae Jinho , Kim Yun Hae , Kim Joon Young
Published: July 2011

This paper describes the hull design, structural analysis and dynamic performance analysis of an Underwater Robotic Vehicle (URV). The dynamic performance analysis was made with the help of computer simulations. The main purpose of this URV is to carry out fundamental tests on its station keeping ability, attitude control, and position tracking accuracy. Its configuration is similar in appearance to a general open frame ROV for underwater works. The octagonal frame was designed to sustain obstacle collision and the material, stainless steel 316L, was chosen to maximize the resistance to corrosion in seawater. The navigation of the vehicle is controlled by an on-board computer and underwater sensors. This gives us an ideal platform to develop various algorithms needed for the further development of URV technology.
Optimization of Underwater Cavity's Shape
Authors: Zhang De Xin , Shao Xue Bo , Lou Li , Liu Lei
Published: July 2011

The steady bubble shape as one of the basic research, plays a decisive role in the cavitation’s study, To study it clearly will be not only basis for the study of non-steady cavitation, but also provide the necessary basis for the design of the control for cavitation bubble. In this paper, cavity shape produced by submerged body is studied, and related to the use of foreign experimental results, super-cavitation resistance, drag reduction is discussed.
Nonlinear Dynamic Behaviors of an Imbalance Rotor Supported on Fixed-Tilting Pad Journal Bearings
Authors: Qi Xiao Bing , Feng Lei , Zhang Yong Fang , Lu Yan Jun
Published: July 2011

Based on the unsteady Reynolds equation with Reynolds boundary, two-dimensional (2D) Reynolds equation is transformed into one-dimensional (1D) by taking the assumption of parabolic pressure distribution in axial direction in oil film field. Finite difference method was employed to solve 1D Reynolds equation, and the approximate pressure distribution was obtained in oil film field. Dynamic behaviors of a flexible rotor system with fixed-tilting pad journal bearings support were analyzed while the inertia of the pads was taken into consideration in the model. Imbalance responses of a symmetrical rotor-combination journal bearings (fixed-tilting pad journal bearings) system were investigated using Poincaré map and self-adaptive Runge-Kutta method. Numerical results reveal rich and complex nonlinear phenomena, such as periodic, quasi-periodic motion, etc.
Experimental Identification for Seals Rotordynamic Coefficients Based on Double Plane Balance Method
Authors: Cao Hao , Yang Jian Gang , Zhang Wan Fu , Guo Rui
Published: July 2011

This paper presents a new rotordynamic measurements conducted on a test rig for evaluation of multiple rings of labyrinth seals. Considering the tilting motion of cylinder occurs in experiments, the impedance matrix of cylinder system is obtained first. An equivalent seal force identification model is set up for multiple seals based on double plane balance theory of rotor dynamics. The resultant seal forces are calculated on two end planes of the cylinder, and resolved to multiple sections that seals located. A frequency domain identification method delivers the test seals stiffness and damping coefficients. Compressed air inlet tests were run from 1000 rpm-2200rpm, 0.1-0.6Mpa supply pressures were used. For each ΔP test condition, the static eccentricity ratio ε=e/Cr is range from zero to approximately 0.6. Results show that 8 rotordynamic coefficients increase almost linearly with inlet/outlet pressure ratio. Increasing eccentricity ratio weakens the stability of seal-rotor system obviously.
Microstructure and Wear Properties of Fe-Based Alloy Hardfacing Layers
Authors: Zong Lin , Liu Zheng Jun
Published: July 2011

The in-situ M7C3–TiC carbides reinforced Fe-based hardfacing coating had been produced by prepared high-carbon ferrochromium, ferrotitanium and graphite power on 20g steel through GTAW. The microstructure and hard phases morphology were investigated by means of OP, SEM and XRD. The results showed that the microstructure of hardfacing coating consists of lamellar martensite, TiC particles and M7C3complex carbides. The TiC particles with flower-like shape and M7C3complex carbides with hexagonal shape are observed in the coating. The hardfacing coating reinforced by M7C3–TiC carbides revealed higher wear resistance than that of the substrate due to the presence of a high volume fraction of hard and wear-resistance primary M7C3carbide uniformly distributed in the fine and strong [M+M7C3+TiC] eutectics matrix.
Experimental Research of Characteristics of Fluid-Induced Force in Eccentric Seal
Authors: Zhang Wan Fu , Yang Jian Gang , Cao Hao , Guo Rui , Sun Dan
Published: July 2011

This paper sets up a dynamic analysis model for cylinder-seal system. A new identification method for fluid-induced force and stiffness coefficients in eccentric seal is presented. The study shows that the system stability decreases with increasing cross-coupled stiffness in a certain range. Beyond this range, the system will be destabilized. Influences of rotating speed, inlet pressure, eccentricity and clearance on fluid-induced force were tested in the rig. It was found that a large tangential fluid-induced force was produced in the direction perpendicular to the eccentric displacement of rotor. The difference between the tangential and radial fluid-induced force became larger and larger with the increasing rotating speeds. Under the action of the seal force, the logarithmic decrement descended with increasing rotating speeds, and the stability of the system decreased. These effects became more and more serious for higher inlet pressure and tighter clearance.
The Research of Civil Structural Damage Identification Based on Lifting Wavelet Entropy Index
Authors: Sun Zeng Shou , Fan Ke Ju , Yin Xu Guang , Han Peng Jie
Published: July 2011

