bluuebunny/crossref_metadata_2025 huggingface dataset:
The Application of Data Mining in Distance Instruction
Authors: Wang Huan
Published: December 2010

With the continuous development of the network technology, a Web-based distance learning system and its use is appealed more and more attention, data mining, artificial intelligence and other technologies’ application in distance teaching Systems are becoming more extensive and more in-depth. Association rules, statistical analysis, classification, etc., these data digging techniques used in teaching system have improved the system's intelligence, Better to improve distance education services, so to help students improve learning efficiency much higher.
Safety Evaluation of Urban Flood Control System Based on Variable Fuzzy Pattern Recognition
Authors: Zhao Ran Hang , Lu Xiao Lei , Wang Min
Published: December 2010

Urban flood control system is in relation to the concentration of the urban population and security of the social wealth, but there has yet to a mature evaluation system. This article establish a security assessment model of urban flood control system which is based on the variable fuzzy set theory. First of all, building an evaluation indicator system according to the influencing factors; secondly, using fuzzy pattern recognition model to introduce model parameters and the time the two variable factors and get multiple levels of membership, then to conduct a consistency inspection; Finally, averaging the effective levels of membership and getting the final evaluation. Choosing the case of Heze in Shandong, it came to the conclusion that the city's flood control system level is between mild warning state and severe alert state, the evaluating result is in accordance with heze flood conditions.
An Evaluation Model of Intrusion-Tolerant Topology Availability for Wireless Sensor Networks
Authors: Xiong Shu Ming , Qu Xiao Qian , Zhan Yong Zhao , Wang Xin Sheng , Wang Liang Min
Published: December 2010

Due to the node failures incurred by intrusion threat, a wireless sensor networks will initiate topology re-generation, which is based on correct availability evaluation of current intrusion-tolerant topology. The paper proposes an availability evaluation model based on semi-Markov process (SMP) to estimate topology availability of the intrusion-tolerant topology concerning the effects from intrusion behaviors. In view of some limitations of node computation ability and storage ability, this model reduces the complexities resulting from modeling the different intrusion threats and is set up on the uniform intruding results to simplify the model design. Using the DTMC model embedded in SMP topology availability is computed and finally we analyze the sensitivity to parameters in the model.
Over-Sifting Components Analysis in Bidimensional Empirical Mode Decomposition
Authors: Ge Guang Tao
Published: December 2010

Define the course of getting mean envelope as an operation (mean envelope operation) in Empirical mode decomposition (EMD), so as to express the Intrinsic Mode Function (IMF) with mean envelopes. Summarize several rules of the mean envelope operation. On this fundamental, the abnormal components exist in the over-sifting IMFs are extracted out, and the conclusion is testified with the infinite sifting experiment.
Research on Machine-Code Level Injection and HOOK Technique
Authors: Zhang Yong Qiang , Bi Hai
Published: December 2010

HOOK and injection are advanced programming techniques. The common windows injection and HOOK techniques are introduced and analyzed in this paper. (1) By using hooks; (2) By using registration table;（3）By Trojan Horse DLL; (4) By PE import table; (5) By using remote thread. Proposed a method of non-DLL and gives a machine code-level implementations of the technology. Finally the paper lists the key technology and gives the main code.
An Indoor Location Algorithm Based on Grid Characteristic Match by TDOA-RSSI
Authors: Guan Wei Guo , Deng Zhong Liang , Ge Yue Tao , Yu Yan Pei
Published: December 2010

According to indoor wireless environment and signal propagation model, an indoor location algorithm based on grid characteristics match by TDOA-RSSI combining is put forward in this paper, in which the RSSI and TDOA parameters are combined as grid characteristic parameters to calculate the weighted Euclidean distance. The location algorithm adopts KWNN algorithms for grid matching and location estimate. Simulation results show that this algorithm has better robustness and accuracy, and can effectively solve the problem of location estimates stability in general RSSI fingerprint location system.
Personnel Archive Management System Based on Three-Layer Architecture
Authors: Zhang Jun Jie , Cai Zhen Shan , Zhang Zhi Qiang
Published: December 2010

In this paper, a personnel archive management system based on three-layer architecture was proposed, in which a middle ware was refered. In addition, relative knowledge about middle ware was introduced and the advantages of this architecture were listed out. Finally, prospect of this architecture was given out.
Estimates for the Lower Bounds on the Inverse Elements of Strictly Diagonally Dominant Tridiagonal Period Matrices in Signal Processing
Authors: Fan Hong Ling
Published: December 2010

The theory and method of matrix computation, as an important tool, have much important applications such as in computational mathematics, physics, image processing and recognition, missile system design, rotor bearing system, nonlinear kinetics, economics and biology etc. In this paper, Motivated by the references, especially [2], we give the estimates for the lower bounds on the inverse elements of strictly diagonally dominant tridiagonal period matrices.
Automatic Generation of Pencil Drawing from Digital Image
Authors: Li Yao
Published: December 2010

