bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization Design of Cable-Frame Antennas Based on Tension Compensation Method
Authors: Zong Ya Li , Cao Hong Jun
Published: January 2014

Tension truss reflectors are flexible structures characterized by strong geometric nonlinearities, thus the surface error and the real cable tensions of a reflector cannot be controlled efficiently to anticipant levels by their initial cable tensions. To ensure both appropriate node positions and anticipant cable tensions, an optimization method based on Tension Compensation Method is presented. First, a parameterized description of the zero-stress states of the front net and the rear net is proposed and the strategy of Tension Compensation Method is used to control the cable tensions to anticipant levels. Second, a mathematical optimization model for the cable tensions and the zero-stress state design of the cable network is established based on Tension Compensation Method with the optimization target of minimizing surface error of the reflector. Finally, the feasibility and effectiveness of the presented method are validated by some numerical examples. The results show that the cable tensions can be effectively controlled by the proposed method, and this method can generate regular zero-stress states of the cable-nets which may bring great convenience to the lofting work of the cable network.
Kinematic Analysis of a Spatial 6-Bar Linkage Mechanism
Authors: Xie Liang Xi , Tian Zhi Xiang , Kong Jian Yi , Jiang Guo Zhang , Li Gong Fa
Published: January 2014

The door operator in metallurgical equipment is a spatial 6-bar linkage mechanism. The numerical model of motion and force of the mechanism was developed and the numerical solution was applied. A computer simulation was implemented. There is a high level of consistency between the solution and simulation. The torques required on driving crank have been studied. The influences of the self-lock conditions on the crank length and con-rod length have been explored. The effects of the length of crank and con-rode on the needed maximal torques of the crank have been studied, too. And the kinematics analysis attributes the lightening design of the slider structure on the basis of considering the sliders rigidness and intensity.
Structure Improvement Analysis of Maize Root Stubble Harvester
Authors: Shao Dong Wei , Wang Jun Fa , Jiang Dong Hua , Li Xu Hui , Wu Gui Fu , Liu Yuan Jun , Xue Di , Luan Ji Yi , Zhao Kun , Li Feng Xia , Wang Lian Yang
Published: January 2014

In order to effectively reduce the crop stubble harvesters digging resistance, enhance stubbles picking rate and intact stubble rate, the Research Group took structure improvement for the Crop stubble harvester and its critical component based on abundant trials. Three physical machines in succession were developed, and a trial contrastive analysis between the optimized harvester and the first harvester was conducted. It turned out that the improved harvester machine was clearly superior to the first machine.
Simulation of Gas-Solid Flow Characteristics in Three-Dimensional Rotational Spouted-Fluidized Bed
Authors: Long Xin Feng , Liu Yi , Lou Bo
Published: January 2014

In order to study the gas-solid flow characteristics in a rotational spouted-fluidized bed dryer, the eulerian multi-phase model was applied in three-dimensional numerical simulation of a rotational spouted-fluidized bed to analyze the effect of different velocity ratios between bottom and tangential wind on gas and particle velocity distribution characteristics, and the change rule of gas-solid flow state with the time at the velocity ratio of 30 m·s-1/30 m·s-1 was derived. The results show that the increase of tangential wind velocity is propitious to enhance the gas flow rate in the region near the wall and make the gas-solid phase mix sufficiently as well as augment of the contact area of gas and particle phase, and decrease of the gas flow dead zones and the adhesion of viscous materials to cylinder wall. However, the negative pressure formed by the entrainment effect of tangential wind goes against the development of gas flow along the axial direction reducing the penetration effect of axial wind to the granular layer.
Analysis of Stimulated Brillouin Scattering in a Single Mode Fiber Ring
Authors: Zhang Xiao Min , Ci Yan Ke , Yao Jin Li
Published: January 2014

Fiber ring resonator is widely used to generate stimulated Brillouin scattering(SBS). In this paper, the operation principle of SBS in a single mode fiber ring is analyzed, and the simulation method is proposed.
Semi-Solid State Joining of Aluminum Alloys under Nitrogen Shielding Gas
Authors: Geaowdee Atsadawoot , Muangjunburee Prapas , Wannasin Jessada
Published: January 2014

The purpose of this research is to investigate the semi-solid state joining of SSM 356 aluminum alloy which welded at its semi-solid state by using oxygen - acetylene as a heat source. Then a stirrer was used to stir the weld seam. Joining was performed under nitrogen shielding gas. The parameters of this study were rotation speed at 1,110 and 1,320 rpm, welding speed at 120 and 160 mm/min, semi-solid state temperatures 575-590 and 590-610 oC. The results indicated that the weld's microstructure consisted of irregular globular structure. In addition, porosities were found at top of weld metal. The highest tensile strength and elongation were obtained from rotation speed at 1,110 rpm, welding speed at 120 mm/min and joining temperature at 575-590 oC.
Simulation of Transmission Efficiency for Different Bending Radius of Aerosol Sampling Inlet
Authors: Wang Bao Qing , Chen Rong Hui , Wang Ze Bei , Li Yang Yang , Yao Shu , Yin Shuai
Published: January 2014

