bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Pretreatment of the Preparation of Bamboo Fiber and its Bleaching Technology
Authors: Li He , Zhou Guo Ying , Zhang Huai Yun , Liu Ya Di , Liu Wen Jin
Published: December 2010

Bamboo fiber is a new natural green environmental protection fiber material with good characteristics of good permeability, unique elasticity, transient absorption, antibacterial, odor resistance and stronger vertical and horizontal intensity. Bamboo pretreatment can improve the biological degumming efficiency of bamboo lignin, reduce microbial degumming time, and reduce production costs. The results show that the removal efficiency of pectin, hemicelluloses and lignin are better after the pretreatment of bamboo mercerization. Through orthogonal experiments, it can be got the optimum combination of bamboo fiber alkali cooking process is A2-B2-C2-D1, namely: concentration of NaOH is 6.0g / L, its time is 60min, temperature 100 °C, and bath ratio 1:20. In these four factors, the greatest impact on the removal of lignin is temperature, followed by is degumming time, then the concentration of alkali, and the bath ratio is the smallest. The best conditions of bamboo fiber bleaching is: hydrogen peroxide 25 ~ 35g / L, temperature 30 ~ 40 °C, treatment 45 ~ 60min. The process of the pretreatment of bamboo is: clip → Roll → high-pressure steaming → roll→ immersion separation → alkali leaching treatment→ scouring → rolling combing →washing→ drying →crude fiber → bleaching.
Longest Cycles Embedding in Faulty Augmented Cube Networks
Authors: Liu Hong Mei , Zhang Yan Juan , Fan Yi Han
Published: December 2010

The augmented cube is one of the most versatile and efficient interconnection networks (networks for short) so far discovered for parallel computation. In this paper, the topological structure of dimensional augmented cube is analyzed. The properties related to cycle embedding in faulty have been investigated. Let denote the set of fault links. This study demonstrates that when , for each nonfault link of augmented cube networks, lies on a longest fault free cycle which contains every nodes of .
Implementation of Mobile CLPR System Based on Smartphone
Authors: Ren Jiang Hong , Han Lu , Gao Shi Yu , Xue Fang Zheng
Published: December 2010

In this paper we propose a prototype of mobile car license plate recognition system for helping user identify car information on smartphone. The research presented here addresses special requirement and challenges in mobile application. The implementation of new architecture and system process flow with functions will help user real-time car image photograph, recognition and identification. We demonstrate the feasibility of this system by experimental results.
A Research on Temperature Dependent Characteristics of Quality Factor of Silicon MEMS Gyroscope
Authors: Feng Rui , Qiu An Ping , Shi Qin , Zhu Xin Hua , Yang Liang , Su Yan
Published: December 2010

The performance of silicon micro gyroscope affected by the quality factor of silicon micro gyroscope is introduced. The temperature characteristics of quality factor of silicon micro gyroscope are also presented. The theoretical analysis suggests that the air damping is the key factor determining the quality factor of silicon micro gyroscope and the quality factor determined by the air damping is in inverse proportion to the square root of temperature. According to the theory, the reciprocal of the quality factor of gyroscope can be approximately expressed as a linear equation with respect to temperature over a temperature range from 238K to 328K. Using the high speed data acquisition card to sample the decayed drive amplitude signal of gyroscope, the quality factor of gyroscope can be calculated from those sample data. The quality factors of gyroscopes at different temperature are experimented in a high accurate thermostat. The experimental results validate the approximate relationship between the quality factor of silicon micro gyroscope and the temperature.
A Kind of Optimal Routing Selection Algorithm of HF Ad Hoc Network
Authors: Wang Xin Hai
Published: December 2010

The characteristic of not easy to be destroyed makes HF communication be widely used in emergency or special circumstance as earthquake relief, military communication and etc. Traditional routing protocols commonly use least hop number as routing selection criteria. In the HF communication network, for its special channel characteristics, in case of poor link quality, the transmission performance of routing whose hop number is less may be poorer than that have more hops. Taking routing quality as selection criteria has become the best choice. Based on analysis on routing quality calculation method of the third-generation HF communication system, the paper brought out a kind of optimal routing selection algorithm of HF Ad Hoc network based on link quality.
Architecture-Specific Mapping Tool for SOI-Based FPGA
Authors: Zhang Qian Li , Yu Fang , Li Yan , Li Ming , Zhao Yan , Chen Liang
Published: December 2010