This paper proposes a novel algorithm for the automatic generation of pencil drawing from digital image. We use multi-scale edge detector to construct an outline map according to the structural importance. Using strokes as the major building blocks, we smooth the boundary and rendering outline according to the pencil sketch style. Then, tone rendering is carried out to convey both the tone and textures of the original image. Experimental results on natural scenery and architectural scenery images show that the pencil sketch drawings produced by our method are of good visual effects. Besides, the implementation require less than 1 second on the image with 400*300 pixels.
The Driver Design for SpaceWire Communication Device Based on Embedded Linux
Authors: Chen Chuan , Shang Yuan Yuan , Zhang Yong Xiang , Zhang Wei Gong
Published: December 2010

SpaceWire is becoming a popular solution for satellite high-speed data buses, because it is a simple standard that provides great flexibility for a wide range of system requirements. This article introduces the driver design for the SpaceWire communication device based on embedded Linux, including the analysis of the driver structure, the design of the interfaces between the upper and lower layers and the responding strategy for interrupts. In the realization link, we choose a mainstream developing platform and realize a camera capturing system for testing, and analyse the test result.
Exploring IEEE 1149.1 EXTEST for External Interconnect of a Multi-FPGA System
Authors: Zhao Yan , Han Xiao Wei , Wu Li Hua , Yu Fang
Published: December 2010

An approach for detecting open and short faults on the interconnect wires of a multi-FPGA system will be presented in this paper. In a multi-FPGA system with N interconnects, this approach can detect whether and where an open fault occurs by executing the IEEE 1149.1 JTAG EXTEST instruction once. To detect a single short fault, on the other hand, needs execution of times where . If multiple short connections exist, this approach will only detect the first short fault. The test time is thus greatly reduced for finding a single short fault per chip. Simulation results demonstrate that this approach can be easily implemented and determines accurate locations of the open/short faults.
A Vehicle Tracking System with Measuring Traffic Parameters
Authors: Lee In Jung
Published: December 2010

We consider the video image detector systems using tracking techniques which can be handling of the all kind of problems in the real world, such as shadow, occlusion, and vehicle detection by nighttime. Also we have derived the traffic information, volume count, speed, and occupancy time, under kaleidoscopic environments. In this system we propose a shadow cast algorithm and this system was tested under typical outdoor field environments at a test site. We evaluated the performance of traffic information, volume counts, speed, and occupancy time, with 4 lanes in which 2 lanes are upstream and the rests are downstream. And the performance of our video-based image detector system is qualified by comparing with laser detector installed on testing place.
Temperature Dependence of the Sole Mn2+ Emissions in Manganese Doped ZnS:Mn Quantum Dots
Authors: Zhang Xiao Song , Zhang Gao Feng , Huang Qing Song , Wei Feng Wei , Zhou Yong Liang
Published: December 2010

ZnS:Mn Quantum dots (QDs) excess of [S2-] were synthesized by the wet chemical precipitation method with an average diameter of 3.9 nm. Temperature dependence photoluminescence measurements of ZnS:Mn QDs excited at 330nm only show a clear broad emission band with peak at ～595nm assigned to the 4T1→6A1 transition within the 3d5 configuration of Mn2+ in QDs. Through the temperature dependence of emission intensity, emission energy and full widths at half maximum (FWHM), the mechanisms are analyzed to explain the temperature behavior of Mn2+ emission observed here reasonably. The Mn2+ emission intensity decreases with increasing temperature. And the blue shift of the Mn2+ emission energy increase is also observed for increasing the temperature. Furthermore, the FWHM shows weak temperature dependence below 110 K and shows an increase with temperature increasing above 110 K. Consequently, the intrinsic mechanisms of temperature dependence photoluminescence are investigated.
Development of Neodymium Oxide (Nd2O3) Doped Nanocomposities Using Sol-Gel Method
Authors: Devi Manisha , Kumar Mukesh , Gaur A.M.
Published: December 2010

In this paper, our aim was to develop the Neodymium oxide (Nd2O3) based nano composites using sol gel method. This work is mainly focused on to study the synthesis of metal composites by sol gel method. We will also observe the morphologies and dimension of neodymium oxide doped nano composites are influenced due to alteration in growth parameters such as different composition or thermal treatment. The structure of the sample prepared was studied using optical microscope. The other objective would be to investigate the synthesis of modem oxide doped nano composites.
An Improved Estimation Method of Permanent Magnet Synchronous Motor without Position Sensor
Authors: Zhang Hua Qiang , Wang Xin Sheng , Wang Fei Fei
Published: December 2010

On the basis of interior electromagnetism relationship and vector control principle, the vector control system of Permanent Magnet Synchronous Motor (PMSM) without position sensor is designed. There are two main identification methods are introduced to estimate the position and speed of PMSM. One scheme is based on the back Electromotive Force (EMF) and the other is Model Reference Adaptive Standard (MRAS). The former method achieves fast dynamic-state response while the later method obtains better steady-state performance. According to both of them advantages, an improved estimate method which combining the back EMF and the MARS is proposed. Simulation results show that the improved method is feasible and stable.
In Silico Cloning of the TIR1 cDNA from Zea Mays and Bioinformatic Analysis
Authors: Meng Qing Dong , Du Jin You
Published: December 2010

