bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Integration Control of Air Suspension and ABS
Authors: Yan Shi Rong , Lu Song Jun
Published: October 2010

In order to get good car rideability, the electronic air suspensions(EAS) are now used in some advanced automotives. Although ABS systems are used in automotives for a long time, in some limit cases such as cornering at high speeds, cars may be still in great dangerous states. It is considered that if electronic air suspensions(EAS) can be adjusted with ABS during some extreme conditions, the cars may become safer. To investigate this possibility and then find out a specific control scheme, some research work is done in the paper. The research work begins from the dynamic analysis for cars with EAS and ABS both, and then based on it an integration control scheme for EAS and ABS is put forward. By means of Matlab/Simulink simulation study, it is found that the braking performances such as braking distance, braking deceleration, and the car vertical acceleration are improved obviously with the integration control technique for both of EAS and ABS during high speed cornering. Therefore the integration control method developed here can work well and improve the car performances obviously.
Feasibility Study on Active Control of Hydraulic Electromagnetic Energy-Regenerative Absorber
Authors: Xu Lin , Guo Xue Xun , Yan Jun
Published: October 2010

This paper proposes a design of a new shock absorber with combined mechanical- electromagnetic- hydraulic structure, and expounds its working principles. This new type of absorber can recyle the vibration energy and transform it into electrical energy for use. However, in its working process, the damping force in extension stroke is always smaller than that in compression stroke, which is determined by the inner structure, while in traditional absorbers, it is just the opposite. This does not meet the practical demands. Directing at this problem, the paper puts out a way to make real-time adjustment to the damping force by controlling the generator load, and tests the feasibility with a simulation model built with AMESim. The test result reveals that the method is feasible. This contributes a lot to the future further research on active control.
Evaluation of Energy-Regenerative Suspension Structure Based on Fuzzy Comprehensive Judgment (FCJ)
Authors: Xu Lin , Guo Xue Xun , Liu Jian
Published: October 2010

Energy regenerative suspension can transform the shock energy produced in the driving process into electrical or hydraulic energy. This paper proposes a new hydraulic electromagnetic energy regenerative suspension design, and makes a comparison with the other two energy regenerative suspension designs by studying their structures and working principles, and makes an evaluation system by using fuzzy comprehensive judgment. According to the importance of the evaluating indexes, their subjective weights are gotten by using analytical hierarchy process (AHP); according to the performance statistics data, their objective weights are gotten by using entropy method; the general weights can be gotten from the subjective and the objective ones; and the evaluating value of suspension comprehensive performance can be calculated according to the general weights and the performance statistics data of evaluating indexes. The result reveals that the hydraulic electromagnetic energy regenerative suspension design has obvious advantages and is the most feasible design.
Prediction of Flow Stress of Stainless Steel 0Cr13Mn by RBF Neural Network
Authors: Fan Bai Lin , Meng Ling Qi , Li Zhong Fu
Published: October 2010

The flow stress of hot deformation about 0Cr13Mn stainless steel was experimentally studied by A Gleeble1500 thermo-mechanical simulator. The effects of deformed temperature, strain rate and strain to flow stress were analyzed. The prediction of RBF neural network with correlation between the flow stress and the chemical composition, deformed temperature, strain rate and strain, etc was established. Simulation data of the flow stress by RBF network with relationship between input and output for 0Cr13Mn stainless steel were stable. Accuracy of the prediction by RBF Neural network was higher than the regression precision by the multiple non-linear regression numerical models. Through a combination of the prediction by RBF neural network and numerical regression model of flow stress, the developing method of BPF neural network on-line calculation based on measured data of flow stress will be feasible under the condition of ensuring the accuracy of the premise.
Modeling and Simulation of Motorcycle Ride Comfort Based on Bump Road
Authors: Yuan Dong Mei , Zheng Xiao Mei , Yang Ying
Published: October 2010

Through analyzing the motion when motorcycle runs on the bump road, the 5-DOF multi-body dynamics model of motorcycle is developed, the degrees of freedom include vertical displacement of sprung mass, rotation of sprung mass, vertical displacement of driver, and vertical displacement of front and rear suspension under sprung mass. According to Lagrange Equation, the differential equations of motion and state-space formulation are derived. Then bump road is simulated by triangle bump, and input displacement is programmed by MATLAB. With the input of bump road, motorcycle ride comfort is simulated, and the simulation results are verified by experiment results combined with two channels tire-coupling road simulator. It indicates that the simulation results and experiment results match well; the 5-DOF model has guidance for development of motorcycle ride comfort.
Study on Impacting Characteristics of a Metro Vehicle
Authors: Zhang Suo Huai , Wan Ming Wei
Published: October 2010

