bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Subcarrier and Power Allocation Based on Nash Bargaining Solution in Symmetric Cooperative OFDMA Networks
Authors: Liu Wei , Tang Jing Min
Published: February 2011

In this paper, subcarrier and power allocation are jointly considered in a three-node symmetric cooperation orthogonal frequency-division multiple access uplink system. With the help of Nash bargaining solution, the dynamic subcarrier allocation scheme and the adaptive power allocation scheme are proposed for joint optimization. The joint resource allocation is decomposed and solved by dynamic subcarrier allocation algorithm and adaptive power allocation algorithm. Simulation results show the effectiveness of the proposed cooperative scheme.
Numerically Testing and Analyzing the Limit Bearing Capacity of Pollution Soil Body
Authors: Liu Li Bo , Jiang An Nan
Published: February 2011

Because actual soil body, especially pollution soil has the complex geotechnical conditions and non-uniformity character, the conventional methods are limited to solve the foundation bearing capacity pressure. The paper proposed an analysis flow of pollution soil foundation bearing capacity evolution, and proposed the numerical test method for pollution soil body combining Fast Lagrange numerical method and limit analysis theory, which utilizes the power ability of numerical simulation and has good flexibility to complex foundation. Using the method to execute a simulation for the pollution soil body of certain sulfuric acid factory, obtained the visual destroy process and got the foundation bearing capacity accurately. And the foundation destroy mechanism is also revealed. The numerical results stated that the proposed method is a good mean to analyze foundation bearing capacity for pollution soil body which has good application prospect.
A Brief Analysis on Computer Laboratory Management in High Schools
Authors: Gao Wei Ming , Liu Min , Wang Ya Qin , Liu Li Mei
Published: February 2011

The computer labotory management in high schools is a vital part in the management of university. In order to take good advantage of computer labotory in high school so as to carry out smooth work on teaching and doing experiments and create the greatest social and economic benefits, it is essential to standardize the management of computer labotory in high schools in a scientific way.
Study on Nanocellulose / Starch Composites
Authors: Zhen Wen Juan
Published: February 2011

Nanocellulose and thermoplastic starch polymer (TSP) composite was prepared by solution casting method for the sports industry. As a biological material, this material had special properties of nanomaterials and the rigidity of cellulose, dimensional stability and biodegradable. Such material might be one of the answers to the disposal problem of waste sports equipments. As a reinforcing material, nanocellulose was added to TSP matrix and composites were made with appropriate solvent systems by solution casting methods. Water absorption, degradation and film mechanical performance were evaluated and compared with the pure thermoplastic starch. The tensile strength and modulus of the nanocomposite films reveled significantly enhanced. Compared to the pure thermoplastic starch, the degradation and water absorption increased significantly. By solution casting, nanocellulose and starch composites were successfully prepared, which had excellent mechanical properties and good performance at biological degradation.
Realizing Technical Synthesis and Digital Reproduction of the Swimming Movements Based on OpenGL Technology
Authors: Wu Chun Xia , Zhou Xiao Dong
Published: February 2011

Sports technique analysis refers to the technical diagnosis on the athletes’ movements in order to enhance the scientificalness and rationality of the actions of sport skills. In this paper, the methods of its application into swimming events with different purposes and in different environments are given. After the athletes’ abovewater and underwater kinematic parameters are obtained, first of all, the OpenGL technology is used to separate the athlete's movement technique from their sports environment and to digitally reproduce the technical movement synthesis, and then the key paddling route of the swimming athlete’s “paddling” motion technique is drawn.
Design and Implementation of Video Monitoring System Based on Linux
Authors: Yu Hong Bo , Li Hui , Zhu Heng Jun , Tao Bai Rui
Published: February 2011

It s a design of video server based on embed Linux system. The platform is integrated with boa server, to realize the dynamic interactivity between remote users and web monitoring server by CGI program. Get the live image data by USB cameras, then transferring the image to PC by internet. By that means, the image display can be realized through any PC which is connected to net. The system realizes remote monitoring and image transmission by its own TCP/IP protocol, which promises the flexibility, sharpness and stable property.
Metal Label Pressed Protuberant Characters Recognition Based on Hidden Markov Model
Authors: Chen Wei
Published: February 2011

A recognition method of pressed protuberant characters based on Hidden Markov models and Neural Network is applied, which the surface curvature properties and the relation of metal label characters are analyzed in detail. The shape index of the characters is extracted. A neural network is used to estimate probabilities for the characters depended on the surface curvature properties, then deriving the best word choice from a sequence of state transition. It is shown in test that the proposed method can be used to recognize the pressed protuberant on metal label.
Bayesian Network with Association Rules Applied in the Recognition of Handwritten Digits
Authors: Zhao Wen Qing , Zhang Yan Fang , Zhang Sheng Long
Published: February 2011