Based on the data of HTGS database and Blast between Zea Mays genome and Oryza Sativa TIR1 gene, putative Zea Mays TIR1 gene of a 3150 bp - length cDNA sequence with an full ORF was obtained. The gene shared high similarity with other plant TIR1 genes, indicating that it might be a new member of TIR1 family. On this base, through public database and related softwares, the primary structure of the protein Zea Mays TIR1 such as physical and chemical characterization was analyzed, and then the secondary and tertiary structure was emulated. We also structured Phylogenetic tree of some plant TIR1. The above resultsmay play an important role in the further research for isolatiion, identification and application of Zea Mays TIR1 gene.
Signal-Noise Separation Method Based on PSO for Vibration Signals
Authors: Pan Hong Xia , Huang Jin Ying
Published: December 2010

The wavelet analysis is combined with particle swarm optimization (PSO) which is applied to the de-noise process of vibration responding signals in this paper. The fault information has been enhanced. Furthermore, the signal-noise separation method based on particle swarm optimization for vibration signal and the diagnosis precision enhancement technology are studied, by means of the blind source separation technique.
Study on In-Depth Processing of Low Strength Leachate by Coagulation with Aluminum Sulfate
Authors: Zhang Hai Ying , Qi Jing Yu
Published: December 2010

In this study, in-depth processing of biologically-pretreated low strength leachate was performed using aluminum sulfate (alum) and alum + PAM, respectively, aiming to study removal efficiency of COD, SS and color of leachate as a function of pH, alum dosage and/or PAM, and to determine the optimal conditions for treatment of the leachate. It was found that the optimum dosage and pH are 750 mg/L and 7 for coagulation/flocculation with alum. The optimal condition for coagulation/flocculation with PAM + alum was 25-minute reaction, pH of 6, alum dosage of 500 mg/L, PAM dosage of 5 mg/L. Effluent quality after coagulation at the optimum conditions didn’t met requirements of the tertiary standard described in “Integrated wastewater discharge standard”. Coagulation using alum was found to be inefficient for advanced treatment of refractory leachate after biological treatment.
Axial Compression Ratio Limits of HSC Columns Confined with High-Strength Stirrups
Authors: Yang Kun , Shi Qing Xuan , Meng He , Men Jin Jie
Published: December 2010

A total of 10 high-strength concrete columns confined by high-strength complex stirrups were tested under cyclic lateral force and a higher constant axial loading. The results indicate that the hysteresis loop of this type of columns still shows plump spindle-shaped at higher axial compression ratio, with better ductility, energy dissipation capability and stronger anti-collapse ability; so setting closed high-strength stirrups is an effective measure to ensure the HSC columns good ductility and enhance its axial compression ratio limits. Additionally based on the experimental research and theoretical analysis, the limits of axial compression ratio of HSC columns at different levels of seismic are present in this paper.
Compressive Test on the Discontinuous Concrete Filled Steel Tubular Column-RC Beam Specimens after Cyclic Reversed Loading
Authors: Chen Qing Jun , Cai Jian , Zhao Xiao Qin , Yang Ping , Yang Chun
Published: December 2010

Concrete filled steel tubular (CFST) column-beam joint with the column tube discontinuous in joint zone is a new type of joint. In this paper, the compressive tests on this joint were carried out after the cyclic reversed loading. First the cyclic loading experiment results were introduced briefly, then the compressive tests were presented. The bearing capacity, crack patterns, deformation, strain of the reinforcements of the specimens were studied. These specimens were also compared with the other specimens only under compressive test. The results show that the specimens have good ductility. The concrete of the reinforced concrete (RC) ring beam cracked before the yield of the steel ring bars or the buckling of the steel tube. Although the cyclic loading caused some damage on the ring beam, it had few effects on the axial bearing capacity. The RC ring beam can still confine the joint zone and ensure the capacity of the joint zone was not lower than the CFST column.
Experimental Study on the Seismic Behavior of Concrete Composite Bearing Walls
Authors: Xu Ming , Chen Zhong Fan , Zhang Wei Jie
Published: December 2010

Concrete composite bearing wall system is an innovated composite structure system, which is assembled by load-bearing walls, enclosure walls and thermal protection and insulation layers. Four concrete composite bearing walls were tested quasi-statically under low cyclic lateral loads. The characteristics including failure modes, hysteretic characteristics, ductility and stiffness degradation are investigated. It is shown that the concrete composite bearing walls possess high strength and ductility. In the elastic stage, the prefabricated slabs and frame could work together very well, and the composite walls exhibited enough stiffness against lateral deformation. With increasing horizontal load, the stiffness of the prefabricated slabs tended to decrease, and finally the composite wall system failed by flexural failure of frame structure with dense columns.
Effects and Mechanisms of Niobium on the Fracture Toughness of Heavy Rail Steel
Authors: Liu Cheng Jun , Huang Ya He , Liu Hong Liang , Jiang Mao Fa
Published: December 2010

