bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional Short-Term Earthquake Prediction Model Based on BP Neural Network
Authors: Hu Wu Sheng , Wang Hao , Nie Hong Lin
Published: June 2012

A method which gives the quantitative prediction for earthquake magnitude is proposed in this paper. By this method, after calculating the earthquake parameters and the astronomical time-varying parameters, an earthquake prediction model can be established to gives the quantitative prediction for earthquake magnitude in the future prediction period. In this research, the research object was the experimental areas, the prediction period was 6 months, and Linear Regression analysis and conventional BP (Back Propagation) Neural Network were used respectively in prediction. Through backtracking test, the RMSEs(root mean square error) of earthquake magnitude prediction are ±0.78 ML and ±0.61 ML. Then after summarizing the advantages and disadvantages of the two methods, an integrated model based on linear regression and neural network was proposed. Through backtracking test, the RMSE of earthquake magnitude prediction reaches ± 0.41 ML, results improving significantly.
Displacement-Based Lateral Stiffness Design for Multi-Storey Structures Subject to Earthquake Motions
Authors: Wang Feng , Li Hong Nan , Yi Ting Hua
Published: June 2012

The determination of structural stiffness for the currently seismic design method depends on subjective experience of designers which is not rational and economical. A method that uses displacements as the basis for the stiffness design procedure is then presented: (1)By means of preliminary design, the initial elastic structure are obtained and the 1th mode shape, period etc are then calculated by modal analyses; (2) The target period and lateral equivalent stiffness of structure are determined according to target displacement used in seismic code; (3)The two periods for initial designed structure and target structure are compared and the lateral stiffness is adjusted to make the displacement responses of the structural weak members meet the limited displacements by adjustment parameter. An example is implemented for demonstrating the process and verifying the accuracy of the procedure.
Wind Pressure Distribution on a Large-Span Roof Structure
Authors: Wang Qin Hua , Shi Bi Qing , Zhang Le Le
Published: June 2012

In this paper, wind tunnel test of a large-span roof structure is firstly introduced. Secondly, data processing on synchronous multi-spots pressure measurement test is given. Wind pressure distribution is calculated by using the method mentioned in this paper. Some results and conclusion are useful for design of large-span roof structure.
Settlement Analysis of Soft Ground Replacement under Earthquake
Authors: Liu Zhong , An Shu Hong , Yuan Rong Hong , Li Fei
Published: June 2012

The dynamic time-history response analysis method was employed to analyze the dynamic response of soft ground replacement with sand-gravel cushion. The deformation distribution of soft ground replacement with different thickness sand-gravel cushion was investigated under seismic wave. The results reveal that the bearing and asti-deformation capacity can be improved effectively for replacement sand-gravel cushion under earthquake loads by increasing the thick of cushion. The vertical displacement of foundation soil decreases gradually with the increase of the thick of cushion. The practice shows that replacement sand-gravel cushion provides a positive contribution to the aseismic effect of foundation soils mass. The present research can provide some references to similar projects.
Three-Dimensional Elastic-Plastic Dynamic Interaction of Earth Dam and Intermountain Basin
Authors: Li Yong Qiang , Jing Li Ping , Liang Hai An , Liu Chun Hui , Zou Yan
Published: June 2012

A new method that based on an interface program and secondary development of the analysis software FLAC3D was used to present the elastic-plastic dynamic interaction of earth dam and intermountain basin in 3D. By this method, we developed a complex 3D numerical model for a typical earth dam which was damaged seriously in the Wenchuan earthquake, along with its surrounding sites, considering the pore water pressure and the hysteretic damping of the soils, inputting the revised ground motion obtained from the station near the dam. The simulation reappeared the dam disaster process, gave the spatial and temporal distribution of PGA (peak ground acceleration) and residual deformation and the ratio of vertical and horizontal PGA. Our data demonstrate the mechanisms of the landslides, collapses and cracks on the earth dams. The present work shows that the existence of the dam has a significant influence on the distribution of ground motion in the intermountain basin.
The Operation Platform Connection Styles’ Influences on the Seismic Behavior of Thermal Power Plant Frame-Bent Structure
Authors: Bai Guo Liang , Niu Shuai , Du Bao Ping
Published: June 2012

Two different models are set up to analyze how the connection styles influence on the seismic behavior of frame-bent structure. In the earthquake input of both directions, mode superposition response spectrum method is used to calculate the parameters of frame-bent structure such as the story shear, seismic action deformation and so on. Analyzing the difference of the parameters of both models, explaining the reasons and drawing some rules are all done in this essay.
The Response of the Bi-Directional Beam String Structure under Vertical Seismic Considering Supporting Frame
Authors: Chen Xiang Rong , Liu Jin Bo , Wang Wen Qing
Published: June 2012

