bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Numerical Simulation of High-Speed Railway Noise Barrier Aerodynamic Pressure
Authors: Li Hong Mei , Xuan Yan , Wang Lan , Li Yan Liang , Fang Xing , Shi Guo Hui
Published: March 2013

Based on finite volume method of finite element method, the aerodynamics models of the train passing through bridge noise barriers (high respectively, for 2.15m, 1.93m) and the subgrade (high respectively, for 2.95m,3.95m) noise barriers is established by large commercial fluid dynamics calculation software. The three dimensional transient outflow field is numerical simulated by applying dynamic mesh technology and large eddy simulation method (LES) for the train passing through noise barriers. The extreme value, schedule curve and pressure cloud contour of fluctuating wind pressures of the different height noise barriers on bridge and roadbed are acquired for 300 ~ 420 km/h different speeds. Extreme values of fluctuating wind pressures product by trains with different speeds are contrast analyzed. The simulation results are very close to the experimental data, proves the validity and feasibility of the finite element model and the accuracy of the parameters. This research provides the theory support to the structural design of the noise barriers and can effectively guide the structural design of the noise barriers.
Dynamic Constitutive Relation and Fracture Model of Q235A Steel
Authors: Lin Li , Fan Feng , Zhi Xu Dong
Published: March 2013

Strength and ductility data for Q235A steel from 20 oC to 950 oC was obtained from a series of experimental tests. The stress rate sensitivity was studied by conducting Split-Hopkinson Tension Bar (SHTB) test and uniaxial tension test on smooth cylindrical specimens while the influence of stress triaxiality on ductility was revealed by conducting upsetting tests, tension tests on pre-notched cylinder specimens and torsion tests on SASs. Slightly modified versions of the two Johnson–Cook (J–C) models describing flow stress and fracture strain are presented to characterize the properties of Q235A steel as function of strain rate, temperature and stress triaxiality. Corresponding model parameters were calibrated based on the test data and with the help of finite element calculation. It was found that the modified Johnson–Cook (MJC) models give more close predictive results compared with the original J–C models.
Design of Distributed Electric Vehicle Battery Management System
Authors: Wang Ye Qin , Liu Yi Xing
Published: March 2013

According to the requirements of the battery pack on pure electric vehicles, designed a distributed battery management system using the bus communication technology, the system can detect various operating parameters of the battery in real-time, diagnose and alarm according to the battery status. The system can also share information with the other systems of the vehicle through CAN bus. Through testing the system, the result shows that it can accurately measure the current and voltage of the battery, and the measurement accuracy meets the actual requirements.
The Study of Reliability Modeling of Machining Center Based on Blocksim and Weibull++
Authors: Chen Chuan Hai , Yang Zhao Jun , Chen Fei , Hao Qing Bo , Xu Bin Bin , Kan Ying Nan , Li Guo Fa
Published: March 2013

There is often more than one failure at the same time when NC machine tools fails, but only one failure data is recorded which leads to that the reliability model of NC machine tools is not rational. In addition, the assumption of “repaired as good as new” for NC machine tools which consists of hydraulic, mechanic and other complicated subsystems is questionable and unreasonable. In this paper a method of reliability modeling using Blocksim and Weibull++ for NC machine tools is proposed. In the end, one example is provided and examined to show its potential applications and benefits. The result shows that the method of reliability modeling is more scientific and more in line with the practice.
Evaluation the Performance of Health Care System Based on Fuzzy Reasoning
Authors: Zhang Ya Jiang , Zhang Tai Fa
Published: March 2013

With the development of the economy and the growth of people, health problem become more and more important, and performance of the health care system need operate effectively. The paper evaluates the performance of health care system from effectiveness, equity, and efficiency. It compares four countries’ health care systems based on fuzzy reasoning method. The C-values of the health care system of Niger, China, Denmark and United States are 53.72, 22.87, 0 and 4.93. The result coincides with the fact very well. We use least squares method to get the predicted value of metrics and reevaluate the health care system and the predicted health system is better than the existing health care system.
The Research of Visualization Data Mining in Industrial Data
Authors: Yu Da Ren , He Hui Xin , He Hui Xia , Zhang Xiao Xian , Liu Jin Fu
Published: March 2013

Based on characteristics of data distribution in the low dimension nature, this paper studies the effect of manifold embedding technology used in typical industrial data set analysis, and manifold learning theory was introduced into the visualization data mining to help get quick effective information in a large number of data. Cognitive process with the help of that information reduces the difficulty of analysis and improves the data utilization efficiency, having a high value in engineering application.
Design of Labview Based Equipment for Measuring Thermally Stimulated Current
Authors: Lin Jia Qi , Xia Ming Hui , Yang Wen Long , Leng Jing
Published: March 2013

In this paper, we improved the home-made EL experimental set-up, have increased the function of TSC, enable the joint measurement of EL and TSC to measure the trap of shallow and deep. It is significant to study material properties. through the Labview8.6 software programming, the data of temperature and current could be collected, then we can get the curve that the current changes with temperature, it is the TSC curve. Experiment result proved the reliability of laboratory equipment.
Researching in Web Technology Classification Based on Improved Support Vector Machine
Authors: Zhang Shuang , Zhang Shi Xiong
Published: March 2013

