bluuebunny/crossref_metadata_2025 huggingface dataset:
Seismic Response Analysis of Unequal Altitude Double-Tower Connecting Structure with the Changes of Connecting Beam Location
Authors: Lei Jin Song , Ma Qing , Xue Bo
Published: December 2010

Dynamic characteristics and seismic response for unequal height double-tower structure models were analyzed by finite element software. The effort of the connecting beam location changes to the structural vibration period, the maximum displacement on top and the maximum shear force at bottom were analyzed and compared. The results indicate that horizontal displacement under the seismic waves in x direction is larger than the displacement under seismic waves in y direction. When the locations of the connecting body vary, the influence to structural vibration period is different as vibration modes change. The effort to the maximum shear force of the structure at bottom under the seismic waves in x direction is larger than the displacement in y direction. The above results provide references for design and further studying.
Studies and Improvements on Modal Pushover Analysis and Application on Bridge
Authors: Mu Ying Na , Shi Lei , Zhang Zhe
Published: December 2010

Because the traditional pushover analysis can not take the contributions of higher modes into account, To overcome this limitation, a modal pushover analysis procedure (MPA) is proposed by some researchers, which can involve the combination of multi-mode contributions to response. In this paper, much improvement on MPA procedure is made with consideration of the changes of seismic response after structural yielding and anew distribution of inertia forces. The method is verified by one example of bridge structure. It is concluded that the improvement part-sectionalized MPA presented in this paper has high accuracy.
Error Study of Displacement Model for Seismic Analysis of Long-Span Structures Subjected to Multi-Support Earthquake Excitations
Authors: Guo Wei , Yu Zhi Wu , Guo Zhen
Published: December 2010

Long-span structure is a more common structural style in the public buildings, and its seismic response often differs from other structures because of the long-span characteristic, and thereby the multi-support earthquake excitation, such as the displacement model and acceleration model, need to be adopted in the seismic analysis. However, relative researches have proved that there exists certain problem in the displacement model. According to previous works, the error causes of displacement model are described firstly and expression is also given to estimate the magnitude of error. Then, the influencing factors on the error of displacement model are also given and analyzed. In the end, numerical studies are carried out to verify the viewpoint proposed in this paper.
Shaking Table Model Test for Vertical Seismic Response of Bent-Type Aqueduct
Authors: Duan Qiu Hua , Lou Meng Lin
Published: December 2010

Based on the shaking table model test of a bent-type aqueduct on the rigidity foundation, the dynamic characteristics and seismic performance of the aqueduct structure subjected to vertical seismic waves are discussed. The test indicates that (1) Water in the aqueduct makes the mass of the structure larger and the frequency of the model structure lower. The water in aqueduct makes fundamental frequency of the model reduce 32% and the modal damping increase 38.5% averagely. (2)The hydrodynamic pressure response at the bottom of the aqueduct is the highest. (3)The dynamic effect of El waves on the aqueduct structure is greater than that of all SEW waves. (4) Different types of earthquake waves have different frequency spectrum characteristics, so that the aqueduct model responses differently to different waves. (5) The water in the aqueduct sometimes plays a role as TLD damping in certain scope. If surpassing this scope, the water sloshing makes the vertical acceleration response of the aqueduct increase. The results of the test not only lead to some significant conclusions for the earthquake-resistant design of large bent-type aqueducts, but also provide a ground for further studies on the effects of soil-pile-aqueduct interaction.
Analysis of Vibration Control due to Strong Earthquakes
Authors: Wu He Len
Published: December 2010

The paper proposes an aseismic hybrid control system to control the response of structures subjected to large ground motions caused by large magnitude earthquakes. The proposed hybrid control system consists of a base isolation system (laminated rubber bearings) connected to an active control system (a tuned mass damper and an actuator). The base isolation system is used to decouple the horizontal ground motions from the structure, whereas the active control system is used to protect the safety and integrity of the base isolation system. A 5-story benchmark building model is developed to study the effectiveness of the hybrid control system against different ground motions. It was found from the numerical results that rubber bearing system alone shows good performance and resists ground motion due to Hachinohe 1968, Kobe 1995, and Northridge 1994 earthquakes, but is somewhat unable to protect the model against El-Centro 1940 earthquake. After the installation of an active control system onto the rubber-isolated model, further improvements to earthquake resistance against these four earthquakes were observed, especially against the El-Centro earthquake. The merit of the hybrid control system lies in its capability to protect against different ground motions, with varying intensity and frequency content.
Analysis of Soil-Structure Interaction (SSI) Effects on Seismic Response of Base-Isolated Structures
Authors: Li Chang Ping , Liu Wei Qing , Wang Shu Guang , Du Dong Sheng
Published: December 2010

