bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on T-Section Aluminium Beam-Columns with Web in Compression
Authors: Zhang Zheng , Yan Gui Yun
Published: May 2011

Parameter analysis based on finite element methods was executed to study the in-plane stability capacity of extruded T-section aluminium beam-columns with the tip of the web in bigger compression. The analysis methods considered the effects of material nonlinearity, geometrical nonlinearity, and initial imperfection. The comparisons of calculate results of three kinds of T-sections of weak hardening alloy and strong hardening alloy between GB 50429, proposed formula and numerical methods were executed. And the analytical results show that GB 50429 is safe and suitable, and the modification formula based on GB 50429 is also safe enough and more exact than the former.
Effects of Large Rock Particles on Permeability of Soil and Rock Mixture
Authors: Xiang Xian Chao , Jiang Guo Sheng
Published: May 2011

The soil and rock mixture is widely spread in the world， which is much different from homogeneous and continuous soil, it is hard to get the permeability of the soil and rock mixture by theories, and it is also hard to get that from the large lab test as the difficulty in sampling. The particle flow code (PFC) method is used to study the permeability character influenced by large rock particles. The result shows that the seepage of the soil and rock mixture obeys the linearity of Darcy’s law in low fluid velocity, but the large particles influence the local pore pressure evidently. The permeability increases while the ratio of rock to soil increase first, and decreases while the ratio enlarge to 0.5, then increases after the ratio enlarge to 0.7. The large rock particles jam the fluid path, but decrease the length of the pipe, the permeability is influenced by the two effects.
Uncertainty of One-Dimensional Consolidation of Multi-Layered Soft Clay Soils
Authors: Li Xiao Yong
Published: May 2011

The measured coefficient of consolidation can have a substantial degree of variation even in a uniform clay layer. The probability characteristic values for such parameters as consolidation coefficient and compression modulus are analyzed from local engineering data. This paper, through a probabilistic analysis, examines the variability of one-dimensional consolidation solutions. The multilayer models are evaluated. Then the Monte Carlo method is used to develop solutions for one dimensional consolidation. It identified the influence of the parameter uncertainty on the probability characteristic of the consolidation degree. The uncertainty of consolidation coefficient has a great impact on the probabilistic characteristics of the consolidation degree, but for compression modulus it is opposite true. It proposed a simplification analysis method that considers only the uncertainty of consolidation coefficient without consideration of the uncertainty of compression modulus, and its erroneous precision can meet the engineering requirements.
Discussion on Application of Electrical Resistivity Method in Cemented Soil after Pollution
Authors: Dong Xiao Qiang , Bai Xiao Hong , Lv Yong Kang
Published: May 2011

As a simplify and effective method , electrical resistivity has been used in geotechnical engineering. In lab the experiment simulated that cemented soil had been polluted by industrial sulphuric acid after mixing. On different age time, the variation trend among electrical resistivity of cemented soil and solution, formation factor and solution concentration were studied. The results indicated that both of electrical resistivity and formation factor have close correlations with sulphuric acid solution concentrations and pollution level of cemented soil. This shows that the electrical resistivity method are very sensitive for groundwater and cemented soil after pollution in the engineering site.
Element-Free Spline Method for the Vibration Analysis of Functionally Graded Material Plate
Authors: Li Shuang Bei , Jia Chun Feng , Jiang Lin Jie , Qin Rong
Published: May 2011

The element-free spline method is proposed to analyze the vibration of the functionally graded material (FGM) plate with various boundaries. The field functions are constructed by using the linear combination of double B-spline basis functions together with mixed displacement parameters and then an equation based on Reddy's third order plate theory is developed for the vibration analysis of the FGM plate. The validity of the proposed method is illustrated by some numerical examples. Six lower vibration frequencies of FGM plate are calculated under various boundaries and the influence of boundary condition and material gradient on vibration frequencies are also discussed. The proposed method needs less computational cost and has high accuracy.
Influencing Parameters Analysis of Chloride Threshold Value on Reinforcements Embedded in Concrete
Authors: Cao Wei Qun , Wan Xiao Mei , Zhao Tie Jun
Published: May 2011

The chloride threshold to develop active corrosion of the reinforcing steel does not seem to be a unique value and it depends on several factors, such as concrete mix proportions, cement type, C3A content of cement, blended materials, water/cement ratio, temperature, relative humidity, steel surface conditions and source of chloride penetration among others. Numerous studies have been already devoted to the study of the chloride threshold value for depassivation of the steel embedded in concrete. One of the reasons found for the scatter is the large number of variables that influence the chloride amount for depassivation. The other reason is the lack of accordance for the definition of the chloride threshold itself, either on the determining parameters (visual observation, corrosion potential or corrosion current) or on the expression of the threshold (as[Cl-]/[OH-] ratio or by weight of cement or concrete). The present paper presents chloride thresholds expressed as total, free and [Cl-]/[OH-] ratio.
The Research Methods of Soil and Structural Dynamic Interaction
Authors: Dong Xiao Li
Published: May 2011