Classification Based on Association (CBA) algorithm built a classifier based on the association rules, but without considering the uncertainty in the classification problem. This paper proposed a Bayesian network classifier based on the association rules. The algorithm extracts the candidate set uses association rules and classification algorithms related to the network, then uses “greedy hill-climbing algorithm” to learn network structure to get a better topology, and verify that this algorithm is valid on handwritten numeral recognition.
The Research and Realization of Traffic Service System Based on GPS and GPRS
Authors: Guo Le Jiang , Liu Yan Bin , Yang Yun Hai , Wang Wei Jiang
Published: February 2011

In recent years, data service has been gaining popularity in embedded system and general packet radio service (GPRS).GPRS is one of the next-generation wireless communication technologies. This paper takes advantage of seamless GPRS data coverage and its good capacity to combine GPRS technology and GPS system, realizing real-time positioning of vehicles. This paper describes structure of the system using GPRS and GPS technology for real-time data acquisition and transmission. It transmits the data through GPRS network to the background system for centralized data processing and analysis. The analysis results are given back to administrator rapidly and timely through the wireless network. This module not only saves development and maintenance costs of a private network, and takes full advantage of the unique advantages of GPRS. Finally, this paper summarizes characteristics and advantages of the system in practical application and has good prospects.
Hydrogen - Hydrogen Adsorption Interaction Energy in Zeolites
Authors: Du Xiao Ming , Huang Yong , Wu Er Dong
Published: February 2011

A general model based on Ono-Kondo lattice theory for hydrogen adsorption, nearest neighbor interaction energy among adsorbate molecules were derived according to thermodynamic principle. A linear form of the above general model was applied to determine the interaction energies among hydrogen molecules inside adsorption layer from the previous experimental data of hydrogen adsorption on A- and X-type zeolites. The results show that the energies of hydrogen-hydrogen interactions inside the adsorption layer are negative values, indicating that the attractions among the adsorbed hydrogen molecules are prominent in the present work. And the influence of hydrogen molecules outside adsorption layer on the adsorbed hydrogen molecule is not important.
Study of Impacts on Students’ Comprehensive Developments by College Physical Education
Authors: Li Zeng
Published: February 2011

As a multi-dimensional open culture and an organic composition of higher education, compared with other forms of education, college physical education has a unique advantage in the promotion of college students to form and develop good personalities. The factors of college physical education that impact college students’ personality developments are divided into two parts of promoting factors and impeding factors. Among them, promoting factors including teaching factors, management factors, and personnel support, etc., play an active role in promoting the process of college students’ personality developments; impeding factors including behind ideas and concepts, various course contents, monotonous teaching mode, rigid management mode and teachers to be improved, etc., seriously impede the progress of college students’ personality developments. College physical education has its impacts on the process of college students’ personality developments in its unique forms and methods, the roles of which are mainly represented in: promoting physical and mental healthy developments; coordinating interpersonal relationships to enhance adaptive capacities to the society; developing firm volitional qualities and magnificent moral sentiments; enhancing the struggling consciousness to participate in competitions and cooperation; and culturing innovative consciousnesses and innovative capacities, etc. aspects.
The Online Assessment Method of Tower Crane Effective Life Based on Tower Crane Group Monitoring System
Authors: Han Ze Guang , Hao Rui Qin , Zheng Xi Jian
Published: February 2011

In this paper, we share our experience in information collection, management and online effective life calculation of tower crane. We propose a framework to complete collecting, classing, storing and processing of the working parameters of tower crane through wireless transmission and some commercial software, such as Visual Basic and SQL Server, based on the monitoring system of tower crane group. The load spectrum of tower crane can be gotten by numerical statement of above-mentioned information. Thus, the real-time effective life of tower crane is calculated and displayed directly through our algorithm. This life can be taken as a reliable reference in the safety detecting of tower crane. The effectiveness of the proposed method has been verified by a simple example of tower crane hoisting mechanism assessment. The results show that the system is accurate and reliable. The main advantage of the new method is its simplicity of implementation in lack of the load spectrum.
Diffusion Study of Al-8%Si Alloy Double-Coating on Steel
Authors: Lu Yu Heng , Huang Cai Min , Zeng Jian Min
Published: February 2011

Al-8%Si alloy double-coating on Q235 steel were produced, Then the samples were executed diffusion at high temperatures protecting with flowing argon gas. Scanning electron microscope (SEM), optical microscope (OM), and energy dispersive X-ray spectroscope (EDS) were employed for microstructure observation of cross-sectional, surface and compositional analysis of coating. The diffusion mathematical model was established with the finite element method. The results show that good quality Al-8%Si coating is made; after heat-diffusion treatment, the new phases FeAl and Fe3Al presents; Silicon atoms in Al-8%Si alloy can hinder the diffusion of aluminum atoms into steel substrate at high temperature; Al-8%Si alloy double-coating sample’s high-temperature oxidation resistance is higher than Q235 steel. This material is hopefully used in the engine exhaust manifold.
Influence on Tribology Characteristic of the Steel-Cast Iron Friction Pair under Different Concentration of the Self-Repairing Additive and Mechanism Analyzing
Authors: Yan Yan Hong , Yang Yu Lin , Zhang Dan
Published: February 2011