This paper using time time-procedure analysis method to analyze seismic response on a 80 m × 80 m bidirectional beam string structure model. Under vertical seismic action, we respectively compared to the seismic performance under the structure have or no supporting frame and have the same supporting frame but different support conditions. Under vertical seismic action, the axial force of brace is almost the same considering or unconsidering the supporting frame, while the upper beam vertical displacement is increased and the surrounding of the roof even increased several times considering supporting frame; the boundary conditions for the sliding hinge support bidirectional beam string structure which under vertical seismic ( middle seismic ) action the brace axial force and winding beam vertical displacement are nearly same with the fixed hinged support, while the horizontal displacement of the winding beam is larger than the fixed hinged support; the change of support conditions affect the order of the various modes of the structure but no affect the structural vibration modes.
Numerical Analysis of Seismic Behavior of Masonry Walls Confined by Precast Tie-Columns
Authors: Luo Wen Wen , Li Ying Min , Zheng Ni Na , Chen Na
Published: June 2012

In order to improve the seismic behavior of the rural masonry buildings and reduce the cost and be convenient for construction, a precast tie-column system was put forward, which was suitable for masonry buildings, constructed by fired common bricks or porous bricks. The uniaxial compression constitutive relation of brick masonry was used for simulating the precast tie-column. And this paper analyzed the difference of the seismic behavior of masonry walls which bearing different vertical compressive stress, and confined by cast-in-place tie-columns or precast tie-columns, and whether contain windows or not. The results show that the uniaxial compression constitutive relation used for simulating precast tie-column is reasonable and the seismic behavior of masonry walls confined by precast tie-columns is better than the wall without tie-colums, and equal to those confined by cast-in-place tie-columns.
Key Issues of Using High Strength Steels in Seismic Structures and some Recent Progress
Authors: Li Guo Qiang , Wang Yan Bo , Chen Su Wen , Sun Fei Fei
Published: June 2012

Since recent advances of technology in material science and increasing demand for high strength steel, Q460 high strength steel has been applied to several landmark buildings and major projects. However, the application of high strength steel in seismic structures is limited by the relative worse ductility, which is usually decreasing with the increasing on yield strength. For this purpose, key issues of using high strength steels in seismic structures are discussed and two design methodologies are proposed. Recent research progress on application of high strength constructional steel achieved at Tongji University is introduced. Finally, future work related to the application of high strength steels are recommended.
Mode I Fracture Toughness of a Tri-Layered Beam with Interfacial Crack
Authors: Her Shiuh Chuan , Su Wei Bo
Published: June 2012

A tri-layered cracked beam under opening loading is developed for the interfacial fracture toughness measurement. Determination of the mode I strain energy release rate along the second and third layers of the tri-layered beam is carried out analytically. The analytical prediction of the strain energy release rate is validated with the finite element results. The influences of the layer thickness and Young’s modulus on the strain energy release rate are examined through a parametric study.
Explosion Resistance Investigation into Sandwich Structure of Steel Fiber Reinforced Concrete Support Plate
Authors: Wang Xin Wu
Published: June 2012

Abstract. In order to avoid the damage of precision guided weapons on target, a steel fiber reinforced concrete sandwich structure with different types of support was proposed. The failure characteristics of penetration plate, steel fiber reinforced concrete plate and support beam were studied by contact explosion test. The results showed that the using of steel fiber sheet sandwich structure could increase a resistance level for the project with the same thickness of the protective layer. The failure mode of steel fiber reinforced concrete sandwich structure under partial blast loading was still the local damage mode, the strength and thickness of steel fiber laminate material, height and spacing of support beam were the main factors to control the effect of wave attenuation in steel fiber reinforced concrete sandwich structure, if some measures to prevent vibration on steel fiber sheet or under-surface of vault would enhance the resistance of structure.
Search of the Most Dangerous in Slide Slope Stability Analysis Based on Genetic Algorithm
Authors: Wang Ke , Wang Chang Ming , Qi Fang , Niu Cen Cen
Published: June 2012

The traditional limit equilibrium method in the analysis of slope stability not only exists some subjective empirical hypothesis that can not meet the equilibrium of force and moment, but also ignores the effects of internal stress and strain on the slope stability. Furthermore, in the stability of the slope evaluation, limit equilibrium method relies too much on experience when hypothesizing the slope slip surface. So that it makes deviation on slope analysis and stability evaluation. This paper is based on simplified Bishop method used to establish the model of slope stability analysis. And it used genetic algorithms to solve the minimum safety factor and the most dangerous slip surface of slope. It was the arithmetic which simulates organisms genetic evolutionary process and it avoided the traditional methods falling into the local extreme value point easily and error propagation leading to convergence. The algorithm had advantages of higher accuracy, quick convergence and applicability. It showed that the genetic algorithm is accurate and reliable in the analysis of slope stability.
Emergency Evacuation from a Multi-Room Compartment
Authors: Liu Jun Feng , Yuan Wei Feng
Published: June 2012

An extensive cellular automaton (CA) model is proposed to simulate the evacuation from a large multi-room compartment. To determine the movement direction, it is assumed that two factors, viz. spatial distance and occupant density, are considered by each occupant. To conduct more reasonable simulation, psychological inertia of human beings is also taken into account in modeling. Numerical results show that the proposed CA model is robust and the model can be applied in the assessment of fire safety.
Modelling of Crowd Behaviour in Emergency Evacuation
Authors: Liu Jun Feng , Yuan Wei Feng
Published: June 2012

