bluuebunny/crossref_metadata_2025 huggingface dataset:
Freeze-Thaw Deterioration Mechanism of Concrete in Different Multi-Aggressive Solution
Authors: Zheng Xiao Ning , Diao Bo , Zhang Jian , Li Yan Dong
Published: December 2010

Deterioration mechanism of concrete suffered slowly freeze-thaw and eroded in different mixed liquor (3%NaCl+5%NaSO4, 3%NaCl+1.5%NaSO4, 5%NaSO4, water) were experimental investigated. The hydration product and microstructure of concrete specimen after 100 circles of freeze-thaw was tested and analyzed with SEM (Scanning Electron Microscope). The result indicated that under the interactions of freeze-thaw and mixed erosive solution, there were not only physical changes but also chemical reactions occurred in concrete, which exacerbate the mechanical properties deterioration of concrete. The mechanical performance and microstructures of concrete deteriorated most significantly in the mixed solution 3%NaCl+5%NaSO4, and deteriorated more significantly in the mixed solution 3%NaCl+1.5%NaSO4.
Equivalent Ductility Damage Model for Seismic Response of RC Structures: Test and Verification
Authors: Chang Guang Ming , Xing Guo Hua , Liu Bo Quan
Published: December 2010

. It is possible to quantify the damage to reinforced concrete members under cyclic loading through a nondimensional parameter known as a “damage index”. The damage index can be either a global damage index for the total structure, or a local damage index for the element level. In this paper, a new damage model termed “equivalent ductility damage model” has been suggested for evaluation of the damage index, which is consistent with accepted definitions of ductility. Substructure method was applied to verify the suggested new damage model. A total of 3 identical half-scale reinforced concrete columns were tested under variable amplitude cyclic loading up to the ultimate failure of the specimens. The imposed displacement histories were obtained from analytical simulations of the model column subjected to a series of earthquakes. Test observations indicate that the proposed model predicts 100 percent damage at the ultimate failure state of the element. The proposed damage index model can be extended to other structural elements, such as shear walls, beams, beam-column junctions, etc.
Research on Transient Temperature of Concrete Surrounding Spiral Case and Temperature Effect on Gaps in a Hydropower Station
Authors: Xu Xin Yong , Ma Zhen Yue , Zhang Hong Zhan
Published: December 2010

The transient temperature field and creep of concrete surrounding a spiral case are analyzed with a three-dimensional method, based on ABAQUS. The mechanism of hydration heat and cooling pipes on temperature is studied. The distribution of temperature with construction is given. The effect of temperature on gap between steel liner and concrete is researched. It is concluded that the influence of the measure parameters and temperature is indispensable.
Effects Analysis of Bending Stiffness of Cables on Stress Distribution and Curve Shape in Super-Long Single Suspension Cable Structures
Authors: Jing Tian Hu , Li Qing Ning
Published: December 2010

The design scheme of a suspension bridge with a super-long-span of 3300 m was taken as an example, and calculating results from 3 mechanics models are compared with each other to study the effects of bending stiffness of cables on stress distribution and curve shape in super-long single suspension cable structures on the basis of the Finite Element Method (FEM) algorithm of ANSYS and the analytical segmental catenary method for cables’ shape-finding. The study shows that the influence of bending stiffness on curve shape-finding of cables is negligible; Although its effects on stress distribution in cross sections of main cables due to dead loads is small, the error of horizontal forces probably results in great one for the calculation of bending moments at the bottom cross-sections of bridge pylons, which needs attention to ensure the structural safety.
The Application of Reinforced Concrete Composite Floor System of Superimposing Box and Net Beam to Zibo Athletes Apartment
Authors: Chen Zheng Fa , Liu Gui Feng
Published: December 2010

According to the construction site of Zibo athlete apartment and the relevant standards, the structure constitution of the composite floor system, construction method and the problems that should be paid attention during construction were introduced in detail. Reinforced concrete composite floor system of superimposing box and net beam consisted of small prefabricated components- two reinforced concrete plates locating at top and bottom of the box and the cast-in-site concrete beam. This composite floor system was a whole structure of beam and plate combination, with a continuous box section. The superimposing box undertook the loads action together with the rib beam. The floor system has many advantages such as the industrial prefabricated components, stable construction quality, reduction of labor intensity in construction site and the environmental pollution, and the integral structure.
Influence of Reinforcement in Outer Frame Column on the Mechanical Behavior of Multi-Ribbed Frame Grid
Authors: Liu Hai Tao , Yao Qian Feng , Wang Xun Liu
Published: December 2010

Multi-ribbed frame grid (hereinafter referred to as MRFG) is the important part of Multi-ribbed composite wall and consisted of outer frame and ribbed grid. The reinforcement in column of outer frame is the main influence factor on the performance of MRFG. In this study, a MRFG specimen under laterally cyclic and axial loading in literature is numerically simulated with 5 kinds of different reinforcement ratio in column of outer frame, by a general finite element software and user-defined material model. The influence of different reinforcement ratio in column of outer frame on the mechanical behavior of MRFG has been discussed.
Analysis on Causes about Concrete Slab Cracks of Residential Projects and Research on Control Measures
Authors: Zhang Li Qun , Xu Yong Feng , Li Rui Jun
Published: December 2010

