bluuebunny/crossref_metadata_2025 huggingface dataset:
Attitude Resolution Algorithm of Gyro-Free Inertial Navigation System
Authors: Zhou Hon Gjin , Wang Xiu Sen , Yi Cheng Tao
Published: August 2011

Gyro-Free Inertial Navigation System(GFINS) is constructed mainly with accelerometers. A nine-accelerometer GFINS scheme is designed and the prototype is manufactured. Then quaternion based attitude resolution algorithm is developed, the algorithm is also applied to the GFINS prototype, the results show that the algorithm can effectively offspring the cone-effect, and the attitude is resolute validly, the maximum attitude error is up to 0.37°, the maximum azimuth error is 0.47°.
Anodic Synthesis of α-PbO2-CeO2-TiO2 Composite Materials from Colloidal Electrolyte: Morphology, Composition and Structure of PbO2-Matrix Composites
Authors: Chen Bu Ming , Guo Zhong Cheng , Huang Hui
Published: August 2011

During electrodepositing pure lead dioxide, the electrocatalytic activity of PbO2 electrodes, as well as their stability, can often be considerably enhanced by the incorporation of some fine particles added to the electrodeposition. The morphology, crystal phase, surface composition, microstructure, of the electrode were characterized by means of SEM, XRD and EDS. SEM-EDS analysis showed the addition of solid particles could inhibit the growth of α-PbO2 unit cells, improving the specific surface areas of coating surface.Under all condition, the matrix was highly oriented α-PbO2. The electrocatalytic activity of the prepared materials has been tested in Zn2+ 50g L-1, H2SO4 150g L-1 solution. It showed that the electrocatalytic activity of the A1/conductive coating/α-PbO2-3.71 wt.% TiO2-2.12 wt.% CeO2 anode is the best.
Study on the Application of QFD Technology in the Whole Conceptual Design of Special-Shaped Stone Machining Center
Authors: Xiao Nan , Wu Yu Hou , Liu Yan , Zhang Ke
Published: August 2011

The Quality Function Deployment (QFD) model and the optimal decision-making model is applied to the design of special-shaped stone Machining Center. Through the establishment of Design of house of quality of Machining Center, it can convert the users' needs and requirements of improvement on machining center into engineering measures of shape design of machining center in manufacturing engineering and at the same time combine resource consumption of various engineering measures implemented and resources of enterprises together. In the constrains of limited resource, in order to make the design of machining center meet the customers’ needs to the maximum extent and enhance the competitiveness of machine tool in the market, the optimal decision model can be used to select the vital engineering measurement on re-designing machining tool.
The Analysis of Dynamic Performance on Four-Wheel Steering Vehicle Model
Authors: Chen Wen
Published: August 2011

Four-wheel steering (4WS) is an advanced vehicle control technique which can improve steering characteristics. Compared with traditional two wheel steering (2WS) vehicles, 4WS vehicle can steer the front wheels and the rear wheels individually when cornering, according to the vehicle motion states such as vehicle speed, yaw velocity and lateral acceleration. Therefore, 4WS can enhance the handling stability and improve the active safety for vehicle. In this paper, the motion characteristics of 4WS vehicle are analyzed. The steering dynamics model of vehicle is established, and the transfer function of deflection angle of mass center to steering angle of 4WS vehicle is deduced. The handling stability of 4WS vehicle is researched by virtue of Matlab/simulink, Simulation results show that the 4WS vehicle is agile to and consistent with steering input and the transient handling stability is improved distinctly without increasing driver’s handling burden.
Study on Solidification Crack Criterion during Laser Welding Pure Aluminum and ZL114A Aluminum Alloy
Authors: Huang An Guo , Zhang Hu , Liu Jing Fu , Yu Wei , Li Zhi Yuan , Li Hao
Published: August 2011

Laser welding of 1A90 pure aluminum and ZL114A aluminum alloy with powder under the same laser welding parameters were carried out in this work. The relation between weld elements and solidification cracking formation of these two materials was investigated in the perspective of metallurgical factor. And the alloy element contents and distribution near the cracks were determined by scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). Then the concept of weld element equivalent was introduced comparing with the carbon equivalent expression. The weld element equivalent expressions were established by using mathematics regress. And the verified results indicate that the weld element equivalent expressions can properly forecast the formation of solidification cracking.
A Calculation Model on Dynamic Response of Opposite-Side Simple-Support-Free Rectangular Plate under Shock Loads
Authors: Xie Fei Hong , Zhang Yong Mou , Kou Zhi Yong
Published: August 2011

The numerical model for opposite-side simple-support-free rectangular plate is established based on the theory of engineering vibration. The basic differential equation of transverse vibration of thin plate and the method of development of trigonometric function series are being used to analyze the behaviors of rectangular plate under moving area-loads in constant speed. The analytical solution of dynamic response for plate was obtained. This model can be used to simulate the dynamic response for thin plate under moving shock load and to assess the yield state of thin plate under shock loads. The Mises' yield criteria was used to judge the dynamic yield case of plate under shock loads. The distribution of stress and strain of dynamic response in parent plate under shock loads was solved according to the free-simple harmonic oscillation equation of plate. The calculation results can be used to analyze the plastic area and visco -plastic area of stress distribution in the plate. It is of some guiding significance for the installation structure of parent plate in explosive welding.
Alarm Device Design for Small Skidding Tractor
Authors: Pan Ming Xu , Wang Li Hai
Published: August 2011