The purpose of the paper is to simulate transmission efficiency for different bending radius of aerosol sampling inlet using CFD. To evaluate the transmission efficiency, we introduced Discrete Phase Model to simulate aerosol movement. Results from simulations show that the greater transmission efficiency aerosol sampling inlet will be, the larger bending radius is. At 300mm bending radius, aerosol transmission efficiency is almost 1 for 10μm diameter of particular matter. The CFD model can effectively simulate the characteristic and loss of aerosol particulate matters through the bending tube.
New Method of Fault Knowledge Acquisition of Electronic Equipment
Authors: Huo Zhi Cheng , Sun Qi Shun , Qi Feng Jun , Ding Guo Bao
Published: January 2014

For the problems like discreteness, tolerance, non-linear of the parts, acquiring the fault knowledge of analog system in electric equipment is hard. This method realized the process of KA automatization through the combination of PSPICE software and C language and taking command lines as combining site. Using the batch file, the programs will form some topological information and parameter information about the fault states of a circuit system each time. The result of a experiment about an Basic Transistor Amplifier circuit proves its feasibility.
Simulation and Optimization on Dynamic Hydraulic Drawing for Spiral Bottom Shell Parts
Authors: Zhou Wen Chao , Zhou Wei , Liu Cun Ping , Xiao Shan Hua
Published: January 2014

The dynamic hydraulic drawing simulation is a valid method that reduces costs, increases quality and discovers hydraulic forming process problems.The simulation process of hydraulic drawing for spiral bottom brake shell parts with space surface feature was investigated and the optimal processing parameters were acquired by using Dynaform software. The results showed that model approaches, model methods, meshing and parameters setting were the foundation of hydraulic drawing simulation and the optimized control of holder force and fluid pressure were the key factors for preventing defects during hydraulic deep drawing. Meanwhile, the suitable blank shape was found good for reducing the defects of Wall Thickness Unevenness and oral flange earing, etc.
Maintenance Study of a Pilot Biomass Pyrolysis Installation
Authors: Honus Stanislav , Bukowski Przemyslaw
Published: January 2014

The article describes the results of studies on a pilot pyrolysis installation with respect to maintenance parameters during pyrolysis of biomass in a form of pellets. Efficiency of raw fuel (pellets made from wood) conversion to processed fuels: coke, oil and post-pyrolytic gas. The described installation is atypical in terms of construction design that is based on the heat conduction mechanism (in most installations, convection in an atmosphere of inert gases or in vacuum is the dominating mechanism). Also, energy balances for biomass pyrolysis are presented.
Based on Maximo Preventive Maintenance of the Crane
Authors: Leng Jian Wei , Zhao Ya Ming
Published: January 2014

Bridge crane is an important tool and equipment in mechanization and automation of industrial production. Reduce the incidence of failure, reducing downtime cranes, to ensure the normal operation of the crane is very important，in this paper we use the maximo to conduct the preventive maintenance for crane，According to the standard crane daily spot check, generate work orders, in order to improve the work efficiency of the crane.
Numerical Simulation Analysis for Influence of Lateral Inclination Angle on the Yacht Resistance
Authors: Fu Fei , Liu Yue Qin , Wu Xin Xin
Published: January 2014

The article analyses the yacht navigation attitude in the navigation process based on ЦАГИ method. It solves RANS equations in the CFD softwareFluent based on VOF method, combined with RNG k model. It calculates numerical simulation on four yachts which have same dimension but different lateral inclination angle and analyses the flow field, then verify the relationship between the yacht sailing resistance and the changes of lateral inclination angle.
Design of Pneumatic System in Warm Extrusion Forming Process Manipulator for Steel Connecting Sleeve
Authors: Zhang Xin Ju , Yang Zhao Min , Yang Song Lin
Published: January 2014

There are three work posts in this warm extruder: upsetting station, backward extrusion station and blanking station. They work continuously. The manipulator is mainly used to passing artifacts from one station to another. The warm extrusion forming process manipulator for steel connecting sleeve typically was designed to reduce labor intensity and enhance production automation level. The machines structure and working principle were described. In the same time, some pneumatic circuits and pneumatic control circuits of the manipulator were designed, so the manipulator can have automatic voltage regulating function and run smoothly. Practices show that the strapping machine has the advantages of simple structure, high efficiency, low cost and small vibrating noise.
Experimental Study on Interfacial Bonded Performance of One-Step Forming BFRP-Rod-Strengthened Bamboo
Authors: Ding Bai Chuan , Lv Qing Fang , Zhu Ran
Published: January 2014

This work attempts a new strengthening method (one-step forming) between BFRP (basalt fiber reinforcement polymer) rod and bamboo. The interfacial bonding properties of the one-step forming pull-out specimens are achieved. The specimens are composed of bamboo sticks lamination and recombined bamboo respectively containing the plutruded BFRP rods. Through the experiment, bonding failure modes and typical load-slip curves are obtained. Besides, the ultimate bonding stress is compared to bonded-in method of FRP rod which embedded in wood. At last, anchoring calculation recommendations are delivered.
Rehabilitation Technology for Excessive Large Gap of Joint between Caissons of Gravity Wharf
Authors: Wei Ming Hui , Li Guo Bao , Xiao Peng Wei
Published: January 2014