In order to analyze impacting characteristics of a metro vehicle, the impacting governing Eq. is established, in which, nonlinear stiffness and damping of a buffer, friction force between rail and wheel of the vehicles is considered. In terms of testing results, nonlinear stiffness and damping of the buffers is simulated. By numerical simulation, it is found that when moving trainset impacts standing trainset, because the impacting force, stroke of buffers located in impacting interface is the maximum, the capacity of the buffers must be large enough to avoid rigid impact; when trainset with different number vehicles impacts each other, the maximum impacting force is not only different from each other, but the stroke and energy dissipation of the buffers is also different; the capacity of buffers far from impacting interface may be small.
Dynamic Study on Vehicle Hydro-Pneumatic Suspension
Authors: Geng Ling Xin , Zhang Li Juan , Wu Ren Zhi
Published: October 2010

The performance of HPS directly influences the comfort of vehicle, dynamic load of wheels and travel distance of suspension. In order to describe and evaluate the performance of HPS, the structure and working principle of main parts of the HPS are introduced and analyzed in this paper firstly. Then the physical model is founded by analyzing and simplifying the structure of HPS. According to the physical model, non-linear mathematical models of HPS with dual gas-accumulators are built up and a special program is composed. The results of computer simulation are carried out through the program. Then a testing rig for HPS is designed and manufactured after rebuilding cylinders and abundant experiments are performed on the testing rig. Comparisons are drawn between the results of simulation and testing, which manifest the mathematical model of HPS built in the thesis is feasible.
The Dynamics Simulation of Braking Process on Automobile Disc Brake
Authors: Fu Chuan Qi , Wang Zhou , Li Bin , Yu Chi
Published: October 2010

For a certain type of automobile disc brakes, brake discs and friction linings were modeled by Pro/E. The dynamics simulations of braking process on disc brake were performed by the frictional contact algorithm and nonlinear finite element method. Distribution of stress, strain and displacement on the brake parts were investigated with different initial velocity. Analysis results shown that redistributions of stress and strain had occurred on the face of brake disc and friction linings in braking process. Meanwhile, the increased initial velocity resulted in increased stress and stain. Besides the stress concentrations appeared in brake disc role and friction lining corners at the beginning of braking, however, stress and stain became uniform along the braking. Analysis results provided the research of the optimum design and testing of disc brake with theoretic gist. And some improvement measures to the structure of disc brake were proposed.
Effect of Manufacturing Tolerances on Stiffness and Damping of Hydrodynamic Journal Bearings
Authors: Xu Wu Bin , Ogrodnik Peter J. , Goodwin Mike J. , Bancroft Gordon
Published: October 2010

From a manufacturing viewpoint, the manufacturing tolerances of a hydrodynamic journal bearing system are inevitable. To examine and understand the effect of manufacturing tolerances on dynamic characteristics of a hydrodynamic journal bearing system can help engineers to confidently choose reasonable tolerances at design stage or to enable the system with certain manufacturing tolerances to operate closer to the theoretical predictions. This study presented a theoretical analysis method to determine and demonstrate the effect of manufacturing tolerances on bearing stiffness and damping, in which the concepts of limits, tolerances and nominal dimensions are introduced in. The results show that the manufacturing tolerances of a hydrodynamic journal bearing system have profound influences on the bearing stiffness and damping, and the magnitude of effect depends on system design parameters in the form of Sommerfeld number. The presented method will better predict system stiffness and damping characteristics.
Stability Margin of Quasi-Periodic Motion in Nonlinear Rotor System: Experimental Validation
Authors: Zheng Hui Ping
Published: October 2010

Rotor systems applied widely in industry are nonlinear dynamic systems of multi-degree of freedom. They must be not only stability but also have enough stability margins. Stability margins for different motion states in rotor systems are defined based on trajectory-based stability-preserving dimensional-reduction (TSPDR) in a quantitative stability analysis method for rotor systems. With the help of stability margin, dynamic behavior analyses of rotor systems become easy. In this paper, experimental method is used to validate definition and law of stability margin of quasi-periodic motion which was presented in above method. Experiment results in a rotor experiment rig show that regular pattern of stability margin of quasi-periodic motion calculated from measured data accords with the rule of above method. Therefore the definition and the law of stability margin of quasi-periodic motion described in the quantitative stability analysis method are valid in real rotor systems.
Study on Dynamic Model and Characteristic of Internal Parallel Moving Gears Transmission
Authors: Wen Fang , Cai Gan Wei , Ni Yuan , Zhang Hai Xia
Published: October 2010

Internal parallel moving gears transmission is a new type of planetary transmission with small tooth number difference. The dynamic model of the system is established by using lumped mass method. In the modeling process, the factors including the elasticity of all eccentric shafts, the elasticity of planetary bearing, the elasticity of supporting bearing on output shaft and the elasticity of meshing gears are considered, and the coordinate relation of the system is derived. The practical example and computer simulation was carried out and the dynamic characteristic is obtained. The results show that the gear transmission becomes steadier when simultaneously inputting the power from the three symmetrical shaft and utilizing multi-phase parallel mechanism, and the load of supporting bearing can be greatly reduced. This paper offers theoretical basis on correctly designing internal parallel moving gears transmission, reducing moving load and extending the service life.
Simulation of Crack Dynamic Characteristics of Rotor Based on FEM Analysis
Authors: Yang Kang , Yang Yi
Published: October 2010