This paper will introduce the basic methods of soil-structure dynamic interaction at home and abroad, and analysis the advantages and disadvantages of these methods. Finally, the paper will put forward opinions on the research tendency of soil-structure dynamic interaction. With the development of urbanization, the urban population, planning area and urban environment are faced with tremendous stress, so developing and utilizing the underground space becomes the concerns of many cities. In recent decades, the underground structure has been widely used in urban construction, transportation, national defense engineering, and hydraulic engineering and so on. Especially in the urban construction, with underground railway which has been seemed as the large-capacity backbone and fast public transport system has become an important issue of urban passenger traffic solution. In our country, there are still large potential in developing and utilizing the underground structure and the structure forms will become more and more complicated. China is a strong and frequent earthquake country, the earthquake-proof problems about the underground structures such as Long-span subway station has become city astigmatic engineering and the important research content on disaster prevention and mitigation. These researches can ensure the safe use of underground structures and reduce natural disasters to humankind. To the subway station and the tunnel structure, soil characteristics significantly influence the structure seismic response and destruction features. In seismic response process, the overburden of gravitational can greatly affect on the structural seismic response. The solution to the underground structure seismic problem should focus on two aspects: on one hand we should focus on the research of soil-structure dynamic interaction; on the other hand, we should deal with soil’s half-limitlessness simulation problem.
Study on the Evaluation of Fatigue Life of RC Beams Strengthened with FRP Laminates
Authors: Huang Li Hua , Li Tian Qing , Wang Yue Fang
Published: May 2011

Extensive tests have shown that externally bonded fiber reinforced polymer (FRP) laminates are particularly suited for improving the short-term and long-term behavior of deficient reinforced concrete (RC) beam. Fatigue tests conducted to date indicate that fatigue life of RC beam bonded with FRP laminates lies in the response of steel rebar. Study on the method of nominal elastic stress (strain) for evaluating life-span of FRP strengthened beam is carried out in this paper. By analyzing fatigue tests, the acceptable stress concentration factors and S-N curves are suggested to be used to account for the fatigue behavior of RC beams strengthened with FRP laminates. Analytical results are compared with experimental data from two sets of fatigue tests on stresses and life-span, which shows agreeable trend. Based on the findings, the approach of nominal elastic stress (strain) can be extended to evaluate the fatigue life of RC beam bonded with FRP laminates.
An Egg Shaped Failure Criterion for Lightweight Aggregate Concrete
Authors: Wang Wan Zhen , Chen Yuan Jiang , Chen Fei Yi
Published: May 2011

Referring to an egg shaped yield function for geotechnical materials, a failure criterion for light-weight aggregate concrete is put forward, in which the tensile and compressive meridians are egg shaped curves and the failure envelopes in deviated plane is smooth elliptic curves. The suggested failure criteria could describe the failure characteristic of lightweight aggregate concrete at different stress state. The precision of the suggested egg shaped failure criteria is verified by comparing with experiment data of lightweight aggregate concrete.
Optimization Research on the Corrugated Web of H-Beam with Trapezoidal Webs
Authors: Zhang Zhe , Zhang Li Hong , Luo Da Hu
Published: May 2011

Based on the theory study of stress characteristics of the H-beam with corrugated web under transverse load, optimization analysis was conducted. The optimization analysis focused on the corrugation configuration of web, by which one optimized dimension was put forward. To verify the optimization result, total 10 specimens are tested. From the results, the optimization configuration can provide relatively high shear strength and ductility property, with low steel usage. So it can be put into production practice.
Observed Performance of a Deep Multistrutted Excavation in Hangzhou Soft Clays with High Confined Water
Authors: Zhang Xue Chan , Gong Xiao Nan
Published: May 2011

It is common to have a foundation pit accident, when failing to deal with the effect of confined water. In order to avoid such accidents, the Jiangnan launching shaft of Qingchun Road River-Crossing Tunnel in Hangzhou was investigated. According to the analysis of on-site monitoring data of wall deflection, settlement, and strut load, some conclusion can be drawn. Firstly, the wall deflection is closely related to the plane size of the foundation pit, and through strengthening the stiffness of the central support, the wall deflection can be greatly controlled. Secondly, the maximum settlement point is 0.5 times depth of the excavation away from retaining wall. Finally, load in the first level strut gradually decreased during the construction, and even can turn to be tensile force.
Making Good Use of Suspension Bridge Health Monitoring System
Authors: Li Xing Xin , Ren Wei Xin , Zhong Ji Wei
Published: May 2011

In order to make good use of large-span suspension bridge health monitoring system, the design for Wuhan Yangluo Yangtze River Bridge health monitoring system(YLBHMS) is outlined, and the implementation of the deformation and vibration on-line monitoring system is introduced. Analysis of the measured temperature, the vertical deformation effect of the main cable and the girder, the longitudinal deformation effect of the main tower and the girder, The fingerprint files are accumulated for the assessment of temperature deformation, the work state of bearing and expansion joints in the follow-up operation; The vibration system recorded the Wenchuan earthquake response, the analysis of the bridge vibration response concluded that the bridge seismic response is in the design scope, the work state of the bridge did not change after the earthquake.
Research on New Type of Prestressed Concrete Double Tee Floor Slabs
Authors: Zhou Wei , Zhang Jian Xin , Zheng Wen Zhong
Published: May 2011