At present, China lacks theoretical guiding and research on the concrete floor cracks control of residential projects, and there is no advanced experience of other countries for reference on some aspects. The concrete slab cracks of residential projects has become the focus of public attention, the hot spot of complaints and the difficult point of government business. To avoid the cracks has become a big problem and an important content in improving the residential projects’ quality, which demands prompt solution. This paper analyzes the causes of cracks from construction point, and puts forward some proposals from four aspects including formwork engineering, reinforced bar engineering, concrete engineering and aspect of construction management. This paper advances some immediate countermeasures, makes some moderate extensions on the strategic development of architectural technology and designs the solution orientation of the long-term countermeasures. These concrete solutions strive to be conveniently carried out, meanwhile give consideration to the economic legitimacy.
Vibration Analysis of Reissner-Mindlin Plates Using Quadrilateral Heterosis Element
Authors: Ru Zhong Liang , Zhao Hong Bo , Zhu Chuan Rui
Published: December 2010

The free vibration of the eigenfrequencies and models of a rectangular p1ate with simply supported comp1eted clamped supported were calculated by finite element method using the quadrilateral heterosis element. Firstly, the basic Governing equations of Reissner-Mindlin plate for elastodynamics was introduced, And then the finite element model of the plate vibration was established, nine nodes heterosis element was adopted, the stiffness matrix and mass matrix were obtained. Selective-reduced integration scheme was carried out to eliminatethe curvature thickness and the transverse shear locking phenomena in the plate bending. Numerical experiments of plate free vibration using heterosis element with quadrilateral linear shape functions for the displacements was studied, eight models ware obtained which were closely to the closed solutions, the results show that the method successfully yields a stabilized element.
Experimental Research and Abaqus Analyses of Eccentric-Loaded L-Shape CFT Columns with Binding Bars
Authors: Zheng Xin Zhi , Cai Jian
Published: December 2010

Investigations have been carried out to study the mechanical performances of L-shaped CFT columns such as high strength, stiffness, good ductility. In the paper, Nine L-shaped CFT columns stiffened by binding bars and one without stiffeners subjected to eccentric-load are reported. The experimental results are compared with the results calculated by the abaqus. The proposed method provide theoretical basis for relative design codes.
Study of Strength Criterion for Dynamic Compression of Concrete under Biaxial Equal Proportion Loading
Authors: Ping Guan , Liu Peng , Xu Tao
Published: December 2010

The dynamic compressive experiments of cubic concrete specimens under various biaxial equal proportion loading were preformed. The biaxial equal proportion stress in the tests were kept constant at 1:0, 1:0.5 and 1:1, respectively, and the tested strain rate ranged from 10−5/s to 10−2/s. Based on the experimental results, the influence of the strain rates on compressive characteristics of concrete under various biaxial stress ratios were researched. The unified strength criterion in terms of principal stress space considering the influence of strain rates and biaxial stress ratio is proposed. The fitting curves by the present strength criterion agree well with experimental data.
Numerical Simulation of Quasi-Brittle Fracture in Concrete Structures with Extended Finite Element Method
Authors: Qu Hong Chang , Xia Xiao Zhou , Xiong Zhi Qiang
Published: December 2010

In this paper, the extended finite element method (XFEM) is used for a discrete crack simulation of concrete using an adaptive crack growth algorithm. An interface model is proposed which includes normal and tangential displacements and allows the transfer of shear stresses through the interface. Different criteria for predicting the direction of the extension of a cohesive crack are conducted in the framework of the XFEM. On the basis of two examples, a comparison between the maximum circumferential stress criterion, the maximum energy release rate and the minimum potential energy criterion with experimental data has been carried out. The considered numerical simulations have confirmed the flexibility and effectiveness of the XFEM for the modelling of crack growth under general mode I and mixed-mode loading conditions.
Experimental Study on the Shear Failurelaw of Gate Slot
Authors: Han Ju Hong , Wu Song Feng , Liu Wen Li
Published: December 2010

The mechanical behavior of 12 concrete specimens under local strain is studied according to simulating principle of work of gate slot. The experimental result indicates that the failure mode of these reinforced members in the test has revealed to be shear failure. The shear failurelaw of gate slot based on the test data is analyzed in the paper, and the main effect factors of the shearing capacity of gate slot are discussed. In this foundation, a corresponding proposed simplified method is put forward in the end.
Behavior of CFT Column Connections with Vertical Plates
Authors: Yang Xin Lei , Wang Hai Liang , Ren Quan Chang , Dong Peng
Published: December 2010

In this research, a CFT column connection with vertical plates is proposed, and studied through a finite element model. For this purpose, three-dimensional finite element models are constructed by a general purpose finite element code, ABAQUS. Comparing the results of the models indicated the effectiveness of the proposed vertical plate scheme in reducing story drift, increasing the shear strength of the panel zone.
Bearing Capacity Calculating of GFRP Tube Filled with Steel-Reinforced Concrete Composite Column Subjected to Eccentric Loading
Authors: Chen Bai Ling , Wang Lian Guang , Qin Guo Peng
Published: December 2010