The influence of frictional wear characteristics were investigated under the Self-repairing Additive condition with different concentration by using MMU-5G end-face friction and wear testing machine. The surface images of friction pair and their chemical composition were detected by using SEM and EDS. The result indicates different concentration has a great influence on frictional wear characteristics of friction pair. The Self-repair coatings are formed on the 45#steel worn surface while nothing on the cast-iron worn surface, study considers that metallographic structure and mechanical performance of cast iron are the prime causation resulting in no Self-repair coatings. Self-repairing Additive of the right concentration has remarkable effect on antifriction and wearing of cast iron.
Different Curing Agents on the Photoaging of Polyurethane Coatings
Authors: Xiang Bin , Xiang Qing , Liao Jin , Chen Shi , Xu Zhong Cheng
Published: February 2011

In this paper, the artificial UV accelerated aging test was used to investigate the effect of curing agents including TDI-TMP prepolymer, N75, N3390 and IPDI propylene acid resin on the photoaging of polyurethane (PU) coatings. The thickness and gloss loss, color difference, as well as UV absorption of PU coatings were measured during the UV exposure, meanwhile FTIR and SEM were utilized to monitor the chemical and mophological change after UV exposure. The TDI-TMP prepolymer coatings showed the worst aging resistance and whilst the results of N3390 coatings are relatively good.
Study on Characteristics of Acoustic Emission Property in the Normal Concrete Fracture Test
Authors: Hu Shao Wei , Lu Jun , Zhong Xiaoqing
Published: February 2011

This paper first elaborates the domestic and foreign study and applying current situation in terms of the concrete testing field regarding to acoustic emission technology, especially the study progress in the large dam concrete field. By improving the current test device and updating and reforming the measuring equipment, the task team introduces the acoustic emission testing system into the concrete double-K fracture parameter test. The new device can not only accurately control the loading velocity in the test, but also correctly judge the time and property of cracking, instability and damage of specimen. This paper establishes the acoustic emission criterion for concrete fracture according to the recognition features of acoustic emission of concrete in fracture critical state. The test result presents that the cracking time of specimen can be correctly judged by using feature parameters of acoustic emission, which properly matches the cracking time measured by the traditional strain method, and this judging is more direct and convenient for on-site operation, providing theoretical and technical support for application in the concrete fracture parameter test by acoustic emission technology.
Effect of Normalizing Pre-Treatment on Microstructure of Laser Hardened Ductile Iron
Authors: Wang Ya Nan , Han Li Ying , Sun Ying
Published: February 2011

We adjusted the pearlite content of ductile iron matrixin by normalizing, finding that the microstructures of laser hardened ductile iron with different pearlite content and distribution were quite different. According to their microstructure characteristics, there are three types: ⑴pearlite transformation type; ⑵ pearlite and ferrite transformation type; ⑶ferrite transformation type. We also studied the microhardness of different ductile iron laser hardened layers and the phase around the graphite ball. The results showed that under the appropriate laser treatment process (laser output power of 1kw, spot diameter of 5.2mm, scan speed of 16mm / s), ledeburite shell, with the hardness up to HV0.11070, formed around the graphite ball in the surface layer of ductile iron hardened layer. Outside the ledeburite was the carbon diffusion zone with hardness of HV0.1850. It was composed by the plate martensite of large needle and large amount of residual austenite. In the hardened layer of ferrite transformation type, martensite formed out around the ledeburite shell or graphite ball.
Anticorrosive Films Prepared by Incorporating Permanganate Modified Carbon Nanotubes into Waterborne Polyurethane Polymer
Authors: Hu Shou Tian , Kong Xiang Hua , Yang Hui , Sun Rui Hong
Published: February 2011

In this paper the influence of carbon nanotubes (CNTs) on anticorrosion properties was discussed. KMnO4 modified carbon nanotubes were added into Waterborne PolyUrethane, then galvanized steel sheets were dipped into this composites to get a thin film and dried at 120 °C for 60 seconds. SEM observation show the film thickness was 3 µm and CNTs were dispersed in the polymer matrix. XRD demonstrated that some KMnO4 decomposed into K2MnO4 and MnO2. Polarization curves demonstrated the film exhibited excellent anticorrosion when the amount of KMnO4 modified CNTs was 6%.
Fault Analysis on Crosshead Fracture of the Reciprocating Piston Compressor C102B
Authors: Zhang Ya Xin , Chen Li Juan , Li Bin Bin
Published: February 2011

The C102B reciprocating piston compressor is an important equipment widely used in methanol production. Because of the complexity of exact dynamics analysis, the traditional and common way to find the reason of fracture is only based on metallographic structure analysis of crosshead material. In this paper, after metallographic structure analysis of crosshead material of the C102B compressor, the maximum loads on it are also calculated and two dangerous crosshead positions with maximum load are determined. Finally, stress analysis of the crosshead in two dangerous positions is implemented by FEM technology. Based on the above study, the reasons of crosshead fracture of the C102B compressor are found. The results has an inportant significance for judging the resaon of crosshead failure.
Effect of Preheating Temperature on the Cooling Curves of BW Quenching Media
Authors: Gao Zhi Ting , Yan Yan Fu , Wang Miao Hui , Zhou Yong Song
Published: February 2011