A new simulation method is proposed for dynamic characteristics of cracked rotor based on the finite element analysis, in which the stiffness model has been derived for the exact description of variation rules of cracked shafts. A non-linear dynamic equation is constituted according to stiffness characteristic of cracked-rotor change in time domain. Then the corresponding dynamic equation of the cracked rotor based on FEM analysis is modeled and the numerical simulation is carried out with solutions of high accuracy. At last, the dynamic characteristics of cracked rotor in diverse conditions are analyzed, and the simulation results are compared. It is shown that the non-linear oil film bearing force coupling with periodicity variety stiffness of cracked rotor has a great effect on dynamic behavior of the rotor and that the cracked rotor can be diagnosed effectively by the criterion that the swing of disk center obviously accretes and the wave crest appears when rotation speed is a half critical speed of rotor shaft system.
Numerical Analysis of Agitated Flow Field of Submersible Mixer
Authors: Xu Wei Xing , Yuan Shou Qi
Published: October 2010

The flow formulation was founded as console formulation, and with the body-fitted coordinate system and standard k - ε turbulent model, the numerical analysis of the internal 3-D incompressible turbulent flow of the agitated flow field was carried out by CFD software Fluent. The results showed that: the mixer impeller produced vortex jet flow, the constant velocity lines advanced as ellipse, the velocity along the centerline are larger than others, and utilized volume flow to transport the liquid. And, by changing some design parameters of mixer impeller, we can compare and analyze the numerical analysis results and find that: for the same impeller diameter, the mixer impeller whose hub/tip radius ratio is smaller has larger advancing speed in the agitated flow field, and the advancing speed is more evenly distributed, so the overall effect is better. Therefore, we should select the hub diameter of the submersible mixer properly.
Strategy Research on Rapid Design of Complex Product Based on Case Reuse Technology
Authors: He Yong Ling , Li Shang Ping , Fan Dong Hong , Nong Hong Liang , Luo Yan
Published: October 2010

This paper proposes the design reuse model of complex product which is integrated with CBR (Case-Based Reasoning) and is established under virtual manufacturing environment. This model is aimed at the issue how to rapidly extract reuse design knowledge and select matching reuse design model to ensure that complex product can quickly respond to customers’ diverse and personalized demands with low costs during designing and manufacturing complex products. This model makes reasonable planning for the existing case design and considers the usability and economy during product design comprehensively. And on this basis, this paper researches the reuse design strategy ensuring the rapid response of complex product and the method of reuse process, develops the design system basing on case reuse technology and achieves the rapid design and analysis of product. Besides, the proposed design reuse approach is going to be tested by integrating with the farm dump truck produced by one certain machinery Co., Ltd.
WC-Co Tool Failure Analysis and the Grinding Effect Study
Authors: Zhao Xiu Xu
Published: October 2010

Grinding is one of the important machining processes for the WC-Co carbide product. Different grinding strategies will have different impact on the work piece material. This study focuses on the WC-Co carbide grinding process, and the effect of grinding condition on the WC-Co carbide microstructure, figures out the relationship between different grinding strategies and material microstructure which relate to the WC-Co carbide tool failure. A specific microstructure analysis with Scanning Electric Microscope (SEM) will be presented based on a series of grinding experiments. The residual stress that generated in the grinding process will also be discussed based on the X-Ray Diffraction (XRD) measurements. It has been found that micro cracks are generated at certain grinding conditions with certain level. The residual stress which generated in the grinding process can be calculated by the d-spacing shift, and the comparison results show micro-cracks level is corresponding with the peaks shift in XRD test.
Test Analysis of Friction Moment between Ball and Cage of Miniature Bearing at Very Low Speed
Authors: Jiang Shao Na , Chen Xiao Yang , Gu Jia Ming , Li Song Sheng
Published: October 2010

In some applications, especially for the attitude control of navigation system, the friction moment of instrument ball bearings is one of the much more important factors. Its magnitude and fluctuation affect not only the energy transfer but also the accuracy of signal transfer even though the bearings work at very low speed. Experimental analysis showed that the cage rotated with a minor fluctuation along its orbital axis and even this minor fluctuation could also make a great contribution to the moment for the ball bearing. A simplified model of deformation within the contact of ball and cage was built to deduce the contact time. Combined with the experimental results, the angular acceleration were obtained by the model of contact, then the value of moment due to sliding, which induced the fluctuation of cage, between ball and ribbon cage pockets of miniature bearing were obtained.
Desert Road Hypothesis: No Subgrade Kevlar Fiber Surface Road
Authors: Wang Xiao Zhao , Wei Guo Xiang
Published: October 2010