Excessive large gap of joint between caissons easily lead to the rear backfill leaking into harbor basin, to cause a differential settlement of the rear terminals and even affect the structural stability. With the case about caisson wharf of a harbor in southern China, this paper puts forward a rehabilitation technology of caisson joints with mold bag concrete as the major filler. The key technologies are introduced in detail including the mold bag production and installation, the height computation of laminated pouring of concrete and underwater concreting, etc. This technical maintenance is reasonable in economy and practicable in technology, worthy of promotion.
Innovation of Old Buildings Repairing and Vierendeel Steel Roof Truss
Authors: Zhang Shao Wen , Zhang Lu Lu , Zhang Qi
Published: January 2014

The old building was saved, protected and transformed with the original technique and measure. After the structure reliability of old building passed to test and evaluate, the architectural function was redesigned, old structure was reinforced and repaired. The structural integrity was strengthened using cement mortar and steel mesh to reinforce inner walls, adding cross walls, enclosure beam and seismic angle-steel. Without change the appearance of the building, a vierendeel steel truss was innovated, the loads of roof, truss and loft ceiling was transferred to small steel-concrete columns placed under truss support, not to walls. Vierendeel steel truss led to open space changed to the third floor within loft, the area increased twenty-six percent and met owner use at lower cost, results show good for ten years.
Fast Analysis of Structural Reliability Using Gaussian Process Classification Based Dynamic Response Surface Method
Authors: Peng Li Feng , Su Guo Shao , Zhao Wei
Published: January 2014

The performance function of large-scale complicated engineering structure is always highly nonlinear and implicit, and its reliability needs to be evaluated through a time-consuming Finite Element method (FEM). A new method, Gaussian process classification (GPC) dynamic response surface based on Monte Carlo Simulation (MCS) was proposed. Small training samples were created using FEM and Markov chain. Then, the most probable point (MPP) is predicted quickly using MCS without any extra FEM analysis. Furthermore, an iterative algorithm is presented to reduce the errors of GPC by using information of MPP to improve the reconstructing precision constantly. Then, Monte Carlo method combined with GPC surface is applied to get the probability of failure. Several examples results demonstrate the efficiency and robustness of the proposed method, compared with the results of common reliability methods.
The Bearing Capacity and Failure Mechanism of Foundations near Slope Based on Nondimensional Parameters
Authors: Jiang Yang , She Yue Xin , Chen Bao Hai , Shen Hua Rong
Published: January 2014

The foundation on slope problem is a special case of the very large bearing capacity problem. Researchers have studied the bearing capacity of slopes as such problems arise quite frequently in practice. The aim of this paper is to study the effect that changing the position of an infinitely long strip foundation, from the edge of the slope to a certain distance away, has on the bearing capacity of a slope. The influence of various nondimensional parameters, such as strength ratio, slope height ratio and so on, on the bearing capacity of slope foundation is also analyzed by the finite element method. Conclusions are as follows: as the foundation is moved away from the slope by increasing D/B, there is a change over point from a slope failure mechanism to a flat ground failure mechanism. As the strength ratio increases for a set D/B, there is a considerable change in the shape of the failure surface initially, followed by only minor changes from strength ratio 10 onwards and so on.
Reliability Analysis of High Pressure Buried Pipeline under Landslide
Authors: Yun Long , Kang Le
Published: January 2014

The landslide disaster tends to cause safe hidden trouble to the normal operation of the pipeline and pipeline is likely to take place accident and get failed under the action of a landslide. According to the theory of winkler, in the condition of pipeline landslide, the mechanical model is established and calculated the stress distribution under different landslide scale. According to the calculation result, the dangerous section of pipe is obtained. Based on the pipeline's own strength and pipeline working stress in the landslide, the limit state equation of the pipes is set up by using the third strength theory. Finally according to the distribution of stress and strength, the pipeline reliability index and failure probability are obtained by means of the first order second moment method improved. The achievement of this paper has great value .to the buried gas pipeline risk assessment. Key words: landslides; The third strength theory; The first order second moment method; Reliability index; Failure probability
Fatigue Reliability Analysis on Connecting Rod of Automobile Engine Using Artificial Neural Network Method
Authors: Sha Li Rong , Shi Yong Chun
Published: January 2014

The artificial neural network method is adopted to solve the reliability analysis of the automobile engine. When the limit state function of structure is highly complex or with non-linearity, it is time-consuming to calculate the reliability with traditional reliability methods. The artificial neural network method is used to analyze the fatigue reliability of connecting rod of automobile engine. The working process of the connecting rod is simulated with UG software, the dynamics analysis on crank-connecting rod-piston mechanism is performed with ANSYS and ADAMS software, with the finite element analysis results, the stress information of the critical point of the connecting rod can be obtained, so the performance function of the structure can be established. The artificial neural network method is used to fit the performance function as well as its derivatives, so as to calculate the reliability of the structure.
Study on the Longitudinal Horizontal Stiffness Limited Value of 20m Simply Supported Beam Pier Top of Urban Rail Transit
Authors: Dai Xian Xing , Liu Ting Lin , Xiong Zhen Wei , Wang Ping
Published: January 2014