Prestressed concrete double Tee floor slabs are widely used for the roof of building construction. Some problems are met during the development practice of this type of precast structures. Firstly, the overhang flange of the traditional double Tee floor slab is not enough large in the view of economic and utilization. Secondly, it is not easy to dispose the skylights on the roof used double Tee floor slabs in the workshops or the gymnasiums. Thirdly, most of the beams are produced in prestressing plants, but very few productions are made in site. Therefore, a new type of prestressed concrete double Tee floor slabs have been designed with some characters such as 3.0-m outside flange, flange slabs with rectangular opening holes for the skylights or not, and the beams produced in the prestressing plants with pre-tensioning prestressing tendons or post-tensioning with the strands in site.
Analysis on Dynamic Response of Building Structure in Blasting Vibration
Authors: Zhang Zhi Yu
Published: May 2011

Based on the characteristics of blasting vibration wave and the design response spectrum, this paper puts forward an analytical method on dynamic response of building structure in blasting vibration. Example analysis shows that this analysis method is more reliable and scientific compared with the analytical method which takes the single physical vibration parameter as the criterion to assess the damage in blasting vibration; the blasting vibration load is determined by the first vibration mode, and the influence of higer level vibration mode can be ignored. The interlaminar shearing force distribution carries the feature that the shearing force on the top of the building structure is smaller than that on the bottom. Therefore, in blasting vibration, the bottom of a building structure is easier to be damaged.
Lateral-Torsional Buckling Strength and Design of Steel Arches
Authors: Yang Yong Hua , Chen Chun Xia , Fang Ming Ji
Published: May 2011

The arches resist general loading by a combination of axial compression and bending actions which vary along the arch. Under these actions, an arch may suddenly deflect laterally and twist out of the plane of loading and fail in a lateral-torsional buckling mode. This paper investigates the lateral buckling strength and design of steel arches under general loading. It is found that the subtended angle and load distribution significantly affect the lateral buckling strength of a steel arch. The rules for designing steel beam-columns against lateral buckling cannot be used directly in the design of steel arches against lateral buckling under general loading, because they do not include the effects of the subtended angle. The buckling loads of arch with different load condition, subtended angle, manner of laying section are calculated by finite element method. The interaction equation against lateral-torsional buckling for steel arches subjected to combination of bending and axial compressive actions is proposed. The safety and applicability of the interaction equation is verified by parameter analysis.
Study on Regional Urban Design
Authors: Li Gang , Wu Shi Gang
Published: May 2011

The concept of regional urban designing is put forward on the foundation of the analysis of the background of modern city designing and the current particular situation of China. This paper contends that this concept combines the place, context and ecological designing, and is founded on the characteristics of time’s development and regional natural and historical resources. This paper also brings forward that the regional urban designing will become the tendency and direction of Chinese urban designing, and that in the regional urban designing. The design and regional characteristics should be combined, in-clouding combining the design and context, and combining the design and ecology.
Investigation and Research of Biological Contamination of HVAC in Public Places
Authors: Li Xin , Wei Ya , Li Liang
Published: May 2011

According to the normal method for sampling in the appendix of “The Central Air-Conditioning Ventilation System of Public Health Standard” by the ministry of health in 2006 were the HVAC on-site examined and sampled. The examined indicators include: total number of bacteria, fungus and beta Streptococcus in air supplied outlet, Legion Ella pneumophila in cooling water, the quantity of dust and microbe amounts to each square meter pipeline surface area and other sanitation indexes.
Study of a New Type SMA Damper
Authors: Sui Jie Ying , Xu Chen Ming , Liu Wen Feng
Published: May 2011

In this paper, a new type SMA damper making use of SMA wire was designed. When the damper was in a tensile, compressed or tensional condition, the SMA wire is always in the condition of tension. The passive energy dissipation control of seismic vibration makes use of the super elasticity and high damping of tensile SMA wire. On the basis of the study of a 10-story building, five groups of the placement of the damper are used in time-history dynamic analysis .By contrasting the five different results, the influencing rules of the placement of the damper on seismic response of the structure can be concluded.
Discontinuous Galerkin (DG) Finite Element Method for the Improved Stokes Equations
Authors: Zhang Shu Hua , Yuan Xiao Jing , Yin Qian
Published: May 2011

In this paper, firstly, discontinuous Galerkin method for improved Stokes equation is proposed. We derive a discontinuous Galerkin (DG) finite element formulation for the improved Stokes equations. Special case of the generalized solution equation for linear and stationary improved Stokes equations retrogresses into generalized solution equation for classical Stokes equation. It is proved that the classical solution and the generalized solution is consistent for the improved Stokes equations, existence and uniqueness of generalized solution for the improved Stokes equations are also proved.
CBD Construction in Sub-Regional City: a Case Study on Changzhou in Yangtze River Delta
Authors: Yuan Yan , Li Yan Kui , Zhu Xiao Xi
Published: May 2011