This paper addresses several key issues in the design of the mapping tool used for the FPGA application implementation in our SRAM-based FPGAs fabricated in a 0.5 micron SOI-CMOS process, with particular emphasis on FPGA architecture interrelated mapping step and packing method for CAD tool. Considering the routability and testability of the FPGA and the CAD tool, the algorithm combines the FPGA structure with the object netlist, mapping the basic elements into basic building blocks in order to reduce the resource usage. The result is proven in extensive test circuits used in our FPGA design.
Verification of Feature Meta-Model Based on Personnel Archive Management System
Authors: Cai Zhen Shan , Zhang Jun Jie , Zhang Zhi Qiang
Published: December 2010

At present, several feature meta-models have been come up with to create domain model. However, they can’t meet the requirements of dynamic Internet environment or software reuse. This paper proposes a feature meta-model based on ontology. In particular, it can adapt to various types of changes in the dynamic environment and can make design and implementation more convenient than traditional methods. Finally, we give out an example of personnel archive management system to verify this model.
Laser Speckle Reduction via Rotating Diffuser in LCOS Projection Display
Authors: Liu Hong , Wang Wei Sheng , Na Bai Lin , Liu Wei Dong
Published: December 2010

Through theoretical analysis the reasons of generating laser speckle, we use an optical scheme for reducing composite speckle in the three LCOS laser projection system. The project of rotating diffuser has a simple optical structure and can be easily implemented. Finally, experimental verification of rotating diffuser plate can effectively suppress laser speckle contrast.
Research on Noise Sources in CMOS Image Sensors
Authors: Han Bao Yuan , Shang Yuan Yuan , Zhao Xiao Xu , Liu Hui
Published: December 2010

CMOS (Complementary Metal Oxide Semiconductor) imagers as a solid state array develop rapidly. This article introduces various types of CMOS image sensors’ noises in detail, the cause of each noise, as well as a brief overview of current methods for reducing different noise.
Anti-Collision Algorithm for RFID Based on Dynamic Packet Query Tree
Authors: Hu Ming Sheng , Lv Guo Ning
Published: December 2010

Based on the analysis of typical binary and dynamic binary search anti-collision algorithm in RFID system, this article proposes a fast and efficient anti-collision algorithm, that is, conduct dynamic packet on tags and adjust query instruction. The performance analysis and experiments show: this algorithm greatly reduces the tag identification time, and increases the identification efficiency of RFID system. At the same time, it reduces information exposure of tags when reader communicates with tags, and effectively decreases the collision probability of tags.
Water Pollution Emergencies in China: Actualities, Prevention and Response
Authors: Wang Xiao Yong , Zhu Geng Shen , Wan Yu Qiu , Zhu Xiao Dong , Miao Xu Bo
Published: December 2010

Significant number of accidental water pollution incidents occurred during the past decades in China, often having transboundary impacts, including the high profile Songhua River toxic chemical spill in November 2005, and drinking water source pollution by algae in the Tai Lake, Wuxi in May 2007. Over half of all river sections monitored for water quality are rated as being unsafe for human contact, and this pollution is estimated to cost several per cent of GDP. If not immediately and effectively controlled, pollution incidents caused by accidental releases or cumulative pollution can worsen water shortages and scarcity problems. The environmental pollution accidents can cause great danger, and there are many potential pollution sources. From the Comparison with the advanced and mature experience by system, mechanism, the article expounds some ideas to improve and strengthen emergency disposal and prevention system for water pollution accidents. It identifies areas for improvement and presents policy recommendations for institutional reform, improving regulations; and strengthening the implementing capacity to maximize the use of existing institutions, regulations and other management resources.
Non-Linear Regression Forecast Model and Learning Algorithm Based on Functional Networks
Authors: Liu Xiang Hu
Published: December 2010

Fitting of forecast function is very difficult and important in non-linear regression forecast problems. The accuracy is directly affected by the fitting of forecast function. Linear model replaced non-linear model in the traditional method is difficult to solve the problem when non-linear is stronger, and the result of fitting and forecast is not ideal. Functional network is a recently introduced extension of neural networks. It has certain advantages solving non-linear problems. Non-linear regression forecast model and learning algorithm based on functional networks is proposed in this article. Example about multi-variable non-linear regression forecast is provided. The simulation results demonstrate that forecast model based on Functional Networks whose accuracy of fitting and forecasting is more than some traditional methods have some value about theory and application.
Improvement on Navigation Behavior Algorithm of Agent in Visual Simulation
Authors: Zhang Yong , Li Cun Hua , Yan Bing Yong
Published: December 2010

In the visual simulation system, especially large visual game or military simulation training systems, the navigation behavior of agent controls movement of agent through a series of actions response to external environment. The combination of multiple navigation behaviors can create complex behaviors of agent. In the current commonly used behavior determination methods, the combination of different behaviors may cause unreasonable result in some circumstance. Based on navigation behavior, the paper brought out an improved algorithm for navigation behavior of agents, which used heuristic method to balance the local and global behavior priority level, so that the selection of navigation behavior is more reasonable.
Using Single-Walled Carbon Nanotubes as Solid-Phase Extraction Adsorbent for the Sensitive Determination of Amino Acid Neurotransmitters in Human Cerebrospinal Fluids
Authors: Zhang Xiao Ling , Yang Qiao
Published: December 2010