A new modified model for assessing the effects of SSI on base-isolated structures is presented from the case of conventional structures. The equations of motion of the equivalent fixed-base 2-DOF system are formulated in frequency domain. Based on this, rigorous and closed-form formulations for fundamental period and composite damping are derived. Finally, analysis of parameters based on frequency independent coefficients in detail is conducted. The analytical model and method presented can serve to assess the effects of SSI in the design of base-isolated structures including high-rise structures. Significant differences between the system with and without radiation damping and the flexibility of supporting soil have been observed in this study. For the results of the analysis, overall SSI effects have been identified as elongation of fundamental period of the system and decreased composite damping, especially for the high-rise and slender isolated structures.
Design and Optimization of a New Type of Sliding Isolated Bearing and its Application
Authors: Huang Wei , Shu Wei , Zhang Li , Wang Ping
Published: December 2010

This paper present a new seismic isolation device which assembled sliding friction, energy dissipation and limit, then clarified the work performance and the optimization of its design ideas. The author utilized FEM analysis software ANSYS to establish a parametric model, taking the working condition of single-ring and stress concentration distribution under the yield state as the research object, the shape of the energy loop was optimum designed, and the hysteresis energy consumption performance of seismic isolation bearings was analyzed before and after optimizing. It can be received that energy consumption performance of the seismic isolation bearings improved 32.7% after optimizing. A 6 layer frame structure FEM model was built, at this basis, the seismic responses of fixed structure and sliding seismic isolation structure of foundations were compared. The results indicated that the seismic responses of sliding structures decreased significantly.
Recent Development in Analytical Models for Earthquake-Induced Pounding between Adjacent Bridge Structures
Authors: Gao Yu Feng , Pu Qian Hui , Shi Zhou
Published: December 2010

Recent development in analytical models on earthquake-induced pounding between adjacent bridge decks are introduced. The bridge damage induced by seismic pounding in recent 30 years strong earthquakes are reviewed, various analytical models used to simulate impact effect between bridge decks are presented, which include impact-restitution approach and contact-element approach. The contact-element approach include the linear spring element model, Kelvin-Voigt element model, Hertz model, Hertz-damp model and updated Hertz-damp model. The areas required to further investigate are proposed.
Stability Analysis of Nantong Sports and Exhibition Center Based on Measured Geometrical Imperfections
Authors: Zhao Cai Qi , Ma Jun , Li De Lin
Published: December 2010

Position deviation of joints is a primary initial geometrical imperfection that affects the stability of long-span spatial structures. It makes field measurement of joint coordinate for the shell and roof initial shape of Nantong Sports Exhibition Center upon its completion. This paper researches the stochastic distribution feature and statistical parameter of geometrical imperfections for the data sources of above position deviation of joints by “abnormal data test method”. The results indicate that the distribution of abnormal data is concentrated, which is related to the difficulty of construction and condition of measurement; the distribution of joint position deviation can be assumed by normal distribution, and its mean μ=0 and mean square deviation σ=R/2 of statistical parameter are tenable. Meanwhile, It also puts forward a stochastic imperfection method based on measured imperfections and ANSYS－PDS platform, establishes a measured model to make nonlinear stability analysis, and respectively compares this critical load with that obtained by the perfect structure of ideal shape and the consistent imperfection method, so as to evaluate the stability and reliability of practical project in an objective manner, and provide reference for project design.
Wind Loads Simulation of Tall Building Structure Subjected to Wind-Structure Interaction
Authors: Bao Wen Bo , Hu Yu Yong , Cui Yang
Published: December 2010

Wind is an important and complex load and an important basis in the structural analysis and the design of high-rise structure. Based on Davenport wind spectrum, multi-dimensional fluctuating wind and random wind load of tall building structure are simulated by using harmonic wave superposition method. To investigate the coupling effect of wind loads, wind-structure system is solved with Wilson-θ step-by-step numerical integration method, and the wind load of Tall building structure subjected to fluid-structure interaction. Turbulence intensity and its variation are presented in this paper.
The Equivalent Damping Ration in Capacity Spectrum Method
Authors: Zhang Jing , Gao Duixian , Chen Zhiwei
Published: December 2010

Study the calculation method of equivalent damping ratio in Capacity Spectrum Method. Analyzing the feature of several methods for the calculation of equivalent damping ratio in the world, from the numeral example, the numeral results of several calculation methods of equivalent damping ratio are compared to the results of time course method. The follow conclusions are reached: Secant stiffness method overestimate the value of equivalent damping ratio for steel structure, therefore, underestimate the supreme seismic reaction. The level of underestimate is interrelate to yield still coefficient; Under the medium earthquakes effect, all the method can fairly good forecast the supreme seismic reaction; But Under the large earthquakes effect, only the Kwan (EP) method can give the best result. The conclusions has impotent value for the perfect of Performance-Based Seismic Design Methods.
Elastic-Plastic Time History Analysis of Self-Anchored Cable-Stayed Suspension Bridge
Authors: Miao Feng , Shi Lei , Zhang Zhe
Published: December 2010