Central Business District (CBD) is not only is the central district of a city, but also the product of economic and the third industry development. Meanwhile, in the metropolitan of China, there are large number requirements of the CBD construction for sub-regional cities. In Yangtze River Delta metropolitan, the cities such as Ningbo, Suzhou, Wuxi, Jiaxing, Huzhou, Shaoxing, Zhoushan, Yangzhou, Changzhou, Taizhou, Zhenjiang, Nantong, most of which GDP have reached 1000 billion Yuan and owned the initial economic base for the CBD construction. However, compared with the regional city or the world city, the sub-regional city’s CBD has the differences in scale, spatial form, the development operation and traffic patterns. In this paper, the sub-regional city in Yangtze River Delta— Changzhou is taken as research object，the CBD construction theory and urban design method are proposed to provide reference for similar area .
Forest Pests and Diseases Forecasting Based on GIS
Authors: Luo She Zhou , Wang Cheng
Published: May 2011

Geographic Information System (GIS) has been widely applied to the field of pest management, which provides the new ways and methods for integrated pest research, prevention and control. The main purpose of this study is to forecast and manage forest pests and diseases. For this purpose, I developed the forest pests diseases forecast system, by using ArcObjects (AO) and Visual Basic as the secondary development platform. The system is able to synthetically analyze and judge relevant data, such as weather forecast and tree species, according to the occurrence laws of the forest pests and diseases and the characteristics of biology. The system uses Markov chain and other methods to forecast the occurrence period, amount, scope and the degree of harm of pests and diseases. To validate the reliability of Markov chain model, the pests and diseases data of Liu'an City of Anhui Province, in China from 1975 to 2001, to be applied. The results show that the method used is reliable. The occurrence area and location of forest pests and diseases can be labelled and displayed on the electronic map with three-dimension.
The Finite Element Analysis of Coupling Law of Stress Field / Seepage Field in Impermeable Stratum Medium
Authors: Li Jing Yan
Published: May 2011

In order to forecast the mining process of oil and gas field rightly, simulate the flow process of reservoir fluid accurately and reveal the fluid distribution law, it must be considered that multiphase fluid seepage caused by water injection and exploitation, the change of stress state and the coupling between the reservoir deformations. According to the basic theory of rock mechanics, fluid mechanics in porous medium, geologic mechanics, calculated mechanics and fluid-solid coupling seepage, a mathematical and numerical model of seepage field and stress field coupling is developed in porous medium and a computer program is designed with the method of finite element technique. The Coupling Law of depressurizing exploitation Seepage field /Stress field in porous medium is studied. By the method of numerical simulation the variation law of stress-strain with time and space around borehole of impermeable rock medium, variety law of rock physical properties parameters is studied. Results show that the quantity of change nearby oil well and the change gradient is bigger, so it reduces very quickly to the oil deposit boundary,the stress and the strain are also biger in the oil well control area's influence area.
Effects of Temperature on Mechanical Performance of Elastocoast® PUR-Stone
Authors: Zhang Bin , Liu Li Jia , Liu Gui Ying
Published: May 2011

This thesis provides a study and analysis of the flexural strength, compression strength of Elastocoast® PUR-stone which is effected by temperature .Through seven tests we find that temperature does not exert any major impact on physics and mechanical properties of Elastocoast® PUR-stone . This tests provide the reliable guidance for cold region engineering.
Transient Numerical Simulation for Air Distribution of Air Conditioning and Ventilation in Subway Island-Platform
Authors: Fan Hong Ming , He Kai Yuan , Yin Zhi Fang , Zhang Dan
Published: May 2011

The typical subway island-platform of Beijing as research object was present in the article. Taking two-equation turbulence model and giving boundary conditions of piston wind and train heat load change with the time, adopting numerical method simulates air distribution of air-conditioning and ventilation system in subway. The results indicate that piston wind effect has significant impact on the area of platform entrance and staircase entrance while station with safety doors can obstruct piston effect at a certain degree. Simultaneity, the supply- exhaust air system offers relatively uniform temperature and velocity field, which meets requirements of transitory comfort for passengers. It is found that numerical simulation method can simulate and forecast air distribution of air conditioning and ventilating system in subway station. In conclusion, it can provide the reference for optimizing air-conditioning and ventilation system, improving thermal environment designing of subway station.
Evolution of Passive Technology in Lhasa Residential Building
Authors: Wang Fang , Liu Jia Ping , Chen Jing , Wang Deng Jia , Wang Li Juan
Published: May 2011

With the rapid urban development of Lhasa in Tibet Autonomous Region, the traditional houses are losing gradually, while a great variety of city housing are springing up all over the city. Spatial patterns of city housing don’t blindly imitate commercial housing in most other cities in china, but have unique characteristics, such as building direction, functional layout, hole set, building construction and so on. The paper selects four types of Lhasa housing, rural traditional dwelling house, low-income apartment, detached house and multi-storey house, to analysis application of passive technology in detail and sums up three developing stages of passive technology in Lhasa area. On the basis, the paper discusses major factors about evolution of passive technology, that they are changes of spatial patterns, structure system and way of energy consumption. In the end, the paper puts forward some suggestions on the passive technology application in new city housing.
Probe into the Problem of Water-Saving and Energy-Saving in Building
Authors: Yang Jie , Tang Zhong Hua , Song Yu
Published: May 2011