GFRP tube filled with steel-reinforced concrete composite column, GSRC, is a new kind of composite column, in which the (shaped steel) reinforcing steel bar is set and the concrete is poured into GFRP tube. Under the action of eccentric loading, the damage signs of the composite columns with smaller and larger eccentricity were respectively that GFRP tube of compressive zone was crushed and the fiber of GFRP tube of tensional zone was ruptured. The tight hoop effect of the concrete given by GFRP tube only existed in compressive zone, and the restriction to the concrete of tensile zone was unobvious. The shaped steel inside GFRP tube had a positive effect on the bending rigidity and the bearing capacity of the member. Using the limit equilibrium theory, the calculation formula of the bearing capacity of GSRC subjected to eccentric loading was created. The calculated results agreed well with the experimental ones.
Influences of Sag-to-Span Ratio and Pre-Stress of Cable on the New Hybrid Structure Composed of Truss Strings and Shell
Authors: Shen Yin Lan , Mu Zai Gen , Fan Zhong
Published: December 2010

Based on the Erdos Dong-sheng Exhibition Center’s structure system, this paper uses finite element analysis software SAP2000 to do integral analysis of a new hybrid structure composed of truss strings and shell. The effects of different sag-span ratios and initial pre-stresses on mechanical behavior and the steel consumption of 11 truss Strings integral Structures are analyzed. Besides, the study may be referable for the design and research on truss strings structure.
Analysis in Seismic Behaviors of the Masonry-Concrete Shear Wall
Authors: Li Ke , Chen Guo Ping , Tang Lan
Published: December 2010

The masonry-concrete shear wall is a kind of new composite structure developed from the masonry wall, and the seismic behavior of it is better than the traditional one. The article used ANSYS to do the time history analysis for the traditional masonry wall and masonry-concrete shear wall with different characteristic stiffness coefficients, different installation modes of shear walls.The calculation data not only proved researches in reasonable value of characteristic stiffness coefficients, but also about the effects in the seismic ability of different masonry-concrete shear walls installation modes.
Numerical Analysis of Post-Tensioned Coupled Wall
Authors: Cai Xiao Ning , Meng Shao Ping , Chen Jia Jia , Sun Wei Wei
Published: December 2010

Based on OpenSEES, nonlinear beam-column element based on fiber model and considered nonlinear shear deformation was used to simulate wall limb; zero-length elements were used to simulate action of prestressing tendon and connecting reinforcement in the interface between coupling beam and wall limb; the hysteretic models of the zero-length elements were established by programming. The low-cyclic loading tests of two PCW specimens were introduced. Results of the numerical analysis and the tests indicate that elasto-plastic performances of PCW can be well simulated by numerical analysis, analysis model based on OpenSEES can be applied to non-linear analysis and of good precision; PCW is of good self-centering ability with little residual deformation after unloading, and damage concentrating in certain parts that can be repaired after earthquake; energy dissipation capacity of PCW is increased because of the connecting reinforcement.
Application of Special Shaped Column Composed of Concrete-Filled Steel Tubes
Authors: Chen Zhi Hua , Zhou Ting , Wang Xiao Dun
Published: December 2010

Special-shaped column composed of concrete-filled steel tubes (SCFT) structure, a new type structure, is adopted to a residential building. This paper represents the design and analysis of this structure. 3D model of the structure is built by finite element procedure software and vibration property, static and seismic performance of the building are also analyzed to check the safety of the structure. At last, the vertical stiffener joint of SCFT structure is proposed and calculated. The application of SCFT for residential building represents that the SCFT is suitable for real constructions.
Research on New Shear Connector in Steel-Concrete Composite Open-Web Plate Frame and Pseudo-Static Analysis of the Construction
Authors: Huang Yong , Ren Xu , Chen Wei Gang
Published: December 2010

Composite construction’s performance depends greatly on shear effectively transfer between steel and concrete, we usually set shear connector between surface of the two different materials, the connector is a determining factor of combinable capability. Composite open-web plate frame is a new type of composite construction, has good performance in application of large span and large load floor or roof. This paper carries on research on two kind of new shear connectors of the composite open-web plate frame, the shell type shear connector and the block type shear connector, and carried on push-out test, also done vertical pseudo-static analysis on composite open-web plate frame which adapt new connector, study the hysteretic behavior ultimate bearing capacity and damage form. Study shows that, block type shear connector which set additional steel bars has good mechanical properties, it’s a shear only connector; Composite construction which adapt the connector has good capability of energy consumption and higher safety storage under vertical load.
Nonlinear Analysis and Design of a Guyed Mast: Comparison of Two Design Proposals
Authors: Bao Wei Li , Zhang Yong
Published: December 2010