Base on the elastic-plastic analytical theory, an elastic-plastic time-history analysis of self-anchored cable-stayed suspension bridge, which engineering background is Dalian Gulf Cross-sea Bridge program, is performed by using general finite element software Midas/Civil. The material nonlinearity of structure is considered with reinforcement concrete fiber model, and distributed hinge type is adopted to simulate for plastic hinge. Compared with the results of an elastic time-history analysis, it is shown that for the structure into the elastic-plastic stage, because of the production of plastic hinge, the input seismic energy is dissipated partially, and the internal forces of structural elements are reduced. The bending moments and axial forces occur mainly in the main tower root. Furthermore, the rotation properties of the plastic hinge causes displacement increasing of certain parts of the structure, which assumes mainly the vertical displacement present on the top of main tower and the main beam. In conclusion, it is proposed that caging devices are set in the design.
Study of the Analysis Methods of Wave-Passage Effect Based on ABAQUS
Authors: Zhang Jue Yang , Mu Zai Gen , Gan Ming
Published: December 2010

Wave-passage effect of the seismic is the main reason of multi-support excitations, and there are always two analysis methods which are large mass method and acceleration method to study on the multi-support excitations, this paper take one kind of trussed structure as an example, use the two methods to consider the wave-passage effect of seismic, compare the difference between the results from using the two methods, and also compare the difference between single-support and multi-support excitations. This paper draw a conclusion that it is a precise way to using ABAQUS to analysis the wave-passage effect of the seismic; wave-passage effect of the seismic has an great influence on the reaction of long-span spatial structures, it must be considered in the similar projects; and the large method and acceleration method both have their advantages and disadvantages, so we should give concrete analysis to concrete problems.
Analysis of Flutter Stability of Cable-Stayed Bridge with Single Cable Plane
Authors: Wang Hui Li , Pan Zhe , Jiang Rong Bin
Published: December 2010

Cable-stayed bridge with single cable plane has advantages in wide field of view. However, the problem of stability becomes especially important, because it can’t provide torsional stiffness. Based on LanQi SongHua River Bridge, a concrete cable-stayed bridge with single cable plane, the dynamic character, wind-resistant stability and flutter instability are analyzed, especially the analysis of the flutter stability at maximum double cantilever stage during construction phase. The paper analyzes the dynamic characters of the finite element model of the whole bridge through response spectrum method to reap the natural frequency, the vibration modes and other parameters, then checking the flutter stability. The results show that the bridge is very safe either at maximum double cantilever stage or finished stage. The analysis method provides a basis and references for the wind-resistant of cable-stayed bridge with single cable plane.
Experimental Study for Single-Angle Beam-Column Members Attached by one Leg
Authors: Cao Xian Lei , Hao Ji Ping , Fan Chun Lei
Published: December 2010

To obtain a better understanding of the behavior and load-carrying capacity of Q460 high-strength single-angle compression members bolted by one leg, using static loading way to 48 angles carried out experimental study. The experiments show test specimens produce biaxial bending, most small slenderness ratio members are controlled by local buckling, and slender specimens are controlled by overall buckling. In addition to these factors in model experiment, influences of residual stresses on ultimate load-carrying capacity were analyzed by finite element numerical simulation analysis, the results show the residual stresses affect the ultimate load-carrying capacity of angles by about 5％ or less. Comparison of the load-carrying capacity of experimental and theoretical results indicate the difference of experimental and finite element values ranges from -9.99％ to +9.76％, American Design of Latticed Steel Transmission Structure (ASCE10-1997) and Chinese Code for Design of Steel Structures (GB50017-2003) underestimate separately the experimental load-carrying capacity by about 2.34％～33.93％ and 1.18％～63.3％, and the agreement is somewhat good between experimental program and the finite element analysis. Based on model experiment and simulated experiment, the formula of stability coefficient of single-angle compression members was established. It provides basic data for spreading Q460 high-strength single-angles members attached by one leg.
Research on Seismic Isolation Properties for DFPS System
Authors: Ge Nan , Chen Hai Bin , Wang Xing Guo
Published: December 2010

A theoretical analyzing approach about a novel seismic isolation system, DFPS (Double Slipping-Surfaced Friction Plate System), is presented in this paper. Its governing equation is similar to that of the FPS friction pendulum system with single slipping surface. It is shown that the inter-storey drift resulted from seismic action could be drastically decreased on buildings equipped with DFPS system. If an optimum combination of slide radius and slipping friction coefficient is adopted, the seismic isolation effectiveness could be as high as 90%.
On Wind-Induced Vibration Respons of Tall Building with Wind-Structure Interaction
Authors: Bao Wen Bo , Cui Yang , Hu Yu Yong
Published: December 2010

In order to reveal the structural dynamic characteristics in natural wind, multi-dimensional random wind load of tall building is simulated by using harmonic wave superposition method. Then the coupling dynamical equations of structural system are solved by using Wilson- integration method considering the coupling effect of wind-induced interaction. Based on the analysis, it is clear that the coupling of wind-structure is equivalent to the damping effect and the dynamic response of the structure has decreased, when taking the wind-structure interaction.
Influence Analysis of Joint's Stiffness on Spatial Reticulated Shell
Authors: Wang Xing , Wang Fan
Published: December 2010