Using KD-CB177 quenching media cooling tester, the cooling curves of 32 oil and 8%BW quenching media was tested and the effect of preheating temperature on the cooling curves of the quenching medias and the hardness of 45 steel was investigated. Results showed that the characteristic temperature, the temperature on the maximum cooling rate and the maximum cooling rate of the 8%BW quenching media decreased with the increasing of the preheating temperature Using 8% BW under the preheating temperature of 50°Cand 32 oil under the preheating temperature of 40°C to [quench the 45 steel, the properties of 45 steel are considerable. So the 8% BW quenching media maybe can be used to substitute the 32 oil under the certain condition.
Research on the Adhesion of Stainless Steel Film on Gd by Magnetron Sputtering
Authors: Zheng Xiao Qiu , Xie Shi Kun , Yi Rong Xi
Published: February 2011

In order to research the adhesion of sputtering protective coating of Gd. Gd substrates was coated with 1Cr18Ni9Ti by means of DC magnetron sputtering technology. The characteristics of the film were investigated by scanning electron microscopy (SEM), EDS, SPM and the adhesions of film was tested by tension test. The results show that the films of 1Cr18Ni9Ti are distributed by means of islands when the sputtering was initiated and the grains are like thin fiber. After a few minutes, the films are smooth and perfect, the interferences between 1Cr18Ni9Ti and Gd join together strongly, and the largest strength of adhesion is 24.7MPa when the sputtering density is 966 w/cm2 and the sputtering time is 8 minutes.
Study on Electron Beam Alloying Micro-Structure and Wear Performance of 3Cr2W8V
Authors: Chen Yuan Fang , Han Chao , Chen Kang , Xu Hong Bin , Wang Chun Huan
Published: February 2011

Ti and TiN were deposited on mold steel 3Cr2W8V by PVD, then processed with the technology of electron beam surface alloying. The microstructure of modified and the influence of modified layer on wear performance of 3Cr2W8V were studied. The result shows that the section hardness of coating Ti material has increased by 35% at most when the times of treatment reach 25, the distribution of the section hardness is waved, the pick point of section hardness is at depth of 100μm to 200μm, The friction of coating Ti layer is decrease by 50% at most when the times of treatment reach 20, and the abrasion loss is totality descend by about 80%;the section hardness of coating TiN material has increased by 35% at most also when the times of treatment reach 25, the pick point of section hardness is at depth of 150μm to 250μm, the friction factor of material is waving with descend while the times of bombardment increased; the abrasion loss is totality descend by about 90%.
Observation of Capillaries after Implanting Porous Silk Fibroin Films in Rats
Authors: Sun Zi Ling , Bai Lun
Published: February 2011

Porous Silk Fibroin Films(PSFFs) as dermis implant were used widely in biomaterials. To investigate angiogenesis in rat at different time after PSFFs implanting, CD34 was observed. Immunohistochemistry showed new blood vessels were mainly formed by sprouting next to PSFFs after 7 days operation. Microvessel Density (MVD) in PSFFs was 0, 3.54, 11.6, 24.5 after 1day, 7days, 15 days and 25days implantation respectively.
Preparation and Stress Calculation Analysis of Light Elastic-Plastic Material
Authors: Chen Lin , Duan Jin Liang , Li Ge , Wang Jian Guo
Published: February 2011

Based on the photo-elastic method, four groups of different ratio light elastic-plastic material were prepared by changing the epoxy resin, the firming agent, the plasticizer mass ratio; and the light elastic-plasticity material stress-strain curve and its elastic modulus E and Poisson's ratio were obtained through the stretch experiment. The light elastic-plastic rail models were made by 1:5, and the computation analyzes stress distribution of the rail head of the heavy rail and carried on the static examination. The stress stripe chart change rule of the light elastic-plasticity material during load and unload process was observed.
Structural Optimization of Ground Vias for 3D ICs
Authors: Li Chun Quan , Kuang Xiao Le
Published: February 2011

Nowadays, IC manufacturing meet the challenges of physical limits, through silicon via(TSV) technology has increasingly become the focus of the microelectronics industry due to its shorter wiring route, better signal integrity, larger bandwidth, lower power consumption and smaller packaging size. In this paper, the transmission performance of TSV was analyzed and the impact of ground vias number, diameter and pitch with TSV on TSV transmission performance. A design of experiment (DOE) was established to investigate the impact of different ground vias parameter combinations on the transmission of TSV and the range analysis of the experiment results was executed. Based on the DOE, two regression equations were formed to estimate the electrical performances of TSV. From the two equations, the structure parameters were optimized, the S11 and S21 results of optimization parameter combination reduced 0.4dB and 0.15dB, respectively.
The Numerical Simulation of Directional Solidification Process Temperature Field for Large-Scale Frustum of a Cone Ingot
Authors: Liu Kun , Wang Zhe , Han Ren Zhi , Ren Zi Ping
Published: February 2011