Hundreds of millions of steamship can navigate without sinking in water which is absent from any shear capacity. Imagine whether buildings can float in the sand when a large enough cavum is given by the same token. China’s desert area is of huge percentage, it is a meaningful thing to drive the development of the desert oasis and expand the available area through road building. In this paper, the authors state the necessity of the desert road building in the first place. Secondly, choose a particular material Kevlar fiber base on the specificity of the desert road. Thirdly, design the profile of this kind of road, testing the capacity in ANSYS software, and lead Maxwell magnetic field into preventing sand burying is an innovative application. Finally, discuss the comprehensive feasibility on the advantages and disadvantages. Difficulties though there are, it is a bright direction for building road through desert.
The Candidate Enterprise Selection on Extended Evaluation Theory
Authors: Chen Lan Zhen , Gao Long Shi , Jia Chun Yang
Published: October 2010

Nowadays the resource organization process has forced the investors to consider the candidate enterprises very carefully. To avoid the effect of the mutual relationships between the similar enterprises, it is helpful to evaluate the candidate enterprise comprehensively and objectively. An extension evaluation method for the candidate enterprise is presented on the analysis of the third party logistics enterprises. Firstly the measuring weights are determined using the AHP method; secondly, the dependent function is established, and calculates the qualification degree of each enterprise using this formula, also we should normalize it. Thirdly the optimal degree is calculated to evaluate the enterprise. The enterprise with the highest optimal degree is the most important enterprises for enterprise.
A New Method for Inspecting Crack of Concrete Bridges Using Image Processing Technique
Authors: E Ming Cheng , Zhang Guo Qi , Wang Ji Wu
Published: October 2010

Crack inspection of bridges is indispensable to maintain the public traffic safety. It is conventionally carried out by specialists through visual inspection manually. Considering the efficiency and security, digital image processing technique is used to inspect the bridges. After analyzing many representative images of cracks, this paper presents the particular region feature, gray value feature and contour feature of cracks on the bridges’ surface and obtains hundreds of cracks’ feature values. We select some representative data to identify cracks from images according to these cracks’ feature values. The software has been developed to distinguish whether cracks exist in an image, and to extract automatically the existent cracks by means of MATLAB. We present experimental results obtained to prove these methods.
Frictional Characteristics of Tool and Material in Turning Particulate Reinforced Iron-Based Composites
Authors: Han Li Fa , Qu Sheng Guan , Zhong Shou Yan , Xie Chun Xiao
Published: October 2010

In this paper, frictional behaviors of tool, workpiece and chip in turning particulate reinforced iron-based composites were investigated. Experimental results reveal that in frictional process, the frictional coefficient decreases with the normal force increasing or with the reinforcement content decreasing. In turning process, the variation rule of such parameter is just similar to that of frictional process, but frictional force and average frictional coefficient on rake face are more than that of frictional process. Meanwhile, the frictional mechanism of cutting tool and material is also studied. It indicates that adhesion occurs on tool-chip interface. The intense scratching of reinforcing particulates blocks the formation of adhesion layer and makes the frictional coefficient decrease, on the other hand, it increases the sliding resistance of chip, which makes the frictional coefficient increase. Since the latter is dominant, the tool-chip frictional coefficient increases with the increase in reinforcing particulates.
The Stability Control to the Mechanical Properties of High-Pressure Gas Cylinder Industrial Production by Using Stability Indicators
Authors: Jin Shun Yao , Huang Zhong Guo , Dong Hong Lei , Yuan Qing Hua , Fan Jia , Wu Chang Sheng
Published: October 2010

To ensure a smooth production, some stability indicators, including mean (μ), standard deviation (σ), standard deviation coefficient (V), as well as the probability (P) of variable values that fall within the scope of the standard were introduced to evaluate and to control the chemical composition and mechanical properties of seamless gas cylinder 30CrMo-M. Stability levels were defined according to the enterprise performance appraisal system. By using SPSS and MATLAB software, a regression equation was established that evolved chemical composition, tensile strength, yield strength and elongation. Tensile strength and yield strength are positive correlated with C, Si, Mn, and elongation is just the opposite. According to the stability indicators and regression equations, the entire mechanical properties meet the standard requirements by reducing Mn, Si content by 0.02%, while maintaining C content constant. According to the stability indicators, the best heat treatment system, quenching at 930 ~ 935°C for 40 minutes and tempering at 580 ~ 595 °C for 90 minutes, was established.
Design and Test on a New Pattern Friction Damper
Authors: Wei Wen Hui , Chen Kai
Published: October 2010

A new piston constant friction damper is designed by the energy principle and hysteresis of friction damper in this paper. The friction damper is composed of steel outer tube, steel shaft, bronze friction wedge, steel pressure wedge, coil spring, and cap, and it can be adjusted the size of friction conveniently. The relationship between friction from sliding force and spring pre-stress are guided. Hysteresis tests under a variety of displacement excitation are conducted. By controlling the displacement amplitude and changing the size of sliding force and the vibration frequency, the restoring force of friction damper were measured, the hysteresis of friction damper at different excitation frequencies and sliding force were obtained. The hysteresis curve of the piston constant friction damper is a rectangle approximately; this is the same with theoretical analysis of friction damper.
The Improvement and Optimization Design of the BF-Type Flexible Drive
Authors: Zhang Ling Yu , Luo Huai Lin , Hu Guang Zhong
Published: October 2010

