bluuebunny/crossref_metadata_2025 huggingface dataset:
An Improved Method for CT/MRI Image Fusion on Bandelets Transform Domain
Authors: Lu Hui Min , Nakashima Shota , Li Yu Jie , Zhang Li Feng , Yang Shi Yuan , Seiichi Serikawa
Published: September 2011

People living in the information age, are more and more attention to their own lives. It is also said, social life is more important in present and future. The social life contains three fields. In this paper, we will propose a new method for adjunctive therapy in social life. Recent years, as the bandelets transform has some benefits, many scholars are interested in this field. They proposed many methods to solve different problems in different fields. In this paper, we propose a new maximum local energy method to calculate the low coefficients of images. And then adopt the sum modified laplacian method to select the high coefficients of images. Later, we compare the results with wedgelets transform. In our experiments, we take wedgelets transform, bandelets transform, and LE-wedgelets transform for comparing the results. Beside the human vision, we also compare the results by quantitative analysis. The numerical experiments state clearly that the maximum local energy is an effect way for image fusion, which can get well performance in visual effect and quantitative analysis. During 100 clinic CT/MR fusion experiments in practice, compare with previous methods, the PSNR of our method is improved respectively 5.836, 5.337, 0.035.
A New Image Segmentation Method Based on Improved Fast Implicit Level Set Scheme in X/γ-Ray Inspection System
Authors: Li Yu Jie , Lu Hui Min , Zhang Li Feng , Yang Shi Yuan , Seiichi Serikawa
Published: September 2011

Digital X/γ-ray imaging technology has been widely used to help people deliver effective and reliable security in airports, train stations, and public buildings. Nowadays, luggage inspection system with digital radiographic/computed tomography (DR/CT) represents a most advanced nondestructive inspection technology in aviation system, which is capable of automatically discerning interesting regions in the luggage objects with CT subsystem. In this paper, we propose a new model for active contours to detect luggage objects in the system, in order to facilitate people to identify the things in luggage. The proposed method is based on techniques of piecewise constant and piecewise smooths Chan-Vese Model, semi-implicit additive operator splitting (AOS) scheme for image segmentation. Different from traditional models, the fast implicit level set scheme (FILS) is ordinary differential equation (ODE). Characterized by no need of any pre-information of topology of images and efficient segmentation of images with complex topology, the FILS scheme is fast more than traditional level set scheme 30 times. At the same time, it performs well in image segmentation of DR images in our experiments.
Co-Occurrence Matrix-Based Statistical Model for Texture Analysis from Images
Authors: Shahera Hossain , Seiichi Serikawa
Published: September 2011

Texture surface analysis is very important for machine vision system. We explore Gray Level Co-occurrence Matrix-based 2ndorder statistical features to understand image texture surface. We employed several features on our ground-truth dataset to understand its nature; and later employed it in a building dataset. Based on our experimental results, we can conclude that these image features can be useful for texture analysis and related fields.
Optical and Physics Investigation of Fe2O3 Doped in Soda-Lime Silicate Glass at Different Melting Temperature
Authors: Kaewkhao Jakrapong , Srisittipokakun N. , Kirdsiri Keerati , Kedkaew C. , Limsuwan Pichet
Published: September 2011

In this work, the effects of melting temperature (1200, 1300, 1400 and 1500 °C) on glass properties, prepared in the composition 64.4SiO2: 10.0CaO: 25.0Na2O: 0.6Fe2O3 have been investigated. The Fe2O3 doped glass shown green color due to the homogeneous distribution of Fe3+ and Fe2+ ions in the glass matrices. Refractive index, dielectric constant, optical dielectric constant and the reflection loss increases when the melting temperature is increased. The absorption bands are observed in the all spectra with the peaks around 380 and 435 nm are attributed to Fe3+ and board peak around 1,050 nm due to Fe2+. The Fe2+ peaks are increased with increasing of melting temperature, correspond with glass color.
Influence of the Selected Fatigue Characteristics of the Material on Calculated Fatigue Life under Variable Amplitude Loading
Authors: Niesłony Adam , Kurek Andrzej
Published: September 2011

The algorithm of fatigue life determination for machine elements subjected to random loading uses fatigue characteristics of the material determined under constant-amplitude loading. They are usually stress or strain characteristics as well as characteristics using the energy parameter. Their correct selection influences correctness of the obtained results related to the experimental data. The paper presents analysis of convergence of the calculated fatigue lives of some constructional materials subjected to random loading under uniaxial loading state. For calculations concerning one material the same loading state was assumed and fatigue characteristics were determined on the basis of one data set obtained under constant strain amplitude tests. Calculated fatigue lives based on different fatigue characteristics were compared and their convergences were tested. It has been proved that convergences are different depending on the material. The comparison results were presented in form of graphs.
The Construction Subcontract Risk Analysis Based on the Information Diffusion Method
Authors: Wei Qing Zhong , Liu Di , Liu Bang Jia
Published: September 2011