Joint’s stiffness has important influence on the stability behavior of large-span spatial reticulated shell. In this paper, the nonlinear beam-column element with end springs is taken as the analysis model of members of single-layer reticulated shell, the whole process of nonlinear stability for single-layer reticulated shell is analyzed with the software ANSYS, the influence of joint’s stiffness on the stability of single-layer reticulated shell is studied. Some important conclusions were obtained, which can provide theoretical foundation for the stability ultimate bearing capacity analysis of large-span spatial reticulated shell considering joint’s stiffness and can be applied on practical design.
Comparison and Research on Seismic Performance between Guidelines for Seismic Design of Highway Bridges and Eurocode 8 for Seismic Design of Bridges
Authors: Lu Ben Yan , Liu Bo Quan , Liu Ming , Xing Guo Hua
Published: December 2010

Earthquake codes have been revised and updated in recent years. The issue and implementation of the guidelines for seismic design of bridges have attracted interests and attentions of many researchs at home and abroad. In this paper, it is compared that the provisions about performance criteria, seismic design categories, response spectrum and earthquake action between guidelines for seismic design of highway bridges and Eurocode 8 for bridges. The main purpose of this study is to investigate the differences caused by the two codes in performance criteria, seismic design categories, response spectrum and earthquake action. The results indicate that it is similar in performance criteria, seismic design categories and response spectrum between guidelines for seismic design of highway bridges and Eurocode 8 for bridges. Based on the lessons learned from significant earthquakes in the last few years, the existing problems of the current code are pointed, and the trends of future study are discussed.
FEM Study on Flange Width-Thickness Ratio of Links in Eccentrically Braced Frames
Authors: Chen Xiang Rong , Lu Xiao Song , Li Gang , Zhou Jian
Published: December 2010

For links in eccentrically braced frames (EBFs), today’s design codes requirement of the flange width-thickness ratio is strict on high-strength steels, which eliminate a number of rolled wide-flange shape from use in EBFs. For this reason, building models using ANSYS program and control procedures for the previous tests to verify the correctness, and then design the specimens. This paper applies unidirectional load and cyclic load on the finite element models respectively. Through the calculation of the inelastic rotation which the link beams reach after the relaxation of the flange width-thickness ratio, the paper analyses the influences on the performance of the three tapes of links by the flange width-thickness ratio.
Calculation of Safety Factor of the Slope under Horizontal Seismic Forces Based on the Inclined Slice Method
Authors: Ge Hai Yu , Tu Jin Song , Wang Jian Guo
Published: December 2010

The vertical slice method is generally adopted for calculation of slope stability safety factor. The algebraic expression of stability safety factor of the slope under horizontal seismic forces is deduced based on the idea of calculation via the inclined slice method and according to the force limit equilibrium conditions of inclined slices. It replaces conventional integral or differential expressions with advantages such as simplified calculation process, convergence performance guarantee and rapid calculation via simple iterative. The example shows that the slope stability safety factor derived from this method is very similar with that from conventional methods, which proves that this method is feasible and brings convenience to technical personnel of slope engineering.
Factors that Contribute to the Generation of Construction Waste at Sites
Authors: Mokhtar Siti Nazziera , Mahmood Noor Zalina , Che Hassan Che Rosmani , Masudi Ahmad Firman , Sulaiman Nik Meriam
Published: December 2010

Construction industry in Malaysia is growing rapidly with high demand due to vast development and urbanization. Therefore, many commercial and residential buildings are being developed. The increasing number of construction projects in Malaysia will indirectly contribute to the increase of construction waste generation. Thus, waste minimization is an important area of concern in the implementation of the construction waste management in the construction industry of Malaysia. Data collection and observations was conducted at three construction sites which adopt different type of method with different type of building and size of project in Klang Valley. The calculation of the construction waste index generated at these sites is adopted from Poon et al., (2001). Result showed that construction method, size of projects (GFA), type of building, storage method system, human error and technical problem can affect the amount of waste index (debris) and amount of wastage level generated at construction sites. Therefore waste index and wastage level can be used as operational an indicator for waste minimization of the construction activities.
The Research on Preparation of a New Building Material with EMR and their Properties
Authors: Wang Yong , Ye Wen Hao , Liu Heng Bo
Published: December 2010

This article describes the physical and chemical properties of EMR and the preparation of a new building material with it. The results show that the main components of EMR are gypsum and quartz, supplemented by a small amount of cement, appropriate siliceous material and quicklime in EMR could be prepared high performance EMR autoclaved brick.
Scale Model Test Research on Cable Supported Barrel Vault Structure
Authors: Qiao Wen Tao , Chen Zhi Hua
Published: December 2010