Carbon nanotubes are a kind of new carbon-based nanomaterials, which have drawn great attention in many application fields including the biomarker analysis in biomedical and clinical research. In the present study, the feasibility of single-walled carbon nanotubes (SWCNTs) as solid-phase extraction (SPE) adsorbent for the determination of amino acid neurotransmitters (AANs) (glutamic, dopamine and γ-amino-n-butyric acid) in human cerebrospinal fluids (CSFs) was investigated. Various parameters affecting SPE efficiency including the eluent and its volume, adsorbent amount and sample volume were systematically studied. The acquired calibration curves were linear (r2 > 0.999) over the concentration range 10 to 500 ng per injection. By using SWCNTs as the SPE adsorbent, the detection limit of 12.9-42.5 fmol (at S/N of 3) were achieved with the preconcentration efficiency of more than 500-folds. The feasibility of the proposed method was validated by successfully applied to the measurements of ANNs in human CSFs sampled from healthy subjects and the patients with human immunodeficiency virus (HIV) infection, malignant melanoma and hypertension. This original application represents a powerful tool to study the kinetics of ANNs release by neuronal cells during neurotransmission, as well as for the understanding of the pathobiological and therapeutic basis of these remarkable molecular for diverse diseases.
Effect of Surfactants on the Morphologies of ZnO Nanostructures Synthesized by Hydrothermal Method and its Gas Sensitivity to Formaldehyde
Authors: Huang Kai Jin , Yan Li , Xie Chang Sheng
Published: December 2010

Based on the principle of the higher surface-to-volume ratios, the higher formaldehyde gas sensitivity, different morphologies’s ZnO nanostructures have been synthesized by hydrother- mal method using different surfactants including polyvinyl alcohol (PVA), cetyltrimethyl ammon- ium bromide (CTAB), sodium tripolyp hosphate (STPP) and citric acid(CA). The crystal structur- es and morphologies were characterized by XRD and FESEM. The results show that different morphologies’s ZnO nanostructures were induced on the surface of alumina substrate, and the surfactants had an important effect on the morphologies of ZnO nanostructures and then affected the formaldehyde gas sensitivity. The ZnO nanorods with diameters of 100-500 nm and lengths of 200-900nm were obtained using PVA surfactant. The ZnO nanosheets with thickness of about 10nm were obtained using CTAB surfactant. The ZnO nanodisks with two layers and thickness of 5-10nm were obtained using STPP surfactant. The ZnO microspheres composed of thin flakes with thickness of about 10 nm were obtained using CA surfactant. The growth mechanisms of different morphologies’s ZnO nanostructures using different surfactants were given in detail. In addition, the formaldehyde gas sensitivities of different morphologies’s ZnO nanostructures were measured and showed the higher formaldehyde gas sensitivity compared with nano-ZnO without surfactant.
Modeling and Comparative Analysis of Carbon Nanotube and Boron Nitride Nanotube Cantilever Biosensors
Authors: Islam Md. Saiful , Kouzani Abbas , Dai Xiu Juan , Michalski Wojtek P.
Published: December 2010

This paper investigates the bending deformation of a cantilever biosensor based on a single-walled carbon nanotube (CNT) and single-walled boron nitride nanotube (BNNT) due to bioparticle detection. Through 3-D modeling and simulations, the performance of the CNT and BNNT cantilever biosensors is analyzed. It is found that the BNNT cantilever has better response and sensitivity compared to the CNT counterpart. Additionally, an algorithm for an electrostatic-mechanical coupled system is developed. The cantilever (both BNNT and CNT) is modelled by accounting that a conductive polymer is deposited onto the nanotube surfaces. Two main approaches are considered for the mechanical deformation of the nanotube beam. The first one is differential surface stress produced by the binding of biomolecules onto the surface. The second one is the charge released from the biomolecular interaction. Also, different ambient conditions are considered in the study of sensitivity. Sodium Dodisyl Sulphate (SDS) provides better bending deformation than the air medium. Other parameters including length of beam, variation of beam’s location, and chiralities are considered in the design. The results are in excellent agreement with the electrostatic equations that govern the deformation of cantilever.
A Collaborative Filtering Recommendation Algorithm Based on Time Weight
Authors: Dai Yae
Published: December 2010