Heavy rail steel was prepared by the process of vacuum induction furnace smelting, forge work and rolling. Effects and mechanisms of niobium on the fracture toughness of heavy rail steel were investigated. In addition, the appropriate range of niobium content for heavy rail steel was determined. With the niobium content increasing, both the austenite grain size and pearlite laminae distance of heavy rail steel were decreased gradually at first and then increased rapidly. When the niobium content was low, the precipitates containing niobium predominantly appeared in the cementite, which improved the toughness of heavy rail steel by fining the austenite grain size and pearlite laminae distance; when the niobium content > 0.024%, the fine dispersed precipitates containing niobium mainly occurred in the ferrite, which improved the toughness of heavy rail steel by pining dislocations and inhibiting crack growth; with the niobium content increasing, both the quantity and size of precipitates containing niobium were increased gradually; when the niobium content > 0.073%, most precipitates containing niobium could not pin dislocations and inhibit crack growth because the particles size was too big, thus the fracture toughness of heavy rail steel was bad. So the optimum range of the niobium content could improve the fracture toughness of heavy rail steel. In the present study, when the niobium content was about 0.053%, the fracture toughness of heavy rail steel was the best. The maximum plane-strain fracture toughness was 49.88 MPam1/2.
Research on Seismic Performance Objectives of High-Rise Diagrid Tube Structures
Authors: Teng Jun , Guo Wei Liang , Rong Bai Sheng , Li Zuo Hua , Dong Zhi Jun
Published: December 2010

Diagrid tube structures have advantages on constructing high-rise buildings for its great lateral stiffness, but its seismic design methodology researches are limited. The two-stage design method in Chinese code is not specific enough for the seismic fortification objectives of this kind of structures. It is necessary to propose some specific seismic performance objectives for the key components. Typical CFST diagrid tube-concrete core tube structures are studied by dynamic elastic-plastic time-history analysis using Perform-3D program. The structure plasticity developing process is summarized and the distribution characteristics of seismic fortification lines between tubes are discussed. The influences of main structure lateral stiffness related factors on the plasticity developing process are researched. The key components of structure lateral stiffness and plastic energy dissipation are studied. The seismic performance objectives of the key components are proposed for the three-level seismic fortification objectives.
Effects and Mechanisms of Chromium on Structural Transformation of Heavy Rail Steel
Authors: Huang Ya He , Liu Cheng Jun , Jiang Mao Fa
Published: December 2010

The different dilatometric curves of continuous cooling transformation with the different cooling rates were determined by means of Gleeble-2000 thermal simulation machine. The CCT curve of heavy rail steel was obtained by measuring the dilatometric curves and metallographic analysis. And the effects and mechanisms of chromium on the phases transformation of heavy rail steel were investigated. It is found that, the heavy rail steel only takes place pearlite and martensite transformation during continuous cooling. The CCT curve of heavy rail steel is moved right with increasing chromium content, which indicates that chromium can obviously improve the stability of super cooled austenite and delay the pearlite transformation. When the content of chromium is increased from 0.21% to 0.40%, the shortest incubation time of pearlite transformation is increased from 25s to 52s. When the cooling rate ≤ 5°C s-1, with increasing chromium content, both starting and finishing temperatures of pearlite transformation are decreased at different extent, meanwhile the pearlite is refined. In addition, when the content of chromium is increased from 0.21% to 0.40%, the critical cooling rate of quenching is decreased from 15°C s-1 to 7°C s-1.
Constitutive Model for Concrete under Multiaxial Loading Conditions
Authors: Sun Li , Huang Wei Min , Purnawali Hendra
Published: December 2010

In this paper we present a new constitutive model for concrete. The framework is originally proposed for shape memory alloy, a kind of crystalline material. We show how to apply this framework for non-crystalline material: concrete. The resulting yield surface and stress-strain relationship are compared with that of experiment reported in the literature.
Numerical Analysis of Reasonable Hinge Joints Size of Reinforced Concrete Hinged Plates
Authors: Tang Xian Xi , Xu Yue , Zou Cun Jun , Chen Fang
Published: December 2010

In order to study the stress distribution in hinge joints of different depth and the effects of hinged plate by hinge joints depth, 5 group ANSYS finite element models of concrete simply supported hinged plates were built, hinge joints stress of models have been compared under the center load and side load, analysis has been made on the hinge joints of maximal stress. The analysis results indicated that with the increase of the depth of hinge joints, the transverse tensile stress, vertical shear stress and longitudinal tension stress were all showed regular distributions, and with the increase of the depth of hinge joints from 10cm to 26cm, the maximum reduction value of transverse tensile stress in hinge joints was 3.25MPa, the reduction range was 51.9%; the maximum reduction value of vertical shear stress was 1.06MPa, the reduction range was 77.9%; longitudinal compressive stress decreased gradually, and longitudinal tensile stress increased; the maximum reduction value of hinged plates deflection difference was 0.16mm, the reduction range was 36.4%; the transverse tensile stress of hinged plates’ bottom increased. Therefore, increasing the depth of hinge joints was the most effective way to increase the transverse stiffness of slab girder and to prevent hinge joints damage. At the same time, the tensile reinforcements setting in transverse and longitudinal at the bottom of hinge joints and the tensile reinforcements setting in transverse at the bottom of slab girder should be strengthened.
Study on Bond Properties of BFRP Bars to Basalt Fiber Reinforced Concrete
Authors: Bi Qiao Wei , Wang Qing Xiang , Wang Hui
Published: December 2010