Abstract. The construction enterprise is one of the important management ways, and it also is main mean of controlling the project schedule, quality and cost. Although outsourcing can be good for integration of resources to realize the optimization of resources, due to the contracting enterprise and the unbalance of interest conflict between them and other factors, the risk is certain to bring. The correct evaluation to the risk is an important basis for decision-making. This paper is used by using information diffusion method to the construction risk analysis on the exploration, and analyzing the error, to proof that the information diffusion method in building construction risk analysis is of the application of the feasibility, which can make full use of the existing information. By adjusting the domain of discrete points the density of the degree so that the request reaches the required accuracy.
Simulation on Expanding Crack of Reinforced Concrete Based on Franc2d
Authors: Chen Yue Shun , Liu Li
Published: September 2011

It is a key point of durability deterioration to reinforced concrete structures that protective layer concrete cracking, so it is essential to assess the durability limit state to determine the critical corrosive ratio. In this paper the Franc2D tool has been used to simulate the corrosive expanding process of protective layer concrete in reinforced concrete structure, and the slope change of the ρ-CMOD curve has been used as the basis to determine the critical corrosive ratio, then the effects of stirrups to critical corrosive ratio and the corrosive expanding crack width has been studied. It has been showed a linear relationship between the corrosive ratio and crack width, and appearance of corrosive expanding cracks has been delay with the stirrups, on the other hand crack propagation speed can be reduced with the stirrups across cracks effectively.
The Measuring Test and Finite Element Analysis for Prestressed Concrete Beams
Authors: Li Yang , Shen Li Jiao
Published: September 2011

Based on one prestressed frame beam in an actual project, both the indirect measuring test and the finite element numerical simulation about the reinforcement prestress are made. The test and simulation results show that the effect prestress obtained from indirect measure methods can reflect the prestress history relatively well. Meanwhile, the indirect measure method has the advantages of low cost and easy operation, which can be exploited and developed in general projects so as to get the stress history of the prestressed reinforcement in time and reduce potential security threat.
Experimental Study on Strengthening the Structure of Tower of Overhead Transmission Line
Authors: Liu Xue Wu , Xia Kai Quan , Gao Yan
Published: September 2011

Serious damage and collapse of steel towers were easily induced by the ice disaster, the wind disaster and so on. After the disaster, to ensure the overhead transmission line working safely, it is necessary to strengthen the structure of the damaged tower perpetually, but there are few strengthening methods for the tower assembled by angle-shaped members at present. If an identical angle-shaped member is connected on the side of the existing angle-shaped member through bolts, the mechanical performance of the damaged tower can be improved effectively. In this paper several methods for strengthening the angle-shaped tower is proposed, and the mechanical behavior of the strengthened member of the tower is discussed experimentally, and some design suggestions for strengthening the towers are given.
Analysis on Mechanics of Complex Concrete about Steel Fiber and Polypropylene Steel-Wire-Like Fiber before and after Freeze-Thaw Cycles
Authors: Huo Dong Fang , Zhang Er Long , Li Qin Zhen
Published: September 2011

Bridge deck pavement material requires sufficient compressive strength, flexural strength, and bending toughness. The bridge structures inevitably bear the impact of the external adverse environment, so pavement layer material should also have impermeability, freeze-thaw resistance and corrosion resistance. This text studies complex concrete of steel fiber and polypropylene steel-wire-like fiber, and compares different dosage and type of fiber on mechanical performance of concrete. The results show that complex fiber concrete has better mechanical performance and durability, and is an ideal choice as bridge deck pavement material.
Strategies on Earthquake Prevention and Disaster Mitigation in Rural
Authors: Shi Yang Hang , Yang Li Dan , Wu Chong , Yu De Hai , Xu Jing Yu
Published: September 2011

Throughout history till today, earthquake prevention and disaster mitigation has been the eternal subject in engineering field. Security is the very premise for the subsistence and development of human beings. Entrusted with government correlation department, the examination of seismic safety and structural health diagnosis will be done in relation to the type, characteristic feature and damage, etc. of current masonry structure in Minnan District, which is in the spirit of “Emphasis on hedge against disaster relief”. According to current criteria as well as considering the actual situation of construction, various constructions will be evaluated scientifically by the on-the-spot survey, investigation, evaluation and analysis, from which get the various morbid state and principle of constructions in concordance with the differences of severity. On the other hand, in line with “rescuing” principle in order of importance and urgency, corresponding classification of disaster prevention and certain applicable and practical disposal ideas will be put forward in order to provide references for engineering practice and application as well as management and policy making for relevant department.
Testing in-Phase Analysis for Adjacent Transmission Towers under Ambient Vibration
Authors: Yan Xiang Mei
Published: September 2011

Based on the random vibration and system identification theory, the ambient vibration testing of two adjacent transmission towers were carried out, dynamic characteristics of the towers were obtained from ambient vibration data. The result shown that the suspended cables not only have mass effects, but have coupled stiffness effects applied to tower on transverse direction and longitudinal direction. At the same, testing value shows that the two adjacent towers have basically the same dynamic characteristics and damping ratio of the two transmission towers less than 0.01. Owing to the influence of conductors, frequency of the insulators is different to the towers at the two directions. It is disadvantage for wind-induced response of transmission line system under ambient loads.
The Fast Cooling Measures and Effect Analysis of Precast Box Girders in Passenger Dedicated Lines
Authors: Li Xue Min , Zhu Er Yu , Zhou Yong Zheng , Qi Yong Qiu
Published: September 2011