By setting cables and struts in place in the single-layer cylindrical latticed shell, a new-style prestressed spatial steel structure--cable supported barrel vault structure is constructed, the static load test research on which is carried out for the first time in this paper. Based on the prototype building, a scale model with the scale of 1:15 is designed and manufactured for the test. The research results indicate, the static behavior of the prototype structure can be reflected approximately by this scale model. The static behavior of the single-layer cylindrical latticed shell is improved significantly by adding cables and struts, i.e., the cable supported barrel vault structure is a kind of highly efficient prestressed spatial steel structure. Compared with the case of full-span load, the half-span load makes the cable supported barrel vault structure unsafer.
The Experimental Study on the Effect of Expansive Agent on Mechanical Properties of CFST Column with the Creep
Authors: Wang Hai Yang , Zha Xiao Xiong
Published: December 2010

In order to study the influence of expansive agent on the performance of CFST column with the creep due to dead load of the practical construction, in this paper, based on the simulation phase of construction, a series of experiments were conducted to study effect of the expansive agent dosage on the ultimate bearing capacity of CFST columns and the creep deformation in the longitudinal direction. Also the experiments were completed to comparative study on the problem of the recycled aggregate concrete -filled steel tube (RACFST) column. It is found that the ultimate bearing capacity of the CFST column is increased a lot when using the expansive agent, while for the RACFST column it has just a little increase. In contrast, for the RACFST column, there is a greatly increase on the creep deformation in the longitudinal direction, and the more expansive agent dosage the larger deformation, but it is not so obvious effect for general CFST column.
The Research on the Dynamic Response of Arched Corrugated Metal Roof Structure with Ring Hoops
Authors: Zhang De Sheng , Li Yuan Ying
Published: December 2010

The paper is based on the relatively large-span, thin thickness of the arched corrugated metal roof (ACMR) and the fact that the structure would suffer asymmetry swinging within the vertical plane and structure vibration under the effect of the wind and earthquake. A structure strengthening method called the arched corrugated metal roof with ring hoops (ACMRH) is adopted. With SAP2000, a finite element model is established, with type of w666-18m span, rise-span ratio 0.25, 1mm of thickness and condition of fixed support as its research object. The dynamic time history response is analyzed and compared with documents [1]. Result is shown as below. With the same earthquake wave on the structure added, the vertical and horizontal deflection displacement of the most unfavorable point of the arched corrugated metal roof with ring hoops is always less than that of the structure without ring hoops. The maximal decrement is about 28%. This result indicates the arched corrugated metal roof with ring hoops has a better effect on controlling the displacement deformation.
Parametric Analysis on Seismic Behavior of Connections to Concrete-Filled Square Steel Tubular Columns with Three Edges Welded Interior Diaphragm
Authors: Xiao Ya Ming , Zhang Ting
Published: December 2010

In order to further understand the seismic behavior of connections to concrete-filled square steel tubular columns with three edges welded interior diaphragm, basic sample and corresponding finite element models are constructed and analyzed according to criterion; furthermore influences on seismic behavior of such connections from many factors such as axial load ratio, height of steel beam, strength of steel beam and interior diaphragm and so on are studied. Results show that the base sample has excellent seismic behavior; such factors as axial load ratio, height of steel beam, strength of steel beam and interior diaphragm have great influence on seismic behavior. Therefore, the feasibility of such connections at edge columns and corner columns is further validated.
A Method for Deformation Analysis of Bar-Reinforced Concrete Filled Steel Tubular Columns under Axial Compression
Authors: Han Jin Sheng , Cong Shu Ping
Published: December 2010

Based on experimental researches, a simple numerical analysis method was presented to simulate the full load-deformation process of bar-reinforced concrete filled steel tubular short columns subjected to axial compression. Firstly, the interaction process of steel tube and concrete was analyzed, and then, the simplified constitutive models of steel tube and concrete were established on the base of previous analysis results. Secondly, the relation between lateral and longitudinal strain of steel tube was analyzed based on experimental results, and a simple method was presented to calculate the lateral strain of steel tube. Finally, a program was worked out to simulate the full load-deformation process of bar-reinforced concrete filled steel tubular short columns. The program’s simulation results of both ultimate bearing capacity and load-deformation curves are in good agreement with the experimental results.
Push-Out Test on Bond Property of Micro-Expansive Concrete-Filled Steel Tube Columns
Authors: Xu Kai Cheng , Chen Meng Cheng , Yuan Fang
Published: December 2010

The shrinkage/expansion behavior and bond carrying capacities of 4 short, micro-expansive concrete-filled steel tube (MCFST) and 3 short, conventional concrete-filled steel tube (CFST) columns were experimentally investigated. The results indicate that pre-stress is produced in the core concrete under the confined by the steel tube. Both expansive agent and water cement ratio have important influence on expansive behaviors of MCFST. The current work also indicates that the MCFST columns have higher bond strength than conventional CFST columns and this recommends a new method to improve the bond strength of composite structures.
Finite Element Study on Seismic Performance of Inclined Joint of Cold- Formed Steel with Plate
Authors: Chen Ming , Sun Yang
Published: December 2010