A numerical model based on cellular automaton is proposed to simulate the human behaviour termed ‘flow with the stream’ in emergency evacuation from a large smoke-filled compartment. In the model, smoke effect in the context of visibility is considered since visibility range can affect crowd behaviour significantly. To simulate the reality that the smoke concentration in a fire compartment is not constant, the proposed model is developed to deal with the scenario in which the visibility range varies in the course of time. An empirical formula is incorporated into the proposed model to estimate the visibility range. The results of numerical tests show that the proposed model can also be used to investigate the effect of the number of guiders through case study.
Effect of Stirrup Ratio on Seismic Behavior of Cross-Shaped Columns with HRB500 Reinforcement
Authors: Li Yan Yan , Rong Xian , Zhang Jian Xin
Published: June 2012

Three cross-shaped columns were tested under low cyclic loading in order to research the effect of stirrup ratio on seismic behavior of cross-shaped columns with HRB500 reinforcement. The damage characteristic, hysteretic curve, load, displacement, ductility and accumulated damage were analyzed. The result show the damage characteristic is improved, the hysteretic performance has great improvement and the ductility of cross-shaped columns is enhanced with the increase of volume stirrup ratio. Besides, the degree of accumulated damage of specially shaped columns with HRB500 reinforcement can also be lighten.
Study on Safety Evaluation for Construction Sites Based on Fuzzy-AHP and Grey Correlation Analysis
Authors: Zhong Zuo Wei , Liu Zi Jie , Mu Li Li , Kang Xiao Long
Published: June 2012

This paper proposes a hybrid evaluation approach combining fuzzy comprehensive assessment method and AHP that measures the safety performance of construction site. The weight of each index was calculated through AHP model which use in fuzzy comprehensive assessment, and then the safety level of construction sites was determined by multi-layer fuzzy comprehensive assessment technique. In order to find out the main causes of safety level of construction site’ changes, the grey correlation analysis was used to quantify the influence degree of each factor of safety level of construction site. The effectiveness of our methodology was verified with an empirical study by using the data of 3 construction sites we investigated. The results show that this approach can be an effective tool to predict the safety performance of construction projects sites, which is useful to provide a scientific basis for the management and decisions of accident prevention.
Research on Urban Storm Flood Processes under Two Measures: Detention Pond and Retention Pond
Authors: Sang Guo Qing , Cao Sheng Le , Wei Ze Biao , Zheng Cong Qi
Published: June 2012

The detention pond and the retention pond are effective means for flood control. In this paper, two different storm runoff processes, used the detention pond and the retention pond, were simulated by SWMM. Through analyzing the results, the detention pond and the retention pond can control the flood obviously. Furthermore, the action effects of detention pond and the retention pond were discussed. In the end, the paper put forwards that the suitable flood control measures should be chosen by regional hydrology characteristics, maximum permitted discharge of downstream, engineering economics and so on.
Studied on Establishing Urban-Rural Disaster Prevention System
Authors: Wang Zhi Tao , Zang Xiu Yan , Wang Peng
Published: June 2012

To improve the ability of disaster prevention in urban-rural integration, the idea of establishing an urban-rural disaster prevention system with two lines of defense has been discussed in this paper. It also presents the framework of the system as well as the spatial mode of urban-rural disaster relief.
Effects of Ice Thickness on the Aerodynamic Characteristics of Crescent Shape Iced Conductors
Authors: Yan Dong , Lou Wen Juan , Huang Ming Feng , Lin Wei
Published: June 2012

Aerodynamic characteristics of iced conductors were investigated by the wind tunnel test. Under the homogeneous turbulence of 5% intensity, aerodynamic force coefficients of single and bundled conductors were obtained at wind angles of 0°~180°. The variation patterns of aerodynamic forces on the iced conductors with respect to wind angels of attack were systematically studied for the ice thickness of 0.25, 0.5, 0.75 and 1 times of the conductor diameter. The difference of aerodynamic force characteristics for single and bundled conductors were identified and discussed. Based on the Den Hartog and Nigol’s mechanisms of galloping, the wind angle ranges sensitive to galloping were analyzed. The results show that lift and torsion force coefficients reach peak values at wind angles of 15°~20°. For bundled conductors, lift force curve is approximately agreed with the curve of single conductor. Drag force coefficients were smaller than these of single conductor at some wind angles. There are noticeably differences of torsion coefficients existed between bundled conductors and single conductor. According to two classical galloping mechanisms, wind angles of 15°~30°are critical for the galloping of iced conductors with crescent shapes.
Numerical Simulation and Analysis of Compartment Fire in Subway Train
Authors: Zhang Bo Si , Lu Shou Xiang
Published: June 2012