In order to study the bonding characteristic of the BFRP(Basalt Fiber Reinforced Plastics for short) bars and the basalt fiber reinforced concrete, the BFRP was embedded into the cubic concrete specimen which mixed the basalt fiber sized the edge length 150 mm. By changing the diameter of the BFRP, the bonding length of the BFRP and the basalt fiber volume content of the basalt fiber reinforced concrete, the experimental results indicate that the average bonding strength decreased while the bonding length increased and it become weaker while the diameter of the BFRP was bigger, and it shows the best effect of the bonding strength when its fiber content was 0.1% comparing with three kinds of fiber content. The bond-slip constitutive model of BFRP bar and the basalt fiber concrete corresponded to the continuous curve model.
Study on Crack Mechanism for Concrete Bedding Cushion on Rock
Authors: Liu Min Zhi , Qiang Sheng , Zhu Zhen Yang
Published: December 2010

Bedding cushion cracking in concrete dam is widespread, and has not been completely prevented [1,2]. There are many cracking causes of bedding cushion, including construction difficulty and structure requirements for concrete dam. Based on the method of FEM simulative calculation of temperature and stress fields of mass concrete using water cooling pipes, this paper makes relatively in-depth study on crack mechanism for concrete bedding cushion on rock. It is revealed that all three factors of uneven thickness of bedding cushion, thickness of new dam concrete placed on cushion after off period and foundation gallery upon bedding cushion have great influence on the tensile stress of bedding cushion and should be paid special attention during construction. The calculation results show that the tensile stress of thinner concrete cushion layer is much greater than the thicker one, and the thinner upon new concrete will also make greater tensile stress in cushion. As a result, both the thinner cushion layer and the cushion with thinner new concrete on it would have a bigger chance to crack than others. The mechanism is used to explain reasonably a dam crack in construction. Then some cracking prevention measures, which should have reference value for the construction of bedding cushion, are put forward in this paper.
Experimental Equipment Research on Uniaxial Compression Stress-Strain Curve of Concrete
Authors: Chen Hai Bin , Su You Po , Zhang Yu Min , Wang Li Na
Published: December 2010

The constitutive relation of concrete under uniaxial compression is the essential theoretical basis for structural analysis of concrete. Because of lack of sufficient stiffness for ordinarily tester, stable falling branch of stress-strain curve cannot be obtained. The common methods to increase rigidity of loading system include direct and indirect method. The condition of realizing the stress-strain complete curve for concrete uniaxial compression is derived. A set of stiffness experimental equipment is designed by using the indirect method, which has the advantages of simple, dependable and strong adaptability. Experiment shows that stress-strain complete curve of uniaxial compression under different strain rate could be achieved by using this equipment and electro-hydraulic loading system of MTS co. ltd. It will lay foundation for putting forward the stress-strain curve equation of uniaxial tension and compression under considering the effect of strain rate. It can provide theoretical basis for structural analysis of concrete.
Analysis on Shearing Deformation of Sectional Joints Affecting Deflection of Cantilever Constructed Box Girder
Authors: Wang Rong Xia , Li Hong Jiang , Jin Ke Xi
Published: December 2010

Over-deflection of beam in continuous rigid frame bridge has become an serious problem in recent years. The reason is complex. Some reseachers think that the bad quality of sectional joints in cantilever construction will cause additional shearing deformation and affect the beam deflection, this idea need to be further studied. In the paper, two three-dimensional models are built up based on a factual bridge, the simulation method of joints is studied, the influence of shearing deformation caused by sectional joints on beam deflection in construction is analysed. The study shows that shearing deformation of sectional joints has influence on deflection in cantilever construction, and it shouldn’t be ignored. This may be important to improve the loading property and renovate the design concept of this kind of bridge.
Measurement of the Internal Relative Humidity Distribution in Concrete
Authors: Zhou Ji Kai , Chen Xu Dong , Zhang Jian , Kan Xiao Wei
Published: December 2010

The internal relative humidity (RH) and humidity gradients in concrete at early ages have a significant influence upon the properties of concrete, where exists a great discrepancy among the test results under different methods. By comparing and analyzing the traditional measuring methods of the RH in concrete, a new measuring method will be developed in this study, which could measure the internal RH in cement-based materials accurately, conveniently and digitally. The changing laws of the internal RH in concrete at early ages were discussed. The results indicate that the measuring results under the new developed system was more accurate than that by the predrilled hole method, while the external environment does not have any effect on the measured results obtained by using the new measurement system. What’s more, the results achieved by the new developed system approached the real RH in concrete very quickly; the RH near the surface of the specimen decreased quickly, while the RH in the center of the specimen decreased slowly, the moisture contents unevenly distributed through the various height of the specimen. Hence, there exists an obvious humidity gradient in concrete.
Experimental Study on the Stress Increment of Prestressed Tendons of Retard-Bonded Prestressed Concrete Continuous Beams
Authors: Fu Qiang , Cao Xia , Jin Ling Zhi , Zhu Wan Xu , Yang Hui Xian , Shu Zhu Bai
Published: December 2010