With the fast development of economy in China, some questions have come out gradually, and more and more obviously. For instance the energy in short supply, the water resource exhausted. I have made a simple analysis on the issue that some extant energy is wasted and the water resource wasted in the water supply and sewerage engineering in China, and have put forward some corresponding measures, such as full use of available municipal water supply network head, reasonable control of the flow of overpressure and decompression cost saving measures, promotion of the technology of water reuse and rainwater reuse and other measures. These measures can effectively reduce the energy and water waste in the water supply and sewerage engineering.
The Finite Element Analysis of Fatigue Performance of Precracked Concrete Beams Strengthened with Prestressed CFRP
Authors: Li Qing Song , Meng Shao Ping
Published: May 2011

The research conducts the numerical analysis of the fatigue performance of precracked concrete beams strengthened with prestressed CFRP, establishing the static analysis model (SM) and fatigue analysis model (FM) respectively, examining the change of the static loading and fatigue performance before and after CFRP strengthens precracked concrete beams in the different prestressed situations, and analyzing the relevant fatigue performance parameters through comparing FEM analysis with experimental results. The research results demonstrate that the method of strengthening concrete beams with prestressed CFRP can improve the static loading and fatigue performance; the increased rate of fatigue performance of precracked concrete beams is parallel to the CFRP prestress; the fatigue life of precracked concrete beams increases with the raising of the CFRP prestress; FEM analysis is in close agreement with experiment results; the fatigue properties of precracked concrete beams strengthened with prestressed CFRP can be analyzed effectively by the finite element method.
Mechanical Characteristics Analysis of Sensitive Parameters of Long-Span Steel Truss Suspension Bridge
Authors: Wang Da , Zhu Yi Zhou
Published: May 2011

In order to study the influences of structure parameters on the structure mechanical characteristics of long-span suspension bridge. The Shiduhe bridge in Hubei Province was taken as the background of this study, The influence on structure line shape and free vibration characteristics of suspension bridge with the change of structure parameters was studied. The results show that main cable stiffness not only has greater effect on the structure shape of long-span suspension bridge, it also has obvious impact on structure free vibration frequency, in addition, the torsion displacement of stiffening girder can be reduced effectively by adding central buckle, it improves structure bending and torsion stiffness significantly, central buckle also can improve free vibration frequency of structure and enhance structure dynamic stability, It shows that the influencing factors of structure static characteristics are restricted by rigidity of main cable, free vibration characteristics are affected by main cable and central buckle, they are not very sensitive to the variations of the parameters of suspender cable, stiffening girder and main tower.
The Symplectic System for Thermo-Viscoelastic Cylinders
Authors: Zhang Wei Xiang , Liu Qi Xia
Published: May 2011

An exact symplectic approach is presented for the isotropic viscoelastic solids subjected to external force and temperature boundary conditions. With the use of the method of separation of variables, all the general solutions of the governing equations are derived in the Laplace domain. These general solutions are expressed in concise analytical forms, and are easily to be transformed into the time domain. Accordingly, various boundary conditions can be conveniently described by the combination of the general solutions due to the completeness of the solution space. In the numerical example, the whole character of total creep of the viscoelastic solid is clearly exhibited.
Application of Rapid Prototyping Technology in Urban Planning and Architectural Model
Authors: Guo Lin , Xu Ren Ping
Published: May 2011

On the basis of discussing the superiority of architectural model applied in urban planning and architectural design, the defect of traditional architectural model was analyzed, and the theory of rapid prototyping technology was introduced. Architectural model flowchart for urban planning and architectural design based on rapid prototyping technology was put forward. And the realization for the flowchart in computer was also drawn. With two architectural model examples being applied, it was shown that the model based on rapid prototyping technology has great advantages in urban planning and architectural design.
Maximum Local Thermal Effects Carpet Plot for Symmetric Laminated Composite Plates
Authors: Kueh Ahmad Beng Hong , Seh Wai Wai , Shek Poi Ngian , Tan Cher Siang , Tahir M.Md.
Published: May 2011

Maximum local thermal effects carpet plots for symmetric laminated composite plates used in the design and optimization for material under heat loads are produced and demonstrated. The independent variables considered in this paper are the proportions of 0, 45, and 90 degrees ply orientations in the laminates. The carpet plots are presented in such a way that when the failure stress or strain of a composite lamina is known, all possible safe ply orientation proportion can be determined. In addition, the dependency of the carpet plots in correspondence to the temperature change is investigated. It is found that the shapes of both thermal stress and strain plots are practically identical.
Influence of Hollow Electrode Ar-CO2 Injection on Carbon Content in Ladle Furnace
Authors: Zhan Dong Ping , Zhang Hui Shu , Jiang Zhou Hua , Gong Wei , Li Hua Bing , Chen Zhao Ping
Published: May 2011