Subway plays an important role in urban transport system. Fire as the major risk of the subway, is gaining increasing concern. In this study, fire simulation is performed to estimate fire safety of different compartments of the subway train. Result shows that the two compartments in the middle become dangerous at 150s and the compartments in the two ends are not safe at 300s approximately. The other two compartments are always safe during the simulation time.
Experiment Study on Dynamic Characteristics of Unbounded Prestressed Concrete Beams
Authors: Li Feng Ge , Li Rong
Published: June 2012

An experimental investigation on the dynamic characteristics of unbounded prestressed concrete simply support beams is presented in this study. A total of 3 unbounded prestressed concrete simply support beams were constructed and tested. The main variables considered in the test study were the prestress level, the position of prestressed steel and concrete damage. The test results shows that the natural frequencies and model shape of prestressed concrete beams change with the prestress level and the position of prestressed steel, and that the existence or not of concrete crack have certain effects on the dynamic characteristics of prestressed concrete beams.
Geometrically Nonlinear Analysis of Composite Girder Cable-Stayed Bridge with Three Towers in Completion Stage
Authors: Zhou Zhi Gang , Wang Feng , Deng Lan Hong
Published: June 2012

Based on nonlinear finite element theory, the spatial nonlinear FE model is proposed by link elements, shell elements and spatial beam elements. The different nonlinear behavior of composite girder cable-stayed bridge is analyzed under dead load in completion stage. The nonlinear analysis involves cable sag, large displacement and beam-column for composite girder cable-stayed bridge with three towers. The various nonlinear factors effect on internal force of side tower, and main girder stress are researched. The results show cable sag effect is larger than large displacement and beam-column for girder upper stress, and the sag effect is 16% on the average at the mid of the main span. The nonlinear effect on bending moments is larger than stress and axial force for side tower. The full nonlinear effect on bending moments is only -3.7%, but less than 1% on stress and axial force.
Application of Real-Time Monitoring and Data Web Sharing to Landslides
Authors: Wang Hong De , Le Qi Lang , Yang Xiu Yuan , Gao You Long
Published: June 2012

Acquiring instant information and sharing massive data are indispensable elements in social informatization. Real-time monitoring is realized with the support of computer and communication technologies. The monitoring facilities which are controlled by communication network terminal computers would collect and transfer data according to established procedures or real-time instructions. That is, data could be acquired under all weather and no duty conditions. Then the acquired massive data could be widely shared by issuing on Internet Web. This whole procedure is called real-time monitoring. Demonstration station for real-time monitoring and prewarning is just used to issue monitoring instructions, collect and transfer real-time data through GPRS wireless network between local monitoring stations and central station on the basis of computer and modern communication technologies. So the monitoring data elements could be gathered on central station server computer through communication network, and then be Web published and shared through the connection of central station sever computer and the Internet. Thus, informatization for landslides monitoring could be realized, and information could be optimally utilized. The geologic hazard monitoring and prewarning demonstration station in Wushan County was a good example of real-time monitoring and data Web sharing for landslides, which has greatly improved the level of geologic hazard monitoring and prewarning in China.
Preliminary Analysis on Wall Beam Force Algorithms under the Action of Vertical Load
Authors: Gao Yan Song , Sha Yong
Published: June 2012

This paper makes a study on the stress state and internal force algorithms of wall beams under the action of vertical load. It also makes a comparative analysis to several typical wall-beam designs at present. Then, by using the finite element, it verifies the accuracy and reliability of internal force algorithm formulas of wall beams in current Code for Design of Masonry Structure, hoping to provide a solid theoretical reference for the selection of wall beam algorithm designs.
Analysis and Simulation of Elastic-Plastic Fracture Parameters at Crack Tip under Biaxial Loading and Uniaxial Loading
Authors: Wang Zhong Xian , Liu Rui
Published: June 2012

Based on the J-A2 two-parameter elastic-plastic fracture theory and finite element numerical method, the elastic-plastic stress field ahead of the crack tip in a single edge cracked eccentric tensile specimen (the load-line is at a finite distance from the crack tip) was analyzed and compared with that of a center cracked large plate under biaxial loading. By using the Ritchie-Knott-Rice fracture criterion, a transformational relation between the two loading modes was obtained based on the J-A2 equivalent principle. As a result, the fracture parameter determined from a single edge cracked eccentric tensile specimen can be applied to the fracture analysis of a center cracked plate under biaxial stress.
The Mechanical Properties Analysis of Rutting Resistance Road Based on ANSYS
Authors: Li Jue Jie , Wang Ya Qiong , Qiao Jian Gang
Published: June 2012

As asphalt Pavement possesses the characteristics of comfort and ease to maintenance, it exerts usually in the road construction. Heavy axle load and high wheel pressure make the asphalt road prone to rutting damage. Based on the constitutive model of asphalt mixture, the paper analyzes mechanical properties of modulus, shear force and peak deflection value for different asphalt surface course after adding the rutting agent using the finite element method. Finally the paper acquires mechanism of variation in rutting, which provides an important theoretical basis for the final asphalt pavement structural design.
Axial Ultimate Capacity of Partially Encased Composite Columns
Authors: Zhao Gen Tian , Feng Chao
Published: June 2012