By using Fluent software, the mathematical model of temperature field is established on directional solidification process for large-scale frustum of a cone ingot, and the result is analyzed by Origin software, Tecplot. The influences of different width/thickness ratio to directional solidification process of cone ingot are discussed in order to provide basis for design optimization and ingot quality improvement.
SVR-Based Predictive Model for Purity of the Mg-Al-Hydrotalcite
Authors: Tang J.L. , Cai C.Z. , Zhu X.J. , Wang G.L.
Published: February 2011

In this study, a prediction model based on support vector regression (SVR) to describing the complex nonlinear relationship between the purity of the resultant (Mg-Al-hydrotalcite) and the raw material amount of reactant (NaOH, Mg2+ and Al3+) was developed. And the partarticle swarm optimization (PSO) algorithm was employ for optimizing the parameters of SVR model.The predicton results from SVR compared with that of BP (back- propagation) neuarl network prediction model by applying identical training and test samples stongly support that, SVR-based predictive model for Mg-Al-hydrotalcite purity is feasible and effective.This study suggest that SVR may be an efficient and novel methodology for conduct the productive process to produce synthetic hydrotacite in high purity and in high yield.
Numerical Study of Defect Free Elbows Subjected to In-Plane Bending Moment
Authors: Chen Wang , Wang Yin Pei , Li Pei Ning , Jin Chen , Sun Xiao Ming
Published: February 2011

Elbow is a type of components widely used in a piping system, and so it is very important to know the plastic carrying capacity of elbow. In this study, the elastic-plastic behavior of elbows with various ratios of t/rm and relative bending radius R/rm were investigated in detail by using of three-dimensional (3D) non-linear finite element (FE) analyses, assuming elastic-perfectly-plastic material behaviour and taking geometric nonlinearity into account. The analyses indicated that elbow exhibited different behavior obviously at the elastic-plastic states subjected to In-Plane opening bending moment and closing bending moment. The closed form equations of elbow involving effect of tangent pipes were established.
Numerical Simulation of Intermediate Frequency Induced Heating Steel Plate with Finite Element Method
Authors: Ma Yong Lin , Cai Miao , Han Qiang , He Wen Li
Published: February 2011

The FEM simulation is used to study the intermediate frequency induced heating process. The temperature distributions and temperature differences are obtained by two kind frequencies of 500 and 1000Hz. It is found that, in this simulation condition, the length of uniform temperature region is about three times of the coil height. It is obvious that, no matter which frequency, the heating rate is very high. With the process of 1000Hz, in less than 20 seconds, the heating temperature can reach a reasonable temperature, and with a process of 500Hz, the temperature can reach a reasonable temperature in more than 40 seconds. It is recommended that the frequency between 500 to 1000Hz could be available for a practical use.
Impact of Float Loss on the Project Costs
Authors: Lo Wei , Chen Yih Tzoo
Published: February 2011

Many techniques have been developed to analyze the time impact and the costs caused by the disruptions of the project works. However, most were limited on the delay of the critical path and the overall project completion date. In recent years, although more attention has been drawn on the impact of the float loss on the overall project cost, not a single research result has been widely accepted and recognized. This study aims to fill this gap. This research firstly introduces a resource-integrated genetic algorithms (G.A.) model, which will be used to develop an optimal schedule including the timing and quantity for each type of resource required to complete each individual activity. Secondly, by using a case study this research intends to identify the impact of float loss on overall project cost through comparing the as-planned optimal schedule with an after-impacted schedule. Based on the research results this research has identified that the relationship between the float loss and project cost can be expressed as a step function and the time span of total float can be divided into and cost-related float and cost-unrelated float, termed as optimal float, in which the consumption of float will not cause the delay of the project completion date, nor the increase of project cost. The findings refute the traditional concept that the total float belongs to neither the owner nor the contractor, and suggest that the utilization float is free only within the optimal float and the float apportionment will never be reasonable unless the cost of float floss has been taken into consideration.
Prediction of Processing Parameters of Laser Clad TiC/NiCrBSiC Coatings on Ti6Al4V by Finite Element Analysis
Authors: Lei Yi Wen , Niu Wei
Published: February 2011

This work deals with the processing parameter prediction of laser clad TiC/NiCrBSiC coatings on Ti6Al4V alloys by Finite Element Method. Temperature distribution and dilution rate were obtained. The temperature distributions were sparse and enlarged when laser power increased. With increasing of scanning velocity, the temperature distributions were compressed and lengthened at the front and at the end of the laser beam, respectively. Under laser power P=2.5 kW, scanning velocity V=5 mm/s, the calculated and experimental dilution rates are 6.25% and 8.3%, respectively. There is a good agreement between the results.
Virtual Measurement of Machining Errors Based on Comparison Method of Three Models
Authors: Gu Li Zhi , Peng Li , Peng Lei , Qiong Li
Published: February 2011