The performance of the BF type flexible drive in using is worse, the pressure of the round is larger and uniform, and even be negative, so it is easy to lapse institutions. Increase the transmission through the gravity balancer equipment; it is the better way to solve existing problems. By designing to transform the structure of the gravity balancer and optimizing the parameters of gravity balancer equipment, the stress of all wheels will be greater than zero and the total pressure of round become smaller, the loaded and no-load pressure of the round is the same. So it is a very good solution to solve the problem of gear wear, the performance can be greatly improved, it provides a way to improve and optimize the existing equipment, and it would have good development prospects and market value.
Anti-Wear and Friction-Reducing Characteristics of Two Kinds of Ceramic Additives
Authors: Gao Yu Zhou , Wang Jiang Tao , Liu Shi Yong , Zhang Hui Chen
Published: October 2010

Two kinds of ceramic additives have been developed that one is the serpentine particles and another is a blend of serpentine particles and catalyst. The tribological properties of the addition of different additives are investigated through a series of friction and wear experiments. Wear surface and the composition of the tribofilm were examined by SEM, EDS and XPS. In case of single serpentine additive, tribo-film can be formed gradually on the worn metal surface. The friction coefficient is about 0.11. The tribofilm mainly consists of Mg and Si elements transferred from the additive. This can compensates part of wear mass loss, avoids the direct contact of the two rubbing surfaces, and thus effectively improves the anti-wear characteristics. In case of the blend oil additive, the tribo-film formed obviously on the worn surface in the initial stage and no obvious film at end of the test. However, the friction coefficient can lower even to 0.007~0.008 compared with the above experiment. The worn surface becomes very smooth. Chemical analysis shows that there is a very thin film of carbon concentration with thickness of 30~50nm on the worn surface. Existence of the very thin carbon-concentrated film and mirror-like surface generates super low friction coefficient.
Study on Filling Capacity of Semi-Solid Magnesium Alloy
Authors: Hu Yong
Published: October 2010

The Semi-Solid Processing technology is an innovation manufacturing process. The filling capacity of the semi-solid metal has very important effects on the properties and qualities of the work pieces. Lots of heat factors have effects on the filling capacity of semi-solid metal. The filling capacity of semi-solid AZ91D magnesium alloy has been studied by means of fluidity test. The results indicate that the filling length increases with the increasing of the temperature and the filling capacity of semi-solid magnesium alloy with shearing is better than that of without shearing. The lower temperature, the more obvious the effect of shearing on the filling capacity is. However, if the temperature is very low, the flow of the slurry is poor and the effect of shearing on filling capacity decreases. The microstructures of semi-solid magnesium alloy after shearing is spherical and homogeneous.
On Isotropic Damage Distributions and Evolutions of HRR Field
Authors: Shi Wei Chen
Published: October 2010

Damage distribution and evolution of the HRR field are characterized by means of a two-scalar damage variable approach under the consideration of isotropic damage. This theory is based on the definition of thermodynamic conjugate forces and the postulation that the plastic damage surface corresponds to the initiation of plastic damage. An asymptotic solution is applied for the non-linear plastic damage evolution equations. It is shown that both the damage variables may be expressed as a function of the accumulated amount of overall damage respectively in exponential and tangential types, which determine the damage characteristics in different areas. It is also revealed that the damage evolution coefficient plays an important role to determine the distributions of the damage variables, effective Young’s modulus and Poisson’s ratio. The obtained largest damage variable, which characterizes the deterioration of the material, and the lowest effective Young’s modulus around the crack tip locate at and respectively for Mode I and II problems.
Quantitative Analysis and Research of Cement Powder Mixing Based on Image Processing
Authors: Ye Tao , Yang Hai Lun
Published: October 2010

As technology develops, digital image processing technology has become a new method for studying particle property and a necessary means for particle analysis. This method helps researchers to gain deeper understanding of microstructure and property of powder particles. In the paper, samples are composed with two kinds of cement powders: cement clinker and slag powder, which have different characteristics and shapes. The paper analyzed the characteristics of different ingredient and mixing evenness degree of cement sample by using the technology of SEM backscattered electron image and the theoretical calculation model. On the basis of experimental analysis, a new method was proposed to quantitatively analyze evenness degree for the cement mixture basing on image processing, which adopts the advanced microscopic analysis technology. This new method is tested by experiments, and results prove that this method is effective and is superior to other methods.
Research on Characteristics of Deposition Precipitation Process in Production of Low Carbon Aluminum-Killed Steel in FTSR Technology
Authors: Feng Yun Li , Song Meng , Yang Jing Bo
Published: October 2010