The guyed mast structure consists of a vertical shaft supported along its height by several layers of inclined pre-tensioned guys. The central shaft is generally made of lattice steel structure, and the guys are spaced at equal angles around the mast to ensure the vertical shaft’s stability. By taking a 102 m meteorological guyed tower in Hainan as an example, this paper made two design proposals using steel pipe and round steel material for the shaft respectively. According to the requirements of the project, this paper then did non-linear static analysis and buckling analysis of the structure by finite element software SAP2000, and compared the results of the two proposals so as to find the optimal one. The results show that steel pipe material is more economical when used for the mast shaft and more reasonable for bearing forces. The choice of the number and the initial tension of guys, as well as the wind vibration coefficient, which have a great effect on a guyed mast, are also discussed in this paper.
Model Test on Joint Segment of Steel Truss and Composite Truss
Authors: Xue Dong Yan , Liu Yu Qing , Wang Qian , Ma Biao
Published: December 2010

The main span is the steel truss and the side spans are the composite truss in Minpu Bridge. A 1:2.5 model is made to study the mechanical behavior of the joint segment of steel truss and composite truss. Both a model test and a numerical finite element analysis(FEA) method have been conducted. The results show that the joint segment remains in a linear elastic state under the condition. The maximum stress in the structure is less than the material allowable strength. The FEA results are in very good agreement with those of model test. This study shows that the force transformation of the joint segment is reliable and the composition details are rational. It is also expected that the results presented in this paper would be useful as references for the further research and the design of composite truss bridge and joint segment.
Experimental Study on Seismic Behavior of Full-Scale New Steel Truss Coupling Beams
Authors: Lin Qian , Deng Zhi Heng , Tang Guang Xian
Published: December 2010

Steel truss coupling beam is a new type of steel coupling beam structure. To investigate seismic behavior of this coupling beam, low cyclic loading tests for four full-scale specimens of steel truss coupling beam are presented. The specimens are designed considering three factors which are T-stub steel, angle steel and material strength. The experimental data show that steel truss coupling beam has good ductility, and can consume a great quantity of earthquake energy. By enlarging the sections of cross abdominal trusses and chord members, bearing capacity and stiffness of the whole coupling beam are greatly increased.
Experimental Research on Concrete-Filled GFRP Tubes and GFRP-Steel Composite Tubes under Axial Compressive Load
Authors: Wang Xiao Lu , Zha Xiao Xiong
Published: December 2010

Axial compression experiments of eighteen concrete-filled GFRP tube (CFFT) and concrete-filled GFRP reinforced steel tube (CFFST) specimens in total have been carried out to study their mechanical behaviors. Experimental results show that, GFRP tubes with different filament-wound angles could enhance the strength and ductility of core concrete at different levels. Fibers with hoop directions provide the best confinement and enhance the ultimate strength up to 266% comparing with unconfined concrete columns. Fibers with ±45° winding angles have minor effects on bearing capacity, but greatly improve the ductility of concrete columns. Compared with CFST columns, GFRP reinforced CFST columns with hoop direction fibers increase the bearing capacity of 35.0%, and the fibers along 45° winding angles could enhance by 17.5%. The mechanical behavior and the failure modes of the six experimental group specimens are also discussed in this paper.
Double-Superposition Assumption for Piezoelectric Laminate Beam Theory
Authors: Yang Xiao Mei
Published: December 2010

An attempt is made to extend the double superposition hypothesis for elastic laminate analysis to piezoelectric laminate structure analysis. In addition to the displacement, the double superposition technique is also applied to the electric potential. The double-superposition hypothesis for piezoelectric laminate analysis can predict the zigzag feature of the field variables along the transverse direction in piezoelectric laminates. Moreover, the elastic field computational cost of double superposition assumption is no more than that of high-order shear theories for global coordinates, and the degrees of freedom by double superposition assumption for electric potential are much fewer than those by layerwise models for electric potential. It will be seen from the numerical examples that the good accuracy and lower computational cost can be presented by the double-superposition assumption for piezoelectric laminate beams.
Vacuum Infusion Molding Process to Produce FRP Shell Used in an Innovative FRP-Concrete Composite Structure
Authors: Zhang Pu , Zhu Hong , Wu Gang , Meng Shao Ping , Wu Zhi Shen
Published: December 2010

In order to improve the structure performance and reduce Life cycle cost of the structures, advanced fiber composite polymer is more and more frequently combined with conventional materials to develop new structures. FRP-concrete composite beams with prefabricated FRP shells, which are designed with steel bar as the main reinforcement and with suitable FRP participation proportion to improve the performance, are developed by us for their good integrated performance. The VIMP production process to produce the thin and large-scale FRP shell was developed and detailed in this paper and performance of the production was also examined. Results show that the FRP shell produced by VIMP are with rather good performance, and can be used in the composite beams. The VIMP is very suitable for this kind of thin and large-scale structures.
Finite Element Analysis on Dynamic Behavior of Gangue Concrete-Filled Circular Steel Tube Beam
Authors: Li Guo Chang , Jiang Qi Feng , Bai Ji , Jiang Jie
Published: December 2010