The test results of nine stub-column tests performed on partially encased composite (PEC) columns made with welded H-section steel are described and presented. The H-section steel is stiffened with transverse link and concrete is poured between the flanges of the steel section. The axial comprehensive study has been conducted on all specimens to investigate the ultimate axial capacity of PEC columns. The failure of all columns is due to local buckling of the flanges along with concrete crushing. Closer link spacing improves the ductility of the columns; however, the measurements show that in general yielding do not occur before the peak load in the links. The additional longitudinal bars have no a remarkable effect to the strength of the composite columns. Finally, an equation is proposed to predict the ultimate axial capacity of the partially encased composite column.
Analysis of Failure Mode and Propagation for Crack in Uniaxial Compression
Authors: Sun Ya Zhen , Zhai Xiao Xing , Liu Jie Min
Published: June 2012

This paper analyzed the failure mode for crack in uniaxial compression according to the stress intensity factor, and obtain that the failure mode for crack in uniaxial compression is compression-shear. The wing crack was deformed, after the crack tip initiate. By analyzing the dimensionless stress intensity factor, we obtain that the failure mode for wing crack in uniaxial compression is tension-shear, and we obtain that the dimensionless stress intensity factor for wing crack decreased with inclined angle increased. The inclined crack propagation in uniaxial compression was numerically studied using rock failure process analysis code (rfpa), and obtain that one inclined crack in uniaxial compression formed mode I offset crack parallel to load direction in the end. The numerical results of failure mode are accordance with stress intensity factor.
Fluctuating Pressure Correlativity Analysis on the Cantilevered Roof of a Stadium
Authors: Zhang Hai Yong , Chen Zhao Hui , Chen Feng
Published: June 2012

The time-history wind pressure data of the rigid model of an annular large-span cantilever roof of a stadium were obtained by the wind tunnel test. Considering the influence of the vortex shedding, the correlation coefficient and coherence function of along-wind and cross-wind points were analyzed to get the characteristics of the fluctuating pressure correlation of the stadium’s roof. The coherence function curves were fitted and the related coherence function was present. The results show that these characteristics of coherence are all coincide with the correlation coefficient. Compared to the Davenport and Nakamura coherence function models, the present coherence function has the same form with the Davenport and Nakamura's models, and a higher fitting accuracy for the cantilevered roof.
The Basic Characteristics of RAC and Mechanical Properties from Experimental
Authors: Gao Chao , Pan Zhu , Gao Shao Xia , Yu Bao Chu , Mao Hong Fei
Published: June 2012

This paper focuses on mechanical properties of RAC, and other relevant characteristics of RAC, also made lateral comparison with NAC. Paper attend to find some features need to pay attention, at the end of paper author determined strength of RAC.
Experimental Research on Dependencies of Mechanical Property of Elastomeric Isolator with Lower Hardness and Parameters Analysis
Authors: Shen Chao Yong , Ma Yu Hong , Zhuang Xue Zhen , Chen Yang Yang , Wang Shi Bin
Published: June 2012

LNR and LRB in which the value of shear modulus of inner rubber is 0.392MPa have been widely used in the practical isolation projects, although there are some test researches about dependency of shear property of them, but there is little complete study under high design compressive stress, such as 15MPa, and equations of dependency of shear property of them have seldom been found. In this paper, completely experiments about dependency of shear property of them have been done, and the fitted equations about various dependencies for LNR and LRB are given. Effect of size of rubber bearing on various dependencies is also studied. Formulas of determination of parameters in bilinear model of LRB are proposed, and have been testified well with FEA program.
Finite Element Model Updating for Unsymmetrical Damping System with Genetic Algorithm
Authors: Zhang Bao Qiang , Chen Guo Ping , Guo Qin Tao
Published: June 2012

Finite element model updating using incomplete complex modal data for unsymmetrical damping system with genetic algorithm is presented. The genetic algorithm method and finite element model updating based on optimization method using complex modal eigenvalue are introduced. The updating for simulation example about a flexible rotor system which is a typical unsymmetrical damping system is performed using bearing stiffness, bearing damping and diameter moment of inertia parameters. The results show that the maximum error of updated parameters is 0.15% and the objective function of genetic algorithm is 0.0081. The study demonstrates that the finite element model updating method using incomplete complex modal data with genetic algorithm is feasible and effective for unsymmetrical damping system.
Study on Twin Shear Strength Theory
Authors: Jin Sheng Ji , Wang Zhen Ping , Liu Zi Xin
Published: June 2012

Strength theory research in concrete, a brittle material, widely used in civil, hydraulic, mining and other engineerings,is of significant meaning.At first, based on the twin τ2 strength theory in this paper, the twin τ2 strength theory of two parameters is derived under the complex stress state in this paper. The relation among the compressive strength and tensile strength is proposed. Secondly, the brittle failure of concrete is analyzed by using the twin τ2 strength theory of two parameters and compared with the available experimental data for some concrete materials. At last, middle principal stress effect is discussed. The results of the twin τ2 strength theory of two parameters are shown to be satisfactory.
Study on the Mechanical Property of Concrete Materials under High Temperature (Fire)
Authors: Ou Man Li , Cao Wei Jun , Jiang Long Min
Published: June 2012