Considering the common application of the 20m simply supported beam in modern urban rail transit, an integrative rail-bridge-pier finite element model is developed. The force imposed on the pier, abutment and rail are calculated in different conditions, including the bridge stretching, bending and braking. In addition, the displacement of pier top and the maximum rapid relative displacement between girder and track are also calculated. The results are shown as follows: in terms of multiple span simply supported beams, the most harmful bending mode is when the load distributes on two adjacent simply supported beams. According to the additional braking tension force, as well as the additional braking pressure and the rapid relative displacement between girder and track, the most harmful breaking mode can be confirmed respectively. In the paper, the minimum value of the longitudinal horizontal linear stiffness of 20m simply supported beam piers is 120 kN/cm (double-line).
Research on Masonry Arch-Bridges Reinforcement and Reconstruction Methods
Authors: Chen Xu Yong , Xie Xiao
Published: January 2014

We analyze existing masonry arch-bridges and corresponding reinforcement methods in this paper and bring about the method of using strip-shaped outer-wrap reinforced concrete with chemically planted bar to improve the new and old concretes cooperative work so as to strengthen the wholeness and improve impermeability of the bridge. We also compare two experiments on one actual bridge of 30 cm strip-shaped outer-wrap reinforced concrete in the main arch ring and 20 cm global outer-wrap reinforcement concrete, of which the data shows the superiority of strip-shaped outer-wrap reinforced concrete for it strengthens both the bridge floor and bottom structure and improve the load capacity.
Dynamic Isolation Model Scheme Optimization Based on Fuzzy Decision Theory of Self-Anchored Cable-Stayed Suspension Bridge
Authors: Mu Ying Na , Shi Lei , Miao Feng
Published: January 2014

Based on fuzzy decision theory, multi objective fuzzy optimization is done for the dynamic isolation model scheme of self-anchored cable-stayed suspension bridge. Using two comparison theory solves the problem of quantifying the qualitative indexes and distinguish the concepts of importance and superiority. Combining the fuzzy decision method with engineering practice and using the results of five cases are proposed for multi objective fuzzy optimization. Comparison results show that it is more reasonable to place lead rubber bearings not only between pier and girder, but also main tower and girder, with viscous dampers between main tower and girder on the same time. This method can provide a reference for structure selection in practical conceptual design phase.
Study on Distributed Properties of Welding Residual Stress in Bridge Nodes
Authors: Liu Jia , Zhang Run Chang , Qu Wei Lian , Jiang Li
Published: January 2014

The distributed properties of residual stress in bridge nodes have been investigated in the paper. Based on some bridge node, the three dimensional thermodynamics finite element model has been established, meanwhile, the double ellipsoidal distributed heat source model are used to simulate the whole welding procedure of bridge nodes according to the welding parameters. Thus, the distributed regularities of residual stress of bridge node have been obtained. Simulating results show that the residual stresses distribute uniformly in the welding direction, and the max value reaches the yield strength of steel Q345qD. Besides, the residual stress in the lateral direction reaches the max value in the place of welding district, and decreases rapidly when far away from the welds.
The Analysis of Stayed Cable Wind-Induced Vibration Morphology and Damping Measures
Authors: Du Xiao Ming , Li Nan
Published: January 2014

The stayed cable is the key part of the cable-stayed bridge and the main bearing section. Stay cables are prone to vibration under the loads of the rains winds, earthquakes and transportation for the long-span bridge is very flexible and the damping is small. A long time effect of cable vibration on the structure durability has become a serious problem of cable-stayed bridge in the development and operation. Wind induced vibration of stay cable shape is analyzed, and some common damping measures are expounded in the article and it provides the basis for further study in the future.
Analysis and Evaluation on Safety of Old Stone Arch Bridge Based on Current Specification
Authors: Zhao Zhi Meng , Wang Xiao Long , Chen Feng Jin , Wang Zhen Ji , Yang Ya Juan
Published: January 2014

This paper examines the bearing capacity and stability of a catenary axis uniform cross-section multi-span stone arch bridge with solid spandrels in the cold areas. Taking the West Ulanhot Large Bridge built in cold area of Inner Mongolia in 1960s as an example, the bearing capacity and stability of early-built stone arch bridge were calculated,in consideration with the effect of dead load, live load and temperature variation as well as multi-arch action on the main arch ring, in the light of current specification, i.e., the Code for Design of Highway Masonry Bridges and Culverts (JTG D61-2005) published by the Ministry of Communications of the People's Republic of China. The aim was to evaluate the safety of the old multi-span arch bridge through the theoretical analysis and checking calculation based on the current specification.
Modeling and Dynamic Characteristics Analysis of the Qiantangjiang Rail-Cum-Road Bridge
Authors: Wang Hui , Xia He , Zhan Jia Wang
Published: January 2014