To understand the seismic performance of inclined joints with gusset plate between double C steel beam-column, in this paper, I used finite element method ABAQUS, and did a good performance in simulating seismic performance of inclined joints between double C steel beam-column. It executed six models by changing gusset-plate’s thickness and bolt space in this simulation. Elements of S4R can give a good description of cold-formed steel’s bearing-capacity, and coupling restriction simulated bolted connections well. This modeling method is facilitating, and the operation time of simulation is not long-playing, and calculation results are accurate. The results of this paper can give a reference to the engineering application of cold-formed thin-walled steel structure.
Buckling Analysis of Two-Span Continuous Beams with Lateral Elastic Brace under Uniform Load
Authors: Zhang Wen Fu , Sui Hai Yan , Wang Zong , Ji Jing
Published: December 2010

Both total potential energy and buckling equation of two-span continuous beam with lateral elastic brace under uniform load are deduced, based on energy variation method and the principle of minimum potential energy. Buckling of H-beams is simulated by ANSYS software, then compared to theoretical value, validated its rationality. High precision buckling moment formula is regressed using 1stOpt which is a famous mathematical optimization analysis software in China. The relationship between lateral brace stiffness and buckling moment is obtained. Results: with lateral brace stiffness increases, critical bending moment of beam increases within up-limit, e.g. when lateral brace stiffness increases to certain extent, buckling moment no longer increases.
Study on the Strategy of Elastic Modulus Adjustment of the Elastic Modulus Reduction Method for Limit Analysis of Structures Containing Flaws
Authors: Zhang Wei , Liu Li Wen , Yang Lu Feng
Published: December 2010

As a limit analysis method lately presented, the elastic modulus reduction method (EMRM) has the advantages of simplicity and high efficiency. In this paper, the strategy of elastic modulus adjustment of the EMRM is studied in order to extend the method applicable to the limit analysis of structures containing flaws (SCF). Two new algorithms of the reference element bearing ratio, reference element bearing ratio based on reference stress (REBS) and reference element bearing ratio based on integral element bearing ratio gradient (REBG), are proposed. Numerical examples show that the problems of instability and non-convergence in iterative process of limit analysis of SCF are improved, when the REBS or REBG is used in the strategy of elastic modulus adjustment of the EMRM.
Hysteretic Performance Analysis of Double-Tube Buckling Restrained Braces with Contact-Ring
Authors: Yin Zhan Zhong , Wang Xiu Li
Published: December 2010

Double-tube buckling restrained braces with contact ring is a new buckling-restrained brace (BRBs), and is a refinement of double-tube buckling restrained braces. Based on the theory of the finite element method, the finite element entity model of double-tube buckling restrained brace with contact-ring has been made. The double-tube buckling restrained braces is systematically analyzed and computed. The analysis results indicate that this kind of buckling restrained brace has good energy dissipation and restoring force characteristics, and can overcome the difficulty in connection.
Preliminary Study on Post-Fire Behavior of Composite Frame with CFST Columns and Composite Beam
Authors: Zhang Peng Peng , Wang Wen Da , Wang Jing Xuan
Published: December 2010

A 3-D finite element model (FEM) using ABAQUS was introduced in this paper to simulate the post-fire behavior of composite frames with concrete-filled steel tubular (CFST) columns and steel beam with reinforced concrete slab. Accurate thermal and material model, element type, and solution method were assumed in the model considering the temperature effect during the fire. Some composite joint specimen post-fire tests were modeled using the FEM. The results obtained from the FEM were verified against those experimental results. The mechanism of the composite frame was investigated based on the FEM.
Research on Application of BRBs in Steel Frame Structures
Authors: Chen Xiang Rong , Zhao Lin , Lu Xiao Song
Published: December 2010

This paper presents an analysis on the seismic behavior of buckling-restrained brace frames（BRBFs）with different rigidity ratios by the finite element analysis software ANSYS. Based on the elastic-plastic time-history analysis, the relationships of maximum story drift ratio and the uniformity of maximum story drift ratio with different rigidity ratios are established for BRBFs subjected to large earthquakes, a reasonable range of rigidity ratio is recommended, which is the reference for the design of BRBFs.
Test of Expansive Soil Roadbed Improving with Fiber Materials and Numerical Simulation Analysis
Authors: Wang Xin Gang , Hu Bin , Liu Yong Lin , Tang Hui Ming
Published: December 2010

Based on the characteristics of expansive soil and polyethylene fibers used and researched, relevant data of fiber improving expansive soil are obtained by laboratory soil tests, and the numerical simulation parameters are derived by some formulas, through the useing of Mohr-Coulomb and elasticity constitutive model of the geotechnical professional software FLAC3D, we simulate the effect of polyethylene fibers improving expansive soil. Results of laboratory tests show that polyethylene fibers have visual effects on the compressibility and compression modulus of expansive soil ; Numerical simulation shows that the polyethylene fiber soil of expansive soil can reduce the settlement and horizontal displacement of roadbed of expansive soil significantly. Both of them show that fiber materials have high value of the promotion and application in engineering.
Dynamic Performance Analysis for a Butterfly-Shaped Arch Bridge
Authors: Huang Hai Yun , Yuan Xiang Rong , Cai Ka Hong
Published: December 2010