Abstract. Web as the main platform of information manufacturing, issuing, processing and transacting, has emerged massive isomerous dynamic semi-structural or non-structural information resources [1], so how to extract useful information from the mass Web resources has become a question which need to be solved. This paper introduces the background and status from domestic and abroad, and expounds the related theory and technology of text classification, constructs the Web text classification system model, gives a Web text collection algorithm and collection system. It verified the theoretical method which proposed in this paper by experiment, the result show that the extraction of information and Web classification is more accurate.
Research of LS-WEDM Finishing in Gas Based on Gray Relation Grade
Authors: Lu Yu Mei , Wang Tong , He Ling , Yan Wen Wen , Fang Shi Cai
Published: March 2013

Authors have presented a new procedure as gas-liquid combined multiple cut. In order to acquire the best machining quality and the greatest efficiency, it is necessary to analyze the WEDM process with multiple performance characteristics including machining time and surface roughness and to optimize some processing parameters such as pulse duration, pulse interval, peak current, main power supply voltage, servo feed, offset and servo voltage. The orthogonal experiment is designed to reveal the relationship among the parameters, the gray relevance theory is used to optimize the processing parameters under the multiple process index of the LS-WEDM in gas, namely optimizing the process parameters under the surface roughness and machining time, and the optimized process parameters can be obtained from gray relation grade.
Seismic Analysis of Fly Ash Plate Sandwich Polyurethane Insulation Composite Wall
Authors: Su Yi Sheng , Luo Yue Chun , Jiang Guo Liang , Quan Jin Yun , Shen Yi
Published: March 2013

In order to study the seismic stress performance of the reinforced concrete frame assembly fly ash plate sandwich polyurethane composite wall insulation system (FW). In this paper, 2 bay single-layer single-span hollow fly ash plate sandwich polyurethane in filled frames were tested under low cyclic horizontal loadings with different ratio of high to width and different stiffness frame . Based on the experiment, the damage process, failure mode, load carrying capacity are studied. The interaction between the fly ash plate sandwich polyurethane infill walls and the overall frame of constraint system are investigated. The results indicate that the bearing capacity has little related to height-width ratio of wall; sandwich polyurethane wall panels and frame has good integrity and energy dissipation capacity; the ratio of high to width smaller, ductility of wall is better . After study the failure pattern of the specimen, we know that the bearing capacity of fly ash powder polyurethane thermal insulation wall is not accord with formula of seismic shear of not bearing masonry.
General Solutions of Plane Problem in One-Dimensional Hexagonal Quasicrystals
Authors: Yang Lian Zhi , Zhang Liang Liang , Gao Yang
Published: March 2013

A theory of general solutions of plane problem is developed for the coupled equations in plane elasticity of one-dimensional (1D) hexagonal quasicrystals (QCs), and three general solutions are presented by an operator method. These solutions are expressed in terms of a displacement function, which satisfies a sixth-order partial differential equation. By utilizing a theorem, a decomposition and superposition procedure is taken to replace the sixth-order function with three second-order displacement functions, and the general solution is simplified in terms of these functions. In consideration of different cases of three characteristic roots, the general solution possesses three cases, but all are in simple forms that are convenient to be used.
Static Fatigue Experimental Research on Orthotropic Deck with Composite Pavement Layer
Authors: Zhu De Rong , Yang Zi Jiang , Zhang Hui , Liu Shi Zhong , Ning Gui Xia
Published: March 2013

The experimental results show that the deck of the bridge displays obviously orthotropic features; shear nails with reasonable density can increase the binding capability of each part of deck pavement and overall mechanical performance. The results of fatigue test on the two groups of specimen indicate that the composite deck pavement added with the shear nails and the transition layer of steel fiber concrete has no sign of fatigue failure after 8.3 million fatigue loading tests, and its fatigue resisting property is obviously better than the deck pavement where the asphalt concrete is directly paved on the surface of deck, that is to say the service life of the deck pavement can be extended by the use of steel fiber concrete layer.
The Elastic-Plastic Analysis of Functionally Graded Plate
Authors: Zhang Li , Yang Yong Qi , Tao Xian Bin
Published: March 2013

The elastic and plastic properties of functionally graded materials in our model are assumed to abide by the mixing law and a program package is developed based on the material subroutines in ABAQUS. Using this package, an elastic-plastic analysis is performed to study a plate made of functionally graded materials. Results of a flexible design and an elastic-plastic design, and those of a continuous structure and a layered structure are compared. It is found that the elastic-plastic design is more reasonable than the flexible design and the continuous structure is more in line with the design concept of functionally graded materials.
Force Cold-Formed Steel Residential System Performance Analysis
Authors: Zhang Xin Zhong , Wang Chong , Tang Ke Dong
Published: March 2013

This paper analysed a cold-formed thin-wall steel-ribbed housing’s internal forces, displacements and the overall stability under different load combinations by the finite element method, the results showed that the structure system could meet the capacity requirements and mitigate the structure weight effectively, save the amount of steel. It also proposed the shoring arrangement of increasing the building overall lateral stiffness by comparative analysis.
Comparative Experiment Research on Mechanical Performance between Sintered Hollow Block Infilled Insulation Masonry and Sintered Perforated Brick Masonry under Vertical and Horizontal Load
Authors: Yuan Zhi Ren , Dou Li Jun , Tan Wang
Published: March 2013