Personalized recommendation systems are web-based systems that aim at predicting a user’s interest on available products and services by relying on previously rated items and dealing with the problem of information and product overload. Collaborative filtering algorithm is one of the most successful technologies for building personalized recommendation system. But traditional collaborative filtering algorithm does not consider the problem of drifting users interests and the nearest neighbor user set in different time periods, leading to the fact that neighbors may not be the nearest set. In view of this problem, a collaborative filtering recommendation algorithm based on time weight is presented. In the algorithm each rating is assigned a weight gradually decreasing along with time and the weighted rating is used to produce recommendation. The collaborative filtering approach based on time weight not only reduced the data sparsity, but also narrowed the area of the nearest neighbor.
Research on Speaker Recognition Based on Wavelet Analysis and Search Tree
Authors: Gao Bo , Kou Zi Ming , Yan Hong Wei
Published: December 2010

Speaker Recognition (SR) is an important branch of speech recognition. The current speech signal processing in SR uses short-time processing technique, namely assuming speech signals are short-time stationary. But in fact, the speech signal is non-stationary. The wavelet analysis is a kind of new analyzing tool and is suitable for analyzing non-stationary signal, which has achieved impressive results in the field of signal coding. Based on this, the wavelet analysis theory was introduced into SR research to improve the traditional speech segmentation methods and characteristics parameters. In order to speed the recognition, a kind of SR model based on search tree was also brought out.
Calculation Analysis on Cracking Load of New Type Composite Wall
Authors: Huang Wei , Zhang Cheng Hua , Yao Qian Feng , Chen Guo Xin , Wu Hao Zhen
Published: December 2010

New type composite wall is the main bearing member in Multi-ribbed Slab Structure (MRSS), whose cracking load is an important parameter to determine the restoring force model and damage index of the wall. Based on the twin shear unified strength theory, when the influence of intermediate principal stress σ2 and SD effect of materials are considered, the study on low-frequency cyclic lateral loading experiment of wall is proceed and the practical formula for the wall’s initial cracking load is deduced. The practical computing formulas for the wall’s initial cracking load based on twin shear unified strength theory and maximum tensile stress theory are contrastingly analyzed. The results show that, comparing the calculated values based on the twin shear unified strength theory and the values based on maximum tensile stress theory, the former are more closed to the experimental values, and it can provide more accurate, economic and applicable results for practical engineering.
Study on the Durability of Concrete Structure of Aviation Oil Wharf of Shenzhen Airport
Authors: Wang Wei Lun , Zhu Ji Hua , Xing Feng
Published: December 2010

Due to the invasion of chloride ion, the reinforcement in coastal concrete structure is corroded, which causes damage to the concrete structure and becomes the major factor affecting the structure’s service life. Aiming at the existing concrete structure under the coastal environment of Shenzhen City, the durability experimental study has been implemented, discussing the main reason for the insufficient durability of the existing structure. The experiment result shows that the higher chloride ion diffusion coefficient (76.1×10-12 m2/s) in the concrete structure leads that the chloride ion concentration of the structure in the depth of 30mm surpasses one percent upon using it for two decades. The half-cell potential value also reflects the relatively high possibility of the reinforcement corrosion of the structure. Combining with the experiment result, the service life of this concrete structure has been analyzed, which is hard to be guaranteed to use for five decades under the current concrete parameters and resistance.
Finite Element Analysis of Behavior in Semi-Rigid Steel Frames
Authors: Wang Qi , Wang Lai , Jiang Bei , Li Hui , Liu Qing Fang
Published: December 2010

A two-span, three-story steel frame with two web and top-seat angle connections was constructed. Then a low-cycled reverse loading experiment with this frame was conducted to obtain elastic-plastic behavior of semi-rigid connections steel frame under cyclic loading. And nonlinear finite element analysis of steel frame with semi-rigid and rigid connection is performed in this paper. At last, comparisons between the analysis results and the testing results are carried out, the behavior and the effects of the two web and top-seat angles connections on steel frame are analyzed.
Plastic Limit Analysis of Ice Coating Transmission Tower-Line Systems
Authors: Chen Jun Qi , Wang Wei
Published: December 2010

Transmission tower-line systems with different elevations in mountainous areas are established in this paper. The change curve of ice increasing with time was given according to the data of ice record. Considering the influences of height difference, ice increasing, plastic analysis of transmission tower is carried out. It can be concluded that the ultimate bearing capacities of ice coating of the tower is significantly influenced by the elevation of the towers beside it. It also can be concluded that the ultimate bearing capacity of ice coating can be improved only when the section of weakness member is increased.
Displacement Based Seismic Performance Evaluation of Reinforcement Concrete Structures
Authors: Shi Qing Xuan , Wang Qiu Wei , Yang Kun
Published: December 2010