The dynamic characteristics of the Qiantangjiang rail-cum-road steel truss bridge is to analyzed by the Beam elements Midas model, beam-Plate element Midas model and plate element Ansys model, and the calculated results are compared with the field experiment data. The natural frequencies and mode shapes simulated with the plate element Ansys model are much closer to the experimental ones, indicating it can more accurately simulate the dynamic characteristics of steel truss structure. The results can provide a reference for modeling the steel truss bridges, and as the foundation of further static and dynamic analyses.
A Theoretical Study on the Cables Fatigue Life Quantitative Analysis Method of Cable Bridges
Authors: Yu Fang , Ye Lie Ping , Dong Zhi Jun
Published: January 2014

Based on the theory of fatigue fracture of metals, quantitative analysis method was proposed for fatigue strength of cables of cable bridges and conclusions were reached through analysis of calculation formula: the analysis method of stress fatigue life was able to consider the section dimensions of the cables, plasticity of the material and stress ration caused by external loads and other factors which affect the fatigue life. This analysis theory was correct which took into consideration of relatively overall factors and was a better way to analyze the cable fatigue life. Meanwhile, the design of fatigue strength of bridge cables should adopt the theoretical fatigue limit represented by equivalent nominal stress amplitude as the design value of fatigue strength of cable. The theory represented by equivalent nominal stress amplitude considered the influence of stress ratio on fatigue life of cables caused by external loads. Compared with traditional method of fatigue strength estimate, with sufficient theory basis and overall consideration of factors, the results of this method were more reliable.
Research on Damage Identification of Cable-Stayed Bridge with Model Test Based on Dynamic Characteristics
Authors: Lu Zhao Hui , Peng Wei , Chang Quan Hui , Guo Jian , Wang Lu Lu
Published: January 2014

Based on the change coefficient of modal flexibility curvature, an experimental research on damage recognition of cable-stayed bridge was conducted. The working conditions are introduced, as well as the design and manufacture of the model that can serve as an important guide to the similar experiments. In the design of this experiment, the optimization of cable tensions and the sensor placement optimization were discussed and the suitable methods were chosen and verified. The results verify the sensitivity of the change coefficient of modal flexibility curvature and compare the identification ability on different parts of the same damage location. In addition, how the number of modes required affects the change coefficient of modal flexibility curvature was discussed and the proper number is given.
Analysis on Pile-Soil Stress Ratio of Composite Foundation with Sparse Capped-Piles under Lime-Soil Embankment Load
Authors: Liu Wei Zheng , Zhang Jun Hui , Zhang Hao
Published: January 2014

The combined effect of the embankment fill, piles and caps, and foundation soils on the load transfer characteristics of sparse capped-piled embankment is very significant. Using the modified cylindrical shear stress transfer model based on Marston soil pressure theory, a new calculation method for pile-soil stress ratio of sparse rigid pile composite foundation incorporating the arching effect in lime-soil and soil-pile interaction was presented. The presented method is verified by comparison between analytical solutions and the observed results from a practical project. In addition, a parametric study was also conducted to evaluate the influence of the embankment height, the cohesion of fill and pile-soil stiffness ratio on the pile-soil stress ratio.
Motor Vehicle Traffic-Induced Vibration Characteristics of the Ground and Urban Pedestrian Overpass
Authors: Cai Qing Chi , Li Yuan , Liu Qi Liang , Li Zhen
Published: January 2014

Since the 21st century, Beijing accelerate the process of internationalization. The level of the construction of Beijing city also faced a new challenge. The city traffic problems in Beijing is badly in need of improving. The stiffness of pedestrian bridge is so low that produce large vibration in the influence of ground traffic, which has a psychological effect on the pedestrian, even may cause psychological panic, anxiety and other adverse reactions. This study by monitoring the footbridge vibration at Beijing City Garden Road ,establishing finite element model to know about its severity under Motor vehicle traffic loads to get Vibration mechanics parameters. Use ISO, UK, Japan bridge design specifications and standard to check to make a scientific and reasonable evaluation on the vibration comfort about it.
Mechanical Analysis of the Superstructure of Prestressed Concrete Composite Box-Girder Bridge with Corrugated Steel Webs
Authors: Li Pei Feng , Wang Qiao , Wan Shui
Published: January 2014

The superstructure of H-bridge is prestressed concrete composite box-girder with corrugated steel webs with a main span of 90m, and the span arrangement is 52m+90m+52m. In this paper, the finite element method is used to model H-bridges superstructure and do analysis of construction stage and completed bridge stage, and the analysis is checked with the current corresponding regulatory of bridge design and construction. Checking results show that under the existing highway-level loads, the main beams carrying capacity, stress, crack resistance, deformation and corrugated steel webs shear strength and shear stability meet the regulatory requirements. The checking process also reflects the mechanical properties of corrugated steel web.
Vibration Analysis of Bridge Structure under Moving Train Load and Earthquake Action
Authors: Fan Bei Bei , Zhang Yuan , Ruan Dong Hua
Published: January 2014