This paper analyses the stress state of sintered hollow block infilled insulation masonry under practical conditions. Based on the fact that the static loading performance of the new masonry block can be used in masonry structure, the comparative experiment research focused on the seismic performance between masonry works made of the new block and traditional sintered perforated brick with horizontal and vertical load working simultaneously, damage regulars and corrective measures are key points. Results show the mechanical performance of the new block masonry is worse than sintered perforated brick masonry in fragility and vertical loading capability. To get the same mechanical performance, the new block masonry should be improved in rib width, rib number and distance, especially in restraint by construction columns and ring beams.
Research on Horizontal Displacement and Torsion Coupling Effect of Structure-Soil System
Authors: Jiang Nan , Zhao Hui Fang
Published: March 2013

In this paper, the vibration equation of the structure-soil nonlinear interaction system was qualitatively analyzed by using the modern dynamic theory. Based on the multilinear kinematic hardening mode, the nonlinear finite element method was applied for the solution of the horizontal and torsional stiffness between the foundation and soil interaction system. And a mechanical model of the structure-soil nonlinear interaction system was established. The Lagrange energy method is used to build the coupling vibration equation of the structural horizontal displacement and torsion. The Primary resonance of the structure-soil nonlinear interaction system was studied by using the multiple scales method. By analyzing the nonlinear coupling interaction between different structures and soil, the coupling effect of structure system was revealed by appearing energy transfer from high order horizontal vibration to low order torsional vibration, and also the vibration characteristics and the behavior of energy transfer were obtained.
Experimental and Finite Element Based Investigations of In-Plane and Out-of-Plane Properties of Aluminum Honeycomb
Authors: Kashif Khan Muhammad , Wang Qing Yuan
Published: March 2013

Experimental and Finite Element analysis was used for the investigation of the effect of cell size and thickness on the compressive properties of Aluminium honeycomb core. Honeycomb cores were compressed experimentally in in-plane and out of plane directions. The effect of sample size, cell size and thickness on the elastic modulus, yield strength and plateau stress was investigated through FEA. It was found that the mechanical response was independent upon the sample size in in-plane direction. The smallest cell size honeycomb core was deformed at higher yield stress. Similarly, with increase in cell wall thickness, the modulus of the core increased.
Theoretical Analysis Research on Story Drift Limit for Steel Rinforced Concrete Composite Structures
Authors: Wang Qiu Wei , Shi Qing Xuan , Wang Peng
Published: March 2013

Steel reinforced concrete structures are organic combination of steel and concrete and the calculation formula of inter-story drift should be between them.The calculation formula of storey yield drift for reinforced concrete frames is obtained by adding the deformantion of beams, columns and joints, and the comparison shows that theoretical results agree with test data. Inter-story yield drift ratio for steel reinforced concrete (SRC) framees are proposed by using the same assumption and procedure, and story drift limit for SRC frames with certain assurance probability are proposed according to relationship of four seismic performance levels. The conclusion obtained provide reference for engineering design of SRC frame structures.
Study on Stresses Distribution Pattern of Wide Box Steel Girder of Arch Bridge
Authors: Su Qing Tian , Ren Fei , Liu Yuan Wei
Published: March 2013

Shell elements were used to simulate the wide box girder of arch bridge. Different load cases on the arch bridge were calculated and the stress distribution pattern of the wide girder was obtained. The results show that the stresses of the top plate and the bottom plate are non-uniformity along transverse direction at same section, the maximum non-uniformity coefficient of the top plate and the bottom plate are 1.89 and 1.73 respectively. To arch bridge with large ratio of width to length, the transverse stress of girder should not be neglected and the combined stress should be used to determine the structure safety.
Programme Design of Precast Shear Wall Structure Seismic Performance Experiment
Authors: Yin Wan Yun , Liu Yun Lin , Ye Juan , Cui Jian Hua , Jin Ren Cai , Liu Shou Chen
Published: March 2013

Based on the needs of housing industrialization, prefabricated experimental study on performance of shear wall structure is essential. This article describes the specific steps 、experimental data processing method and finite element analysis of prefabricated shear walls and cast shear wall under the low cyclic reversed loading. It is to solve the error of the measurement results from error experimental methods of operation. Finally, we also look forward to the expected results of the comparative test of the shear wall structure.
The Numerical Simulation of Moisture Transportation in Unsaturated Concrete of Underwater Tunnel
Authors: Zhang Yuan Zhu , Li Xiao Zhen , Wei Xin Jiang
Published: March 2013

Moisture transportation is a key factor to affect the long-term safety of underwater concrete tunnel. According to the inside and outside environment of tunnel, the moisture transportation equation in unsaturated concrete of underwater tunnel was raised. Finite difference method was adopted to solve the nonlinear partial differential equation of moisture diffusion. The study shows that the changes of water saturation in concrete are mainly concentrated in the surface of tunnel wall and amplitude is gradually slowing down over time. Saturation changes greater in the outside than inside. The wetting state is more obvious than drying state.
Analytical Model on the Bond Stress-Slip Relationship between Steel Reinforcement and Concrete for RC Beam-Column Joints
Authors: Long Xu , Tan Kang Hai , Lee Chi King
Published: March 2013