The dynamic characteristics are not only the important indexes for evaluating the bridge structural rigidity, but also the principal parameters for structural dynamic analysis and earthquake resistant analysis. In this paper, a three dimensional solid finite element model for a butterfly-shape arch bridge in Zhongshan city was established to analyze the dynamic characteristics. By comparison the numerical calculation results with measured results of the dynamic loading test, an analysis and evaluation of the dynamic performance of this new type spatial arch bridge was made, and can serve as reference to the dynamic analysis and seismic design of similar bridges.
Motion Analysis of Kinematically Indeterminate Structure Using Inextensional Mechanism: A Unified Approach
Authors: Lu Jin Yu , Li Na
Published: December 2010

Kinematically indeterminate structure is a type of special structure that consists of internal mechanism. This paper mainly proposes a unified approach for the motion analysis of kinematically indeterminate structure based on inextensional mechanism, which is achieved by the equilibrium matrix SVD. The physical meaning of inextensional mechanism is studied and the detail procedure for the simulation algorithm is presented. Further more, it is applied to trace the motion paths of unfolding process of an expanded octahedron tensegrity unit and the deployment of radial retractable structure. Simulation results show the validation and efficiency of the presented method.
Finite Element Analysis on Joint of Ultra-High Steel Columns and Steel Core Barrel Outrigger Truss
Authors: Dong Lijuan , Sui Wei Ning , Li Guo Chang
Published: December 2010

The elastic and plastic characteristics of the Y-joint of frame-core tube structures with steel pipe column and steel pipe outrigger truss is studied in this paper. The finite-element method is adopted in the numerical study. To avoid the damage of the joint, controlling the relatively convex-concave deformation of the column wall through adding internal stiffener plate is discussed. Through the comparison of numerical study of the Y-joint with different shape of stiffener plate, a feasible design of the Y-joint is given.
Experimental and Numerical Study on Mode I-II Crack Propagation for Small Size Specimens of Concrete
Authors: Dong Wei , He Hua Nan , Wu Zhi Min
Published: December 2010

The crack criterion is important to determine the crack propagation for mode I-II fracture in concrete. The paper aims to obtain the initial crack criterion of four-point shearing beams experimentally, which can be applied in the numerical simulation for crack propagation process. A series of experiments of four-point shearing notched beams of concrete with five different heights of 80mm, 100mm, 120mm, 140mm and 160mm respectively were carried out to measure the initial loading Pini. The different combinations of KiniI and KiniII corresponding to Pini were obtained according to different positions of pre-cracks in the specimens, and the initial crack criterion was fitted using the combinations of KiniI and KiniII. With the assumption that the crack will extend when the difference between the stress intensity factor at the crack tip caused by the load P and the one caused by the cohesive force attained the above KiniI- KiniII curve, the criterion was applied to simulate the crack propagation process in the paper. It was found that the numerical analysis showed a good agreement with the experimental results and that the size effect is not remarkable for the KiniI-KiniII curves of different heights specimens in the test.
Study on Stay-in-Place Cement Formwork and the Application
Authors: Song Xiao Ruan , Liu Pei Ge , Zhao Dong Fu , Qu Yu Ting , Zhang Xiao Yun
Published: December 2010

Three contents are included in this paper: 1) Through orthogonal experiment, some principal materials and their use levels which will influence performances of cement formwork are optimized and researched. A matched group could bring best comprehensive performance plate suitable to be used as construction formwork is obtained. 2) Through study the strength retention rate of specimens after immersing in various solutions for different ages, the alkali resistance property and lasting quality of the formwork are investigated, and it indicates that during general serviceable life specified by China Structure Design Code, the failure probability due to durability is very low. 3) Through mechanical experiments of combined slabs with different conjoint methods, cooperation performance between formwork and concrete is studied, which prove composite slabs work well.
Experimental Investigation on Effective Bond Length of Flexurally CFRP-Strengthened RC Beams Failed by Intermediate Crack Debonding
Authors: Li Gui Bing , Zhang Ai Hui , Jin Wei Liang
Published: December 2010

The models to calculate the effective bond length determined by single-lap or double-lap shear tests are more suitable for the end-debonding failure; and the improved models based on the simply shear test models to calculate the effective bond length of flexural CFRP-strengthened beams failed by intermediate crack debonding (IC debonding) are also lack of the support of experimental data. To investigate the effective bond length of flexural CFRP-strengthened beams, a total of 9 flexurally CFRP-strengthened beams were tested. The experimental results show that the existing models are very conservative for calculating the effective bond length in flexural FRP-strengthened RC beams failed by IC debonding. Based on the experimental results, this paper presents a model to calculate the effective bond length of flexural FRP-strengthened RC beams failed by IC debonding, and a model to calculate the plastic hinge length at the shear-flexure span.
Theoretical Assessment of FRP Tendon Wedge Anchorage System
Authors: Zhuge Ping , Hou Su Wei , Qiang Shi Zhong , Liu Ming Hu
Published: December 2010