Based on the development of forestry machinery and the causes for tractor accident, this paper analyzed the necessity of improving the small skidding tractors. Then the automatic overload alarm and automatic anti-tipping alarm were designed through the research on overload and tipping point of small skidding tractors. The main parameters of the devices were calculated, the operational principle was described and the two wiring diagrams were given. The feasibility of these two alarm devices is proved theoretically in this paper. Two ways are provided to improve the safety of logging operations of the tractor and an effective research method for its intelligent development in China is planed.
Design of Beacon Light Switch Based on FPGA
Authors: Xing Xue Feng , Li Hong Zuo
Published: August 2011

A new design of using FPGA to realize array beacon light switching is preferred. Based on spatial diversity laser communication, the problem of multiplexing beacon light celerity and synchronism switching has been settled. Karnaugh map method was used in the paper to generate the time sequencing driving four motors, which was used in the schematic diagram design. Experiment results show that the system(or the design) in this paper cooperated with multiplexing beacon light has been realized, which simplifys the traditional beacon light switch system frame.
Advanced Manufacturing Method of Engine Turbine Blade of Continuous Fiber Toughening SiC Ceramics
Authors: Lu Zhong Liang , Li Di Chen
Published: August 2011

A free form surface reconstruction method based on least square support vector regression is presented. Firstly in order to eliminate noise points, some sample points are chosen from the measured data to construct LS-SVM model. Thus a LS-SVM model to approximate the measured points is obtained. And the distribution probability of the approximation error is figured out. In result, the noise points are eliminated when their error probability is less than the specified threshold value. Then the boundary points are extracted. Lastly the surface model is reconstructed by use of the measured points from which noise points have been eliminated. The results indicate that the reconstruction precision can satisfy the demands of engineering application.
Research on Polymerization Processes of Cationic Polyacrylate Emulsion and its Optimization
Authors: Liu Quan Xiao , Lv Yu Bin , Li Jin Li , Xu Wen Cai
Published: August 2011

Cationic polyacrylate emulsion was prepared in lab by semi-continuous seed pre-emulsification process. After the single factor experiments, the orthogonal experiments were made to get the optimal polymerization processes. Through the single factor experiment and further the orthogonal experiment optimization, it shows that the sequence of the effect of these factors on the viscosity of emulsion is drop time > reaction time > reaction temperature. The sequence of the effect of these factors on the solid content of emulsion is drop time > reaction time > reaction temperature. The sequence of the effect of these factors on the conversion rate of emulsion is drop time > reaction time > reaction temperature. The obtained best polymerization processes are the drop time is 1.5h, the reaction time is 5h, the reaction temperature is 85 °C. Under the best polymerization processes, the properties of the emulsion are the solid content is 35.40%, the conversion rate is 96.33%, the viscosity is 456.67mPa.s, the particle size is 490.20nm, the Zeta potential is 30.50 mV and pH is 2.50.
Experimental Study on Temperature External-Characteristics of Ni-Mn-Ga Shape Memory Alloy
Authors: Cai Yong Zhi
Published: August 2011

Temperature characteristics are essential to reasonable application of Ni-Mn-Ga alloy. This paper reports an experiment equipment which is used as the research of variable temperature effect. The relationship between deformation rate and temperature is studied. Dynamic and static experiments are done. The results show that critical temperature is around 40°C. It can be predicted that thermo-elasticity and magnetically-controlled characteristics will disappear with the increase of temperature.
Effect of High-Energy Ball Milling on Microstructure and Microwave Absorbing Properties of NdFe Material
Authors: Lin Pei Hao , Wang Lei , Pan Shun Kang , Wan Hua Mei
Published: August 2011

The NdFe magnetic absorbing materials were prepared by rapid solidification and high-energy ball milling method. The effect of high-energy ball milling on particle morphology, organizational structure and microwave absorbing properties of NdFe magnetic absorbing materials were analyzed with the aid of X-ray diffractometer, scanning electron microscope and vector network analysis. The results show that the Nd2Fe17 and α-Fe phase are refined, the particles become smaller and thinner; the span-ratio of the particles increases along with time during the process of high-energy ball milling; and meanwhile, the frequency of absorbing peak reduces. The absorbing bandwidth broadens as the increase of the time of ball milling, except that of 48h.The minimum reflectance of the powder decreases from -22dB to - 44dB under the circumstances that the time of high energy ball milling reaches 48h and the thickness of the microwave absorbing coating is 1.5mm. But it rebounds to about - 6dB when the time of ball milling reaches 72h.
Investigation on Structure and Electrochemical Properties of MgNi+x%B (x=0,2,5,10) Hydrogen Storage Alloys
Authors: Liu Zi Li , Liu Xin Bo , Yan Xin Chun , Zhou Gui Bin
Published: August 2011

Amorphous MgNi+x%B(x=0,2,5,10) hydrogen storage alloys have been prepared by mechanical alloying (MA) and tested as hydrogen storage electrodes. The addition of boron can promote the MgNi alloy to form amorphous phase, increase the atom ratio of Ni/Mg at the alloy powders’ surface, and improve the thermal stability of MgNi alloy. The discharge capacity, the high rate dischargeability (HRD) and the exchange current density of the alloy electrodes all increased first, and then decreased with increasing the addition of boron. The maximum discharge capacity, the HRD400 and the exchange current density of the alloy with 5%B were 411.6mAh/g, 58.3% and 293.5mA/g respectively, which were 21.8%, 40.0% and 351.5% higher respectively, comparing with that of no boron addition. The electrochemical cycle stability of the alloy electrodes increased with increasing boron additions, and compared with no boron addition, the cycle capacity retention rate S20 of the alloy with 10%B increased 64.2%.
Multi-Objective Optimization Design of Complex Mechanical and Electrical Products Based on Improved Evolutionary Algorithm
Authors: Wei Wei , Qiao Li Hong
Published: August 2011