The argon and carbon dioxide co-injection tests were carried out with low carbon steel melts of 100 kg in a multi-function direct current ladle furnace (DC-LF) equipped with a hollow graphite electrode. It is shown that, the electrode consumption rate and the carburetion rate decrease when Ar-CO2gas mixtures are blown into the furnace. The carburetion rate is 3.6×10-6per minute for the steel heated by conventional LF, and is 1.35 and 3.22 times of the heats blown 85%Ar-15%CO2 and 80%Ar-20%CO2, respectively. The carburetion rate is reduced by 25.8% at least than normal LF. The more the carbon dioxide content in the gas mixtures is, the less the carburetion rate and the electrode consumption rate are. With the increasing of the electrode consumption rate, the carburetion rate becomes bigger.
Mathematical Modeling of Heat Transfer through Clothing System
Authors: Sun Yu Chai , Cheng Zhong Hao
Published: May 2011

Based on fundamental principles of Fourier's law of heat conduction, Newton's law of cooling, Stefan-Boltzmann law and the law of conservation of energy, this paper gave out mathematical equations for description of the general heat transfer process through clothing system, and compares the theoretical results with experimental results. The result of the experiment is in accordance with the theoretical prediction.
Numerical Simulation of Operating Performance of Heat Exchangers in a Residential Split Air-Conditioner
Authors: Su Shun Yu , Tian Tian , Chen Jian
Published: May 2011

The mechanism of fluid flow and heat transfer in the heat exchangers was investigated in this paper. Using R22 as the working fluid, the steady distributed parameter models of condenser and evaporator in a residential split air-conditioner were established based on thermophysical laws such as mass, momentum and energy conservation equations. The regions of two-phase fluid and superheated gas in evaporator and the regions of superheated gas, two-phase fluid and subcooled liquid in condenser were respectively simulated under designed conditions of air-conditioning system. Based on the calculated results, the flow and heat transfer performances of heat exchangers were analyzed. The results show that the two-phase fluid regions in both evaporator and condenser have great influence on the fluid flow and heat transfer performances in it.
Numerical Limit Equilibrium Method of Three-Dimensional Stability for Landslide
Authors: Zhong Wei , Chen Xiao Qing , Yang Tao
Published: May 2011

The three-dimensional model of slop in numerical calculation is established. And high precision eight-node hexahedron element is used to build the finite element grid of slip layer. The slip layer material is simulated by an ideal elastic-plastic model based on the Mohr-Coulomb Criterion. Three-dimensional stress state and slide direction of the slip layer zone is obtained by numerical computation. So, based on the analysis of the three-dimensional stress state of the slip layer zone, in this article, the author defines the point safety factor as the ratio of the shear strength of the slip zone to the shear stress parallel to the sliding direction, and defines the safety factor of the landslide as the average of the zone point safety factor with its zone as weight number. The sliding mechanism is studied through zone point safety factor, and stability of landslide can be evaluated through the safety factor. Sample case shows that the calculated result is in accordance with the actual case.
An Analysis of Seepage Prevention Wall Behaviours of Deep Overburden Dam with Clay Core
Authors: Zhang Bo
Published: May 2011

The Duncan－Chang nonlinear constitutive model is used to carry out a three- dimensional finite element analysis of Xia Ban Di deep overburden dam with clay core (147.95m). The regularity of the change of stress and displacement with the change of material parameters under nine kinds of materials mix proportion is obtained and the optimum analysis result of stress and displacement for the seepage prevention wall is given in this paper.
Wellbore Stability Research to the Direction Well in the Salt Layer
Authors: Wu Hui Mei , Lou Yi Shan , Li Zhong Hui , Zhu Liang , Huang Wan Long
Published: May 2011

The creep of salt layer often leads to tight hole and pipe sticking, while the deviation angle has an important impact on creep rate when drilling directional wells in salt layer. This paper firstly built the creep constitutive model according to the creep property of salt layers, and defined the creep parameters by field data and log data; then built geomechanics model and applied FLAC3Dsoftware to simulate the creep of salt layer, so the safe mud density window drilling the salt layers smoothly is obtained. at the same time, at last analyzed the effect of the deviation angle to the drilling in the salt layer, The conclusion is that when the overburden pressure is major principal stress, drilling mud density is certain, the creep rate increases with the increasing of the deviation angle, the safe mud density also increased, the high deviation angle directional well in salt layers is much more risky. The conclude makes great contribution to the optimizing deviation angle, designing well track and reducing the drilling troubles when drilling directional wells in the salt layer.
Numerical Simulation of Extrusion Pressure of Non-Plug Flow Solid Conveying in Feeding Section
Authors: Liu Chun Hui , Shi Da Li , Wu Yan Yang , Qin Jian Hua
Published: May 2011