To further understand displacement based seismic theory of building structures, the seismic performance evaluation using capacity spectrum method related to damping is carried out for the reinforced concrete frame-shear wall model structure of a thermal power main plant. By comparing with time-history analysis results, it can be seen that some problems such as equivalence of multi-degree-of-freedom system and value of equivalent damping ratio in capacity spectrum method remains to be further investigated. Force and displacement response of structures and plastic hinges position of all members could be obtained through nonlinear push-over analysis after determining the top displacement; weak parts and damage pattern of structures could also be easily found out by this method. At last, research shows that dynamic time-history analysis can be replaced by static push-over analysis, which is regarded as an exact seismic performance evaluation method by contrast.
Study on the Application of Cooling Pipe in Thin-Walled Concrete Structure
Authors: Wang Zhen Hong , Zhang Guo Xin , Liu Yi , Liu You Zhi
Published: December 2010

Cracks of concrete structure easily appear in the period of construction and the difference between the inside and outside temperature at early stage and the basic difference of the temperature at later stage are considered as the main factors causing cracks, so the temperature control becomes the key of problem. In view of this problem, this paper puts forward the pipe cooling technology which is usually used in the mass concrete to the thin-walled concrete structure. Under the basic theories of concrete temperature field and numerical algorithm of pipe cooling, the 3-D FEM is adopted to simulate the thermal field of concrete sluice with and without cooling pipe during construction. The results of comparison show that cooling pipe in thin-walled concrete structure can achieve better effect on temperature control, so it should have great reference signification to similar concrete projects in the future.
Finite Element Analysis of Vibrating Frequency for Skew Slab Bridge Based on Finite Strip Thought
Authors: Yang Mei Liang , Xia Gui Yun , Zhang Jian Ren
Published: December 2010

Based on the finite strip thought and displacement interpolation function of Bernoulli-Euler beam element, using the transformation relationship between skew coordinate and Cartesian coordinate system, a new kind of thin parallel slab element was established, element stiffness matrix and consistent mass matrix were derived. The vibrating frequency of simply supported skewed slab was calculated. Computing results were compared with theoretical results and Ansys results. The maximum error was 2.68%. Changing the mesh density of skew slab, the convergence of present element was tested. Examples show that this element has the features of high precision and strong convergence. At last, the vibrating frequency coefficients of skew slab bridge with different ratios of span to width were provided, which can be adopted to compute the vehicle’s impact factor of skew slab bridge by specification method.
Prediction Methods for Ultimate Strengths in GFRP Reinforced Concrete Bridge Deck Slabs
Authors: Zheng Yu , Pan Yun Feng
Published: December 2010

The corrosion of reinforcement embedded in concrete bridge deck slabs has been the cause of major deterioration and of high costs in repair and maintenance. Fibre reinforced polymers (FRP) exhibit high durability in combination with high strength and light weight. The majority of research with FRP bars for reinforcing concrete has been on simply supported beams and slabs where the low value of elasticity of FRP has meant that the service behaviour has been critical. These differences have been attributed to the low value of elasticity of many FRPs compared to steel. However, laterally restrained slabs, such as those in bridge deck slabs, exhibit arching action or compressive membrane action (CMA), which has a beneficial influence on the service behaviour such as the deflection. Based on the previous research on CMA in steel reinforced concrete bridge deck slabs, a modified theoretical method were established according to the material properties of GFRP reinforcement. The proposed prediction method showed a good collection of some reported GFRP reinforced slabs experimental tests.
Field Damage Inspection and Static Load Test Analysis of Jiamusi Highway Prestressed Concrete Bridge in China
Authors: Naser Ali Fadhil , Wang Zong Lin
Published: December 2010

The main purpose of damage inspection of the bridge components is to ensure the safety of a bridge and to identify any maintenance, repair, or strengthening which that need to be carried out. The essential damages that occur in reinforced concrete bridge include different type of cracks, scalling and spalling of concrete, corrosion of steel reinforcement, deformation, excessive deflection, and stain. The main objectives of this study are to inspect the appearance of Jiamusi highway prestressed concrete bridge and describe all the damages in the bridge structural components, and to evaluate the structural performance of the bridge structure under dead and live loads. The field tests that are adopted in this study are the depth of concrete carbonation test, compressive strength of concrete test, corrosion of steel reinforcement test, and static load test. According to inspection of the bridge structure appearance, the overall states of bridge structure in good and there are not serious damages, but there are diagonal and longitudinal cracks in the inside web of box girder within block No.8 and 9. Expansion joints suffer from serious damage such as deformation of expansion joint rubber, dislocating, shedding, and cracking. The field test results show that the concrete of the bridge structure has not carbonation; the strength of concrete in good state; there is not corrosion in steel reinforcement; The values of load test for vertical deflection, strain, and stress are less than the theoretical values and the results of cracks observation show that there is not changing in the length of diagonal cracks in the web of box girder when the load test is applied. This indicates that the working state and carrying capacity of the bridge structure in good state.
A New Approach for Bearing Capacity of SRC Columns with Bond Failure
Authors: Wu Kai , Xue Jian Yang , Cao Ping Zhou , Zhao Hong Tie , Yue Jian Guang
Published: December 2010