The construction of precast box girder plays a pivotal role in the process of building passenger dedicated lines. But the high temperature and low-speed of cooling rate inside the box girder will seriously reduce the box girders’ quality and delay the project duration. So, some methods such as cooling by means of circulating water in drill way etc. are presented in this paper. Then temperature tests are carried out for the box girders with different cooling measures, and the respective data are analyzed. The results show that the proposed cooling methods can effectively reduce the highest temperature, speed up the cooling rate inside the box girder and decrease the temperature difference between the interior and the exterior of the concrete.
Collapse Pattern Identification for Cable-Stayed Bridges Based on Ultimate Limit Analysis
Authors: Yan Dong
Published: September 2011

A method based on ultimate limit analysis (ULA) was proposed to identify collapse pattern for cable-stayed bridges. The proposed method had no need to model the whole process of structural progressive failure, but assumed plastic hinge model of cable-stayed bridges, which had two sets of variables describing plastic hinges’ positions and rotational angles. By a two-stage sequential optimization, the variables could be solved to reveal the bridge collapse pattern. Parametric studies could be further conducted to identify the bridge critical components, and explore the effects of some design parameters on collapse pattern and ultimate load-carrying capacity (ULC). The proposed technique was illustrated on a twin-pylon cable-stayed bridge. Comparing with the results of nonlinear finite element analysis (FEA), the yielded components forming collapse pattern can be correctly extracted from the plastic hinge model. This technique results in small errors (less than 3.1%) for estimating the ULCs.
The Influences on Turnout Dynamic Responses due to its Irregularities
Authors: Cao Yang , Ping Wang , Zhao Wei Hua , Zhao Cai You
Published: September 2011

A vehicle model and a movable-point simple turnout model were established, and the influences on dynamic responses caused by turnout irregularities when train passes through No.18 turnout was analyzed by using the turnout dynamics simulation software based on finite element method. It shows that turnout dynamic responses are influenced by the combined effects of various types of irregularities, which produce bigger dynamic response than single irregularity. In the turnout devise and use, the distance between slide plate and switch rail or nose rail should be as close as possible, the position arrangements of traction points should be optimized and the insufficient displacement should be eliminated as much as possible; No.18 turnout structure design is reasonable, which can ensure the safety and the stability when train passes over turnout.
Numerical Simulation on Underwater Shock Wave Focusing
Authors: Zhang Zhen Fu , Zeng Xin Wu , Cai Qing Yu , Han Kai Feng
Published: September 2011

Shock wave focusing by an ellipsoidal reflector can produce higher pressure in the focal region. The focusing process of shock wave was studied by theory analyses and numerical results. Base on the experimental observation the shock wave source is equivalent to the explosion of an underwater explosive. A finite element model was set up to investigate the shock wave focusing behaviors. Both the pressure-time history and the peak pressure along the axial position were presented. The shock wave focusing process was shown. The interactions of waves in the focal region are shown. A modified EOS of water was applied, which can be used to analyze the negative pressure observed; the numerical results based on the modified EOS agree well with the experimental data.
Numerical Simulation of Acoustic Wave Propagation in Cylindrical Fluid-Saturated Poroelastic Shell Immersed in Fluids
Authors: Gao Wen Yang , Wu Qian , Cui Zhi Wen , Wang Kei Xie , Dong He Feng
Published: September 2011

Acoustic wave propagation in fluid-saturated porous cylindrical shell is investigated in this paper by using the Biot’s theory. The Expressions for acoustic pressure and radical displacement in and out fluid, the expressions for components of solid and filtration displacement and pore fluid pressure and stress tensor are given. The numerical simulation is operated on acoustic field in fluid of poroelastic cylindrical shell, and the full-waveform is obtained by Fourier transform, and acoustic pressure field in frequency-wavenumber domain is analyzed, as well as the influence of inner and outer radii on wave amplitude is discussed. It shows that if the thickness of shell remains constant, the amplitude of longitudinal mode increases and that of Stoneley wave decreases when inner and outer radii increasing. In the fast formation the influence of inner and outer radii on the amplitude of longitudinal mode is notable. In the slow formation the amplitude of Stoneley wave will decrease with inner and outer radii increasing.
A Theory Research of Asphalt Pavement Dynamic Response under Vehicle Random Stimulation
Authors: Liu Xiao Yun , Shi Chun Juan , Chen Shui Jing
Published: September 2011

In order to study the dynamic response of the asphalt pavement under vehicle random stimulation, the random vibration model of vehicles and the mathematic model of pavement dynamic response in which the base and surface are all viscoelasticity are established respectively. The analytical solution of the stochastic response for the pavement is deduced. The stochastic load acted on the pavement can be gotten by the mathematic model of the vehicle vibration. The numeral feature functions of the random response, such as even function, time-space correlation function, time correlation function and mean square function, are obtained by the analytical solution. The paper provides a theory method for studying the random response of the asphalt pavement.
Synthesized Ground Motions as Inconsistent Input for Seismic Analysis of Large Span Bridges
Authors: Tao Xia Xin , Liu Hai Ming
Published: September 2011