According to the theory of extrusion pressure by molding in barrel of the single screw extruder specially designed for pure UHMWPE, extrusion pressure generated during the process must be sufficient while extrusion molding with single-screw extruder. The mathematical model for formation of extrusion pressure in feeding section during single-screw extrusion molding has been established. This paper conducted a research on theory of extrusion pressure which is part of n-lamina model of non-plug flow solid conveying in feeding section by single-screw extrusion molding.
An Empirical Study of Regional Differences of Chinese Construction Industry
Authors: Cui Jin Rong
Published: May 2011

This paper aimed to research the regional characteristic on Chinese construction industry. Depend on Factor Analysis, three factors were extracted from The index of Chinese Construction .Then the factors were explained that it can describe Chinese construction industry .Using these factors, the region scores were calculated. As those scores, the regional differences were dissected.
Impact Property of Concrete Containing Nano-Particles for Pavement
Authors: Zhang Mao Hua , Yu Song Nan
Published: May 2011

Impact property of concrete containing nano-particles (TiO2 or SiO2) for pavement is experimentally studied and compared with that of plain concrete, concrete containing PP fibers and concrete containing both nano-TiO2 and PP fibers. The test results indicate that the impact property of concrete is enhanced when the amount of nano-particles is smaller. However, the impact property of concrete is reduced when the amount of nano-particles is larger. The impact property of concrete containing PP fibers is improved, and the impact property of concrete containing both nano-TiO2 and PP fibers is decreased. There is a significant linear relationship between impact property and flexural strength of pavement concrete.
Influencing Factors of the Fluidity and Strength of Phosphate Concrete
Authors: Wang Hong Tao , Cao Ju Hui , Li Shuang Mei , Xue Ming
Published: May 2011

The influence of water binder ratio, content of borax and fly ash on the fluidity and strength of phosphate concrete were investigated. Results showed that the slump and slump flow of phosphate concrete improved with content of water and borax increasing. But the strength decreased, especially early strength. While the mixing amount of borax was less than 1.5% of the magnesium phosphate cement, the influence on later strength was relatively less. The fluidity decreased significantly and the cohesiveness and water retention improved while the content of fly ash was between 10% and 30%.The compressive strength increased while the content of fly ash was 10%.The better curing methods was curing in the natural conditions, the compressive increased with the age prolonged.
Microstructure of Alkali-Activated Granulated Blast Furnace Slag-Based Geopolymer
Authors: Zhang Yao Jun , Li Hai Hong , Zhao Yong Lin , Wang Ya Chao , Xu De Long
Published: May 2011

The microstructure of alkali-activated granulated blast furnace slag-based geopolymer was studied by means of field emission scanning electron microscope (FESEM) coupled with energy dispersive X-ray analysis (EDXA). FESEM images showed that the geopolymer material has worm-like microstructure in the nanoscale with an average particle size of 20 nm. EDXA results demonstrated that the Na-based and Ca-based geopolymers were produced via the disintegration of amorphous phases and some minerals in GBFS and polycondensation reaction of oxygen-silicon and oxygen-aluminum tetrahedrons under alkaline condition.
Experimental Study on the Mechanical Properties of Q460C Construction Steel at Low Temperature
Authors: Wang Yuan Qing , Lin Yun , Zhang Yan Nian , Shi Yong Jiu
Published: May 2011

Currently, brittle mechanics and designing methods of high-strength construction-structure steel and its weld at low temperature are little studied at home or abroad. In addition, global climatic anomalies bring with extremely low temperature at cold region from time to time in recent winters; therefore it is imminent to research about the rule of the brittle fracture of high-strength construction-structure steel at low temperature. The main mechanical properties of steel are precondition and foundation for its toughness studying. In this paper, uniaxial tensile test of Q460C(14mm at thick), the high-strength construction-structure steel has been carried out at the low temperature to obtaining the intensity index (including yield strength σs, tensile strength Rm), the plastic index (including elongation at break A, reduction of area Z), and the rule of these index along the temperature changing, as well as calculating the Q460C steel’s temperature sensitive coefficient, which may be used to forecast the intensity index of Q460C at low temperature. The experimental data show that: The yield ratio of the Q460C was found to increase with the elongation at break A and the reduction of area Z decreasing while the plasticity and toughness decrease as the testing temperature drops. The result indicates that the Q460C steel is inclined to low temperature brittle fracture, so brittle fracture prevention measures should be strengthened.
Linear Analysis and Strength Prediction of Experiment on Lightweight Heterogeneous Soil Mixed with Expanded Polystyrene
Authors: Sui Xiao Long , He Ming Sheng , Fu Xiao Jian
Published: May 2011

16 groups of compressive strength with different mix proportion of lightweight heterogeneous soil mixed with expanded polystyrene (EPS-soil) has been gained by means of orthogonal test. Regression model is obtained, checked and evaluated by linear regression .48 groups of EPS-soil’s compressive strength is predicted by using strength predictable formula. Results show that: the formula’s precision is high and satisfy the actual need of project.
Fly Ash-Desulfurization Gypsum Mortar and Concrete Part I: Mix Proportions and Hydration
Authors: Chen Yu , Gao Ying Li
Published: May 2011