The dynamic behavior of gangue concrete filled circular steel tube beam with different steel ratio under the cyclic loads are analyzed and studied based on finite element analysis software ABAQUS. Through reasonable modeling established, parameter set, an effective grid meshed, the hysteresis curve of gangue concrete filled circular steel tube beam under low-cycle reversed loading is given, and verified compared with the experimental results. The comparison shows that the simulated hysteretic curve gives results in close agreement with the experimental results. The simulated curve shows that there has the characteristic of spindle-shaped and no significant decline in stiffness of the hysteresis curve. And the fatness of hysteresis loop is better.
Effect of Concrete-Filled in Chord Tubes on Mechanical Behavior of RHS Steel Tube Trusses
Authors: Liu Jun Ping , Liu Yong Jian , Yang Jian
Published: December 2010

Based on the experimental results, this paper presents the effects of concrete-filled in chord on the static behavior of rectangular hollow section (RHS) steel tubular trusses, including failure modes, load bearing capacity and structural stiffness. Failure of RHS trusses occurs at joints wether concrete-filled in chord or not, concrete-filled in chord changed the failure mode. Load bearing capacity and stiffness of joints subjected to compression load increased significantly, while it is limited to the tension joints. Concrete-filled in the compression chord tube can increase its stiffness significantly, while tension chord tube, it is not that obvious. Finally, based on the results discussed, failure modes and their formulas of calculating the load bearing capacity are discussed. Meanwhile, two methods, that is, amplified factor method and stiffness discounting method, which calculate the structural displacement when considering the joint deformation effects are presented.
Loading Capacity of Simply Supported Steel-Concrete Composite Slim Beams
Authors: Yang Lu , Wang Yuan Qing , Shi Yong Jiu
Published: December 2010

A steel-concrete composite slim beam, with its steel section encased in a concrete slab, provides a composite steel-concrete floor construction with minimum depth and high fire resistance. It has become popular in multi-storey steel buildings throughout Europe in recent years and also been used in some projects in China. For the structural engineer, it is critical to understand the behavior of composite slim beam in the sagging moment region. In this paper, the bending capacity and flexural stiffness of the composite slim beams in sagging moment region are investigated theoretically. Meanwhile, the stiffness and bending capacity are given by Finite Element Analysis (FEA). The experiment of a simply supported beam has been carried out in order to validate the theoretical results.
Experimental Research on Seismic Behavior for Lightweight Aggregate Concrete-Filled Steel Tubular Frame
Authors: Gao Chun Yan , Li Bin
Published: December 2010

In order to research the seismic behavior of lightweight aggregate concrete-filled rectangular steel tubular (CFRST) frame, four test specimens were experimentally studied under constant axial load and cyclically lateral load. The form of beam section and steel ratio of column section were considered as experimental parameters. The results show that the lightweight aggregate CFRST frame has plump hysteretic loops without obvious shrinkage phenomenon; the displacement ductility coefficients is between 3.00 and 3.74, which can meet the requirement of ductile frames; the bearing capacity, ductility and energy dissipation capability improve with the increase of the steel ratio; when the steel ratio is the same, the steel beam frames have plumper hysteretic loops, the ductility and energy dissipation capability increase to some extent, the stiffness degradation is slower compared with the CFRST beam frames. Conclusively, the lightweight aggregate CFRST frame has excellent seismic behavior and mechanical performance and there is the value to further research.
Effect of Viscous Damper on Seismic Performance of Steel-Concrete Hybrid Structure for High-Rise Building
Authors: Shen De Jian , Qiu Sen , Song Ling , Huang Cong Bin
Published: December 2010

In this paper, the effect of viscous damper on seismic performance of steel-concrete hybrid structure for high-rise building is analyzed. The result shows that viscous damper has little effect on dynamic properties of structure. The story lateral displacement, story drift rotation and damage of structure can be reduced effectively by viscous damper. The effect of the viscous damper on structure seismic performance is better with the increase of seismic intensity. Under the 7, 8 and 9 degree seismic seldom intensity, the story lateral displacement of the top floor decreases at 17.2%, 23.3%, 33.4% and the story drift rotation decreases at 20.8%, 27.2%, 44.7% respectively. The seismic analysis result may be referred by designer and researcher.
Analysis of Mechanical Behaviors of a Single Pylon Cable-Stayed and Continuous Rigid-Frame Composite Bridge
Authors: Feng Dong Ming , Li Ai Qun , Li Jian Hui , Yang Guang
Published: December 2010

Xijiang River Bridge is the first hybrid railway bridge composed of single pylon cable-stayed and continuous rigid-frame system in China. To study the mechanical behaviors of the novel bridge, 3-D finite element model (FEM) based on Midas/Civil software is created; spatial effect of stayed cable is discussed; the self-vibration behavior of this unique bridge is analyzed by adopting the subspace iteration method; then by means of simulating analysis of the whole construction process, stress paths of critical parts in different construction stages are calculated and presented to study its mechanical behaviors. Results reveal that the composite bridge embodies features of both traditional cable-stayed bridge and rigid-frame bridge. Further study, however, shows that the unique hybrid system is mostly characterized by the rigid-frame type, meanwhile, as safety storage, the stay cable will play an important role in the “stiffness kept” of the whole structure, improving the actual stress and working condition of the whole structure in the long run.
Experimental Study on Residual Load Bearing Capacity of SRC Eccentric Columns after Exposure to Fire
Authors: Li Jun Hua , Tang Yue Feng , Liu Ming Zhe
Published: December 2010