A virtual measurement system for geometric surfaces of some specific mechanical components was created with Cage Method and Virtual Probe technique based on Three Model Method. The fundamental constituents of the system, the key part of the Three model Method, measured model, were presented in detail with weighed random number technique. Measuring accuracy may properly be controlled by alteration of the number of sampling points of the measured model. Principle of the measuring system, with extendable function, was put forward and explained. The system was operated by VC++ and OpenGL with characteristics of lifelike, function-extension, and immersion. Virtual measurement on a bar-shaft for cylindricalness is given as an example, and it has been shown that the results have much good agreement with those of experiments and that the system worked stably.
Microstructures, Thermal Shock Resistance and Isothermal Oxidation Resistance of Nanostructured Ceria Stabilized Zirconia Coatings
Authors: Wang Wen Quan , Gong Wen Biao , Sun Da Qian
Published: February 2011

Microstructures, thermal shock resistance and isothermal oxidation resistance of plasma-sprayed nanostructured ceria stabilized zirconia (CSZ) coatings were investigated. The results revealed that the nanostructured CSZ coatings mainly included two kinds of typical microstructures, nanosized CSZ particles embedded in the so-called matrix and micrometer-sized columnar grain structures of CSZ similar to those of the conventional coatings. Compared with the conventional CSZ coatings, the nanostructured CSZ coatings were denser and had finer and fewer porous structures and microcracks. Further study showed that the nanostructured CSZ coatings had higher thermal shock resistance and isothermal oxidation resistance compared with conventional CSZ coatings. The improved properties of the nanostructured CSZ coatings were attributed to the better coating toughness and decreased porosities and microcracks in the coatings.
Radiative Transfer Modeling and Monte Carlo Simulating of a New Digital Airborne Camera
Authors: Yan Lei , Zhao Shi Hu , Duan Yi Ni
Published: February 2011

Application of digital aerial camera was a milestone in the development of Photogrammetry and Remote Sensing. The new digital sensor leads to the changes of remote sensing imaging models. Generally, remote sensing imaging models have two kinds: geometric model and radiative model, in which radiative model mainly focus on the radiative quality of remote sensing images. In this paper, a new kind of airborne camera, namely Twice Imaging Digital Camera (TIDC), is introduced, which integrates the advantages of film airborne camera and digital one. It adopts twice imaging techniques to acquire large format, strict central projection images. The radiative transfer model of TIDC is built on the physical processing of digital imaging. The intermediate imaging device of TIDC influences digital images’ quality badly, such as luminous intensity distribution, decay and noise. For this reason, the approach of light tracing based on Monte Carlo is used to simulate radiative transfer in TIDC and test the performance of the intermediate imaging device. The importance of this work is: The Monte Carlo simulating experiment proposed by this paper can be widely applied in the simulation and modeling of other digital imaging systems, and has great practical value in the evaluation and optimization of image quality, the improvement of remote sending imaging system, as well as the estimate of image acquirement results.
Simulation on Pipe Joints Expansion Technology of NiTiNb Shape Memory Alloy
Authors: Yang Gen Lin , Ni Zhi Ming , Han Jin , Wang Er Min
Published: February 2011

In order to study the low-temperature expansion process of NiTiNb shape memory alloy, this paper makes use of numerical simulation method to complete the simulations and analysis. The shape memory effect of NiTiNb alloy pipe joints under different expansion temperatures and expansion strains have been compared and evaluated. Through simulations of low-temperature expansion and elevated temperature shape recovery of NiTiNb alloy pipe joints, the relationships between elastic deformation, phase transformation deformation and recovery ratio under different expansion temperatures and expansion strains have been acquired. The results show that the highest expansion strain should below 11%, in consideration of recovery ratio and recovery temperature, the optimal expansion temperature range is -60~-50°C .
Modelling the Grain Pattern and Orientation in Radiata Pine Boards
Authors: Liu Hua Wu , Xu Ping , Xie Kai Fang
Published: February 2011

This study developed new algorithms to simulate the grain pattern and orientation of radiata pine boards based on the geometrical and growth features of radiata pine trees. Scenario simulation is presented in the article. The established methodology offers insights for sawmills to establish feasible log breakdown strategies and maximize radiata pine timber value.
Modeling of Aluminum Extrusion Process Using Non-Orthogonal Block Structured Grids Based FVM
Authors: Wang Rui , Li Hong Zhong
Published: February 2011

The mathematic model of 3D aluminum extrusion processes using finite volume method (FVM) was established in this paper. The basic theories and rigid-plastic flow theories of this model were researched and built. Non-orthogonal structured grids were used to match complex geometric boundaries and local refinement of grids was also realized. The collocated arrangement is used to discretize the governing equations on non-orthogonal grids directly, pressure oscillations bring by this arrangement and error caused by grid’s non-orthogonality is eliminated by special treatment. A pocket die extrusion process was simulated using the program developed in this paper. The simulation results were also compared with that simulated by FEM software Deform in the same process, material and die conditions. The feasibility and efficiency of the mathematic model built in this paper was demonstrated by the simulation results and the comparison.
Spatial Cam Modeling and Analysis on Curvature of Conjugated Surfaces
Authors: Cheng Yun Jian , Jiang Hong , Wang Xiao Chun
Published: February 2011