The design of complex mechanical and electrical products has to achieve various objectives and satisfy various constraints. In many cases, there are trade-off relationships between these objectives, and thus it is difficult to optimize these objectives simultaneously. This invokes the need of the multiobjective optimization to achieve these objectives collectively. In this paper, multiple objectives for complex mechanical and electrical products are optimized, simultaneously using an improved multiobjective evolutionary algorithm: ISPEA2. The results showed that ISPEA2 could generate uniformly a pareto optimal set in the design space and has better robustness and convergence than SPEA2 and NSGA-II.
Ultra-Light Photovoltaic Embedded Structures for Solar-Powered Aircrafts
Authors: Zhang Li , Yao Lei Jiang , Wang Jing Shen , Li Bin , Tong Xiao Yan
Published: August 2011

This work evaluated a new ultra-light photovoltaic embedded structure for solar-powered aircrafts, in which the mono-crystalline silicon (m-Si) solar cells encapsulated by epoxy were adhesively bonded to the upper wing skin made of rigid polyurethane foam (RPUF). To evaluate the effect on the cell encapsulation, static tests were carried out. The results showed that the encapsulated cells had better flexibility. The bonded-point and multi-cell models for the embedded structure were analyzed by FEA software. As the number of the bonded points increasing, the stress and deformation of the embedded structure decreased; once exceeded 16 points, the stress and deformation changed little. The deformation of the non-reinforced multi-cell model was very large; the stiffness improved greatly after reinforced by the glass fiber ribbons.
Using Cow Bone Char for Improvement of Domestic Water Quality in Chiang Mai, Thailand
Authors: Laosatirawong Surasit , Thiensem Sakdiphon , Punyanitya Sittiporn
Published: August 2011

Characterization of Environmentally friendly materials used as wastewater treatment material has been studied in order to compare the quality of wastewater in Chiang Mai, Thailand on two types of treatment materials, which are cow bone char (CBC) made from Thai cow bone char cleaned and calcined at 850๐C and the a mineral called “zeolite” (ZLT) bought from Kamthiang market, Chiang Mai. The physical characteristics of both types of materials indicate that the CBC has a higher density than the ZLT but has lower pore volume than the ZLT. The effect of density on the water quality improvement was showed that CBC was a suitable type of wastewater treatment material because their high density can fix them in the batch system.
Chinese Design Recommendations for External Strengthening by FRP Laminates and Related Works in ACI and ISIS Code Provisions
Authors: Ma Jian Xun , Carlson Piers , Zhang Ling Ling
Published: August 2011

By comparing the Chinese CECS 146:2003, the American ACI 440.2R-02 and the Canadian ISIS Design manual No.4, discussion is extended in terms of ways to improve the performance of concrete structures. Although the Chinese code treats only carbon fibers, the basic concepts for FRP strengthening are common to all three examined design. However, safety factors differ because of the different backgrounds and application experience. The ACI 440.2R-02 goes into great detail concerning FRP materials and utilization where creep and fatigue are important factors. The ISIS manual No.4 gives many design examples and promotes the use of FRP through easy-to-use design charts. The CECS 146:2003 also mentions applications for seismic resistance. Further improvement in the area of design stipulations for use of FRP laminates will include standardization of safety factors, and also promotion of these guides for a wide use around the industry.
Fabrication of Polycaprolactone/Chitosan Scaffolds by Freeze-Solvent Extraction Method
Authors: Xiao Xiu Feng , Jiao Jian Jin , Huang Qiong Yu , Liu Rong Fang
Published: August 2011

The polycaprolactone (PCL)/chitosan (CS) scaffolds were prepared by the freeze-solvent extraction method using glacial acetic acid with little water as a common blend system. The effect of different solvents on the crystallinity, the morphology, the structure and the mechanical properties of the scaffolds was studied. The results indicate that alkaline solvent favors the deposition of CS, solvent extraction in the frozen condition perfects the crystal of PCL and improves the crystallinity of PCL/CS scaffolds, in the mean while, the compression property enhances. The porosity of PCL/CS reaches 81%, when immersed in water solvent.
Influence of Chitosan on Electrospun PVA Nanofiber Mat
Authors: Jeannie Tan Ziang Yie , Zhang Xi Wen
Published: August 2011

Many efforts had been reported to modify the structure of electropun nanofibers in order to obtain superior functional properties of poly(vinyl-alcohol) (PVA). This paper discusses the influence of chitosan on the morphology of electropun PVA nanofibers and their related properties. Spider–net and fiber–bridging structured PVA nanofibers are successfully fabricated by blending with chitosan. Chitosan as natural cationic polysaccharide increases the excess charge of the host polymer PVA. Nanofibers are diverged into thinner nanofibers and a continuous web formed when electrical voltage applied. The presence of additional OH- groups from chitosan and larger surface area of the net structure for hydrogen bonding enhance the hydrophilicity and mechanical properties of the nanofiber mat as compare to pure PVA which are evaluated through water contact angle and tensile testing respectively.
Characterization of Wood-Polymer Composite prepared by Muchelia macclurei Wood and Methyl Methacrylate Monomer
Authors: Li Yong Feng , Fu Yun Lin , Huang Hua Wei , Liu Yi Xing
Published: August 2011