Fly ash (FA) and flue gas desulphurization gypsum (FGD) were blended in proportion into a new composite binder added with cement, lime and some modifiers. In the paper, the mix proportions of composite binder with low-quality FA and FGD were studied. FA-FGD more than 80% with FA:FGD 3:2 was suggested for mortar, plastering and slurry while FA:FGD 2:1 and FA-FGD 30~40% was recommended for middle-strength concrete. Hydration process of typical mixtures of FA-FGD paste was investigated through SEM and XRD tests. The conclusion could be made that FA showed much improved pozzolana activity especially at early ages due to the existence of FGD as an ideal sulfate activator, which also crystallized later to strengthen the hardened paste. The microstructure of hydrated FA-FGD paste was more excellent than that of neat cement stone or one blended with the same percentage of pure FA.
Mechanical Properties of the Ecological Filling Blocks of the New Composite Wall Based on the Unified Strength Theory
Authors: Huang Wei , Wu Hao Zhen , Chen Guo Xin , Zhang Yin , Wang Jun Yuan , Zhao Dong
Published: May 2011

In order to make the new composite wall structure the group developed to adapt different regional natural conditions, and along with the demand of gradually in-depth study the damage characteristics of the new composite wall, need to research the mechanical properties of the wall filling materials. In this paper, the ZG-CSS Electronic Universal Testing Machine was used on the uniaxial compressive test of the three blocks(the mud billet block, the cotton stalk block, the recycled EPS lightweight concrete block), to analyze the failure characteristics of the blocks and the other mechanical properties, such as Poisson’s ratio, elastic modulus, then the full compressive stress-strain curves are given, and at last fitting the mathematical expression of the uniaxial compressive stress - strain curves. And this paper also gives the yield criterion based on the unified strength theory of the three ecological filling blocks.
Study on Preparation and Dispersion Effect of Polycarboxylate Superplasticizer with Broken Dentiform Structure
Authors: Liu Zhi Yong , Cui Chong , Li Li
Published: May 2011

Based on the analysis of the chemical structure of polycarboxylate-type SPs grafted PEO side chains, as well as sulfonic and carboxylic acid groups, a kind of polycarboxylate-based SPs grafted varied PEO side chains were synthesized by using radical polymerisation techniques.The relative dispersing effectiveness of the SPs was evaluated in cement paste and concrete by measuring paste flow and concrete slumps. The test results indicat that the copolymers with shorter PEO side chains (with 9 and 14 EO units) give lower initial dispersing power but higher time retention,with the prolonging of PEO side chains the higher initial dispersing effect and the lower time retention can be received. The excellent dispersing property and time retention of synthesized SPs for cementious systems can be achieved by grafted long side chain(with 45 EO units) integrated with short side chain(9 or 14 EO) at the backbone of anionic polymer.
Anti-Biofouling of a Novel Cross-Linked Copolymer Containing a HMBA Side Chain
Authors: Wang Qiang , Yu Zhuan Ni , Yu Liang Min
Published: May 2011

Biofouling on underwater engineered structures, especially on ship hulls, results in increased operational and maintenance costs. Fouling is not only of an ecological interest, but it is also important from applied and commercial perspectives. With the development of society, widely used Tributyltin compounds (TBT) for biofouling control have been prohibited worldwide at the end of 2008. The need to develop new environment friendly antifouling agents has been highlighted. Herein we report on the synthesis and characterization of a novel cross-linkable copolymer containing a HMBA side chain. The paper is mainly focused on the synthesis of novel resin and its antifouling performance. Apart from use of acrylate monomer, the two other important monomers γ-methacryloxypropyltrimethoxysilane (HD-70) and N-(4-Hydroxy-3-Methoxy-Benzyl) acrylanine (HMBA) were selected to construct low surface energy materials. Finally, the antifouling properties of resins were carried through by the colonization of benthic diatoms (Nitzschia flosterium) and ocean plates of an offshore platform. Experimental results indicated the novel resins containing a HMBA side chain possessing better antifouling properties than a standard polydimethyl siloxane (PDMS) coating in the Qingdao ocean.
Subject Specific Modelling of Electrical Conduction in the Body: A Case Study
Authors: Lau Howard , Ruys Andrew John , Carter P. , Wang Xiu , Li Qing
Published: May 2011

Modelling of bioelectric phenomena in the human body poses unique problems compared to those encountered in other fields of engineering. Accurate definition of the physical domain and material properties is difficult due to geometrical complexity and uncertainty in tissue characterisation. A workflow is presented for finite element simulation of electric current in the body. This is illustrated through an application on a subject-specific cranial model for simulation of a cochlear implant. Operations required for the full workflow include: data acquisition, image registration and segmentation, material property assignment, numerical analysis, and visualisation. The case study described uses MRI imaging and diffusion tensor MRI for definition of the analysis domain and material properties with analysis conducted in ANSYS. Image registration and segmentation were accomplished using custom designed algorithms. Visualisation was achieved using a 24-bit red-green-blue colour scheme to represent directional vectors.