Bond stress between concrete and shape steel makes both materials cooperate as a whole, but diminished at final stage of loading period. A shear model is established to throw illumination on mechanism of bond failure. Tensile stress in concrete leaded to bond cracks and eventually the bond failure, which is due to the shear passing from concrete to shape steel. A new approach for bearing capacity of SRC columns with bond failure is put forward which based on the equivalent law of shear stress and shear stress distribution of rectangular section for formula derivation, the calculated results are consistent with those of the test.
Experimental Study of Ultimate Bearing Capacity of Hinged Plates with Different Configuration Hinge Joints
Authors: Tang Xian Xi , Xu Yue , Xu Zhi , Li Lei Lei
Published: December 2010

To study the role of vertical shear stress on the ultimate bearing capacity of hinge plates under fatigue loading, and different configurations of hinge joints on ultimate bearing capacity of hinged plates, three groups of hinged plate experiments were studied. Two groups of hinge plates with shallow hinge joint configurations were tested with static loading and fatigue loading respective, a group of hinge plates with deep hinge joint configurations were tested with fatigue loading directly. The ultimate bearing capacity analysis of hinge plates was carried out through mid-span deflection differences of hinged plates on both sides of hinge joints and transverse strains on top and bottom of hinge joints. Shown from the experimental results, for the hinge plates with shallow hinge joints, the ultimate bearing capacity under static load was 342.9kN, and under fatigue load was 340kN, but the ultimate bearing capacity under fatigue load of hinge plate with deep hinge joints was 610kN. Therefore, the vertical shear stress is not the main factor which cause the hinge joints destruction of hinge plates; hinge joints configurations, especially the depth of the hinge joints have great impact of ultimate bearing capacity of hinge plates; in the strengthen checking of hinge joints while hinge plates design, checking the vertical shear strength only is not comprehensive, various factors should be taken into account.
Effects Analysis of Web Cracks on Long-Term Deformation of Large Span Pre-Stressed Concrete Continuous Box Girder Bridge
Authors: Shao Fei , Pan Da Rong , Li Feng , Liu Ya Wen
Published: December 2010

Excessive deflection and its long-term sustainable development has become a common disease of large span pre-stressed concrete continuous box girder bridge, but the causes of it is difficult to reach consensus. A three-spans continuous pre-stressed concrete box girder bridge is studied in this paper. The web inclined cracks near L/4 of the continuous girder bridge is simulated by FEM (finite element method), in order to explore the influences of web inclined cracks near L/4 on the overall deflection of the bridge and the effect differences of the crack width, length and numbers. The results show that when the web inclined cracks reach a certain level, it will cause a long-term sustainable development of the deflection of the bridge. Therefore, web inclined crack is the main factor that causes the sustainable development of long-term deflection of large span pre-stressed concrete continuous box girder bridges.
Study on Influences of Thickness of Flange of U Rib on Mechanical Behaviors of Orthotropic Monolithic Steel Bridge Deck System
Authors: Luo Ru Deng , Ye Mei Xin , Zhang Ye Zhi
Published: December 2010

Orthotropic monolithic steel bridge deck system stiffened by U rib is very fit for high-speed railway steel bridges because of its excellent mechanical behaviors. Thickness of flange is a very important parameter of U rib and has influence on mechanical behaviors of orthotropic monolithic steel bridge deck system. Based on the engineering practice of Anqing Yangtze River Railway Grand Bridge, the kind and the extents of influences of thickness of flange of U rib on mechanical behaviors of orthotropic monolithic steel bridge deck system are studied with finite element analysis. The results show that thickness of flange of U rib has relative large positive influences on rigidity, strength and stability of orthotropic monolithic steel bridge deck system. 14~18mm is the appropriate range of thickness of flange of U rib for high-speed railway steel bridges.
An Analytical Solution for the Elastic Moduli of Concrete with Interfacial Cracks
Authors: Zhou Xin Zhu , Ding Jian Jiang , Zheng Jian Jun
Published: December 2010