Based on the bending experiment for two-span continuous beams of retard-bonded prestress concrete, the analysis of the stress increment of prestressed tendons is made in the loading process. The theory that the working performance of retard-bonded prestressed concrete members is as same as unbonded prestressed concrete members during the retarding period is demonstrated. It is feasible to use the formulas for the reference (Technical specification for concrete structures prestressed with unbonded tendons) to calculate σputhe ultimate stress and Δσp the Stress increment of the retard-bonded prestressed tendons and the recommended formulas are advised to use. It is also demonstrated that retard-bonded prestressed concrete members have the same working performance as bonded prestressed concrete members after the retarding period. The conclusion of this paper can provide the reference date for the design of retard-bonded prestressed concrete continuous beam.
Behavior of Four-Line High-Speed Railway Bridge with Two Main Trusses and K-Shaped Brace
Authors: Liang Jiong , Ye Mei Xin
Published: December 2010

Taking Jinan Yellow River Bridge as an example, using 3D finite element method, displacement and behavior of four-line high-speed railway bridge with two main trusses, K-shaped brace and middle suspender is studied. The results show that transversal wave of displacement of floor system is significant, and the difference of the displacement in transversal direction reaches 6 mm. The causes includes: large distance between two main trusses, large stiffness of stringers, longitudinal stiffeners and crossbeams, weak transversal stiffeners which do not connect to lower chords. About 90% of the loads are transferred to the crossbeam through path 1 and about 60% to 80% of these loads through K-shaped braces. Less than 10% of the loads transferred to lower chords through path 2.
Simulation of the Effect of Solar Radiation on Hardening and Hardened Concrete Wall
Authors: Huang Dong Hui , Wu Sheng Xing , Zhao Hai Tao
Published: December 2010

The purpose of the present study is to assess the effect of solar radiation on the development of thermal stress in hardening and hardened concrete structures. A mathematical model for solar radiation is investigated. A finite element method program is developed for the temperature and thermal stress analysis including the heat of hydration, creep, shrinkage, and ambient temperature, especially the solar radiation. Meanwhile, the effect of solar radiation on the concrete wall during its service life is considered. The results obtained from the numerical models show that for the hardening concrete wall, solar radiation reduce the stress at the first 36 hours on surface and first 48 hours in the center of the wall, after that the stresses both on surface and in the center of the wall increases quickly; for the hardened concrete wall, solar radiation increase the stress in the center of the wall. This program is useful to estimate the stress development and the effect of the solar radiation on the hardening and hardened concrete structures.
Research on Deformation Capacity Design Method of Steel High Performance Concrete Structural Walls
Authors: Bai Liang , Zhou Tian Hua , Liang Xing Wen
Published: December 2010

The cyclic loading test of three steel high performance concrete(SHPC) structural walls was conducted and the failure pattern of the structural walls under the combined effect of axial force, bending moment, and shear force was researched. Based on the experimental results, the displacement-based deformation capacity design method was proposed for SHPC structural walls. It is obtained for the interrelated relationships among the ultimate drift ratio, the axial load ratio, the characteristic value of stirrup content and the aspect ratio. It is concluded that the increasing the characteristic value of stirrup content and limiting the axial load ratio were effective means to improve ductility. The characteristic value of stirrup content of SHPC structural walls with different ultimate drift ratio and axial load ratio were proposed and the conclusion can be referred by the design of SHPC structural walls.
Cyclic Tests and Simulations of Spatial RC Frame-Shear Wall Structures
Authors: Huang Shi Xiang , Zhao Xin Yu
Published: December 2010

The cyclic tests of three one-storey spatial RC frame-shear wall structures with slabs were conducted to investigate the failure modes and the base shear-floor displacement hysteretic responses of the model structures. Then three dimensional numerical simulations were performed using the finite element program ABAQUS/Standard and ABAQUS/Explicit. The test results are detailed in this paper and compared to those of the numerical simulations. It is shown that: (a) plastic hinges initiated at the bottom of the shear wall and followed by forming near the upper ends of columns, resulting in wall-column hinges side-sway failure mechanism; (b) to a certain extent, the horizontal force bearing capacity of the structure increases with the increasing of the vertical load; (c) it is verified that the pushover results of both ABAQUS/Standard and ABAQUS/Explicit solutions agree well with the test results in the case that the parameters are reasonably chosen.
The Effects of the No-Load Factors on Static Response of the Gravity Dam
Authors: Qiu Zhi Dong , Wei De Min
Published: December 2010

By using finite element method, analysis the static response of internal force and displacement of gravity dam under water and no-load factors. The change of the stiffness ratio and the difference of dam and foundation stiffness at the dam heel and toe are considered. The stress in the key parts of the dam and the maximal displacement on the dam top are obtained. It is found that the change of foundation stiffness affects the stress of the dam, and the displacement decreases with the increasing of the foundation stiffness. Some computational results and conclusions are the theoretical basis for the optimization design of the gravity dam.
Causes and Control Measures of Mass Concrete Crack of High-Rise Building Basement Foundation Slab
Authors: Feng Hui Hong , Wang Xi
Published: December 2010