In order to improve designing and well understanding the working mechanism for fiber reinforced polymer (FRP) tendon wedge anchorage system (FWAS), a theory for solving the anchorage system was presented in this paper. A designing guidelines of anchorage system was established. The theory was checked by comparing the analytical and test results of a Carbon FRP tendon anchrage system. Effect of presetting load and friction coefficient of sleeve-FRP tendon interface on anchorage performance were evaluated by the theory. The results show that, The theory was proved to be correct, it can be used to predict the carrying capacity of FWAS, and it can calculate the stress and transverse displacement of any point of the anchorage system. The presetting load and friction coefficient of sleeve-FRP tendon interface have great impact to anchorage performance.
Production of High-Performance Composite Concrete Segment and Experimental Investigation of Materials
Authors: Gao Ying Li , Ma Bao Guo
Published: December 2010

Tunnel lining concrete segment is the most critical and important structural member of shield tunneling. This investigation designed and produced high-performance composite concrete segment (HCCS). Some key indexes that affect the properties of segment were tested, such as impermeability, volume stability, mechanical property, etc. The results indicated that the impermeability of HCCS concrete cover was excellent and the chloride diffusion coefficient decreased one order of magnitude compared to that of the ordinary segment concrete cover, while the service-life of HCCS increased more than ten-fold. The volume stability of HCCS concrete cover and concrete structure layer were good and the better compatibility in the volume deformation of the whole structure was shown. Furthermore, the mechanical properties of concrete cover and concrete structure layer met the project requirement perfectly, ensuring the higher durability and longer service-life of HCCS effectively.
Fabrication and Mechanical Characterization of Carbon Nanotubes-Enhanced Epoxy
Authors: Faleh Haydar , Shen Lu Ming , Al Mahaidi Riadh
Published: December 2010

Owing to its outstanding characteristics in good affinity to heterogeneous materials, corrosion resistance and on-the-spot processing capability, epoxy has been widely used as adhesives in retrofitting structures with carbon fibre reinforced polymer (CFRP). In this study, different weight fractions of multi-walled carbon nanotubes (MWCNTs) will be dispersed into epoxy to produce toughened adhesives that can improve the CFRP/structure bonding performance. The preliminary results indicate that adding 2% MWCNTs to Araldite-420 increase its ultimate strength by 17% and its elastic modulus by 14%. Ultrasonic mixing may increase Sikadur-30’s elastic modulus but reduce its strength and ductility regardless of the MWCNTs concentration. The mechanism of MWCNTs infusion effects on the mechanical properties of epoxy is also examined using SEM.
Study on Crystallinity Degree of Hydration Products in Autoclaved Samples with Solid Wastes
Authors: Ni Tie Quan , Ke Chang Jun
Published: December 2010

The ratio of the dissolved amount difference between in cool hydrochloride and hot hydrochloride to the bound water amount of the samples is regarded as crystallinity degree; approximate expressed the proportion relation of crystal and gel in the samples. And studied the relationship of compressive strength and dissolved amount difference, bound water amount and crystallinity degree of autoclaved silicate products using solid waste. The results shown, dissolved amount difference, bound water amount and crystallinity degree of autoclaved samples are related to kinds of hydration products. When well-crystallized hydrated amount is smaller, the crystallinity degree and its change are also smaller, and compressive strength of the sample increases with bound water amount increasing. When well-crystallized hydrated amount is larger, dissolved amount difference is larger, and crystallinity degree is larger, compressive strength of the sample increases with crystallinity degree decreased. There is an optimal value of crystallinity degree for compressive strength of the autoclaved samples.
Computer Simulation of Magnetic Fluids in Turbulent Pipe Flow
Authors: Sun Ming Li , Wang Bin , Zhan Feng , Lu Shuang , Cui Hai Rong
Published: December 2010

Based on the finite element software COMSOL, the magnetic-circuit field of the complex coupling between the magnetic and hydrodynamic forces is analyzed. The results of computer simulation show that the flow field is disturbed near the magnet and at the left end there is a laminar flow profile, where there is a maximum throughput in the pipeline; the magnetic fluid is not rest but rather agitated in local eddies where the net throughput is zero.
Energy Efficiency Analysis of Existing Rural Residence in Hot Summer and Cold Winter Area of China
Authors: Wu Shan Shan , Wu Wei Bo
Published: December 2010

In order to research deeply on the measure of energy efficiency reconstruction of existing rural residence in hot summer and cold winter area, the typical rural residence building in the country of Ningbo, Zhejiang province is chosen as the object. On the basis of comparing the thermal status of existing and reconstruction rural residence, which were simulated by DEST-H software, some practicable suggestion on energy efficiency reconstruction are put forward.