There are no conventionally accepted failure criteria for progressive collapse, and often times, deflection of affected beams over the “missing column” are often used as performance criteria. However, when simulating the deformation behaviour and the strength of reinforced concrete (RC) framed structures for progressive collapse analysis, besides the flexural deformations, the so-called “fixed end” rotation induced by the longitudinal bar slip at the beam-column ends connected to the joints can be significant and result in additional lateral deformations not accounted for in the initial analysis. Hence, it is important to quantify the deformations arising from fixed end rotations. Several bond stress-slip relationships between steel reinforcement and concrete were previously proposed in the literature. In the present work, their merits and demerits are discussed in terms of application limitation. To address the limitations of previous bond-slip models, a new analytical model based on the bond stress integration along the bar stress propagation length is proposed to predict the bar-slip behaviour in the RC beam-column joints. The proposed analytical model on the bond stress-slip relationship is validated against experimental studies from the literature and is shown to be simple and reliable.
A New Method to Estimate the Projection Angles of Fragments from a D Shape Configuration
Authors: Wang Ma Fa , Lu Fang Yun , Li Xiang Yu , Cao Lei
Published: March 2013

The oblique shock wave theory is used to describe the process of detonation wave shocking on the metal surface. And after the transmission wave in metal transmitted to the free surface of metal, the velocity multiplication law of free surface is used to simplify the shock wave theory to estimate the velocity of particles in metal. Then the projection angle is obtained from the velocity direction to the normal of initial metal surface. In addition, the explosion experiments of a D shape configuration have been done to validate this method. And the results show that this method is in better agreement with experimental projection angles than traditional Taylor equation.
Experimental Study on Reinforcement of Failure Reinforced Concrete Beams
Authors: Chen Qian , Liu Ling Yong , Meng Yang Jun
Published: March 2013

Through repair and reinforcement of breaking reinforced concrete beams by epoxy resin and carbon cloth, and its experiment, the crack and deformation and bearing capacity as well as ductility of such beams are obtained. Experimental results show that the ultimate bearing capacity of beams after reinforcement increased by 210%, the structure ductility fell by 170%, structural failure form is similar to failure in normal cross section.
Impact Analysis of Geogrid Node Size in Stretch Forming
Authors: Yi Zhen Hua
Published: March 2013

Numerical simulations are done for stretch forming of uniaxial geogrid. And influence of different punching radius on the stress and strain of geogrid are studied. It shows that the maximum stress and strain in tensile process appear at the corner of the circle and straight edge. And the biggest stress is decreased with the radius. At the same time, radius increases reduce the deformation along the stretching direction on some extent. Based on this, a new optimization method for geogrid stretch forming is proposed. The shapes and sizes of punching can change the stress and strain distribution in the geogrid, which can reduce the probability of defect in the process of stretch forming.
Quick Drawing of Internal Forces Diagram of Beam
Authors: Song Xue Jing
Published: March 2013

It is very important to draw internal forces diagram(shear diagram, bending moment diagram)of beam quickly and accurately for students. Only hold its regular and can use proficiently, we can laid a solid foundation for the study of specialized course .This article mainly based on the characteristics of the beam, analyzed shape and laws of the internal forces diagram and summary of the methods ----"pithy formula law"
Q3 Loess-Like Silt Bearing Capacity of Foundation Partition Statistical Analysis in the Shanxi Yuncheng
Authors: Yan Jia Qing , Bai Xiao Hong
Published: March 2013

Currently it is still a lack of reliable evidences on the evaluation of the bearing capacity of foundation in highway construction of Shanxi Province. Mainly reason is that the method widely used to determine in bearing capacity of loess foundation in building structures is not completely suitable to length and wide range of highway subgrade project. Because Shanxi loess region terrain is very complex, the capacity of Q3 loess-like silt in Yuncheng of Shanxi is collected and analyzed, based on statistics of a large number of bearing capacity from site loading tect. A linear regression relationship is established between loess foundation bearing capacities and water content, liquid limit, void ratio. Another linear regression relationship is established between saturation and liquid limit void ratio . Meanwhile, it compares these two sets of linear regression relationship with the measured bearing capacity and the carrying capacity by specification. Applied result show that the relative errors of the bearing capacities computed by the formulas are less than 10%, compared with other standard methods to determine the loess bearing capacity. It is significantly improvement for meeting the requirements of the highway construction.
Spillway Design for Zuocun Reservoir Danger Control and Reinforcement Project
Authors: Zhang Xin Zhong , Gao Yan Ke , Tang Ke Dong
Published: March 2013

As a specific example，this paper introduces the whole arrangement of the spillway of Zuocun reservoir，and explains a specific course of spillway design for small-scale reservoir danger control and reinforcement project from three aspects, the calculation of discharge capacity、water surface profile of chute and hydraulic calculation of stilling pool. The project can provide a reference for similar engineering.
Solutions of Technical Problems in Ultra-Soft Soil Improving Projects
Authors: Cao Yong Hua , Yin Chang Quan
Published: March 2013