In this paper, vibration of a steel truss bridge under moving train and earthquake action is analyzed. The following conclusions are drawn by modal analysis and time-history analysis. 1) Lateral dynamic response of this structure is more obvious under earthquake action and lateral dynamic effect of train running load; 2) seismic response in the directions different from train load is small, and dynamic response becomes larger obviously when they are considered together.
Fuzzy Mathematics Analysis for the Survey Result of Large Span Continuous Box Girder Bridges' Common Quality Defects
Authors: Jiang Tian Hua , Gong Jie , Zhang Hai Long
Published: January 2014

The essay was initiated by Hubei Provincial Communications Department, endorsed by Traffic Planning and Design Institute of Hubei Province, Bridge Science Research Institute (China Zhongtie Major Bridge Engineering Group), Huazhong University of Science and Technology, Wuhan University of Science and Technology. 6 kinds of common bridge diseases and 6 kinds of effective improvement measures were ranked and graded using questionnaire, and counted and calculated the weight using dual contrast fuzzy decision method. The calculation result shows that the concrete crack, bridge damage and main girder downwarping were accounted for larger proportion in the current common bridge diseases. In improvement measures, strengthening bridge linear control, mastering the concrete ages and strengthening dual control of prestressed reinforcement are particularly important.
The Tensile Force Test Model of Vertical Prestressing Finishing Rolling Rebar in Box Girder
Authors: Xu Xiang Feng
Published: January 2014

Vertical prestressing tendons finishing twisted steel is widely used in the concrete box girder, but ,it is hard to effectively control the loss of anchor stress. Based on the dynamic, the three-parameter model was built which include the frequency of the exposed segmentthe segment length of the exposed steel reinforcements and effective tensile force. The vertical tensioning force of the box girder webs model was designed at laboratory .The natural frequency was obtained through test. Relying on experimental test data ,the model of the nonlinear relationship between fine bundle the rebar tensile force and the exposed segment frequency was established. Here in NDT methods to be able to quickly and effectively measured vertical prestressing tension.
Dynamical Analysis of a Cable-Stayed Bridge with One Tower
Authors: Cao San Peng , Meng Xiang Bin , Han Yue Zhen
Published: January 2014

With a double-beam calculation model, the study on dynamic characteristics of the cable-stayed bridge with one tower was carried out. Modal analysis and space nonlinear time history analysis were adopted.The latter used EI-Centro earthquake wave, it acted on the structure from three different direction:transverse, longitudinal and vertical respectively. From these analysis, dynamic characteristics of the bridge are acquired, internal force and displacement in critical position of the beam and tower are given too. At the same time, wind-resistant stability of the bridge is also calculated through a experienced formula. All the results provide important reference for design and construction.
Damage Identification of T-Beam Bridge Based on Distributed Long-Gauge Strain Mode Theory
Authors: Wu Bi Tao , Wu Gang , Yang Cai Qian
Published: January 2014

Damage identification of a T-beam bridge which contains five T-beams is conducted based on distributed long - gauge strain mode theory, considering the damage and aging problems of widely used simple-supported reinforced concrete T-beam bridges. Assuming that the damage occurs in the different T-beams, the normalized strain mode is used to identify the damage. The sensitivity of the normalized strain mode of each T-beam and change rule of strain mode curve is studied at the same time. It is effective to apply modal strain amplitude variation degree to detect damages. If sensors are arranged reasonablely, a good damage identification can be obtained by utilizing distributed long-gauge strain mode theory even if the damage is slight.Some suggestions are given for the sensor arrangement and health monitoring of this kind of bridge when using the distributed long-gauge strain mode theory at last.
Research on the Structural Damage Detection with Virtual Laminated Element Modeling Technique
Authors: Yang Wan Li , Li Ji Ping , Ju Xiao Hui
Published: January 2014

A new kind of combined finite element named three-dimensional virtual laminated element and its deduce process is introduced. The new finite element was proved to be convenient, accurate and efficient in the calculation of bridge structures by a modal test and corresponding numerical example. Then some research and discussion were done, which show that with small modal construction scale being comparative with beam element, the static and dynamic spatial behavior of complicated structures can be simulated precisely. Furthermore, it is sensitive to structural damages, and more damage information can be obtained than corresponding spatial beam element, which means it is highly promising in the application of structural damage detection.
Design Optimization of Steel Anchor Beam in Cable-Pylon Composite Anchor Structure
Authors: Zhao Min , Lu Wen Ru , Ma Lin
Published: January 2014

Because the stress concentration usually appears in the plate corner or discontinuity zone, it is necessary to optimize design for local plate of steel anchor beam bearing huge cable force. Based on 3D elaborate finite-element method, the stress distribution of steel anchor beam of cable-pylon composite anchor structure was analyzed. The results showed that the steel anchor beam of cable-pylon composite anchorage structure was safe and reliable, the application of the vertical stiffened plate of the side plate in anchor box and the middle diaphragm efficiently improved the force state of the steel anchor beam, on the other hand the stress conditions of the concrete pylon was more ideal when the steel anchor beam was within the boundary condition of one end of anchor beam fixed and the other end with sliding support.
Analysis and Evaluation of Loading Test for Simple Supported Beams and Cantilever Beams in the Nanxi Bridge of Lechangxia Water Complex
Authors: Yang Yong Min , Chen Ze Peng , Wang Heng Chang , Zhang Jun Lu
Published: January 2014