Michelia macclurei wood with moderate strength is a fast-growing wood in South China. However, it has not been fully utilized. We first prepared it into wood-polymer composite with purpose of good performance by impregnating methyl methacrylate monomer (MMA) into wood pores and following in-situ polymerization. The micro structure of wood-polymer composite, and the morphology and reaction of polymer in wood were characterized by SEM, FTIR and XRD. The SEM observation showed that the MMA monomer polymerized into polymer under the employed conditions and filled up wood cell cavity. FTIR analysis indicated that the monomer rarely reacted with wood cell wall during its polymerization. XRD characterized that the polymer from MMA monomer mainly physically existed in wood pores and remained as an amorphous form.
Synthesis of the Water-Compatible P-Aminophenol Resin and its Adsorption for Salicylic Acid
Authors: Xiao Gu Qing , Zhang Xue Jun
Published: August 2011

A novel water-compatible hypercrosslinked resin modified by p-aminophenol was synthesized with chloromethylated polystyrene and p-aminophenol by Friedel-Crafts reaction. The objective of this work was to study the adsorption performances for salicylic acid onto p-aminophenol resin. The results showed that the adsorption capacity of salicylic acid onto p-aminophenol resin was superior to XAD-4 resin. It is seen that the maximum adsorption capacity is observed at pH of 3.0. It was found the adsorption dynamics obeyed the pseudo-first-order rate equation and the intra-particle diffusion was the rate-limiting step. The maximum adsorption capacity of salicylic acid for p-aminophenol resin was measured to be 283.7 mg/g with the equilibrium concentration at 404.6mg/L. The micropore structure, the pore diameter of p-aminophenol resin, the hydrogen bond between p-aminophenol resin and salicylic acid bring the larger adsorption capacity.
Microstructure and Mechanical Properties of as-Forged Ti-47Al-2Cr-2Nb-Y Alloy
Authors: Zhang Shu Zhi , Kong Fan Tao , Chen Yu Yong , Xiao Shu Long , Cao Chao
Published: August 2011

Ti-47Al-2Cr-2Nb-Y alloy pancake were produced by hot-pack forging. The microstructure of as-forged Ti-47Al-2Cr-2Nb-Y alloy were investigated by optical microscopy and scanning electron microscopy, showing that the forged alloy was composed of fine γ grains and retain cast lamella colonies surrounded by elongated B2 phase. Tensile properties of the material showed that yield strength (YS) and ultimate tensile strength (UTS) were decreased from 500MPa and 612MPa at room temperature to 420 MPa and 462 MPa at 800°C, respectively. With the temperature increasing to 900°C, elongation reached 120%.
Numerical Simulation of Embedded and Co-Cured Composite Damping Structure under Low Velocity Impact
Authors: Mi Peng , Liang Sen , Zhang Sarah
Published: August 2011

Embedded and co-cured composite damping structure is a novel damping processing structure, which possesses excellent damping properties and mechanical performances. In this paper, explicit dynamic analysis software LS-DYNA is employed to simulate low velocity impact on embedded co-cured composite damping structure panels. To illustrate the validity of modeling and calculation method, the simulation results are compared with the experimental data. And the results show that the impact resistance of embedded co-cured composite damping structure is much better than composite panel without damping material.
Hydrothermal Synthesis and Ferromagnetic Properties of Mn-Doped Na0.5Bi0.5TiO3 Crystals
Authors: Wang Yong Gang , Wang Yu Jiang
Published: August 2011

Pure phase Mn-doped Na0.5Bi0.5TiO3 crystals were successfully synthesized by a hydrothermal method. Magnetic loops measured at room temperature indicate that ferromagnetism can be obtained in Mn-doped Na0.5Bi0.5TiO3 crystals, and the magnetism of Na0.5Bi0.5TiO3 crystals can be controlled by adjusting Mn doping concentration. The magnetism of the Mn-doped Na0.5Bi0.5TiO3 crystals varied from diamagnetism, ferromagnetism, and paramagnetic on increasing Mn doping concentration from 0 to 30mol%. The results showed in this study may provide an approach to widely exploring more multiferroic materials.
Design and Analysis of MR Damper with Radial Duct for Tracked Vehicle Suspension
Authors: Liu Yi Le , Peng Zhi Zhao , Gao Yong Qiang , Yue Jie
Published: August 2011

This study presents the development of a MR damper applied to the suspension of tracked vehicles to improve the ride comfort and mobility. The MR valve is constrained to a specific cylindrical volume in order to keep the same geometry with the original damper. Radial duct is selected for its high efficiency and small volume requirement. The design rule is to enlarge the dynamic force range of the damper under the condition that the off-state force accords with the fail-safe principle. So the mechanical modeling is established and the influencing factors of adjustable coefficient are analyzed so as to determine the geometry parameters of MR valve. A set of experiments are performed to verify the theoritical analysis. The experimental results illustrate the designed MR damper has a good performance of energy dissipation and can be used to practical applications.
Preparation of Brunet Reflective Exterior Insulation Coating
Authors: Zhao Su , Qiu Li Yuan , Tian Jing
Published: August 2011