Ultra-soft soil improvement projects are new trend in present China because of the limitation of construction period. Technical problems occur when traditional vacuum preloading method is applied for ultra-soft soil. This paper firstly gave an analysis of the main technical problems which include construction channel problems for building materials and workers, portion division problems of project area, installation problems of prefabricated vertical drains and formation problems of horizontal drainage cushion. Then solutions for these problems were presented. Based on the solutions and traditional vacuum preloading method, a new method for ultra-soft soil improving was put forward. A typical application of this new method was give at the end of this paper.
The Stability Analysis of a Slope under the Complex Conditions
Authors: Zhang Jin , Zhang Peng , Wang Xu Chun
Published: March 2013

The unstable failure of slope is frequent and the prevention is high difficult in the process of engineering construction. To provide reference for the prevention and control of slope landslide disaster, this paper take an engineer slope as the study background and make the strength stability analysis and evaluation of this slope. Through simulating different conditions by using the current comparatively mature limit equilibrium theory, analyzed and evaluated the stability of the slope under the conditions of precipitation, drainage and reinforced and master stability condition of this slope in the corresponding condition. The slope stability evaluation analysis results under different conditions showed that the landslide is more easily to take place under the conditions of natural state, heavy rainfall and earthquake. Slope stability improved in the drainage condition. At the same time, this paper combined the evaluation results of the analysis, putting forward prevention measures and suggestions for slope.
Deep Excavation Caused by the Impact of the Adjacent Buried Pipeline Destroy the Analysis
Authors: Tian Hao , Ju Yu Wen , Bai Xiao Hong
Published: March 2013

The subject of Foundation Excavation near the buried pipeline line. Compared with each other using a scale model of the buried pipeline foundation excavation factor of the vertical displacement, and connected with the buried pipeline displacement of both ends of the fixed elastic beam theory; analysis of the factors affecting the displacement of buried pipelines, the good agreement of the theoretical results with the scale model test value.
Seismic Design and Analysis of Tall Shear Wall-Frame Structure Using Viscous Damping Wall
Authors: Zhang Qiang , Liu Wen Guang , He Wen Fu , Liu Yang
Published: March 2013

The design and analysis procedures of a viscous damping wall for a tall shear wall-frame structure in a high seismic region are briefly introduced. Design method and theoretical basis of viscous damping wall are described, and then the layout scheme is put forward. Under frequent and rare earthquake action, the analysis results of damping structure show that the responses can be reduced perfectly. The maximum story drift angle of viscous damping structure can satisfy the limitations of the seismic code and the additional damping ratio is increased to 3%, all of them can satisfy the target of damping performance.
An Interaction Energy Integral Method for an Interface Crack in Two Nonhomogeneous Plates under Thermal Loading
Authors: Guo Feng Nan , Guo Li Cheng , Zhang Li , Yu Hong Jun , Li Xin
Published: March 2013

An interface crack problem in two nonhomogeneous plates under thermal loading is investigated. The interaction energy integral method (IEIM) is developed for obtaining the mixed-mode thermal stress intensity factors (TSIFs) of interface crack. The domain-independence of the present IEIM is verified. Numerical examples are presented and the results show good agreement with the analytic ones. Numerical results show that the method is very effective for the thermal interface crack of nonhomogeneous plate.
Property Prediction of Composites with Different Fiber Volume Fractions by Representative Volume Element Method
Authors: Zhang Nan , Duan Cheng Hong
Published: March 2013

In this paper, a representative volume element (RVE) model of composites with different fiber volume fraction is established by ANSYS finite element software. The stiffness matrix of the RVE model can be calculated by studying its stress field, and then the elastic properties of composites could be obtained. By comparing with the results from NASA empirical equation, the reliability of the method can be proved. This is a new way to predict the elastic properties of composites.
Study on Rheological Properties of Sodium Alginate/Polyethyleneglycol/Molecular Sieve Composite System
Authors: Guo Jing , Chen Qian He , Zhang Yu Yan , Qu Min Jie , Guan Fu Cheng
Published: March 2013

In this paper, Brookfield viscometer was used to test the rheological properties of sodium alginate solution and blends of sodium alginate/polyethyleneglycol（PEG）/molecular sieve in which the molecular weight of sodium alginate solution was respectively 1.59*105Da and 3.27*105Da. Besides, thermal stability and the thermal property of alginate fibers were also investigated by TGA and DSC. The fracture strength of blended alginate fibers was discussed by electronic monofilament tensile strength tester. The results showed that the system was a typical kind of non-Newtonian fluid. The apparent viscosity declined with the increase of shear rate. Rheological properties were affected by temperature and contents of the blends, at the same time, non-Newtonian index and structure viscosity index also changed. Research results were very important to the choice of wet spinning process. The thermal property and energy storage effect of alginate fibers was good, so was the fracture strength.
The Research on the Method of Simulating Crack Size Based on Reducing Local Structural Stiffness
Authors: You Yuan Cheng , Sun Hong Chun , Zhang Mei Ling
Published: March 2013