Owing to their importance to the assessment of reinforced concrete structures, it is of great practical significance to predict the elastic moduli of concrete with interfacial cracks. The intention of this paper is to present an analytical solution for the elastic moduli of cracked concrete. According to the theory of stereology, the 2D scalar crack density is expressed as an explicit function of the aggregate area fraction and the central angle of interfacial cracks. For uniformly oriented and mutually interacted interfacial cracks, the effective medium method is used to derive the relative elastic moduli of cracked concrete. Based on the numerical results, it is found that the relative elastic moduli decrease with the increase of the aggregate area fraction and/or the central angle of interfacial cracks. It is also found that the relative elastic moduli are independent of the minimum aggregate diameter, the maximum aggregate diameter, and the aggregate gradation.
Measuring and Analysis of Local Stress under Anchorage of Continuous Rigid Frame Bridge
Authors: Wang Wei Feng , Zheng Guo Qing , Zhang Zhi Lin , Song Xiao
Published: December 2010

Under the Large Tonnage Pre-Stress, the stress of concrete which is under the anchor plate is complicated. To ensure the safety of construction and structure, the condition of local stress of the bridge structure should be investigated. When the pre-stress steel of Segment 1# of Pier 1# of Hongwuwo Bridge is tensioned, the strain situation of concrete near the anchor plate of the box girder is measured. The measured value is compared with the analytical value which is obtained through space finite element method.
Experimental Study on SNCF of Welded CHS-CFSHS T-Joints under Axial Loading
Authors: Yang De Lei , Tong Le Wei , Zhao Xiao Lin
Published: December 2010

The initiation position can be predicted by studying on strain concentration factors (SNCF) and SNCF distributions. This paper concerns an experimental investigation of SNCF of welded T-joints composed of circular hollow section (CHS) braces and concrete-filled square hollow section (CFSHS) chords under axial loading on the braces with two load cases of tension and compression. Static experiments were performed on eight test specimens designed for considering different non-dimensional geometric parameters and C50 grade concrete. Compared with joints made of CHS-SHS, the experimental results indicate that the CHS-CFSHS T-joints have lower strain concentration factors which may increase fatigue strength. The position of the maximum SNCF is usually located at 00 or 900 of the intersection line between a CHS brace and a CFSHS chord.
Seismic Performance Evaluation of a High-Rise Building with Lapping Transfer Columns by Shaking Table Tests
Authors: Wang Bin , Jiang Huan Jun , Li Jian Bao , Lu Wen Sheng , Lu Xi Lin
Published: December 2010

The reinforced concrete (RC) frame-tube structure considered in the study has two towers with lapping transfer columns. The lapping transfer columns, considering aesthetic requirement in elevation, lead to a complex vertical force transfer system. The large irregularity in elevation, according to Chinese code, necessitates a detailed study. A 1/15-scaled model of the high-rise building was tested on a shaking table to evaluate its seismic performance. The model was subjected to earthquake inputs representing frequent, basic, rare, and extremly rare earthquakes. The results of shaking table test in terms of the global and local responses as well as the dynamic properties are presented. The tests demonstrate that the designed structural system satisfies the pre-defined performance objectives and the lapping transfer columns have good seismic peformance. To better control seismic damages of the building, some suggestions for improving the design of this structure are also put forward at last.
A Study on Parameters Affect Seismic Behavior of Reinforced Concrete Specially Shaped Columns
Authors: Yang Pu , Tang Jing
Published: December 2010

Using flexibility-based finite element method based on fiber model, several experiments of reinforced concrete specially shaped columns under cyclic loading which cross section is ‘L’, ‘T’ and ‘+’ shape with different longitudinal reinforcement and hoop reinforcement have been simulated, and the seismic behavior of columns such as strength, ductility and energy dissipation are analyzed. Results from the analytical study indicate that: 1) ductility of the column increases as quantity of hoop reinforcement increases. 2) strength capacity of the column increase linearly as ratio of longitudinal reinforcement increase, but is not seriously affected by hoop reinforcement; 3) energy dissipation capacity of the column is not significantly affected by hoop and longitudinal reinforcement, particularly in slightly nonlinear range.
FEM Analysis in Thermal Stresses of Basement Wall and Floor
Authors: Liang De Zhi , Liu Yue
Published: December 2010

In this paper, thermal stresses due to variation of air temperature , surrounding soil elastic constraint and other effects on the basement wall and floor. Though finite element method (FEM )elastic analysis, thermal stresses distribution on the wall and floor to be drawn and qualitative summary of the variation thermal stresses with the change of walls` length and floor`s thickness.
Ansys Analysis of Post-Tensioned Unbonded Prestressed Concrete Board with Open-Hole
Authors: Jin Ling Zhi , Fu Qiang , Cao Xia , Deng Ning , Chen Yi Hu , Chen Min , Wan Xiao Ming
Published: December 2010