This paper provided three test data pertaining to the mechanical properties of steel reinforced concrete (SRC) eccentric columns after exposure to fire and one comparative test data pertaining to the mechanical properties of steel reinforced concrete columns at room temperature. The influence of eccentricity on failure mode, distortion performance and ultimate load bearing capacity are mainly studied. Test results show that the failure modes of steel reinforced concrete eccentric columns after exposure to fire are similar to that at room temperature. Strain along the section height at mid-span section of eccentric columns before loaded to 90% ultimate load bearing capacity is linearly distributed and well agree with the plane section supposition. After exposure to fire, the flexural rigidity and load bearing capacity of specimens are all declined compared with that at normal temperature. In various loading stages from the initial loading to 80% ultimate strength, the ratio of flexural rigidity of SRC eccentric columns after exposure to fire and at normal temperature is ranged from 0.30 to 0.59. With the same concrete strength and heating condition, the ultimate strength of specimens decreases with the increasing of eccentricity. The ultimate bearing capacity of all specimens at normal room temperature is calculated on the method proposed by Chinese regulation JGJ 138-2001. The compared results of experimental values and calculating values show that the residual load bearing capacity of SRC eccentric columns after exposure to fire is about 69% to 81% of that at room temperature.
Research and Application of Level Rotational Construction Technology of DWT Cable-Stayed Bridge
Authors: Wang Shi Jie , Zhu Xun , Gao Zhen Dong
Published: December 2010

Rotational construction for bridges attracts much attention of people because it is featured by its low initial cost, fast and easy operation and minimum traffic interruption. Nowadays, rotational bridges have been mostly built by the level rotation method of the ring combining with ball joints at home and abroad, which is more safe and easy to control the closed precision, but the large rotating friction restrict the promotion of the rotational weight and span. The author takes flat hinge supported by single point as the rotating bearing type, using embedded four fluorine board, controlling wheel construction precision strictly. In that case, Suifen He cabl-stayed bridge, weigh up to to 14000t, has been successfully complished rotational construction with the help of continuous jack. The built bridge axis deviation is limited within 3mm, and maximum deck height deviation is only 12mm. It is proved that rotational construction of flat hinge joints supported by single point can efficiently solve the colsed accuracy which is difficult to control and problems of heavy rotating traction, as long as the installation precision and the sliding performance can be controlled.
Nonlinear Seismic Analysis and Structural Performance Evaluation of a Complex High-Rise Building
Authors: Chen Yue
Published: December 2010

The height of a complex supertall building is 250m. The central RC tube and peripheral SRC frame with two outrigger trusses are employed to resist vertical and lateral loads. It is classified as B grade complex tall building due to the structural characteristic. Due to the over-restriction and complexity of the super tall-building, Pushover Analysis is carried out in order to find it’s behaviors under rare intensity earthquakes. The analytical results demonstrate that the SRC supertall building with high level transfer story possesses good energy-consuming capacity, ductility and ideal yield failure mechanism under rare seismic excitation. Seismic performance of the SRC supertall building is evaluated through Capacity Spectrum Method and good results are obtained.
The Truss Structural Optimization Design Based on Improved Hybrid Genetic Algorithm
Authors: Jiang Feng Guo , Wang Zhen Qing
Published: December 2010

Genetic arithmetic operators in genetic algorithm be improved , and a hybrid genetic algorithm of a gradient algorithm combining with the genetic algorithm be given against to the defects such as premature，slow on convergence rate，weak in the ability of local search ，all these appeared on the progress of genetic algorithm's iteration. Analysis result indicate that not only strong on the local search capacity of gradient algorithm be exhibited but also strong on the general search capacity of genetic algorithm be combined based on the hybrid genetic algorithm ,which make phenomenon of premature avoid, and the rate of convergence be improved greatly. Concrete calculated example indicated that the hybrid genetic algorithm is an effective structural optimization method.
Optimal Design Research of Shear Wall Structure for Board High-Rise Residential Building
Authors: Wang Er Lei , Lu Zhe An , Zhou Lang
Published: December 2010

Take a High-rise Residential Building in Wuhan as research object, in assigns the construction plan under the premise, the optical mathematics model of the shear wall is established. Based on research of structure dynamic characteristics, displacement, mechanic character, structure measure, uses the criterion method and the exhaustion method, design principle of board high-rise residential building is conducted from the optical of shear wall arrangement，furthermore, site condition and seismic precaution intensity influence to the optical structure is analyzed.
Consolidation Settlement Analyses on a Composite Foundation System Combined with Walled and Columniform Soil Improvement
Authors: Li Wei , Gao Fei , Huang He , Yamamoto Haruyuki , Takeuchi Kinji
Published: December 2010