A brunet reflective exterior wall insulation coating was prepared. The influence of titanium dioxide crystal and particle shape on coating solar reflectance was studied, and the result showed that the coating contains Rutile titanium dioxide has good reflective performance. The influence of non-ferrous pigment on coating reflective properties was studied. Among these pigments, the reflectivity of iron oxide red which has darker color is comparatively higher, and has good compatibility with coating system. It was selected as non-ferrous pigment of this brunet department coating. Iron oxide black and medium chromium yellow was added to mix the coating color, when the dosage of pigment is iron oxide red 3.72%, Iron oxide black 0.036%, medium chromium yellow 0.24%, the coating is brown, and the solar reflectance could reach 80.22%. The basic properties of coating were all conform to the National Standards, and it is a brunet exterior wall coating which has uniform atomization performance and good reflection insulation performance.
Dynamic Coupling Hysteresis Model for Giant Magnetostrictive Materials
Authors: Meng Ai Hua , Li Ming Fan , He Han Lin , Ji Hua Wei
Published: August 2011

The giant magnetostrictive material (GMM) in dynamic magnetic field has nonlinear and hysteretic characters. Based on the nonlinear constitutive model of the material, the quasi-static hysteresis model with magneto-elastic coupling was built on the Jiles-Atherton model. Considering the eddy current and anomalous losses, the hysteresis model was modified, and the dynamic coupling hysteresis model was established on the basis. Compared with the experimental data, the areas of hysteresis curves increased with frequency, and the maximum magnetostriction strain of the curves increased with prestress. The model agreed well with the experiments within the range of 500Hz.
The Research of Nonlinearity Error Control on Five-Axis Machining Post Processor
Authors: Tang Qing Chun , He Jun , Gao Lan Lan , Lai Yu Huo , Fang Xue Ming
Published: August 2011

Abstract：This paper analyses the causes and effective estimation method of nonlinear error; By machine tool motion solution, established a five-axis machine tool BV100 motion transformation mathematical models, combined with linear interpolation principle established the error compensation and nonlinear motion error model of the machine tool .by VB language, developed nonlinear error compensation function of special post process; and through the impeller cutting experiment validate the processor is correct and practical.
Study on the Performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ Membrane after Laser Ablation for Methane Conversion
Authors: Shen Zi Gang , Guo Xiao Rui , Zhang Wu Qing , Pan Li Jun
Published: August 2011

A cross-shaped pattern was formed on the surface of Ba0.5Sr0.5Co0.8Fe0.2O3−δoxygen permeation membrane by laser ablation in order to increase the specific surface area of the membrane. The membrane was used to assemble a reactor for partial oxidation of methane (POM) to syngas in the present of Ni/ZrO2catalyst. The CH4conversion and CO selectivity of the membrane reactor can reach 98.8% and 91.5%, respectively, and the oxygen permeation flux through the membrane was 11.0 ml/cm2min at 850°C. The effect of space velocity (SV) on CH4conversion rate and CO selectivity in such reactor was discussed.
Study on the Preparation of Ni-P-TiO2 Coatings by Electroless Plating and its Photocatalytic Properties
Authors: Xiong Liang , Zhang Guo Qing , Pan Hua Geng
Published: August 2011

The Ni-P-TiO2 coatings were successfully obtained on foamed nickel by electroless plating technique. Materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive analysis (EDS) studies. The degradation effect of the prepared coating for the dyes was studied at the same time. Results showed that the appearances of coatings were fine and the amount of TiO2 in the coatings reached at 9.85wt%. The specimens exhibited excellent photocatalytic activity, the decolorization ratio of reactive black GR and methylene blue reached to 92.40% and 95.27% after 4 hours and 6 hours respectively irradiated by the same ultraviolet lamp.
Modal Analysis Theories and Methods for Bridge
Authors: He Wei , He Rong , Li Yu Wei
Published: August 2011

According to the dynamic theory and characteristics of the bridge modal analysis theories and methods for bridge were introduced which mainly included solving the nature frequency, mode shape, and damping ratio with the Rayleigh-Ritz method, subspace iteration method. And the application of bridge modal shape sequences and frequencies with their changes were illustrated in the diagnosis of the bridge disaster. Dynamic testing of the bridge should be measured for vibration mode and frequency which could be used to analyze the change of supports, constraints and other facilities of the bridge and to predict the working condition of the structure.
Studies on Low-Velocity Impact Damage of Metal Ion Implanted Composite Laminates
Authors: Yan Li , An Xue Feng , Cui Hai Chao , Yi Xiao Su
Published: August 2011

composite laminates, metal ion implantation, low-velocity impact damage, BVID Abstract. Metal ion implantation was carried out on composite laminates to modify the surface properties, so that after low-velocity impact barely visible impact damage (BVID) was easy to realize. Surface topography of laminates was observed by SEM. Microhardness and drop-weight impact was tested on composite laminates. The results showed that after metal ion implantation microhardness of laminates increased obviously and resin was easy to generate plastic deforming. Dent depth had been improved so as to realize visible impact damage more easily. And compression-after-impact (CAI) had not decreased. Comparison with Ti ion implantation, Cu ion implantation had better influence on realizing visible impact damage (VID).
Growth of Nanostructure on Cu0.62Zn0.38 after SMAT during Thermal Oxidation
Authors: Wang Jun Peng , Xu Chun Hua , Li Xiang Li , Shi San Qiang
Published: August 2011