When conducting modal analysis to the structure with crack defect using ansys finite element, we usually adopt the method of cutting a rectangular notch to simulate the crack on the model structure. As a result, the different crack simulation requires repeated modeling, which is a waste of time, and we cannot guarantee the accuracy of the calculation. In this paper, mathematical model between the local stiffness and crack size is established based on the finite element simulation of a diameter of 8mm steel bar. Thus, we can simulate varisized crack defects through a fixed crack notch by the method of modifying local stiffness. The method we used is more simple and accurate than the traditionary one by cutting a rectangular notch to form cracks, and reduces the workload, and has certain research significances.
Study on Hypolipidemic Activities of Safflower Seed Oil
Authors: Guo Jian Xia , Wang Chang Lu , Wu Zhi Jian
Published: March 2013

Safflower seed oil is known to be one of the richest natural sources of linoleic acid (LA), with values of up to 69.5% of the total fatty acids. Linoleic acid is known to has important biological activity and its absence in a normal diet has been described as responsible for the development of a wide variety of diseases. This work reported purified LA from safflower seed oil could lower blood liquids level of rats with hyperlipidemia. It showed that purified LA from safflower seed oil could decrease the serum total cholesterol and triglyceride concentration significantly, as well as increase the serum high density lipoprotein cholesterol. The serum atherosclerosis index (AI) was decreased remarkably. It demonstrated purified LA from safflower seed oil could improve metabolism of serum lipids and it could play active role of preventing atherosclerosis.
Study on the Tensile Damage Behavior of Self-Healing 2.5D-C/SiC Composite in Weft Direction
Authors: Liang Shi Fei , Jiao Gui Qiong
Published: March 2013

Base on the micro-structure of self-healing 2.5D-C/SiC composite, a new mechanical model was established, By changing the tensile strength of matrix and volume fraction of boron carbide, the tensile behavior of self-healing 2.5D-C/SiC composite in weft direction was studied. The result shows that the increase of volume fraction of boron carbide has little influence on the tensile behavior in weft direction, and the influence is primarily due to the change of the tensile strength of matrix.
Synthesis of NiFe2O4 Nanoparticles and its Supercapacitive Properties
Authors: Yang Zi Tao , Cheng Bo Wen , Zhao Yong Nan
Published: March 2013

NiFe2O4 nanoparticles was successfully synthesized by hydrothermal decomposition of a gel of Ni-Fe-EG (EG=ethylene glycol) in water solution. The crystal structure and morphologies of the products were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). All the diffraction peaks in XRD patterns revealed that the as-synthesized nanoparticles were pure NiFe2O4. TEM images disclosed that the particle sizes of the nanoparticles were in the range of 10 − 25nm. The cyclic voltammetry (CV) and galvanostatic charge/discharge results tested in 6M KOH solution revealed a double layer capacitive behavior and a revisable charge/discharge property.
Structural Evolution of Mechanically Alloyed Nanocrystalline Al70Fe25Ni5 Intermetallics
Authors: Jing Zhang , Cao Qi Zhi , Li Zheng Liang
Published: March 2013

Nanostructured Al-25at.%Fe-5at.%Ni intermetallics were prepared directly by mechanical alloying (MA) in a high-energy planetary ball-mill. The phase transformations and structural changes occurring in the studied material during mechanical alloying were investigated by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was employed to examine the morphology of the powders. Thermal behavior of the milled powders was examined by differential thermal analysis (DTA). The solid solutions of Fe (Al) and Ni (Fe) in the Al70Fe25Ni5 system are observed at the early milling stage. The solid solutions transforms into amorphous and disordered Al (Fe, Ni) phase. The last milling products in the Al70Fe25Ni5 system are Al3Ni2, AlFe3 and AlFe0.23Ni0.77 phases.
Fabrication of WO3 with Macroscopic Structures via CNFs Template
Authors: Wu Qiang , Zhao Li
Published: March 2013

Uniform growth of WO3 with macroscopic structures was successfully achieved by using carbon nanofibers (CNFs) as template. Field emission scanning electron microscopy (FE-SEM), coupled with X-ray diffraction (XRD) analysis confirmed the template effect and the existence of WO3 immobilized on the macroscopic silica fiber.
Effect of Ni Addition on Formation of Nanocrystalline Phase during Mechanical Alloying of (Fe Al)-40(60) at.% Ni and (Fe Al3)-10(30) at.% Ni Powders
Authors: Jing Zhang , Cao Qi Zhi , Huang Guo Hua , Huang Jin Li
Published: March 2013

Al-Fe-Ni ternary powder mixtures containing (FeAl)-40(60) at.% Ni and (FeAl3)-10(30) at.% Ni were mechanically alloyed by a high-energry planetary ball mill. The structural evolution of the powders during milling was studied by X-ray diffraction technique (XRD). During milling of (FeAl)-40(60) at.% Ni system, Al and Fe solid solutions formed at the early stage change to FeAl, AlNi3 and FeNi3 intermetallic compounds. However, the Al and Fe solid solutions observed at the early stage transform into Al3Ni2, AlFe3 and AlFe0.23Ni0.77 intermetallic compound at last. The experimental results showed that the last milling products were decided by the proportion of atom between Al and Fe in the powder and the Ni content in the power had not affected to the last products.
Atom-Rich and Defect Effects on Electronic Structure and Magnetism in Co2MnGe/MgO Heterojunction
Authors: Cai Feng , Wu Bo , Feng Yu , Chen Ying , Yuan Hong Kuan , Chen Hong
Published: March 2013