A specific issue in seismic analysis of large span bridge, study on inconsistent ground motion input is reviewed in this paper. The building of spatial model for ground motion field based on observation of motions on dense arrays and coherence validation of the synthesized ground motion field are deal with respectively. Points are emphasized that spatial correlation between motions with distance of several hundred meters to each other comes from one same source and very similar path, similar/different site condition. A comprehensive procedure taking source, path and site condition all into account to synthesize the motion field is convenient to reveal and express the physical nature of the motion field. Spatial structure of a synthesized motion field is validated by means of the coherency coefficients. The result is consistent with the conclusion from the statistics of the observed data on some dense arrays.
Experimental Study on Deformation Properties of Lining Structure of Hydraulic Tunnel
Authors: Xu Shi Lang , Shen Wei
Published: September 2011

A large-scale indoor model test with water pressure is conducted in order to investigate the stress and deformation properties of reinforced concrete lining structures with circular cross-sections. After lining structure cracks, the stress and deformation of reinforcement in lining structures tend to decrease. Although the interaction force between lining structure and surrounding rock increases with the increase of water pressure, but the ratio of interaction force and water pressure decreases, which reveals that the load-bearing capacity of lining structures decreases, and surrounding rock gradually performs as the primary load-bearing body. The internal water pressure carried by lining structure is about 20%~40% of water pressure before cracking and less than 30% after cracking. Test results illustrate that surrounding rock and inner water seepage significantly influence the stress and deformation properties of lining structure, and inner water seepage is the main reason for the reduction of load-bearing capacity of lining structures.
Mining Damage and Prevention Countermeasures of Coal Exploitation in West of China
Authors: Wang Xiao Peng , Zhang Zhi Gang , Dong Hong Kai , Li Rui Bin
Published: September 2011

In order to carry on control and countermeasure of mining damage effectively, by analyzing the conditions of geology, mining and entironment in west of china, the text discusses the possibly arisen problems of structural establishment, traffic establishment and environment and so on when western regions enter a large-scale mining phase. It analyses all these problems which will restrict and affect continuable development of mining area’s economy, and advances some thoughts about harmonious development of mining industry and environment protection by controlling mining technology and approach of synthetical treatment.
The Parameters Research on Considering the Influence of Dynamic Torsion Impedance of the Radial Inhomogeneous Viscoelastic Soil
Authors: Wu Ji Min , Feng Shu Zhen , Cui Hai
Published: September 2011

Based on the recursion method of shearing ragidity of soil layer, dynamic torsional impedance of the radial inhomogeneous viscoelastic soil is studied.Under the certain fundamental assumption,combined with displacement basic solution of the plane axial symmetry strain question,the displacement the continuous and boundary of the soil layers, the formula of dynamic torsional impedance of the pile-soil contact surface is deduced.Degenerated into homogeneous viscoelastic model,the model is further confirmed accurate.Finally, the conclusion is obtained:(1) The bigger is G2/G1,the larger the soil body actual stiffness is. The dynamic damping presents the trend of increase;(2)In the area of the radial disturbance soil,as ‘d’increases, the soil body actual stiffness is increasing. When G2/G1 is smaller than 1,the dynamic damping is reducing along with increases of ‘d’,when G2/G1 is bigger than 1,the dynamic damping is increasing along with increases of ‘d’.(3)Actual stiffness and dynamic damping assumes the linear variation along with increasing of material damping.
Study on Compressive Stress of Face Slab of Ultra-High Concrete Face Rockfill Dam
Authors: Zhou Yang , Zou De Gao , Kong Xian Jing , Fu Meng
Published: September 2011

In this paper, three-dimensional(3-D) finite element(FE) method is used to analyze the stresses of face slab of the 300m high concrete face rockfill dam(CFRD) before and after earthquake. Meanwhile, the effect of valley shape on the stress of face slab is considered. The results show that the maximum deflection and axial stress are located near the bottom of face slab in the central valley area before earthquake. And there are compressive stresses in mostly area of face slab. After earthquake, the positions of maximum deflection and axial stress of face slab were changed to the crest of the central valley area. As the valley aspect ratio increases, compressive stress of face slab decreases. For the 300m ultra-high CFRD, the maximum axial stresses exceed the concrete compressive strength before and after earthquake. Therefore, the compression damage of face slab should be considered during the design.
FEM Analysis of Composite Soil-Nailing Considering Tensile Failure
Authors: Yan Zhi Gang
Published: September 2011