Precipitation characteristics of second phase in low-carbon steel produced by FTSR technology have been researched by TEM and EDS in this article. And preliminary research of precipitation conditions of second phase particles in thermodynamics and dynamics have been took. The results indicate that: there’re second phase particles precipitated dispersively in hot rolled low-carbon steels by FTSR technology. These particles mainly contain particles of Al2O3, MnS and AlN, and the precipitate size is about tens to hundreds of nano. Thermodynamical analysis declares that most of the Al2O3 and all of the MnS, AlN particles are precipitated in solid state. That’s why the precipitation process is slowed down by the diffusion velocity of the elements in solid, and thinner particles are precipitated while the material is in solid state than in liquid state. Different from the traditional plate rolling production of Al-killed steel, the precipitation of AlN particles are mainly controlled by the continuous casting process in thin slab casting and rolling process, but almost no precipitation of AlN particles in the rolling process.
Comparison of the Electrochemical Behaviors Among 5083/6082 Friction Stir Welding Dissimilar Weld and Parent Materials
Authors: Shen C.B. , Chen Y. , Ge J.P.
Published: October 2010

At the ambient temperature, in the 0.2 M NaHSO3 and 0.6 M NaCl solution, by gravimetric test, potentiodynamic polarization curve test and electrochemical impedance spectra (EIS), the electrochemical behavior of 5083/6082 friction stir welding dissimilar weld and two parent materials were comparatively investigated. The results indicated: at the given processing parameters, the anti-corrosion ability of the dissimilar weld was superior to those of the 6082 and 5083 parent materials.
Influence of Nano-CaCO3 on the Properties of Magneto-Rheological Fluid
Authors: Du Cheng Bin , Yu Guo Jun , Chen Wei Qing
Published: October 2010

Nanometer calcium carbonate (nano-CaCO3) is an inorganic material that does not have the rheological properties of a magneto-rheological fluid (MRF) but has some effects on the sedimentary stability and rheological properties of MRF. The MRF was prepared by adding nano-CaCO3 to improve its comprehensive and practical properties. The results showed that, with an increase in the amount of nano-CaCO3, the sedimentary stability of MRF would be improved. The off-state viscosity of MRFs increased with an increasing amount of nano-CaCO3. The shear stress of MRF was decreased slightly by adding nano-CaCO3. To some extent, the comprehensive and practical properties can be improved by adding a certain amount of nano-CaCO3. However, there is also certain localization that properties of MRF are improved by adding Nano-Inorganic Materials in the high temperature environment.
Study on Method to Dissected Data of Wood Cell Image
Authors: Zhang Shao Qun , Xu Wei , Meng Zhao Xin
Published: October 2010

Wood cell images are observed by the In-Situ SEM plays a very important role in wood structure. Because of the nature of cell image, automatic segmentation for wood cell image becomes one difficult question. According to the characteristics of image of anatomical structure of wood based on image processing theory, the theory and method of binarization algorithm for image of anatomical structure of wood is presented. The machine vision detecting of edge tracing of wood cell is processed to the binarized wood image. Use this method to dissected Yunnan ormosia and Manchurian ash image of anatomical structure of wood cell, this study provides the theory base for feature abstraction and pattern recognization for the further study on image of anatomical structure of wood
Study on the Ballistic Performance of Ceramic Composite Armor with Different Adhesive
Authors: Gao Ju Bin , Wang Yang Wei , Zhang Ling Yu , Han Guo Feng , Wang Fu Chi
Published: October 2010

Adhesive is an important part of ceramic-metal composite armor. In order to obtain excellent ballistic performance, some adhesive with a variety of content of nano-SiO2 was prepared, and mechanical properties and ballistic test were conducted. The results show that the pores in adhesive decrease the strength of the adhesive, and the fracture happens along with the pores. To add nano-SiO2 in adhesive can decrease the porosity and the scale of the pores. In the ballistic performance, the adhesive enhance the acoustic impedance, the greater acoustic impedance can increase the energy of transmission wave and decrease the energy of reflection wave, leading to that the ceramic is destroyed slightly. The targets with adhesive added in 20% nano-SiO2 express the best anti-bullet properties. There are so many big blocks left in targets and the height of back convex is only 2.36mm.
Accelerating Corrosion Test Study on Galvanized Q345 Steel
Authors: Yang Xiao Hua , Zhang Ding , Zhang Yong
Published: October 2010

Galvanized Q345 steel specimens were accelerating corroded with accelerating environment spectrum for equivalent 1, 3, 4 and 5 years, and then its corrosion behavior was studied based on macro corrosion appearances, micro corrosion appearances, weight loss, pits depth and fatigue strength. The results show that, i because the zinc coating can protect the matrix metal from corroding, the corrosion resistance of galvanized Q345 is much better than Q345; ii between the 1st year and the 4th year, pitting corrosion is dominative, and after the 4th year, the corrosion form transforms from pitting corrosion to uniform corrosion; iii after corrosion for 5 years, the zinc coating was not destroyed completely, and with the turning point of the 4th year, the corrosion rate of the zinc coating becomes higher firstly and then gets lower, which agrees with previous study.
Corrosion Parameters Distribution Rule and Influence Factors of LY12CZ Aluminum Alloy
Authors: Mu Zhi Tao , Zhu Zuo Tao , Chen Ding Hai , Ye Bin
Published: October 2010