This paper discusses that the causes and the corresponding control measures of mass concrete crack in the construction stage. And through the analysis of engineering example, it describes the application of the control measures of mass concrete crack in the basement foundation slab of high-rise building in construction process, and analyses the construction effect of its.
Ultimate Load Analysis of RC Beam under Combined Action of Axial, Bending and Shear Loading
Authors: Diao Bo , Zhang Yun Peng , Ye Ying Hua
Published: December 2010

Based on Timoshenko beam theory, a section model for the ultimate load analysis of RC beam under combined action of axial force, bending and shear force is presented in this paper. Especially, the transverse deformation is considered with the appearance of diagonal cracks. The validity of the model is established by comparing its results with several tests. These simulations include ultimate bending moments of pure bending tests and ultimate shear loads with different shear-span ratios. The analytical results show excellent agreement with experimental data.
Stochastic Finite Element Analysis for Shrinkage and Creep of a Concrete Bridge Based on LHS
Authors: Lu Zhi Fang , Liu Mu Yu
Published: December 2010

Shrinkage and creep are the inherent properties of concrete bridge. According to Latin Hypercube Sampling method (LHS) and concrete bridge shrinkage and creep uncertainty parameters, this paper promotes stochastic finite element method based on LHS for concrete bridge shrinkage and creep uncertainty analysis in ANSYS random analysis model. Based on this stochastic finite element method, internal force and long-term deformation of a continuous rigid frame bridge with density gradient concrete is analyzed. Result show, internal force and deformation of continuous rigid frame bridge after completing are reasonable and satisfy Code requirement, and are various in previous 3 years at service stage and trend to steadily after 3 years. Research result provides theoretical basis for shrinkage and creep uncertainty further analysis in concrete bridge.
Experimental Study of Stress-Strain Curves of Lightweight Aggregate Concrete
Authors: Liu Xiang , Kong Jiang Tao
Published: December 2010

According to the contrast test of LC30, LC40 lightweight aggregate concrete and C30, C40 common concrete , the text researched the mechanical property of lightweight aggregate concrete and ordinary concrete in the same strength grade and obtained the regularity of stress-strain curve of lightweight aggregate concrete in different strength grade. Then we contrasted the experimental results and planning model, analysed the difference, and suggested that the standards should improve the descent stage of the stress-strain curve of lightweight aggregate concrete combined with correlative experiments data, and give the equation of the descent stage of stress-strain curves. Concrete material in axial compression is the basic physical mechanical performance of concrete material, and is the main basis for researching bearing capacity and deformation of concrete construction. The stress-strain relationship is all-around macroscopic reaction of basal compressive property . There have been many experiments work about the stress-strain relationship of lightweight aggregate concrete at home and abroad , and found the peak strain of lightweight aggregate concrete is higher than that of ordinary concrete in the context of same peak stress .In this paper, on the basis of experimental investigations of lightweight aggregate concrete , aim at the stress-strain relationship ,we have take comparison experiment about LC30,LC40 lightweight aggregate concrete and C30,C40 ordinary concrete , and sort out stress-strain curve under the condition of the shaft center being compressed, so get the average tress-strain curve of LC30,LC40 lightweight aggregate concrete , and analyse the curve.
Study on Early Cracking Resistance of PC Box Girder Bridge
Authors: Zhong Wei Chun , Zhang Xiao Yi , Zhou Hui , Zheng Chuang Sheng
Published: December 2010

Early cracks of box girder are widespread during the construction stage of PC box girder bridges. The cracking resistance of a prestressed concrete continuous beam bridge was conducted from the point of construction technique. Experimental study on hydration heat and mechanical properties of box girder concrete at early age were carried out. The results shown that the casting temperature of the concrete, the peak temperature and the maximum temperature difference between inside and outside of the hydration heat were very low, which were 15.7°C, 8°C and 10.2°C, respectively. The strength development of the concrete was stable, and the mixture ratio was optimal. The concrete appearance quality was fairly good without visible cracks in the construction stage. The study reveals that the crack of girder bridges during the construction stage can be avoided by taking effective measures in the construction.
The Research and Application on Calculation Model of the Stagger-Jointed Assemble Lining Structure
Authors: Jiang An Long , Yang Zhao
Published: December 2010

A new calculation model of stagger-joint assemble is presented. The model can reflect three ways to transfer shear force between adjacent rings. To simplify the calculation model, a friction shear contact element is coded on ABAQUS secondary development platform and the nut of bolt is embedded in the segment. Using the model to analysis the Tunnel Through Yellow River, the results show that the integral rigidity of the lining structure improve obviously and the local modify effective have an impact on the adjacent area near ring-joint surface more than away from area.
A Practical Calculation Method of P-Δ Effect in Frame Structure
Authors: Liu Shu Zhi , Guo Xiao Yan
Published: December 2010