Nowadays, safety evaluation before bridge opening is increasingly emphasized in China. Bridge inspection is important to guarantee the safe operation of the bridge. In order to comprehensively assess the bearing capability and working conditions of Nanxi bridge of Lechangxia water complex, through static loading test and dynamic loading test, we measured the deformability and mechanical properties of bridge beams with different span-ratios and different forms. Basing on the results of dynamic/static loading test as well as the analysis of structure calculation, we conclude that the bearing capability and working state of the bridge are excellent. The knowledge gained from this study can be used as an evaluation reference in the quality evaluation of the same type of projects.
Steel Box Girder - Steel Tube Arch Bridge Fall-Girder System Conversion Technology Construction Control Research
Authors: Xie Kai Zhong , Fan Feng , Huang Xian Zhi
Published: January 2014

In order to make steel box girder - steel tube arch bridge into the bridge state more reasonable, this paper studies the construction monitoring method regarding the fall girder method adopted to conduct system transformation. Using optimal control theory to determine the fall girder method girder jack-up height, control the line shape and stress of arch and girder and derrick force, and control the Vietnam Da Nang Dragon Bridge construction process. Studies have shown that fall girder method to conduct the system conversion can meet the design requirements, and optimal control method in fall girder method system conversion can obtain good effects. Fall girder method and optimization control method is worth extending to the similar bridge construction and control.
Evaluation of Track Geometry on a Long Span Steel Trussed Cable-Stayed Bridge
Authors: Xu Jin Hui , Wang Biao , Wang Li , Wang Ping
Published: January 2014

In order to investigate the track geometry on a long span steel trussed cable-stayed bridge, in this paper, a plane model is built include suspension cable, pylons, floating system and so on based on FEM to calculate the track geometry under temperature load, wind load and train load. Then evaluate the track geometry from the aspects of line profile and track static geometry size deviation. The result shows that the track geometry indicators like vertical curve radius, gradients and static geometric deviation under temperature load and wind load are better than the indicators under train load. The maximum values of track geometry indicators are all appeared in the bridge piers, mainly because the support stiffness is great different between in the bridge pier and in the mid-span cross-section. It is suggested that the flexibility of piers should be appropriate increased to reduce the support stiffness mutation.
Three-Dimensional Simulations of Strong Ground Motion in the Shidian Basin
Authors: Yu Yan Yan , Liu Qi Fang
Published: January 2014

Seismic response of the Shidian basin to moderate scenario earthquake is investigated considering 3D basin model incorporated with real topography by using the spectral-element method and parallel computing technique. The wave propagation process, the generation of surface wave, and the impact of soil deposits velocity to the basin-induced surface wave are studied in this paper. The results show that the amplification behavior of the basin is the interactions of basin geometry and low velocity soil deposits. First, locally small hollows in the basin are apt to trap seismic waves and produce much stronger ground motion, basin edge and areas with deep sediments are also characterized with large amplification. Then, basin with softer soil deposits produces stronger surface waves with lower propagation velocity and higher mode.
Seismic Response Analysis of Multi-Span Continuous Deck-Type Reinforced Concrete Double Ribs Arch Bridge
Authors: Xie Kai Zhong , Huang Xian Zhi , Fan Feng , Huang Jun
Published: January 2014

Reinforced concrete rib arch bridge is widely used in southwest of china, therefore, it is practically significant to assess the seismic performance of this kind of bridge. In this paper, a deck-type double ribs arch bridge which has eleven large continuous spans is taken for instance. The finite element calculation models for the bridge are established considering arch effect. The M-method principle is used to simulate the pile-soil-structure interaction (PSSI), and multiple Ritz vector method is introduced to analyze the dynamic characteristics. Moreover, the seismic response of arch bridge is analyzed by the response spectrum method. Numeral results show that, the dominant vibration mode of the Multi-span continuous deck-type reinforced concrete rib arch bridge is out-of-plane mode, owing to the weak lateral stiffness. The arch effect can reinforce the longitudinal stiffness of bridge, but weaken the lateral stiffness. Combined with horizontal direction orthogonal seismic action, arch effect can significantly reduce the axial force of rib, while increase the moment and shear of the arch foot and the displacement of the arch. The rib arch, the 1/4 points and the junctions of ribs and beams are the seismic control points. PSSI is the key factor of bridge seismic.
Analysis on Seismic Performance of Corrugated Steel Web Continuous Rigid Frame Bridge
Authors: Wang Yi Qiang , Fan Bing Bing , Li Liang
Published: January 2014