Commercial Cu0.62Zn0.38foil was subjected to surface mechanical attrition treatment (SMAT) processing. The original and SMAT Cu0.62Zn0.38foils are thermally oxidized at 500°C under N2-5%O2gas environments, at a pressure of 1 atm for 3 hours. The oxidized specimens were characterized with a scanning electron microscope, an X-ray diffractometer. It is found that nanosheets are easily formed on the SMAT specimen surface. The favorable formation of nanosheets relates to twin–matrix lamellae structure.
Constitutive Modeling of Nanocrystalline Materials with Shear Band
Authors: Zhou Jian Qiu , Zhang Shu , Wang Ying
Published: August 2011

In hardening stage, a model was used to study the plastic deformation behaviors of nanocrystalline materials. The material was considered as a composite of grain interior phase and grain boundary (GB) phase. The constitutive equations of the two phases were determined in term of their main deformation mechanisms. In softening stage, a shear band deformation mechanism and the corresponding constitutive relation were presented. Calculation results have shown that the predications fit well with experimental data. The investigation using the ﬁnite-element method (FEM) provided a direct insight into quantifying shear localization effect in nanocrystalline materials.
Microstructure Refinement by Y2O3 in Semisolid A356 Alloy
Authors: Liu Zheng , Liu Xiao Mei , Hu Yong Mei
Published: August 2011

The semisolid A356 alloy slurry, which was grain-refined by Y2O3, was manufactured by low superheat pouring. The effects of grain-refine on the morphology and the grain size of the primary phase in semisolid A356 alloy were researched. The results indicated that semisolid A356 alloy contained Y2O3 with particle-like and rosette-like primary phases could be prepared by low superheat pouring. The grain size and particle morphology of primary phase in semisolid A356 alloy were markedly improved by Y2O3. The refining mechanism of Y2O3 on the morphology and the grain size of the primary α phase in semisolid A356 alloy was delved.
Experimental Study of Energy Absorption Capability of Metallic-Palm Fiber-Metallic Hybrid Composite Plate
Authors: Aminanda Yulfian , Hamid Wan Luqwan Hakim
Published: August 2011

An experimental campaign on metallic-palm fiber-metallic hybrid subjected to impact loading using spherical projectile has been carried out. High initial energy impact with projectile mass of 24 kg and speed of 1, 3 and 5 mm/s, has been set enabling to determine the energy absorption capability of hybrid composite panel. The influence of stacking sequences metallic-palm-fiber-metallic and metallic-palm fiber-metallic-palm fiber-metallic with different thickness of metallic and palm fiber, to the energy absorption were investigated. The effect of different striker radius; 10, 13 and 20 mm were carried out as well. The mechanism of failure and energy absorbed by the hybrid composite panel and its components; metallic alone and palm fiber alone, were carried out to understand the advantage of having hybrid structure. The optimum configuration of hybrid panel in term of stacking sequence to absorb the energy of impact is proposed. The methodology of this study can be used for designing the armor to absorb the energy of projectile using palm fiber composite panel.
Experiment Study on Disrepair Principle for the Waved-Edge Milling Insert with Complex 3D Grooves
Authors: Cheng Yao Nan , Li Zhen Jia , Liu Yi Zhi , Zhang Hui Ping , Wang Xian Zhou
Published: August 2011

The impact disrepair and adhering disrepair of milling insert are the important factors that affect the normally running of the automated processing system. Based on machining the 45 steel, find out the difference of the impact disrepair invalidation types between the waved-edge milling insert and flat rake milling insert, build the impact disrepair life cumulating distribution function mathematic models by the mathematics statistic method and have contrast analysis of the impact disrepair average lives between them. Based on the experiments on milling the 3Cr-1Mo-1/4Vsteel, find out the difference of the adhering disrepair invalidation types between them, build the quantitative mathematic relation between milling temperature and maximal adhering disrepair depth on rake face, and analyze the rule that the milling temperature affects the adhering disrepair. All these studies provide the theoretic and experimental bases for the groove optimization.
Influence of Nitrogen Content on the Microstructure and Precipitate of the Medium-Carbon Vanadium Microalloyed Steel
Authors: Guan Yun , Zhang Xian Zhong , Ma Jia Yan
Published: August 2011

The microstructure and precipitate of the two kinds of medium-carbon vanadium microalloyed steels whose nitrogen contents were 0.0035% and 0.012% respectively, were studied by image analysis and transmission electron microscope (TEM). The results show there are the large amount of 10~20nm dispersion distribution irregular flake VC precipitates within the ferrite, the part of clustered fibrous VC precipitates with the diameter of 4~13nm that grow toward to ferrite intracrystalline along the grain boundary with some angle in the local area, and only a very small amount of 20 ~ 50nm spherical particles V (C, N) in the low-nitrogen steel. However, in the high-nitrogen steel, the precipitates are divided into two stages: the first stage is the part of 30~80nm spherical particles V(C, N) which precipitation in austenite, the second stage is flakiness VC which precipitation in ferrite during the following γ → α phase transformation and cooling process. Compared with the low-nitrogen steel, the number of precipitates in decreased significantly and the size increased obviously in the high-nitrogen steel. The substantial increase of nitrogen content leads to the rapid increase of driving force that V (C, N) precipitation in austenite. A lot of V (C, N) that precipitation before phase transformation results in the significant increase of ferrite nucleation rate, which leads to the microstructure of high-nitrogen steel fined obviously.
Corrosion Study on X70-Carbon Steel Material Influenced by Soil Engineering Properties
Authors: Md Noor Norhazilan , Lim Kar Sing , Nordin Yahaya , Abdullah Arman
Published: August 2011