To satisfy the geotechnical strength requirements and the serviceability requirements, types of foundation systems (such as shallow foundation, pile foundation and composite foundation) have been developed. Of course, the type of foundation system is determined by many factors such as ground condition, economy and environmental influence of construction. To cope with weak or compressible soils, the authors present a raft foundation system with walled and columniform soil improvement for multistory buildings, which is economical and environment-friendly. In this raft foundation system, different columniform soil improvements in size and depth are used, and the subgrade under the edge of the foundation is walled by soil improvement. It can effectively control differential settlement and prevent relative rising of the structure by adjusting the size and depth of columniform soil improvements according to the soil layer difference of geological situation under the building. We have performed series numerical analyses under two-dimensional plane strain condition to study the settlement behaviors of the composite foundation system, and its effects on controlling differential settlement and improving bearing capacity were verified for immediate condition. As a continuous research, consolidation settlement analyses are performed, the process of excess hydraulic pressure dispersion with time and the consolidation settlement development are studied in this paper.
Static and Dynamic Behaviours of Three-Tower Suspension Bridges and the Structure Selection of the Mid-Tower
Authors: Liang Peng , Wu Xiang Nan , Xu Yue
Published: December 2010

In order to discuss the mechanical behaviour differences between the two-tower and three-tower suspension bridges, based on the Taizhou Yangtze River Bridge, three dimensional space finite element models of two-tower, three-tower with concrete mid-tower and with steel mid-tower were constructed. Through the comprehensive analysis, main conclusions are got as follows: due to the mid-tower lack of effective restraint from side cable, compared with two-tower suspension bridges, three-tower suspension bridges have lower total stiffness and natural frequency, with larger deflection-to-span ratio of main girder. So, some factors such as anti-slipping safety factor between the main cable and saddle, deflection-to-span ratio of main girder and force in mid-tower, which are not important in two-tower design, become controlling ones in three-tower suspension bridges. These factors are related to anti-pushing rigidity of mid-tower, but in contradictory demanding for the rigidity of mid-tower. After comprehensive analysis, steel tower with shape of upside-down ‘Y’ meets all demands, and then, was selected as appropriate structure for the mid-tower.
Optimization Design of Beam Based on Genetic Algorithm
Authors: Qiao Shu Ling , Han Zhi Jun
Published: December 2010

In this paper, determinate beam and indeterminate beam with multiple span are optimized by using genetic algorithm, the mathematic model of optimize beam is built and the processing method of constraint conditions is given. The examples show that the algorithm could be used for optimizing determinate structure, and also optimizing indeterminate structure. Compared to the linear approximation method, genetic algorithm has advantages of being simple, easy, fast convergence and has no use for changing the objective function and constraint conditions to linearity or other processing. Its results agree with linear approximation method’s. It is the other method that can be adopt in engineering field.
Application of Genetic Algorithm in Optimum Design of Structure
Authors: Liu Xue Bing , Zeng Fan Kui , Li Fu Qiang , Wang Jing
Published: December 2010

This paper introduces the basic principle and characteristic of genetic algorithm (called GA), and it points out the shortcoming of ordinary optimum algorithm and the merit of GA. Comparing the optimum results of GA with accurate value by exemplification, and it is good. This paper provides a systematic thought model and a good method for readers.
Prediction of Parameters Error in Method of Construction Control in Cable-Stayed Bridge
Authors: Chen Chang Song , Yan Dong Huang , Dong Dao Fu
Published: December 2010

To reach the optimum mechanics state of long span cable-stayed bridge after it erected, a method is proposed to predict and adjust parameter in construct control of cable-stayed bridge, which integrates the grey prediction theory model and influence matrix adjustment method compositively. The selection of parameters of construct control, reasonable objects of adjustment and determination of state variable during prediction data process are also studied deeply, and a perfect procedure and method is established to identify, predict and optimizing adjust parameters. The method is also verified by construct control of the longest span pre-stressed concrete bridge in Asia, and the effect of construct is very successful. This work of construct control can absolutely demonstrate the validity and practicability of the method.
Optimization Design of Earthquake-Resistant Structure Taking Discrete Variables into Account
Authors: Ji Hui , Zhao Hong Sheng
Published: December 2010

Conventionally, when optimizing a structure, the single target structural optimization design method is usually used. However, this design result often can not meet with the multiple requirements of construction; furthermore its optimizing efficiency is low; so its application is limited. And more, as the objective function being generally continuous variable, the optimized result is not the structural module and this is inconvenient for construction. This paper, taking the structural strain energy and the cost of construction as the targets to be optimized, and the design variable being discrete, provides multiple-target earthquake-resistant optimization design method aiming at obtaining the largest stain energy and the lowest construction cost, and established the function relation formula between the strain energy and the cost of construction and obtained the satisfied result. The highlight of this process is adopting discrete variables as the design variables, therefore the optimized results (cross-sectional dimensions) will conform to the requirements of structural module and the engineering practice. The optimization process presented in this paper conforms entirely to the national standards: “Code for Design of Reinforced Concrete Structures” (GB50010-2002) and “Code for Earthquake-resistant Design of Buildings” (GB50011). The theory and methods presented in this paper will be helpful for the structural design engineers and the researchers.
Optimization of Structures Using Improved Genetic Algorithms for Discrete Variables
Authors: Tian Yuan , Shi Qing Xuan , Zhu Chao Yan
Published: December 2010