Corrugated steel web continuous rigid frame bridge is a new form of bridge. Using the finite element analysis software Midas Civil to analyze dynamic characteristics of the corrugated steel web continuous rigid frame bridge in a method of subspace iron and the nonlinear dynamic time history analysis method is used to analyze the seismic performance of the bridge, then compared with the ordinary concrete web continuous rigid frame bridge. The results show that the natural frequency of the corrugated steel web continuous rigid frame bridge is smaller than that of the concrete web continuous rigid frame bridge, and the seismic performance of the corrugated steel web continuous rigid frame bridge is superior to that of concrete web continuous rigid frame bridge, the improvement of the seismic performance of piers is most significant.
Discussion on Determination Methods for Coefficient of Subgrade Reaction in Response Displacement Method
Authors: Ding De Yun
Published: January 2014

With the increasing focus on the earthquake resistant problems of subway engineering, the response displacement method is used in the seismic design of subway structures. The determination method for coefficient of subgrade reaction in seismic design of subway structures is very important. Four typical determination methods including test method, Lis method, MIDAS method and finite element method are introduced. Based on the values of coefficient of subgrade reaction from four methods, models of the response displacement method are used to obtain the bending moment of the subway structures. The advantages and disadvantages of four determination methods for coefficient of subgrade reaction are compared. The results show that the test method is the preferred one for designers, the tangential coefficient should be in a range of one to two third of the normal coefficient, and the internal force of subway structures can be obtained by the test method and modified by a correction factor that is 1.05.
The Seismic Damage Investigation and Phenomenon Analysis of Space Grid Structures in Lushan Ms 7.0 Earthquake
Authors: Xing Jue Hui , Lu Ming , Li Hai Wang , Zhao Ya Min , Yu Yan
Published: January 2014

People remained optimistic about the safety of the space grid structures, because the seismic damages of space grid structures were quite rare and rather light. However, two space grid structures got damaged in 2013 Lushan Ms 7.0 earthquake. The two structures are the double-layer reticulated shell structure and flatbed grid structure, namely Lushan Gymnasium and Lushan Middle School Gymnasium respectively. This paper briefly reviews the seismic damage phenomena of grid structures in historical earthquakes, and then focuses on the two damaged space grid structures in Lushan earthquake. The reason why the two space grid structures got damaged are derived from the force state analysis of the rods, ball joints and bearings. Finally, we come up with the effective advice for the seismic design and construction of the space grid structure.
Experimental Research on Seismic Behavior of Seismically Damaged RC Frame Column Strengthened with Sprayed Hybrid BF/CFRP
Authors: Peng Yu Jia , Gu Qian , Gao Rui , Bitewlgn Getahune
Published: January 2014

This experimental program was designed for investigating the seismic behaviors and strengthening effect of pre-damaged RC frame columns retrofitted with sprayed BFRP and hybrid BF/CFRP. Four RC frame column specimens, among which one was unstrengthened and three was pre-damaged and strengthened with sprayed FRP, were tested under an incremental loading procedure of the pseudo-static, cyclic shear loads combined with constant gravity loads. The test results including the failure mode, ultimate bearing load capacity, load-displacement hysteresis curves and ductility of specimens were obtained and analyzed. It indicates that spraying hybrid BF/CFRP strengthening scheme can effectively improve the ductility and energy dissipation ability of pre-damaged concrete frame columns. Although the improvement of the peak loads and ultimate lateral deformation of damaged frame columns were not obvious compared with those of the reference column, but it should be pointed out that the strengthened columns were pre-damaged seriously with yielded steel bars and the recover of load bearing ability resulted from spraying FRP retrofit can not be neglected. It also shows that increasing the thickness of spraying overcoat can effectively improve the energy dissipation ability of damaged frame columns.
Study on the Effect of Modified Differential Restoring Force Model on Seismic Response of Isolation Structure
Authors: Jin Jian Min , Tan Ping , Huang Xiang Yun , Liu Yan Hui
Published: January 2014

Based on the compression-shear tests of different specifications LRBs (diameter 700mm,1000mm,1100mm) and shear strain correlation formula, the modified differential restoring force model (modified Bouc-Wen model) is suggested to simulate LRB. An isolated model, nine-story superstructure, is used as the numerical example. Using the unmodified and the modified differential restoring force model of the LRB, the differences of the seismic response of isolated structure are studied by numerical analysis and comparison. Result shows that, unmodified differential restoring force model commonly used in isolation design, except for acceleration response, other earthquake response has not significant error.
Study on Layout Scheme of Sliding Rails for Immersed Tunnel Section Prefabrication Plant
Authors: Deng Bo , Niu Zhao , Wu Qi He
Published: January 2014

The cracking and deformation analysis of concrete tunnel segment in the jacking process is made by ANSYS. First, we analyzed the effect of such measures as placing a hydraulic jack between the section and rail beam sliding plane described in the four sliding rails scheme upon the cracking and deformation of segment concrete, then the influence of change in spacing of two sliding rails at the same side on the cracking and deformation of segment concrete stated in the six sliding rails scheme. Meanwhile, we made a comparison between the two layout schemes, thereby providing a basis and reference for the layout scheme of sliding rails in the practice.