The performance of concrete materials under high temperature is more complex than that under room temperature. This paper, by analyzing the mechanical property of concrete materials under high temperature(fire), probes into the changing law of the concrete materials' compressive strength under different temperatures (16 °C-800 °C) and different static placing time and makes a comparison on the concrete materials' strength between natural cooling and water cooling; illustrates the relationships of concrete materials' compressive strength and temperature, holding time and cooling and other factors under high temperature(fire).
Research on the Calculation Model of Concrete Bending Member in Freeze-Thaw & Corrosion Environment
Authors: Sha Yong , Gao Yan Song
Published: June 2012

An experiment studies the forced performances of concrete bending members in three different times of freeze-thaw cycles and reinforced corrosion through fast freeze-thaw method and electrochemical method, it analyzes the influencing law on the anti-deformed capacity of concrete bending member influenced by the phenomenon of frost-heave and reinforced. On this basis, it builds a stiffness calculation model of concrete bending member in freeze-thaw & Corrosion environment.
Error Analysis of Superposition Method in Bearing Capacity Calculation
Authors: Chen Le Yi
Published: June 2012

Duo to non-linearity of ground material’s behavior, the error will be introduced using traditional superposition method to calculate bearing capacity. The main cause of superposition error is that bearing capacity factors based on failure mechanism of weightless soil is not applicable for weight soil. Based on slip line method, variation trend of error introduced by superposition method is investigated. The investigation of this paper showed that, bearing capacity calculated by traditional superposition method is conservative, and the error increased with increasing of internal fractional angle.
Study on Linear Calculation Method for the Refracturing Total Stress Field
Authors: Zhao Wan Chun , Wang Ting Ting , Sun Chen Yan , Liu Ying , Yang Cai Ping
Published: June 2012

In order to accurately describe the impact is on the redirection of the secondary fracturing caused by stress field distribution of the reservoir , according to the superposition principle of the potential, builds the pore pressure induced model around refracturing wells ; introduces the fluid influence factor coefficient , builds initial artificial crack induced stress field model. Finally, the three stress applies the linear superposition principle .Obtaining the total stress field before the refracturing , provides a reliable theoretical calculation basis for the induced stress calculation
Analysis of Small Non-Sand Concrete Pile Grouting Pressure Based on Unified Strength Theory
Authors: Tong Huai Feng
Published: June 2012

Analysis of stress state of soil around the pile and grouting pressure of small non-sand concrete pile is given based on the expansion elastic theory of cylindrical cavity and the unified strength theory, the grouting pressure formula is obtained in the elastic limit state and elastic-plastic state of soil around the pile considered the intermediate principal stress, and the relationship is obtained between the grouting pressure and the plastic radius; When the soil around the pile is in different stress state, the correlativity of crack and densification of grouting is analyzed, and the relationship between the grouting pressure and the plastic radius is discussed with the right coefficient of the intermediate principal stress and initial press under different values. The obtained results have provided efficient analysis means for grouting optimal design of post-processing technology with small non-sand concrete pile.
The Influence of Process Force on the Wall Thickness
Authors: Wen Hua Dian , Xiao Xiao Ting , Tan Li Guang , Chen Ying , Zhang Kai
Published: June 2012

Multi-way tubes on air conditioning condenser are considered as research objective. The ordinal hydro-forming method and finite element simulation method are utilized to analyze the influence of process force on wall thickness such as internal pressure, axial force ,balance force and their matching relationship. The uniform experimental design method and regression method are utilized to solve the prediction model of wall thickness. The results show that the slope of straight line loading path has a significant effect on branch height, the greater the slope is, and the higher the height is. What’s more, the fold line loading path can effectively improve the branch height while the shock loading path can effectively improve the wall thickness‘s uniformity.
Influence Analysis of Mortar Elastic Modulus to CRTS III Slab Track Vertical Dynamic Response
Authors: Zeng Zhi Ping , Wang Xue Song , Chen Wen Rong , Long Guang Cheng
Published: June 2012

A train-CRTS Ⅲ slab track coupling dynamic model was proposed to study the dynamic performance of the system. Rail was modeled as space beam element. Both slab and HGT layer were modeled as plate element respectively. The vertical and lateral connections between rail, slab, HGT layer, and subgrade were modeled as spring-damper element. The vibration matrix equation of the system was established on the basis of the principle of the total potential energy with stationary value in elastic system dynamics and the rule of “set-in-right-position” for formulating system matrices. The influence of mortar elastic modulus to CRTS Ⅲ slab track vertical dynamic response was calculated when the train runs at 350 km/h. The results show that the larger of mortar elastic modulus, the faster the vibration between rail and slab decays, and the slower the vibration between slab and HGT layer decays.
Thermal Stress Analysis of a Certain Concrete Wind Cover
Authors: Zhang Yi Na , Zhao Shu Ping
Published: June 2012