Composite soil-nailing is a new technology developed from abroad in recent years, to be used in excavation of soil, slope stability. This paper studied the stress and deformation of composite soil nailing wall by nonlinear FEM. According to the structure characteristic, the finite element analysis for composite soil nailing construction process is carried out. Based on geotechnical elastic-plastic constitutive model, the adopted failure criterion was a composite Drucker-Prager criterion with tension cut-off. A kind of rotational Goodman interface element is employed to simulate the behavior of interface between the soil-mixed cement which forms the barrier of seepage flow along the boundary of foundation pit, and soil ground. Through the comparative analysis with on-site monitoring data, the finite element calculation results have good precision.
Similitude Derivation of Stabilizing Model Pile in Centrifugal Model Test
Authors: Li Rong Jian , Zheng Wen , Yu Yu Zhen
Published: September 2011

Similitude design of a model test concerns the size and materials of the model. For the similitude design, the most important factors include not only that the test should simulate well the interaction of soil-pile of the prototype, but also that the model test should reflect well the failure mechanism of the corresponding prototype. In this paper, firstly, the similitude relation between the model pile and the prototype pile in the soil-pile interaction centrifugal modeling is derived by means of analytical equation method. Then, in order to investigate the failure mechanism of stabilizing pile, the physical properties of model materials and the difficulty of making of model pile are taken into consideration. The results show that the failure mechanism of stabilizing pile in the centrifugal model tests can be reflected reasonably.
Vibration Troubleshooting of Two Turbine Generator Units in a Power Plant by Bearing Elevation Adjustment
Authors: Guo Yu Jie , Tian Yong Wei , Liu Jing Yu , Zhang Wen Tao , Liu Zhan Hui
Published: September 2011

Two turbine generator units with unstable vibration faults caused by unreasonable bearing elevation distribution are presented. Using the communicating vessel principle, elevation change among bearings with condenser vacuum and power are measured and analyzed. We found that elevation of bearings on low pressure cylinder in high vacuum state is the lowest among bearings. Shaft alignment in the cold state is not unreasonable. We pre-compensated and adjusted bearing elevation in the cold state on the base of the measured bearing elevation data. Vibration faults of two units were solved successfully. Vibration phenomenon, bearing elevation change monitoring data and fault troubleshooting method are presented. It is verified that bearing elevation pre-compensation method for solving such kind of faults is valuable.
Geotechnical Engineering Intelligent Monitoring and Controlling System and its Application in Pit Engineering
Authors: Zhang You Feng , Cai Mei Feng
Published: September 2011

The shortages and drawbacks of traditional geotechnical engineering monitoring and controlling system(GEMCS) is reviewed and the necessity and inevitability to establish a modern GEMCS are argued and discussed sufficiently. Modern GEMCS are fundamentally divided into two subsystems, remote management subsystem and site management subsystem respectively. Each of the subsystems is introduced and described subsequently by their components, main functions and capability in solving issues. Then, the predominant characteristics and advantages of the modern GEMCS are specified with two facets: components features and unlimited time-spatial domain monitoring. Applications in deep pit constructions are illustrated to visualize the functions of the modern GEMCS, followed by three research strategies of scholars from home and abroad are analyzed and summed up. Last, based on two levels, which are completions and evolutions of monitoring and controlling system itself as well as its generalizations in applications and promotions in geomechanics, developments supposed to achieve in modern intelligent GEMCS in 21st century are prospected and forecasted.
Elasto-Plastic Analysis Method for Vertically Loaded Pile Considering Pile-Soil Slip
Authors: Yao Wen Juan , Chen Shang Ping , Zhu Sheng Qing
Published: September 2011

The calculation and analysis of single pile settlement was one of the important geotechnical engineering issues, and many geotechnical engineers and scholars investigated and formed a systematic analysis method. Among the existing methods of analysis methods, the elasticity theory method was relatively mature. However, the traditional elasticity theory method could not consider the slip properties between pile and soil, and did not match the actual working properties of pile foundation. In this paper, based on Mindlin's solution, the pile is assumed to be elastic and the relationship between shear stress and relative displacement at the pile-soil interface is assumed to follow hyperbolic function, then series equations were derived and solved by Finite Difference Method. Two cases were demonstrated and the computed results agreed very well with testing data. The advantage of the analysis method proposed was that the interaction of pile and pile, and pile and soil can be considered.
Composite Grid Method on Computation of Stress Intensity Factors of Biomaterial Interface Crack
Authors: Zhong Zhi Peng , Wan Shui
Published: September 2011

The stress intensity factors (SIFs) of biomaterial interface crack were analyzed using the Composite Grid Method (CGM). Two different scale grids were adopted: a coarse mesh for the whole area without considering interface crack and a fine mesh for the local singular area considering the impact of interface crack. It solved the global coarse mesh problem and the local fine mesh problem iteratively and obtained the final results. The calculation was carried out by CGM but without the demand of dense mesh near the crack tip and special crack tip elements compared with other methods. The numerical extrapolation method of determining the SIFs to avoid the oscillation singularity of asymptotic fields of elastic interface crack. Reasonable agreement was achieved and efficiency of CGM for such kind of problem was displayed.
Dynamic Shear Modulus and Damping Ratio for Threshold Strain in Cohesionless Soils
Authors: Guo Xiao Xia
Published: September 2011