A practical calculation method of considering the P-Δ effect is introduced. According to the lateral frame, the calculation model and the action load of calculating the P-Δ effect are established. The model characteristic is that the shear force of the lateral displacement member is statically, and the internal force of the first-order analysis is the same as the original structure. The effects each other of each column in the same layer are analyzed, the equivalence coefficients of embodying the P-Δ effect are deduced, the nonlinear analysis becomes the linear analysis. The internal forces are calculated by using no-shear moment distribution method.
Axial Strain of Reinforced Concrete Columns
Authors: Park Jong Wook , Cha Sang A , Kang Ji Eun , Mansour Mohamad , Lee Jung Yoon
Published: December 2010

The reinforced concrete members are designed to fail in flexural member to behave ductilely. Also the failure doesn’t impose on columns but beams. But according to the plastic collapse mechanism, the plastic hinge potentially developed at the bottom of the RC column near the base of the structure after flexural yielding. These columns are generally dominated by shear which led to sudden failure in post yielding region because of its relatively short span-to-depth ratio, so special care is needed. The deformability of column with short span-to-depth ratio is small compared with larger span-to-depth ratio column under reversed cyclic loading. Therefore the design of these kinds of RC columns necessitates the prediction of both the shear strength after flexural yielding and corresponding ductility of such members. Ten RC columns with varying axial force ratio and shear reinforcement ratio were tested under monotonic and reversed cyclic loading. The most affectable factor to column behavior was the axial force. The result indicates that concrete contribution to shear resistance in the plastic hinge region and axial strain were decreased as axial force.
Stochastic Gaussian Optimized Inversion of Mechanical Parameters of Reinforced Concrete Single T-Shaped Beam
Authors: Zhang Jian , Lan Wen Gai , Yu Bo
Published: December 2010

The reinforced concrete single T-shaped beam is of common use. Compared with mechanical analysis, little attraction has been put on the stochastic optimized inversion problem. The present study is aimed to carry out stochastic optimized inversion of mechanical parameters of reinforced concrete single T-shaped beam based on degraded solid element theory. Firstly for the reinforced concrete single T-shaped beam, degraded solid element theory is deduced and the displacement function is obtained. Then Gaussian error function of mechanical parameters of the reinforced concrete single T-shaped beam is founded and the corresponding formulas of Gaussian expectation and variance are derived. The stochastic optimized inversion computing formulas are also obtained by adopting optimization method including conjugate gradient method. Then the steps of stochastic Gaussian optimized inversion of mechanical parameters of the reinforced concrete single T-shaped beam are listed. Through analysis of a classic example, some important conclusions about stochastic Gaussian optimized inversion of mechanical parameters of the reinforced concrete single T-shaped beam are drawn.
Stress Distribution Regularity Analysis of Ring Plate of Concrete Filled Steel Tube Connections with Exterior Diaphragms
Authors: Lee Cheng Yu , Luo Lie , Guo Yao Jie
Published: December 2010

Connections with exterior diaphragms are used widely in concrete filled steel tubular structures. The stress distribution regularity of ring plate has crucial influence to the right joint design as well as construction. Finite element simulation is applied to the two common types of connections with stiffener ring. The stress distribution regularity of ring plate a well as the development regularity of dangerous section are studied through changing loading methods and ring plate size . The main conclusions are achieved as follows: (1) The high stress plastic region of the 2 types will all not appear in the beam end, but inner the ring plate .This phenomenon will not be different as the changing of ring plate size. (2) The stress distribution of concentric arc ring plate is accord with the present test conclusions, which is to say, high stress regions are all in the corner of the boundary of beam and ring plate despite one way or two way loading. (3) The high stress region of side curved arc joint ring plate distribute in the 30 degree angle section of ring plate under one way loading, and between the 30 degree angle section of ring plate and the 45 degree inner ring plate under two way loading ,the ultimate stress in 45 degree region is a bit higher than 30 degree ,but penetrated plastic region was formed in the 30 degree section ,which indicates that the dangerous section is still in the 30 degree section. (4)Different loading methods can only change the stress distribution of ring plate but can not change the dangerous section, and even have no influence to the ultimate ring plate stress.
Dynamic Plastoelastic Time-History Analysis on a Super High-Rise Building Structure of Anhui
Authors: Huang Yuan , Song Xing Yu , Xu Feng Bo
Published: December 2010

The first high-rise to be completed in Anhui Province in China adopts concrete-filled steel tubular frame- reinforced concrete tube composite structure, which can be classified as the out-of-codes hybrid structure. The structure analysis model is established through the use of the large-scale general finite element software ABAQUS. The dynamic plastoelastic analytical method based on explicit integration which is not theoretically simplified is used to directly imitate the nonlinear reaction of the structure subject to the seismic force. The deformation, internal force and the damage of the structure are studied through the dynamic plastoelastic time-history analytical method subject to the 7-magnitude rarely met earthquake. The calculation result indicates that the maximum inter-layer displacement angle is 1/366 on the X direction and 1/279 on the Y direction, both of which are smaller than 1/100, thus they meet the standards; except for the local cracks, no obvious compression damage is found on the main bearing wall, no plastic strain is found on the internal steel skeleton of the shear wall and the steel reinforcement of the edge member, and the shear wall is of good earthquake resistance performance. Lastly based on the loading and damage conditions of the components, suggestions for the improved design are put forward.