As an important part of hydroelectric power station,wind cover is under a high temperature stress in the process of running the station,and the structure may be in danger.This paper analyze a hydropower turbine wind cover’s temperature stress in two different conditions with large general-purpose finite element analysis software ANSYS.Study shows that in the worst case of load combination,Wind cover appears higher tensile stress values.In order to ensure the structural safety, the measures of arranging ring bar and vertical bar on the outer wall of the wind cover are suggested.
Study on the Influence of M Value to Internal Force and Deformation for Transverse Bent of High-Piled Wharf
Authors: Gui Jin Song , Li Zhen Guo , Zhang Bo
Published: June 2012

As m value is not an inherent property of soil and affected by many factors, limited to the current level of theorey and technology, m value of soil around each pile can not be accurately taken when using “m” method to simulate the pile-soil interaction in engineering. In this paper, finite element software is used for the systematic study on the influence of m value to internal force and deformation for transverse bent of high-piled wharf. By analysis, it is considered that the influence is little and can meet the project accuracy requirements when taking m value through experience.
A Correction Algorithm of Aberration of Light for Spacecraft Attitude Determination System
Authors: Li Bao Hua , Chen Xi Jun , Pang Yang , Xi Bo Qi
Published: June 2012

There is the long periodicity attitude error between true attitude and measurement attitude using star sensor for spacecraft attitude determination system because of aberration of light. Aberration of light occurs because the spacecraft’s velocity has a component that is perpendicular to the line traveled by the light incoming from the star. The type of aberration is analyzed and their constants of aberration are calculated in this paper. According to the constants the aberration, the correction mathematical models of parallax of aberration of light of these types of aberration are derived. The parallax of aberration of light of the recognized stars in the FOV of star sensor is calculated with the mathematical models. Then the true vectors of recognized stars at image space coordinate system of star sensor are calculated. The measurement attitude of star sensor is calculated with the true vectors of recognized stars and their vectors at celestial sphere coordinate system. The simulations show the long periodicity attitude error is corrected with the method in this paper. At last the correction of aberration of light was successfully demonstrated using two star sensors with real sky experiment in 2011.
Experimental Investigation of Cold-Formed Steel Tubes Subjected to Web Crippling
Authors: Peng Huai Lin , Zhou Feng , Tong Le Wei
Published: June 2012

A series of tests on cold-formed steel square and rectangular hollow sections subjected to web crippling is reported in this paper. The web crippling tests were conducted under two loading conditions of end-two-flange (ETF) and interior-two-flange (ITF), which are specified in the current North American Specification for cold-formed steel structures. The concentrated load was applied by means of bearing plates, which act across the full flange width of the specimen sections. Different bearing lengths were investigated. The test specimens were fabricated by cold-rolling from steel sheet with nominal yield strength of 345MPa. The measured web slenderness values of the tubes ranged from 15.5 to 46.0. The test strengths obtained from this study are compared with the design strengths obtained using the current North American Specification, Australia Standard, European Code and Chinese Code for cold-formed steel structures. It is shown that the design strengths predicted by the specifications are either unreliable or too conservative.
Mechanical Research on Bond-Slip Behaviors of Recycled Aggregate Concrete-Filled Square Steel Tubes
Authors: Li Jun Tao , Xu Jin Jun , Chen Zong Ping , Li Yi , Liang Ying
Published: June 2012

In order to research the interface bond-slip behaviors of recycled aggregate concrete-filled square steel tube (RACFSST), ten specimens using waste concrete were designed for launch test. The three changing parameters were concrete strength grade, embedded length and recycled coarse aggregate replacement rate. The load–slip curves of square steel tubes and recycled aggregate concrete were obtained, and starting bond strength and ultimate bond strength influenced by each changing parameter were analyzed. The results show that the replacement rate had a slight influence on the starting bond strength and ultimate bond strength, while the embedded length had the opposite effect. The shorter embedded length specimens had larger bond strength. The concrete strength had a relatively large influence on them.
III-Posedness and Regularization Method for Nonlinear Identification Equations in Time Domain
Authors: Xie Xian Zhong , Zhang Feng , Li Yang , Tan Yong
Published: June 2012

The ill-posedness of nonlinear identification equation in time domain of structural dynamics system is studied and a new calculating method to weaken the influence of ill-posedness is proposed. Damped least squares method is an algorithm of Jacobian matrix positive-definable, which can obtain the solution of ill-posed nonlinear identification equation. But the solution is sensitive to the test noise of response in time domain of the structure. To solve the problem of instability of the solution, a new calculating method is proposed which combines damped least squares method with Tikhonov regularization method. First, the estimate of structural parameters is introduced to Tikhonov regularization function, and a more stable identification equation in time domain can be obtained. Second, the identification equation is solved with damped least squares method, and the iterative result is an approximate solution of the former ill-posed problem. The numerical example shows that the new method in this paper is efficient to solve the ill-posed nonlinear identification equation in time domain.
Experimental Tests on Composite Beam with Various Slab Systems
Authors: Saggaff Anis , Tahir M.Md. , Jamaluddin Norwati , Shek Poi Ngian , Tan Cher Siang
Published: June 2012