We investigated the atomic rich and defect effects on the half-metallicity of the full-Heusler alloy Co2MnGe from the first principles. Our results show that both Mn-rich and Co-rich could increase the tunnel magnetoresistance (TMR) of the Co2MnGe/MgO magnetic tunnel junctions (MTJs). As for defect, all of investigated Co, Mn and Ge defect show that the spin polarization at Efand the TMR in the MTJs with Co and Mn defect is significatively decreased except for Ge-defected MTJs.
Microstructure of TC21 Titanium Alloy after Superplastic Deformation and Heat Treatment
Authors: Ling Zhi Wei , Dong Hong Bo
Published: March 2013

The isothermal constant strain rate tensile tests of the TC21 titanium alloy were conducted by SSAN-CMT4104 electronic tensile testing machine at different temperature. After superplastic deformation, the alloy was treated with double annealing heat treatment, and microstructure of the alloy was analyzed. The results show that dynamically recrystallization occurs during the superplastic tensile deformation. The primary α-grains aggregated and merged to form new crystal grains with irregular grain boundaries. The amount and morphology of primary α phase change gradually with the increasing of temperature. The alloy has duplex microstructure composed of primary α phase and different forms of β-transformed structure after superplastic deformation and double annealing. At deformation temperature of 930°C, the basket weave structure with equiaxed α phase appears.
Dynamic Tensile Behaviour and Full Field Strain Measurement of High Strength Steel
Authors: Qin Jin Gui , Lu Fang Yun , Lin Yu Liang , Wen Xue Jun , Liang Ming Zu
Published: March 2013

Uniaxial tensile tests were conducted on high strength steel 600 (HS600) in Split-Hopkinson Tension Bar at different strain rates in the range of 1100 to 3200s-1and in electromechanical universal testing machine at the strain rate of 1.1×10-3s-1. Digital image correlation was used together with high-speed photography to obtain full-field displacement and strain in the tensile specimens at dynamic strain rate tests. This high strength steel shows significant strain rate sensitivity. Based on the experimental results, the material parameters of Johnson-Cook model are determined. This model fits the experimental data well in the plastic zone.
Calculation of Fatigue Crack Initiation Life by Coupled Finite Element Method
Authors: Tan Wen Feng , Chen Tao
Published: March 2013

Applied damage mechanics and coupled finite element method, to study the fatigue crack initiation life problem. Application of coupling finite element method, the damage coupling effect can be modified through the global stiffness matrix to achieve. The step length of the damage evolution is divided by the damage variable of the critical element, and then the damage evolution is analysised. The corresponding stiffness matrix and loading matrix can be obtained continually under the condition of increasing the damage evolution step of the critical element,then the equivalent stress can be calculated. The corresponding fatigue crack initiation life can be calculated by using the damage evolution equation, the progress will not stop until the damage degree of the critical element reaches to one. The fatigue crack initiation life is obtained by adding the fatigue crack initiation lives with different damage variable.
The Improved Friction Properties of Bonded MoS2 Films by MAO Treating of Al Substrate
Authors: Hu Han Jun , Zhou Hui , Zheng Yu Gang , Zhang Kai Feng , Wan Zhi Hua
Published: March 2013

The bonded MoS2 films are widely used as solid lubricants in aerospace mechanisms due to their excellent tribological properties. Traditionally, the MoS2 was directly bonded on the Al substrate that was only treated by the technique named of sandblast. For improving the tribological properties of MoS2 films, micro arc oxidation (MAO) instead of sandblast was introduced as a new technique for treating of Al substrate. In this article, the tribological properties of MoS2 films which were bonded on different surface of Al substrate as mentioned above were discussed, respectively. It was concluded from the test results that the MoS2 films bonded on substrate treated by MAO have better tribological properties than those samples treated by sandblast. The endurance life against abrasion of the former is as high as twenty times of the latter by the stand test method of ball on disk using the UMT Multi-Specimen Test System. This test results could be illustrated by the following reasons. The first is the porous microstructures of MAO ceramic coatings on the Al substrate. The coatings have numerous pits to be good at increasing the binding force with the MoS2 films, and the pits can also provide a MoS2 lubricants reservoir during processes of friction. Both of them improved the MoS2 film’s ability of wear-protective. The second is that hardness of the coating is higher than the Al, and this ensures well wearing resistance, especially in practical application to big load-supporting moving parts, such as bearing, gear, etc…
Mechanical Properties of WC-Co Cemented Carbide Prepared via Vacuum Sintering
Authors: Liang Bing Liang , Ai Yun Long , Liu Chang Hong , Jiang Nan
Published: March 2013