A novel limited slip differential mechanism for wheeled vehicle is introduced in this paper. A new modeling method for spatial cam mechanism used in the differential is detailed derived. The melding method and the formulas of induced normal curvature for conjugate surfaces of the cam mechanisms is derived on basis of meshing theory of conjugated surfaces and differential geometry theory, and the results provide theoretical foundation for the cam optimization.
Dynamic Contact Analysis of the Offset Face Gear
Authors: Li Qing , Guo Yu , Wang Tai Yong
Published: February 2011

The face gear drive is a gear meshing drive with cylindrical gear and bevel gear. Because of its small space, high contact ratio, large transmission torque, low vibration and noise, not sensitive to the axial phase error of the worm and so on, face gear transmission is widely applied. In the traditional gear transmission dynamic contact analysis (TCA), first, simulate the meshing equation; second, calculate the contact trajectory that is formed by the adherent point; last, solve each of the instantaneous contact areas and solve tooth contact region in meshing process. But it can’t solve the tail, diamond and other high contact defects. In the real mesh transmission, tooth meshing is very complex, including edges contact, multi-tooth engagement and many other issues. With the progress of the times, using finite element analysis software ANSYS, it will be able to simulate the dynamic contact analysis of the gear. In this paper, the offset face gear as the research object, with MATLAB program, Solidworks and ANSYS software, establish the mathematical model of the orthogonal offset face gear, simulate its geometric model in the three-dimensional software. Finally, implement the simulation of its dynamic contact meshing in the finite element analysis software.
The Wave-Load Analysis of the Offshore Wind Power Installation Vessel Based on Frequency-Domain Methods
Authors: Zhao Ya Nan , Wang Li Quan , Du Hong Wang
Published: February 2011

The wave force spectrum expressed in terms of Morison's equation was deduced by ocean wave theory and spectral analysis theory, and the spectral analysis of wave force were analyzed with the finite element method which was applied to the leg of the offshore wind power installation vessel, the natural frequencies and the vibration model were accomplished with boundary conditions. The dynamic response of the leg were studied in different conditions, it can be concluded that the wave force of the leg is only related with geometric shape and working depth of truss legs.
Application of the Arbitrary Lagrangian Eulerian Formalism to Stationary Roll Forming Simulations
Authors: Boman Romain , Ponthot Jean Philippe
Published: February 2011

Due to the length of the mill, accurate modelling of stationary solution of continuous cold roll forming by the finite element method using the classical Lagrangian formulation usually requires a very large mesh leading to huge CPU times. In order to model industrial forming lines including many tools in a reasonable time, the sheet has to be shortened or the element size has to be increased leading to inaccurate results. On top of this, applying loads and boundary conditions on this smaller sheet is usually more difficult than in the continuous case. Moreover, transient dynamic vibrations, which are unnecessarily computed, may appear when the sheet hits each tool, decreasing the convergence rate of the numerical simulation. Beside this classical Lagrangian approach, an alternative method is given by the Arbitrary Lagrangian Eulerian (ALE) formalism which consists in decoupling the motion of the material and the mesh. Starting from an initial guess of the sheet geometry between the rolls, the numerical simulation is performed until the stationary state is reached with a mesh, the nodes of which are fixed in the rolling direction but are free to move on perpendicular plane, following the geometrical boundary of the sheet. The whole forming line can then be modelled using a limited number of brick and contact elements because the mesh is only refined near the tools where bending and contact occur. In this paper, ALE results are compared to previous Lagrangian simulations and experimental measurement on a U-channel, including springback.
Temperature Simulation in High-Speed Grinding by Using Deform-3D
Authors: Pang Jing Zhu , Li Bei Zhi , Yang Jian Guo , Zhou Zhen Xin
Published: February 2011

Grinding is one of the most important operations in material processing. The study on grinding mechanism is difficult to carry out because of the difficulty in measuring the actual grinding temperature, stress and strain by experiments. Finite element analysis software Deform-3D is employed to create the Johnson-Cook material constitutive model for high-speed grinding simulation. Grinding model was constructed to reflect the temperature, strain and strain rate in the process of grinding 40Cr steel. The temperature of grinding area in simulation is analyzed to verify whether the finite element model is reasonable.
The Research on Friction Impacting on Drawing High-Strength Steel
Authors: Wang Zhong Jin , Wang Jian Wei , Shen Yu Wei
Published: February 2011

The paper’s main content is that simulating the process—drawing the high-strength steel-DP500 which is used on automobile to the cylindrical cup through the commercial finite element simulation software—Dynaform. Through the simulation, the author analyzes the effect that friction impacts on drawing high-strength steel. The result is that: if the friction coefficient between the blank and the die declines, it can significantly improve the uniform of the blank’s thickness distribution; it can enlarge the processing range of DP500 steel through decreasing the friction coefficient; the springback is sensitive to the change of the friction condition. Generally speaking, in drawing process, improving the friction coefficient is very important to increase the drawing performance of the cylindrical parts.
Study on the Burning Characteristics of Poor-Quality Anthracite in Supercritical W-Shaped Flame Boiler
Authors: Wang Wei Shu , Liu Jun , Wei Hong , Zhang Hong Sheng , Pan Long Gang , Yan Guang , Li Shuai Shuai
Published: February 2011