The failure of civil engineering structure will lead to heavy losses. So, identifying structural damage is necessary as early as possible. The excellent localization performance of lifting wavelet transform will facilitate significantly damage diagnosis. On the base of wavelet energy distribution of structural acceleration response, taking advantage of characteristics of lifting wavelet and entropy, the structural damage identification method based on lifting wavelet entropy is proposed in this paper. And the lifting wavelet time entropy index and the relative lifting wavelet entropy index are established. The new method and damage indexes are verified in numerical simulation and laboratory test of simple beam. The analysis results show that lifting wavelet time entropy can identify structural damage moment and the relative lifting wavelet entropy can identify structural damage location. The feasibility of method proposed is instructed.
The Testing and Improving of Acoustic Performance on Muffler
Authors: Hu Guo You , Xia Pin Qi , Lu Wen Feng
Published: July 2011

The main sound source of motorcycle noise is engine exhaust noise in the paper. Installing muffler can effectively reduce the exhaust noise, in the other word, if the acoustic performance of muffler can be improved, exhaust noise of engine will effectively be suppressed. Based on the FEM, establishing the acoustic simulation model, the performance of muffler relates to acoustic is studied. Based on muffling theory, the optimal projects of the interior structure for muffler are proposed. Through doing experiments of insertion loss for muffler and the pass-by noise for motorcycle, these confirmed that the improved muffler can reduce the motorcycle’s noise.
A Study on Relevance between Distortion of Distributed Mode Loudspeaker and Characteristic of Sound Panel
Authors: Luo Liang Jin
Published: July 2011

From flat-plate flexural vibration and radiated sound power discussed the inherent relationship between panel vibration frequency of distributed mode loudspeaker and geometric parameters, impedance matrix of soundboard and studied the relationship between soundboard structure of polyester foam sandwich panel and distortion of loudspeaker. Experimental results showed that distortion increases as the cell size and compress modulus, cell ratio, cell open ratio and thickness increases, but the sound sensitivity decreases as the compress modulus increases.
Hybrid Multi-Mode Input Shaping Suppresses the Vibration of a 3-DOF Parallel Manipulator
Authors: Li Bing , Wei Yu Lan , Zhu Shou Xin , Zheng Yu Qing
Published: July 2011

The methodologies and application of hybrid multi-mode positive impulses input shaping of a 3-DOF flexible parallel manipulator in this paper. First, the structural system and the dynamic equations are expressed for a 3-DOF manipulator. Second, the hybrid multi-mode positive impulses input shaping is introduced to reduce the residual vibration of the multi-mode system or to decrease the time-delay of the system response at the same time. The theory of the hybrid multi-mode positive impulses input shapers are presented, and the hybrid two-mode positive impulses input shapers of a 3-DOF manipulator are established and compared with the classic multi-mode positive impulses input shapers. Finally, the numerical simulations are made, and the robust of the input shapers are presented and compared.
Reliability Assessment of a Certain Diesel Engine with Multi-Parameter Degradation Based on SVDD
Authors: Cong Hua , Wu Guang Ping , Feng Fu Zhou
Published: July 2011

Reliability of equipment has long been considered as an important quality characteristic. But the reliability assessment of multi-parameter system still remains a problem. Based on the multi-parameter degradation process of a certain diesel engine, the article proposes a reliability assessing method for multi-parameter degradation system. The method uses SVDD to convert multi-parameter into one single degradation measure which reveals the overall system degradation. Using degradation measure distribution, a reliability assessment model is built. Through experiments on vehicle, the method shows the degradation regular of vehicle diesel engine, builds the reliability curve, provides evidences for equipment maintenance.
Analysis of Latest Application Movement of Laser Surface Heat Treatment Technologies
Authors: Lin Guo Min , Peng Li Xia , Zhao Yu Feng
Published: July 2011

The application of two representative laser surface treatments technologies which are laser shock processing technology and laser coating treatment technology are described. The application of laser shock processing in the fields of aero engine disc, wing panel formation, structural welding and strengthening, nuclear power station pressure container strengthening etc and also evaluates the effects are analyzed. The applications of laser coating treatment in the field of aeronautic manufacturing are analyzed in detail. The development direction of laser shock processing and laser coating treatment are indicated finally.
Design Improvement through Reliability Analysis of Belt-Type CVT Systems for Scooters
Authors: You Jang Shyong , Wu Wen Fang
Published: July 2011