Based on modern ideas of thermomechanics, small strain dynamic dissipation function of Hardin-Drnevich model for soils is formulated using the assumptions of the beeline and the skeleton curve shift laws. Fundamentally, for cohesionless soils, two types of cyclic strain thresholds are identified: first threshold strain and second threshold strain represent boundaries between fundamentally different dynamic characteristics of cyclic soil behavior. Comparison between the two threshold shear strain values and dynamic degradation curves obtained on exactly the same soils, the results showed that the ratio of secant modulus and maximum dynamic shear modulus for the first threshold strain are almost 1.0, and the damping ratio is almost constant. When dynamic strain level exceeds the second threshold strain, the soil behavior is considerably at nonlinear, and the primary deformation mechanism is related to fabric changes during cyclic loading. The first and the second threshold strains are therefore essential for the understanding and solving soil dynamic problems.
Study on Single-Diameter SMA High-Temperature Stability Test
Authors: Liu Zhong Gen , Xu Xiao Dong , Sun Li Bin
Published: September 2011

Based on the classical theory, and according to the structural features of SMA (stone matrix asphalt), this paper analyzes the road performance of SMA such as high-temperature stability, etc. The analytical result shows that good road performance of SMA comes from its structural characteristics. Through analysis of SMA design methods adopted in different countries, The tests are carried out in the following procedures: this paper has studied aggregate gradation to ensure which kind of coarse aggregates contributes more for high-temperature stability. The coarse aggregate of equal size is used as sample to do Marshall test (Asphalt compound test ) and rutting test. According to the analysis of test results, it is difficult to decide which kind of coarse aggregates does more contribution for high-temperature stability of SMA, and therefore, comprehensive analysis should be made on coarse aggregates of different grades so as to achieve satisfactory result.
Dynamic Elasto-Plastic Analysis on the Steel Spatial Arch Truss with 30 m Span and 0.1 Rise-Span Ratio
Authors: Li Hai Wang , Wang Zhi Wei , Liu Jin
Published: September 2011

Abstract. In this paper, the elasto-plastic dynamic analysis on the steel spatial arch truss with 30 m span and 0.1 rise-span ratio is carried out under earthquake wave with SAP2000. In the analyses, the geometric and material nonlinear effects are considered at the same time based on the plastic-hinge theory. Under the action of EL wave with the peak increasing gradually, its elasto-plastic dynamic responses have been obtained. The results show that its failure mode under the earthquake action is elasto-plastic dynamic buckling; that its critical peak acceleration of EL earthquake wave when applied in horizontal direction is 517 gal, and is 387 gal when applied in vertical direction; The ratio of its maximal node horizontal displacement and its structural height is 1/96, and its displacement ductility coefficient is 2.636; The ratio of its maximal node vertical displacement and its structural span is 1/589, and its displacement ductility coefficient is 1.08.
Research on the Planar Near-Field Acoustic Holography for Cyclostationary Sound Field
Authors: Chen Zhi Min , Zhu Hai Chao , Mao Rong Fu
Published: September 2011

The conventional planar near-field acoustic holography is not suitable for cyclostationary sound field radiated by the rotating machines. When the cyclic spectral density (CSD), instead of the complex sound pressure, is adopted as reconstructed physical quantity, the modulating wave and carrier wave components of the cyclostationary sound field can be extracted exactly and so the cyclostationary planar near-field acoustic holography (CPNAH) technique was proposed. Simulation and experimental results show that the modulation characteristics of the cyclostationary sound field can be extracted effectively and the sound source can be localized accurately.
Effect of Immersion Time on Corrosion Resistance of Phytic Acid Coatings on AZ91D-Mg Alloy
Authors: Lin Bi Lan , Xu Yu Ye , Su Wei
Published: September 2011

Phytic acid coatings were formed on AZ91D-Mg alloy during immersion in 5.0 g/L phytic acid solution for different time. The corrosion resistance of the bare and coated samples was investigated using Tafel polarization and Electrochemical Impedance Spectroscopy (EIS) methods, and the corresponding electrochemical corrosion parameters were analyzed. The results show that the anodic and cathodic corrosion processes of AZ91D-Mg alloy are conspicuously inhibited with phytic acid coatings; the overall corrosion resistance index of AZ91D-Mg alloy is increased with immersion time; and the corrosion protection efficiency of phytic acid coatings is up to 97.8%.
Thermal Degradation Characteristics and Kinetics of High Temperature Vulcanized (HTV) Silicone Rubber/POSS Hybrid
Authors: Yang Dong , Zhang Wei , Yao Ru Liang , Jiang Ben Zheng
Published: September 2011

A high temperature vulcanized (HTV) silicone rubber/octavinyl polyhedral oligomeric silsesquioxane (POSS) hybrid was prepared. The micromorphology of the cured hybrid was investigated by scanning electron microscopy (SEM); the thermal degradation stability of this hybrid was studied by means of thermal gravimetric analyses (TGA); the degradation kinetics of this hybrid was also studied using Doyle method and Coats-Redfern method. Results showed that aggregation of self-cross-linked octavinyl POSS appeared in the HTV silicon rubber/POSS hybrid. The incorporation of POSS into silicon rubber networks enhanced the thermal degradation resistance of the matrix. Activation energy derived by the Coats-Redfern method (142.24 kJ/mol) showed a good agreement with the mean value derived by the Doyle method (146.51 kJ/mol); the thermal degradation reaction of the hybrid followed a three-dimensional diffusion law (D4).
Finite Element Analysis of the Tractor Front Axle Housing Based on ANSYS
Authors: Hu Dong Fang , Liu Wen Hui
Published: September 2011