Soil as a corrosive medium is probably of greater complexity than other environment. This paper studies the influence of soil engineering properties towards metal loss of buried X70 carbon steel coupons. The study focuses on soil engineering properties which are soil moisture content, clay content and plasticity index. A total of 160 pieces of X70 carbon steel coupon were buried in 5 different locations in Peninsular Malaysia for a period of 12 months to study the effect of the abovementioned parameters towards metal loss caused by soil-corrosion. The samples were retrieved periodically for every 3 months to determine its weight loss and consequently the corrosion rate. It was found that the rapid growth of corrosion is relatively correlated with the high moisture content of soil. Yet, corrosion initiated at a slow pace for high plasticity soil and clayey soil. The highest and the lowest corrosion growth rate were calculated at 0.218mm/year and 0.051mm/year respectively. No strong indication can be found to relate the dominant influence of soil engineering properties towards measured corrosion rate of buried steel coupons.
Research on Thermal Stress of Slab Heating Process Based on Transient Non-Linear Analysis
Authors: Wan Xiao Hang , Dong Zhao Wei , Li Shu Jun , Liu Sheng Yong
Published: August 2011

Polycrystalline α-HgI2 films have been grown through combining vertical deposition method with hot wall vapor phase deposition (HWPVD) method. The influence of the α-HgI2 seed layers on the structural and electrical properties of the polycrystalline α-HgI2 films was investigated. It is found that the α-HgI2 seed layers play an important role in reducing the grain sizes, increasing the density improving the crystallographic orientation and electrical properties of the polycrystalline α-HgI2 films.
Experimental Study of Plastic Flow during Linear Friction Welding by Physical Simulation Method
Authors: Wang Ying Jie , Zhang Yong , Yuan Xu Chao , Wen Guo Dong , Ma Tie Jun , Gao Da Lu
Published: August 2011

Abstract. In order to study the plastic flow during linear friction welding (LFW), copper particles were added as tracers on the surface of lead block. The flowing state of interior metal in LFW was simulated by the home-made simulator. Results show that the upset speed promotes the plastic flow of metal and the oscillation frequency restrains it. The upset speed influences the plastic flow of metal more significantly than the oscillation frequency. Only when the pressure reaches 800N and the increasing rate reaches 100N/s, can obvious plastic flow of lead happen in the direction perpendicular to the compression. But the plastic flow of lead in the compression direction is visible even if the pressure and its increasing rate are small.
High Speed CO2 Arc Welding Based on Constant Power Control
Authors: Chen Huan Ming
Published: August 2011

The experiments were performed with the self-made inverter power source of CO2 arc welding under constant power control and constant voltage control. Electrical signals in welding process were analyzed by Hanover analyzer and Matlab software, and the effects of the two control methods on welding stability and arc energy were compared. The results show that the weld appearance under constant voltage control is worse due to less energy in arc burning period, the method of constant power control increases the arc energy effectively and improves weld formation and welding stability.
Numerical Simulation of Dispersed Phase Flow in a Tube Considering Bubbles Erosion and Cl- Ions Concentration Effects
Authors: Chen Song Ying , Mao Jun Jie , Wang Wei Qiang
Published: August 2011

It is found that the tube damage is caused by two induced factors: bubbles erosion as a dispersed phase and chemical composition of water rich in Cl- ions that result in loss of stability of protective oxide layer. The tube is subject to be erosion–corrosion in a given set of conditions, using numerical simulation techniques. The results prove to be erosion–corrosion effects owing to turbulence, bubbles dynamics affect and ensuing erosion rates. In addition, the bulk of Cl- ions which are concentrated at the bend position play a role in that.
Influence of δ Phase Content on Hot Deformation Behavior of Ni-Based Superalloy IN718
Authors: Zhang Hai Yan , Zhang Shi Hong , Cheng Ming
Published: August 2011

The effect of δ phase content on the hot deformation behavior of alloy IN718 has been investigated using isothermal compression tests. The results indicated that the δ phase has a significant effect on the deformation behavior of alloy IN718 during hot working. After the peak stress, the decreasing speed of the stress raises as the increase in the δ phase content. The deformation activation energy for alloy IN718 increases with the raise of the δ phase content. And the peak strain for the alloy decreases with the increase of the δ phase content, which indicates that the δ phase can stimulate the occurrence of dynamic recrystallization during hot working.
Piecing Failure Analysis of Drill Pipe Upset
Authors: Li Fang Po , Liu Yong Gang , Yong Wang
Published: August 2011

The failure cause of Φ127mm G105 IEU drill pipe upset was investigated through mechanical properties testing, optical morphologies and fracture surface analysis. The result show that drill pipe upset’s failure reason is the elephant hide and decarburization layer in its out-surface caused by improper upset treatment in forging process. Elephant hide and decarburization layer existing in drill pipe upset changed seriously reduced its strength and fatigue property. Under the effect of alternating stresses, the crack first initiated from the deepest position of elephant hide and developed quickly. In the end, it leaded the drill pipe to early piecing failure.
Vector Calculation for Tool Envelope Surface in Five-Axis NC Machining
Authors: Zhou Yuan Sheng , Yang Xu Jing , Chen Ze Zhong Chevy
Published: August 2011