This paper presents the structural behaviour of composite beams with various floor systems tested in full-scale arrangement. Six full-scale specimens with staggered and non-staggered arrangement of studs on the composite beams were tested until failure. The moment capacities obtained from the experiment are compared with the theoretical values established from BS 5950 and Eurocode 4. The experimental results showed good agreement with theoretical predictions while no significant influences were found between staggered and non-staggered arrangement of studs.
The Analysis of ZF6 AT Based on the Expansion Lever Method
Authors: Li Jiang Jiang , Li Jing Hua
Published: June 2012

A new transmission scheme based on expansion lever method was used. The transmission and transmission scheme of ZF6 AT were detailedly analyzed by using the explanded Lever method.
An Inverse Eigenvalue Problem for Star Spring-Mass System
Authors: Tian Xia , Li Chuan Xiao
Published: June 2012

The mass-normalized stiffness matrix of the star spring-mass system is an arrowhead matrix. Given two eigenpairs of the arrowhead matrix. It is assumed that the total mass of a star spring-mass system is known. The problem of constructing the physical elements of the system from the known data is considered. The necessary and sufficient conditions for the construction of a physical realizable system with positive mass and spring stiffness are established. If these conditions are satisfied, the system may be constructed uniquely.
Reinforcing Design of the Crane Girder in a Factory
Authors: Yu Ling Ling , Xu Lin
Published: June 2012

The advantages of reinforcing methods for crane girder were compared with disadvantages and it was found that external prestressing method was the most reasonable reinforcing method. Thereafter, this method was used for reinforcing crane girder. Some reinforcing points such as determining calculation view, the control stress calculation, the prestress loss calculation and the tension length calculation etc. were described in detail. Finally, maintenance of the steel components and the prestressed reinforcements should be paid attention during the use of crane girder.
Topology Optimization of Building Structures Considering Wind Loading
Authors: Tang Ji Wu , Xie Mike , Felicetti Peter
Published: June 2012

The latest developments in structural topological optimization have been integrated with CFD for the optimization of building structures considering wind loading. Wind loads on a building are numerically simulated in ANSYS CFX and then transferred to ANSYS Static to get the structural response of the building in wind. The bi-directional evolutionary structural optimization (BESO) algorithm has been applied to buildings for an automatic structural topological optimization considering wind loading. The proposed approach is demonstrated by examples of the optimum structural design of exterior bracing system of a high-rise building.
Eccentrically Braced Steel Frame Design Theory and Application Research in China
Authors: Zhao Chun Rong , Wei Cui , Zhang Ya Ying
Published: June 2012

Eccentrically braced steel frame is a good anti-seismic structure which can be used in seismic area. A series of experiments and theoretical researches have been conducted in developed countries. However, research on this kind of structure in China is at an early stage. This paper reviews experimental, theoretical and practical application researches in China. The aim is to contribute to a better understanding of the development of the structure for designers in China, to provide a reference for researchers in this area, and to accelerate practical usage of the structure in seismic areas.
Method Study for Finite Element Modeling of Large Oil Storage Tanks
Authors: Ge Qi , Xiong Feng , Peng Xiao Yang
Published: June 2012

This article, basing on the field test stress of an oil-storage tank in the site, investigated finite element modeling method for large oil storage tanks. To study the effects of contact conditions among the tank wall, bottom plate and the foundation, the soil of the foundation, and holing on the tank stress, six different finite element models were built by ANSYS finite element analysis software. The stresses in the tank were calculated under the gravity load and the water pressure. Results of the six models have been compared with the field test values. It was obtained for the stress distribution in the tank wall, bottom plate, and big horn weld and around the manhole from which the influence scope and extent to the tank was investigated. It shows that the calculated stresses have a good agreement with measurement. The plane model has enough precision for the tank stress analysis. The contact conditions and soil affect on the stress in the scope with 0.2H and 0.24H (the height of the tank), and holing affects the adjacent area with 2D (the diameter of the manhole).
Structural Optimization of Transmission Line of Steel Poles
Authors: Qin Li , Luo Ya Nan , Huang Peng
Published: June 2012

For the structural optimization of transmission line of steel pipe poles,the structural mass was considered the objective of the economic optimization, the taper of shaft and then the thickness of each wall with the taper of shaft were successively regarded as the design variables, established mathematical modal of transmission line of steel-pipe pole. Various conditions of load calculation were accomplished. Themost unfavorable load condition founded were taken as the design load condition.And LIN-GO is introduced to solve some optimization problems about the design variables. From what has been analysed , it is proved using L INGO on structural optimization of transmission line of steel pipe poles Can significantly reduce the amount of steel used.