The corrosion depth, corrosion area, corrosion pit volume and area of LY12CZ aluminum alloy with different corrosion time were obtained from accelerated corrosion experiment. Four distribution models such as normal, Gumbel, Logistic and double parameter Weibull were used to test their distributions. It can found that the corrosion depth and corrosion area obey Gumbel distribution and the area and volume of corrosion pits obey double parameter Weibull distribution; Choose ten variables as the parameters of influence corrosion fatigue life, through grey relational analyze we can found that the deepest corrosion depth is the biggest influence gene of corrosion fatigue life, and the corrosion grade is an important influence gene almost equal to the deepest depth because it considered the influence of corrosion area and corrosion depth, so we can use it as an parameter to evaluate the calendar life of corrosion conditions.
Study on the Quality of TA2 Sheet in Laser Bending Deforming Area
Authors: Zhou Yi Jun
Published: October 2010

In order to study the quality of TA2 sheet in laser bending deforming area, SM2000 CO2 laser of 2.5kW is used to irradiate 0.6 mm thick TA2 sheet, and the change of the surface properties of the TA2 plate after laser forming was investigated with the X-ray stress analysis instrument (type: X-350A), Digital Micro hardness Tester HVS-1000 and Scanning Electric Mirror (SEM ) respectively. The result of the experiment indicates: the roughness of the forming sheet after bending will increase. The roughness of deforming area increases dramatically. The further the surface from the bending area, the less roughness in the bending area, residual stress changes regularly. The organization of the deforming area is changed, and the branch crystal forms on the surface of the forming sheet. The diameter is about 0.5μm. The branch crystal grows upward.
Predicting the Wearable Property of YT 715 Cemented Carbide Cutting Tool
Authors: Chen Shun Qing , Meng Guang Yao
Published: October 2010

The thermoelectric potential of the cemented carbide is the one of the major properties of material. The analysis and the test about the relationship between the wear and the thermoelectric potential of YT715 cemented carbide inserts have been finished in this paper. The influence rules and the influence extent of thermoelectric potential to the wear have been emphasized. The thermoelectric potential E and the wear value VB of YT715 cemented carbide inserts are very closely relationship, the bigger thermoelectric potential E, the more serious wear. Then the new method of forecasting the life of cemented carbide has been also discussed.
Dry Sliding Wear Behavior of Sintered Copper-Diamond Composite Fabricated by Powder Metallurgy
Authors: Zheng Run Guo , Zhan Zai Ji , Peng Xiao Ting , Wang Wen Kui
Published: October 2010

Copper matrix composites with 3wt% diamond particles were fabricated by powder metallurgy method. Sliding wear behavior of the copper-diamond composites was carried out by using a pin-on-disk wear tester under dry sliding conditions at a constant sliding speed of 100 m/s. The results showed that the wear rate of the composites was significantly lower than that of pure copper. The addition of diamond particles can markedly increase hardness and wear resistance of the copper-diamond composites. For determination of the wear mechanisms of the copper-diamond composites, a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS) was employed to observe the microstructure and analyze the chemical compositions of the worn surface. It is found that the main wear mechanisms of the sintered copper-diamond composites were abrasive wear and adhesive wear.
Study on the Preparation of Fe3O4 Nano-Magnetic Fluid for Seal
Authors: Chen Bing , Fan Yu Guang
Published: October 2010

Water-based Fe3O4 nano-magnetic fluid for seal was prepared by coprecipitation. In order to obtain nano-magnetic fluid preparation technology which can produce industrially, the choice of second coating surfactant has been studied. Factors affecting nano-particle size and particle saturation magnetization were investigated using five factors and three level orthogonal experimental design. The size of nano-particles and particle saturation magnetization were characterized by transmission electron microscopy (TEM) and WSM vibration magnetometer. The results showed that the adding speed of NaOH solution and heat-maintaining time after adding, adding speed and reaction temperature of sodium oleate solution, as well as the heating temperature of sodium oleate solution influence the properties of nano-magnetic particles more. With the optimum process parameters, Fe3O4 nano-magnetic fluid which is below 15nm and can meet the nano-magnetic fluid sealing technology requirements has been prepared.
Theoretical Analysis on the Bond-Slip Constitutive Relationship between FRP Bars and Concrete under High Temperature
Authors: Wang Zhen Qing , Ju Zhu , Han Yu Lai , Li Xiao Ji
Published: October 2010

The primary objective of this study is to develop equations of the bond stress and relative slippage between fiber-reinforced polymer (FRP) bars and concrete exposed to different temperature ranging from 20°C to 190°C. Equations were established through theoretical analysis and simulation of the bond-slip constitutive relationship between FRP bars and concrete. According to the expressions, the variations of the bond stress and relative slippage between the two diffident materials can be evaluated at different locations. This paper made the analysis based on the theory of elasticity, using a bilinear model. An example to compare the results between experiment and theory had been proposed. It is indicated that the theoretical analysis here is in good agreement with the experimental data in related literature. The results can be applied to fire resistance design of FRP reinforced concrete structures.
Study on Improving Cutting Tools Lifespan of W6Mo5Cr4V2 High-Speed Steel
Authors: Li Guang Ming , Yan Li , Yu Shu Min
Published: October 2010