Genetic algorithms (GA) have been shown to be very effective optimization tools for a number of engineering problems. Genetic algorithms which are based upon the principles of Darwinian evolution explores the region of the whole solution space and can obtain the golbal optimum. This paper introduces the standard GA and the forward-and-back search algorithms (FBSA) and demonstrates the use of improved genetic algorithms (IGA) for structure optimization of discrete variables. The mathematical model of structural optimization is derived. A 10-bar benchmark example is studied, the result shows that IGA, as an efficient method,can be applied to structure optimization of discrete variables.
Design of Ocean Data Buoys Based on CFD
Authors: Song Qiu Hong , Tang Xin , Lan Ya Mei , Liang Yong Cheng
Published: December 2010

Ocean Data Buoy with fixed-point, real-time, long-term, continuous and accurate data collection capabilities is a modern ocean observing tools and instruments. Therefore, the reliability of information is essential, which depends on the stability of the working buoy. While the waves are acting, the buoys are difficult to maintain their stability. Based on Computational Fluid Dynamics, the force situations of buoy at wave conditions are simulated by using Variable Operating Frequency method and Fluent software. The variation of lift and drag forces and the changing trend of movement of buoy are obtained. And then the numerical value of force is adjusted by changing the height of waterline. At last, the digital design of shell structure is carried out with SolidWorks to improve the stability of buoys in surface wave.
Analysis on Integral Performance of Unit Glazing Curtain Wall Considering the Contribution of Glass Rigidity
Authors: Gao Yong Tao , Hu Xiao
Published: December 2010

Based on integral property of unit glazing curtain wall (UGCW), considering the co-effect of glass and grids, set up the calculating method of cooperation of glass and grids; through the numerical simulation analysis with this method, we can conclude that take the glass’s rigidity into consideration is both reasonable and economical.
Effect of Attribute Reduction on Rough-Probabilistic Neural Network for Structural Damage Detection
Authors: Jiang Shao Fei , Wu Zhao Qi
Published: December 2010

In this paper, a new rough-probabilistic neural network (RSPNN) model, whereby rough set data and a probabilistic neural network (PNN) are integrated, is proposed. This model is used for structural damage detection, particularly for cases where the measurement data has many uncertainties. To verify the proposed method, an example is presented to identify both single and multi-damage case patterns. The effects of measurement noise and attribute reduction on the damage detection results are also discussed. The results show that the proposed model not only has good damage detection capability and noise tolerance, but also reduces data storage memory requirements.
Study on Damage Performance of Oil Storage Tank in the Basis of Modal Test and FEA
Authors: Du Guo Feng , Xu Cheng Xiang , Jia Shan Po
Published: December 2010

In order to learn about the dynamic characteristics of the oil storage tank, detect and identify the damaged oil storage tank, based on the basic principle of the experimental modal analysis, the modal test was maken on the vertical dome roof steel oil storage tank model with the hammer method of multi-point input and output on single point, and the identification ability of the modal parameter was studied when the oil storage tank model is damaged. At the same time, we carried out the model's simulation calculation with FEA, considering the effects of the structural physical parameters and the foundation parameters of the oil storage tank. The calculated results of modal test are in accordance with test values, the analysis results provides certain basis for the damage identification and health monitoring work of the oil storage tank structure.
Damage Analysis of RC Beams Strengthened with CFRP Sheets by Acoustic Emission Technique
Authors: Masera Davide , Bocca Pietro G.
Published: December 2010

The aim of this work is to develop a procedure to follow the evolution of fracture in RC Beams strengthened with CFRP sheets by means of Acoustic Emission signal analysis. In particular the main goal of this experimental work wants to be the definition of a characteristic signal parameter able to represent the evolution of the fracture dimension in the RC Beams during load test. To this end, laboratory tests were carried out at the Non-Destructive Testing Laboratory of the Politecnico di Torino.
The Modal Identification of Structure Using Distributed ERA and EFDD Methods
Authors: Lei Ying , Lai Zhi Lu
Published: December 2010

Structural health monitoring (SHM) is an emerging field in civil engineering, offering the potential for continuous and periodic assessment of the safety and integrity of civil infrastructure. In this paper, a distributed computing strategy for modal identification of structure is proposed, which is suitable for the problem of solving large volume of data set in structural health monitoring. Numerical example of distribute computing the modal properties of truss illustrates the distributed out-put only modal identification algorithm based on NExT / ERA techniques and EFDD. This strategy can also be applied to other complicated structure to determine modal parameters.