With the good characteristics of high efficiency, energy saving and environmental protection, supercritical W-flame boiler can effectively solve the problems of clean and high efficiency combustion of poor-quality anthracite using for supercritical pressure boilers. In light of a 600MW supercritical W-shaped flame boiler, combustion models in fluent 6.3 were used to study the combustion law of poor-quality anthracite in the furnace, the effect of air distribution on the combustion process was analyzed. The results indicate that symmetrical air distribution can not form symmetrical flow field because of the structure effect of the nose of the furnace. The effect of the nose of the furnace can be effectively balanced by increasing the velocity on the front wall and there exists an optimal ratio of air distribution. In the central zone of the lower furnace, the temperature is high and the O2 concentration is low, which is beneficial to the ignition and combustion of pulverized coal. Because the pressure in the center of the furnace is higher than that near the side walls, the pulverized coal are forced to move towards the side walls, which can cause the sidewalls to be eroded by the flame and slagging. The study results have great significance for the optimization design and improving the efficiency of pulverized coal combustion of supercritical W-shaped flame boiler.
Coupled-Field Analysis of the Compliant Slider Mechanism with Rectangle Flexure Hinges Based on ANSYS
Authors: Duan Lei , Qiu Li Fang , Weng Hai Shan , Xie Zhi Yong
Published: February 2011

The compliant slider mechanism with rectangle flexure hinges was designed, and its pseudo-rigid-body model was built. The theoretical value of the relationship between force and displacement was given after analysis; the electrostatic-structural-coupled field finite element model of this mechanism was also built and analyzed by ANSYS, and the simulation value of the relationship between voltage and displacement was obtained; According to the relationship of voltage and force, the theoretical value was compared with the simulation value. The result indicates that the model is valid and the analysis is correct.
Power Flow and Energy Sharing between an Oscillator and a Continuous Receiver Structure
Authors: Ji Lin
Published: February 2011

A key assumption of conventional Statistical Energy Analysis (SEA) theory is that, for two coupled subsystems, the transmitted power from one to another is proportional to the energy differences between the mode pairs of the two subsystems. Previous research has shown that such an assumption remains valid if each individual subsystem is of high modal density. This thus limits the successful applications of SEA theory mostly to the regime of high frequency vibration modeling. This paper argues that, under certain coupling conditions, conventional SEA can be extended to solve the mid-frequency vibration problems where systems may consist of both mode-dense and mode-spare subsystems, e.g. ribbed-plates.
Numerical Simulation of Effect of Slip Conditions on PVC Co-Rotating Twin-Screw Extrusion
Authors: Cao Ying Han , Chen Jin Nan
Published: February 2011

The effect of wall conditions on the co-rotating parallel twin-screw extrusion of rigid polyvinyl chloride (RPVC) is studied. The relationship between the shear stress at the screw wall and the slip velocity of the flowing melt obeys Navier’s linear law. At zero pressure difference between the entrance and exit of the melting section of twin-screw extruder, the volumetric flow rate and 3D isothermal flow fields of RPVC are calculated under different wall slip conditions in the metering section of the twin-screw extruder by using the evolution technique in POLYFLOW. The results show that when the slip coefficient is smaller than 104Pa*s/m , the volumetric flow rate of the melt is constant, corresponding to the full slip condition. When the slip coefficient is larger than 104Pa*s/m , with the slip coefficient decreasing, the volumetric flow rate and viscosity increase, but the gradients of velocity, pressure, and shear rate decrease. The residual stress of the product is thus reduced. Therefore, increasing wall slip is good for the stability of polymer extrusion and the product quality. The dispersive and the distributive mixing of the twin-screw extruder under full slip and no slip conditions are also studied. Results show that the mixing performance under no-slip condition is better than under full-slip condition, but slip at the wall is good for the extrusion of heat-sensitive materials.
3D FE Modeling of Three Rolls Cross Rolling Process of a Rotary Disk Part
Authors: Zhou Xiu Mei , Hua Lin , Qian Dong Sheng
Published: February 2011

Special rolling is also called rotary forming process, which is an advanced manufacture technology of making workpiece generate deformation in a rotary state by continuous local plastic forming. Disk rotary parts with outer stepped cross-section, such as wheels, flanges, valves and so on, are widely used in engineering machinery. Traditionally, this kind of part is manufactured by forging and cutting, which consumes a lot of energy and materials especially to the large size part. In this paper, a new specific rolling technique called three rolls cross rolling is first presented to produce this kind of part, and the principle and characteristics of this technique are described in detail. Then, base on the principle of the three rolls cross rolling, a 3D coupled thermo-mechanical FE model is developed under ABAQUS software environment. As a result, under the simulation and analyses of a real example, the feasibility of this technique is verified, and the evolutional laws of the strain, temperature and rolling force and power parameters during the process are investigated as well. The obtained results provide valuable guidelines for the further investigation on the forming characteristic of the three rolls cross rolling technique.