This paper shows the static strength analysis of the tractor front axle housing by using of the finite element analysis software ANSYS, visually shows equivalent stress and strain distribution and vertical displacement distribution of the front axle housing. At the same time it also shows the analysis results of the model processing, the results of accuracy and reliability, and the weak links of the structure. By analyzing the weakest link and the difference in strength between each node for the overall structure in the condition, it can provide a direction and theoretical basis for the design and optimization of geometric entities. And the results of the analysis may be as the basis for structural improvement. In this way, it can be verified that using computer virtual software for product development is positive.
Analysis of Dynamic Characteristics of the Magnetostrictive Power Ultrasonic Transducer
Authors: Zeng Geng Xin , Cao Biao , Zeng Hai Quan
Published: September 2011

The giant magnetostrictive material (GMM) is a novel smart material based on magnetostrictive effect, and it is well suited to power ultrasonic transducer. Based on electromagnetic theory and vibration theory, the design and working principle of the magnetostrictive power ultrasonic transducer has been explained. This paper analyzed the dynamic characteristics of giant magnetostrictive materials under the outside magnetic field and deduced the wave equation of Terfenol-D rod, and the steady-state solution to the equation was obtained under given excitation. The speed and acceleration expressions of Terfenol-D were deduced by differentiating with respect to displacement equation. Based on developing mathematical models, computer imitation was made, and the result of modulation was analyzed from external conditions of transducer and inner structure of magnetostrictive material.
Numerical Assessment of the Boundary Layer Effect Predicted by the Shear Flexible Beam Theory with the Sixth-Order Differential Equations
Authors: Wang Xiao Dan , Shi Guang Yu
Published: September 2011

The analytical solutions of shear flexible beams with displacement boundary conditions are derived by using the new sixth-order differential equation beam theory presented by Shi and Voyiadjis (ASME J. Appl. Mech., Vol. 78, 021019, 2011), in which the boundary layer effects are included. The accuracy of the boundary layer effects predicted by the new sixth-order beam theory is evaluated by the finite element analysis in this study. The numerical results show that the new sixth-order beam theory is capable of taking account of the displacement boundary conditions of shear deformable beams and predicting good results of the boundary layer effects induced by the displacement boundaries and the continuity constraints.
Study on Toughening Effect in EPS Concrete
Authors: Zhao De Hui , Xu Jin Yu , Bai Er Lei
Published: September 2011

To study on the toughing effect of EPS in the plain concrete, the EPS concrete with 10%,20%,30%,40%,50% EPS volume fraction were prepared. Taking specific energy absorption as the index, the toughing effect of EPS concrete with different EPS volume fraction under impact loading were studied using a 100-mm-diameter split Hopkinson pressure bar(SHPB) apparatus, and the toughing effect mechanism of the concrete was discussed. The results show that the toughing effect of the EPS concrete increases with the average strain rate for the strain rate effect, which takes on obvious strain rate dependency. For the EPS microscopic structure effect, the toughing effect of the EPS concrete increases with the EPS volume fraction in 10~30%. Its toughing effect reduces somewhat when the EPS volume fraction reaches 40~50%. To improve the deformation property, the optimum volume fraction of EPS is 20%.
Study on Experiment of Concrete Compounding XYPEX and Steel Fiber
Authors: Zhou Ming Ru , Cui Guo Jing , Gao Li Jian , Qiao Hong Xia
Published: September 2011

To the exacting underwater engineering and waterproof projects, the impervious performance of concrete plays a crucial role in the whole project. XYPEX is a special crystalline powder waterproof material, it is new and effective which is widely used in the basements, dams and other waterproof projects. Adding steel fiber into concrete, the strength of concrete will obviously be improved. The paper makes a comparison of the compressive strength, splitting strength and impermeability test of concrete specimens with two different materials-XYPEX (waterproof material) and steel fiber, and also studies the effect of the two different materials on concrete compressive strength, splitting strength, impermeability and relevant laws, along with discussing the reaction mechanism because of the addition of this two materials.
Dynamic Elasto-Plastic Analysis on the Steel Spatial Arch Truss with 90 m Span and 0.1 Rise-Span Ratio
Authors: Li Hai Wang , Zhang Xun , Liu Jing
Published: September 2011