The purpose of the present study is to carry out failure analysis of a scooter’s continuously variable transmission (CVT) system that is considered to be one of the key components of the scooter. In the study, several reliability analytical tools such as failure mode, effect and criticality analysis (FMECA) and fault tree analysis (FTA) are used to identify possible failure modes of the CVT system and its subsystems. The failure effects of components on the CVT system are emphasized in particular. Aside from the qualitative evaluation, simulation algorithms are developed to examine the performance of the CVT system and assess the reliability of the belt. Through the study, it is found that mechanical wear at both sides of the V-belt is the most serious problem that affects the CVT performance. The sliding collar of the driven pulley is another component that has to be observed carefully. Some design improvements are pointed out at the end of the paper.
A Research of Parting Design Frame of Telecontrolled Boat Hull by UG on Case-Based Reasoning
Authors: Ren Yun Dan , Wang Xiang , Rui Xiao Guang
Published: July 2011

Parting design, a classic work of strong experience and weak theory, has a direct impact on mold structure design and tooling. The method on the basis of case-based reasoning called CBR is one of the effective methods to solve problems of strong experience and weak theory. This paper proposes a frame of mold parting design of boat hull by UG on case-based reasoning, aimed at parting problems of telecontrolled boat hull.
Parametric Design of Roller Oscillating Follower Disc Cam on UG
Authors: Ye Hai Jian , Zhang Ya
Published: July 2011

The paper use UG to make parametric designs of the contour of the cam, which has the advantages of high precision, better design of using parameter and simpler process. In this article, the parametric design of roller oscillating follower disc cam is taken as an example to introduce the process, getting the equation of cam contour with the help of "reversal method”, making sure of the mathematical relationship between the angle of the pendulum swing and the cam angle in terms of the constant acceleration and constant deceleration motion law. Construct the formula expression of each part for the cam profile, then get theoretical profile curve according to UG formula, and finally form the actual cam profile curve through using command of offset curve. In addition, a new cam can be made by simply changing the design parameters.
Optimization of Cooling System of Linac Collinear Load
Authors: Xu Gui Xiang , Shen Lian Guan , Shu Zhao , Sun Yuan , Pei Yuan Ji
Published: July 2011

Collinear load, coating with microwave-absorbing material, determined to linear accelerator (LINAC) to absorb the remnant power. It forms a part of actual accelerating structure and substitutes for traditional waveguide-type load to make the accelerating structure compacter and size smaller. In order to guarantee operational reliability, it is necessary to keep the operation frequency of cavities of the collinear load at 2856MHz and at a small shift. An approach utilized to accurately evaluate the frequency change caused by non-uniform thermal deformation is presented and a strategy for optimizing its cooling system is also described simultaneously. A six-cavity collinear load, coated with FeSiAl alloy, is researched. The results show that the frequency shift of cavities of the collinear load can be controlled within -56~35kHz, when it runs on 2856MHz and 2π/3 mode and the structure of its cooling system becomes much more compact and economic.
Boundary Conditions for Numerical Simulation of Diesel Water Jacket
Authors: Xin Zhe , Wang Shun Xi , Zhang Ke Peng , Li Zhao Jing , Yun Feng
Published: July 2011

In the research of flow and heat transfer of the diesel engine cooling system, the boundary condition determination was often a difficult problem. The paper calculated the flow velocity and convective heat transfer coefficient respectively for a six-cylinder diesel engine under different boundary conditions which including the water jacket wall as adiabatic condition, average temperature condition, and the boundary conditions from the solid-fluid coupling calculating. And the calculated values of the jacket wall temperatures were compared with that of test. The results showed that the simulation with solid-fluid coupling boundary conditions had better precision. Based on the research, an improved structure design was conducted for the six-cylinder diesel engine, the results of simulation showed that the average flow speed at the internal surface of water jacket could reach up to 0.5m/s, the flow symmetry in each jacket got improved, and the convective heat transfer coefficient could reach more than 2000 W/m2·K. The improved cooling system can meet the design requirements.
Analysis of Morphology and Growth Kinetics of Zn-Mn and Zn-0.2wt.%Al-Mn Hot-Dip Galvanizing Coatings
Authors: Wang Jian Hua , Wu Zi Shi , Su Xu Ping , Wu Chang Jun , Liu Ya , Tu Hao
Published: July 2011

The influence of manganese in Zn-Mn and Zn-0.2wt.%Al-Mn bath on the morphology and growth kinetics of the galvanizing coatings has been studied using scanning electron microscopy equipped with energy dispersive spectroscopy. When galvanized in zinc bath, the coating consists mainly h and ζphase. When manganese is added in zinc bath, the morphology of ζ phase changes from fragmental to compact. Manganese favors the formation of the δ phase and inhibits the growth of the ζ phase.When galvanized in Zn-0.2wt.%Al bath, the coating consists only δ and h phase. With the addition of manganese in Zn-0.2wt.%Al bath, the morphology of δ phase changes from fragmental to compact The thickness of the Fe-Zn intermetallic phase layer in coatings decreases obviously when manganese is added into zinc and Zn-0.2wt.%Al bath, and the thickness increases slowly with the increase of immersion time.