This paper mainly discusses the technique of using quenching at 1000°C and tempering at 650°C for 2 hours to replace the heat treatment process of quenching at 1225°C and tempering at 560°C for 1 hour for three times.Due to the old heat treatment process is traditional multifarious waste energy and relatively backward.The experiment results prove that after the new treatment using the W6Mo5Cr4V2 high-speed steel to make cutting tools such as cutters, drill, taps and so on. It aslo achieves better abrasion resistance and ductility. This meeting the objective of improving the wear resistance, toughness, lifespan enhancement and energy conservation.It opens up a new way of simple and energy saving for W6Mo5Cr4V2 high-speed steel heat treatment process.The material of W6Mo5Cr4V2 high-speed steel has certain value to research.
Effect of Alkali Treatment of Coir Fiber on Its Morphology and Performance of the Fiber/LLDPE Bio-Composites
Authors: Tan Hong Sheng , Yu Yuan Zhang , Liu Lin Lin , Xing Li Xue
Published: October 2010

The morphology of the coir fiber by alkali treatment and untreated was analyzed by scanning electron microscope (SEM). The main component of wax layer on coir fiber surface and the mechanical performance of coir fiber/line low density polyethylene (LLDPE) bio-composites were studied. The flexural and impact strength of the composites after alkali treatment for the fibers were lower obviously than that of the composites without treatment. The result of Infrared Spectrumetry-Fouorier Transform (FTIR) shows that fatty acid and waxy material on the surface of the coir fiber were disposed of by alkali solution. The fatty acid and waxy material are compatible with non-polar LLDPE matrix. The compatibility between the coir and matrix was reduced obviously with loss of them. Therefore, the alkali treatment weakens significantly the compatibility between the coir and LLDPE, and this is a main reason that the mechanical performance of the composites was markedly declined.
Microstructures and Mechanical Properties of Weld Joint between B610CF and 16MnR Steel
Authors: Zhang Tian Hui , Fu Hong Cai , Yan Pei Jun , Jin Fang Wei , Wang Qiong
Published: October 2010

Weldability analysis, metallographic experiments and mechanical property experiments were carried out on weld joint between B610CF and 16MnR steel using shielded metal arc welding method and mixed active-gas arc welding method. Weldability analysis shows that the weld joint has some tendency to cold crack, and preheat is needed before welding. Metallographic results show that there are ferrite and bainite in weld metal, and in heat-affected zone of B610CF side there are ferrite and bainite, on which there is much dispersed slight Fe3C, and in heat-affected zone of 16MnR side there are ferrite, pearlite. There is no quenching microstructure resulting in crack in weld joint. From mechanical property results, it can be concluded that the weld joints have excellent impact toughness at low temperature and the tensile strength and plasticity of weld joints is matched to the ones of 16MnR steel. So the welding parameters in this paper are appropriate to get qualified weld joints.
Creep Based Prediction Model of Stress Relaxation Behavior for High Temperature Materials
Authors: Guo Jin Quan , Wang Li Xin , Xuan Fu Zhen
Published: October 2010

An average creep rate conversion model based on Schlottner-Seeley creep assessment procedure and creep damage equation has been developed by considering the relationship that two stages of stress relaxation are corresponding to the first and the second creep stage respectively and the effect of these two kinds of creep rate on relaxation, and stress relaxation is creep at various stresses. And an incremental calculation prediction methodology of stress relaxation performance was established. The predicted results are compared with the data of stress relaxation tests conducted on bolting steel 1Cr10NiMoW2VNbN used in ultra-supercritical turbines. Validation results indicate that the developed model has led to better consistent results with the measured data and thus can be recommended in stress relaxation behavior prediction of high temperature materials.
Research on Contact Fatigue Properties of Some Materials Used for Heavy Load Gear
Authors: Yu Ying Xia , He Bo Lin , Shao Er Yu
Published: October 2010

The contact fatigue tests were carried out using three kind of steel(45, 42CrMo, 40CrNi2Mo) which were quenched and tempered to the same medium hardness(HRC37±1). The experimental equipment is JPM-1 type contact fatigue tester. During the experiment process, the contact stress is 1600MPa and the surface roughness is 0.4 um. The crack initiation and the crack propagation direction were observed by using SEM. The contact fatigue failure mechanism was also analyzed. The experimental results were analyzed by using Weibull distribution. The experimental results show that the contact fatigue crack was initiated in the roller surface. With increasing of the cycle, the initiated crack propagates into subsurface and becomes to pitting. The pitting becomes bigger and bigger and leads to failure finally. The maximum shear stress is the main driving force for the crack propagation. The contact fatigue life increases in sequence of 45, 42CrMo, 40CrNi2Mo. The contact fatigue life has the relationship with the shearing resistant stress Тk. About the same carbon content, the value of the shearing resistant stress Тk becomes greater with increasing the alloying elements. The best material used for making heavy duty gear is 40CrNi2Mo steel.