WC-Co cemented carbide specimens were prepared via vacuum sintering. The influences of composition and sintering temperature on phase composition, microstructure and mechanical properties of WC-Co cemented carbide were investigated. The results show that dense specimens were obtained in the sintering temperature range of 1280~1400°C and the relative density reached over 95%. Only WC and Co3W3C (-phase) were detected by XRD without any else phases, even though Co. With the ascended sintering temperature, hardness increased and the transverse rupture strength (TRS) ascended to peak value and then descended. WC-Co cemented carbide with excellent mechanical properties (HRA>90, TRS~700MPa and KIC>10MPa•m1/2) were obtained.
Properties of N-Doped ZnO Films by RF Magnetron Sputtering
Authors: Hua Zhu , Wan Wen Qiong , Feng Xiao Wei , Kuang Hui Yun
Published: March 2013

Using the radio frequency reactive magnetron sputtering technique, ZnO:N thin films were fabricated on glass substrate by changing the Ar/N2 flow ratio from 9/1 to 9/4. The samples were characterizated on the film microstructure and optical properties by XRD, UV- visible spectrophotometer and Fourier transform infrared spectroscopy. The XRD results show that no significant peaks appeared at less N flow and the light transmission rate of UV-Vis has Small fluctuations between 320~780nm wavelength ; with increasing N flow, there was only (002) single peak in curves of XRD, transmittance of UV had a sharp decline below the 400nm wavelength; when argon-nitrogen flow ratio was increased to 9/4, it is show that there were two peaks near 34°of 2θ in curves of XRD but no significant change in UV transmittance.
Absolute Luminous Flux and Quantum Yield of Sm3+-Doped Cadmium-Aluminum-Silicate Glasses under the Pumping of Blue Light Emitting Diode
Authors: Lei Yu , Fu Fang Fang , Zheng Li , Wang Zhi Qiang , Zhao Xin , Lin Hai
Published: March 2013

Absolute luminous flux and quantum yield for multichannel transition emissions have been determined in samarium ion (Sm3+)-doped cadmium-aluminum-silicate (CAS) glasses under the pumping of blue light emitting diode (LED) using an integrating sphere of 30 cm diameter, which connected to a CCD detector with a 400 μm-core optical fiber. The radiant flux and luminous flux for the visible transition emissions (550–750 nm) of Sm3+under the blue LED excitation were solved to be 123 μW and 32 mlm, respectively, which occupied 1.51% and 7.16% of the whole. The total quantum yield of the visible fluorescence of Sm3+has been calculated to be 2.52%. Investigation on optical radiation parameters for multichannel visible transition emissions of Sm3+in CAS glasses provides a reference in developing luminescence and display materials.
Effect of High-K Material on Gate Threshold Voltage for Double-Gate Tunnel FET
Authors: Li Yu Chen , Zhang He Ming , Hu Hui Yong , Zhang Yu Ming , Wang Bin , Zhou Chun Yu , Lou Yong Le
Published: March 2013

The effect of high-k material on gate threshold voltage for double gate tunnel field-effect transistor (DG-TFET) is studied in this paper. By physically derived the model of threshold voltage for DG-TFET, the quantitative relationship between threshold voltage and gate length is also discussed. It is shown that the proposed model is consistent with the simulation results, and can also easily predict the improved performance on the gate threshold voltage when using high-κ dielectrics and the limited effect on gate threshold voltage when changing the gate length.
Experimental Research of Foaming Concrete Performance with Different Blowing Agent
Authors: Yue Jian Wei , Meng Xiu Ying
Published: March 2013

Low-density foam concrete is inorganic silicate material replace to traditional organic materials for external wall insulation system. Based on the analysis of structure formation mechanism of foaming foam concrete prepared with chemical method, investigation by a large number of comparative tests and quantitative analysis, quantitative relationship of compressive strength, tensile strength, and blowing agent dosage quantitative of 3d, 7d and 28d foaming concrete are analyzed. The relationship between blowing agent and foam concrete strength and thermal conductivity variation is revealed by the research of doped foaming agent concrete strength, improved workability mechanism. And further, independent sealing pores, high mechanical strength of pore wall, pore structure approximate to sphere and pore diameter with similar and small size were all favorable factors for higher strength of foam concrete.
Experimental Research of Foaming Concrete Performance with Different Fly Ash
Authors: Wang Yong Feng , Gu Li Hua , Yue Jian Wei
Published: March 2013

Low-density foam concrete is inorganic silicate material that can replace traditional organic materials for external wall insulation system. Based on the analysis of structure formation mechanism of foaming foam concrete prepared with chemical method, investigation by a large number of comparative tests and quantitative analysis, quantitative relationship of compressive strength, tensile strength, and blowing agent dosage quantitative of 3d, 7d and 28d foaming concrete are analyzed. The relationship between blowing agent and foam concrete strength and thermal conductivity variation is revealed by the research of doped fly ash concrete strength, improved workability mechanism. And further, independent sealing pores, high mechanical strength of pore wall, pore structure approximate to sphere and pore diameter with similar and small size were all favorable factors for higher strength of foam concrete.
Fully Graded Concrete Creep Models and Parameters
Authors: Wang Ya Jun , Wu Chang Yu , Gan Xiao Qing , Dong Zhi Hong
Published: March 2013

In this paper, the key parameters and functions for quantification of temperature creep stress were offered. These key parameters established the creep-heat-change fluctuation on fully graded concrete. The information is helpful for simulation of super arch dam concrete pouring process.