A vector calculation method is proposed to compute the tool envelope surface in five-axis machining. By introducing the typical five-axis machine tool motion, the velocity of cutter is obtained with rigid body motion theory. Based on envelope theory and some geometric characteristic of the cutter, the envelope condition is be simplified to find the grazing point with vector calculation method. The results can be applied to NC machining simulation, toolpath verification and optimization.
The Application of FEA in High-Speed Cutting Tool
Authors: Ji Lian Qing , Liu Kun
Published: August 2011

The history and application of the FEA are briefly presented in this paper. Several key technologies such as the building of material model, the establishment of the chip - tool friction model as well as meshing are described. Taking the high-speed cutting of titanium alloy (Ti - 10V - 2Fe - 3Al) as an example , reasonable cutting tools parameters are determined by simulating the influences of cutting temperature, cutting force on the tools parameters using FEA.
Thermodynamic Modeling of the Mg-Ni-La-Cu System
Authors: An Xue Hui , Li Qian , Zhang Jie Yu
Published: August 2011

The isothermal section at 573 K of the Ni-Cu-La system was experimentally validated as well as the Mg-La-Cu system was thermodynamically evaluated. Four sample alloys in the Ni-Cu-La system were prepared and analyzed by ICP, XRD and BSE/EDS. All the experimental results were compared favorably with the calculated phase relationships. For the Mg-La-Cu ternary system, the isothermal section at 673 K was assessed on the basis of the available results in literatures, which showed a good agreement with the experimental data. Based on the thermodynamic models and parameters of the six binaries and four ternaries, the Mg-Ni-La-Cu system was finally modeled. The non-equilibrium solidification path La0.7Mg0.3Ni2.8-xCux (x=0-0.4) and the vertical section of LaNi5-Mg2Cu were calculated and analyzed from the viewpoint of hydrogen storage alloys design.
Effect of Abrasive and Surfactant on Chemical Mechanical Polishing of Hard Disk Substrates
Authors: Wang Sheng Li , Li Zhen Xia , Yang Li Bing , Liu Li Bin , Tian Yu
Published: August 2011

Chemical mechanical polishing (CMP) has been a widely applied process for hard disk substrates with nickel–phosphorous (Ni–P) plated. In this paper, the effects of abrasive and surfactant on the polishing performance of hard disk substrates using prepared colloidal silica-based alkaline slurry were investigated. The experimental results indicate that the material removal rate (MRR) strongly depends on the abrasive concentration and nonionic surfactant have little influence on the material removal rate. Under the testing conditions, smaller SiO2, moderate SiO2 concentration and higher surfactant concentration can obtain high surface quality in the prepared slurry. These results have been explained by which the abrasive particles move through the cover layer caused by surfactant adsorption on the disk substrates surface being polished.
Effect of Modulation Frequency on Detecting Metal Materials with Microcracks Based on Ultrasound Infrared Lock-in Thermography
Authors: Tang Qing Ju , Liu Jun Yan , Wang Yang
Published: August 2011

The non-destructive ultrasound infrared lock-in thermography (ULT) testing method was used to detect metal specimens with defects of micro cracks. An experimental platform was built based on the analysis of the ULT principle. Experiments had been carried out to Q235 plates with different testing parameters. The testing effect of thermography, amplitude and phase images was analyzed, and the relations between amplitude difference, phase difference, signal-to-noise ratio and modulation frequency were discussed.
Design and Lubricating Property Research on Radial Supporting Bearing of Marine Main Thrust Bearing
Authors: Zhou Jian Hui , Chen Ru Gang , Li De Zhi
Published: August 2011

The radial supporting bearing of main thrust bearing is the key equipments of shafting on large-scale ships, whose working lubricating property has an important influence on the working condition of the shaft. By means of theoretical analysis and Matlab programming, investigations have done on the main working condition lubricating of the radial supporting bearings. And the distribution rules of oil film thickness and pressure under same vertical load and different rotate speed is given, which lays a foundation for the design of large marine’s thrust bearing.
Research on Cutting-Tooth Outline Distortion of Internal Helical Gearing Machine Tool
Authors: Liu Yu Xi , Wu Su Zheng
Published: August 2011

Based on sports of machine tool and characteristic of involute outline internal helical gear , so gain mathematic model and tooth face equation of outline internal helical gear. Upbuild and analyzed milling load conditions of machine tool on the base of this, Upbuild milling load model of outline internal gear on the base of cutting-tooth distortion of machine tool, provide theory for involute outline internal helical gearing machine tool.
Evaluation of Rheological Measurement of Polymer Blends Melts in Torque Rheometer
Authors: Jin Gang , Zhao Xin Liang , Wang Meng Meng
Published: August 2011

A detailed experimental research on the rheological measurement by torque-rheometer (TR) based on a measuring model established by former researcher is presented. The influence of measuring conditions, material type and rotor geometric were discussed. Measuring results from the torque-rheometer were compared with those from capillary rheometer. It’s confirmed that under certain measurement conditions, torque-rheometer can accurately measure the melt rheological properties of polymer composites or blends. Measuring conditions and material type have little effect on the results accuracy. The rotor geometry has great impact on the reliability of measurement.