Abstract. In this paper, the elasto-plastic dynamic analysis on the steel spatial arch truss with 90m span and 0.1rise-span ratio is carried out under earthquake wave with SAP2000. In the analyses, the geometric and material nonlinear effects are considered simultaneously based on the plastic-hinge theory. Under the action of EL-centro wave with the peak increasing gradually, its elasto-plastic dynamic responses have been obtained. The results show that its failure mode under the earthquake action is elasto-plastic dynamic buckling; that its critical peak acceleration of EL earthquake wave when applied in X direction is 635gal, and is 465gal when applied in Z direction; The ratio of its maximal node horizontal displacement and its rise height is 1/486, and its displacement ductility coefficient is 1.029 and the ratio of its bars with plastic hinge appearing when buckling is 0.7% when EL-Centro waves applied on structure in X direction; The ratio of its maximal node vertical and its structural span is 1/604, and its displacement ductility coefficient is 1.022 and the ratio of its bars with plastic hinge appearing when buckling is 2.8% when EL-Centro waves applied in Z direction.
Vibration Analysis of Axially Compressed Nanobeams and its Critical Pressure Using a New Nonlocal Stress Theory
Authors: Li Cheng , Lim C.W. , Zhu Zhong Kui
Published: September 2011

The transverse vibration of a nanobeam subject to initial axial compressive forces based on nonlocal elasticity theory is investigated. The effects of a small nanoscale parameter at molecular level unavailable in classical mechanics theory are presented and analyzed. Explicit solutions for natural frequency, vibration mode shapes are derived through two different methods: separation of variables and multiple scales. The respective numerical solutions are in close agreement. Validity of the models and approaches presented in the work are verified. Unlike the previous studies for a nonlocal nanostructure, this paper adopts the effective nonlocal bending moment instead of the pure traditional nonlocal bending moment. The analysis yields an infinite-order differential equation of motion which governs the vibrational behaviors. For practical analysis and as examples, an eight-order governing differential equation of motion is solved and the results are discussed. The paper presents a complete nonlocal nanobeam model and the results may be helpful for the application and design of various nano-electro-mechanical devices, e.g. nano-drivers, nano-oscillators, nano-sensors, etc., where a nanobeam acts as a basic element.
Research on Strain of Structure about Leg of Cantilever Side Material Piling Machine Based on ANSYS
Authors: Cui Qiang
Published: September 2011

With a experiment calculation example, this paper presents the dynamic simulation method based on virtual prototype according to the cantilever material piling machine with the stress of the big leg problems. first We established virtual prototype of the side cantilever material piling machine pig leg and analyzed the stress of the incoming car pig leg in three different work conditions , it is concluded that the stress and strain distribution. Combine the date of dynamic strain and static train in field surveys, by comparing the data, we can think finite element model is correct, and work on the model of stress and strain problem, and propose the reasonable design improvement. The result provides reliable date for improving and optimizing of the Big-Leg of Cantilever Side Material Piling Machine.
Evaluation of Serviceability Criteria in Wireless Sensor Network for Civil Infrastructure Applications
Authors: Jang Won Suk , Shin Young Shik , Kim Yun Yong , Kim Hee Joong , Kim Kyungsik
Published: September 2011

The nature of civil infrastructure projects can be described as complex and large-scale systems that are dynamically associated with diverse organizations and participants. Large budgets, collaboration efforts, and IT strategies are involved in major projects to increase the efficiency and effectiveness of all site activities involved. Emerging IT-based computational environments are providing a feasible vision of ubiquitous computing for the improvement of productivity and efficiency. This paper introduces the serviceability criteria of wireless sensor network to investigate the practical and technical considerations. Among the criteria, reliability issue was chosen for experimental analysis to analyze the equivalent distance between receiver and transmitter. The performance measurement indicates that the degraded ratio compared with the line-of-sight condition increases in accordance with the thickness and dielectric constant of construction material.
Recording and Reconstruction of Digital Holography
Authors: Hu Nan , Pu Li Chun , Wei Jian Wei
Published: September 2011

Holography is an important non-destructive testing method for its unique idea of recording the complete wave field, i.e. both the amplitude and the phase of the light wave scattered by the object. In digital holography (DH), hologram is recorded digitally by CCD and then numerically reconstructed in the computer. The biggest limitation for digital holography is the constraint of the resolution of the CCD camera and the recording distance is very important for DH. This article presents the principles of recording and reconstruction in digital holography. The experimental results and conclusion are also provided in this paper.
Noise Characteristics Corresponding to High-Level Rotor Blades Nonsynchronous Vibrations in an Axial Compressor
Authors: Sha Yun Dong , Zhao Feng Tong , Han Jia , Cui Xian Zhi
Published: September 2011

Nonsynchronous vibrations (NSVs) with high amplitude levels in the first rotor blades of a multi-stage axial compressor have been observed. The excitation is aerodynamically caused and associated with a unsteady flow field, including sound field. In order to investigate the characteristics of sound field in the axial compressor, the noise inner compressor casing are measured simultaneously with the vibration of the rotor blades on a high pressure compressor component rig testing. The results show that noise with specific frequency structures appear in the axial compressor under a pre-arranged structure adjustment and the specific operating conditions, and the noise spectrum characteristics are analyzed detailedly. Some influence factors such as rotating speed and corrected mass flow rate on noise characteristics are discussed emphatically. The results presented in this paper can be a reference for further understand of the characteristics of unsteady flow field and the effects of the high intensity sound waves on the rotor blades.