Owing to the outstanding advantages of unbonded prestressed technology, it has been widely used in high-rise building floor. However, with the continuous improvement of the function requirements of the building, the boards with openings become more and more common, not only in new constructions but also in renovation projects. These holes will change the mechanical properties of the original floor, and cause stress concentration around the holes easily. This article carries on the simulation analysis by modeling the experimental model using ANSYS software, focuses on the deflection, crack and ultimate load of unbonded post-tensioned prestressed concrete board with open-hole (under uniform load in tensioning and loading stage). After making the comparative analyses to the mechanical behavior and failure mechanism under the different locations of the holes, the simulation results are compared with experimental results, shows that ANSYS can simulate the whole process of loading better, provides theoretical basis for its application and promotion in practical engineering.
Investigating Vertical Load Distribution and Shoring Systems of Reinforced Concrete Buildings during Construction
Authors: Cong Shu Ping , Han Jin Sheng , Liang Shu Ting
Published: December 2010

The loads of reinforced concrete buildings are bore by shores and early age concrete members during construction. In order to analysis the distribution of vertical load between concrete members and shores, the approximate method was developed based on the finite element method and simplified method. According to the process of construction, seven primary structures were brought forward in the approximate method. The coefficients of vertical load distribution between concrete members and shores are confirmed through the finite element method. The loads of concrete members and shores could be obtained conveniently through the distribution coefficients. Three shoring systems (2S, 2S1R and 3S) could be calculated by the approximate method, so the suitable shoring systems for reinforced concrete buildings would be confirmed.
Research on Complex Shear Wall Bending Design
Authors: Fu Xue Yi , Qu Jia Xin
Published: December 2010

Based on reference [1], complex shear wall bending design was researched farther. It was shown that reinforcement partitioned design was belonged to asymmetric reinforcement design method. It might result in the unsafe problem that ‘shear walls were designed as a little eccentric compression member, but failed as a large eccentric compression member’. Then adjusted reinforcement partitioned design method was brought forward. And it was adjusted to symmetric reinforcement design method. Then its unsafe problem was solved. But its uneconomical problem was aggravated. If this uneconomical problem could not be accepted, whole section design method of reference [1] would be suggested.
Physical Filling Effects of Limestone Powders with Different Particle Size
Authors: Wang Yu Li , Wang Wei Dong , Guan Xue Mao
Published: December 2010

Physical filling effects of limestone powders, which are stated by compactness change of mixtures of limestone powders and cement, play an important role in the pore structure and strength of cement stone. The compactness of mixture of limestone powders and cement has been analyzed by the method of wet packing density, tested the void structure of cement stone by mercury intrusion porosimetry(MIP) and strength of cement stone. Effects of limestone powders with specific areas of individually 416m2/kg, 841m2/kg, 1243m2/kg on compactness of cement, compressive strength of concrete as mineral admixture, and pore structure of cement stone were studied when its cement is substituted for the mass proportion of 5, 10, 15% with it. The results show that the compactness of powder mixtures and compressive strength of concrete are biggest, and the improvement of pore structure of cement stone is the best when limestone powder is 10%; the compactness of powder mixtures and compressive strength of concrete are bigger, and the improvement of pore structure of cement stone is better when limestone powder is finer. That is to say, the proportion of limestone powder is the best substitution at 10%; physical filling effects of limestone powder are better when limestone powder is finer from particle sizes. It is important guiding meaning for the application of limestone powder in cement materials.
Investigation into Impact of Column Rectangularity on Shear Strength of No-Stirrup Rc Members in General Shear
Authors: Ren Da , Zhou Chao Yang
Published: December 2010

Based on the links among various shear failure modes and the unified model for beam-like shear and symmetrical punching previously proposed, a new approach is presented to allow for the effect of column rectangularity on the shear capacities of members in general shear, which includes punching and beam-like shear as two particular extremes. In succeeded regression analysis, linear metric form is selected out of practical concern, and a lower-bound design equation is finally developed that can not only measure the influence of this variable on members in general shear, but can give a clear physical explanation to the measurement, as is absent in certain codes.
Effect of Beam Depth and Longitudinal Reinforcement Ratio on Shear Strength of RC Beams
Authors: Yu Lei , Che Yi , Zheng Xin Feng , Gong Jin Xin , Song Yu Pu
Published: December 2010

Seven beams were tested to investigate the effects of beam depth and longitudinal reinforcement ratio on the shear strength of reinforced concrete beams. To investigate the effects of beam depth on shear strength, beams of five different sizes were tested. Two beams were designed to investigate the shear behaviour of beams with small percentage of longitudinal reinforcement. In addition to an experimental investigation, a survey of data in the literature was performed to gain insight into the influence of beam depth and longitudinal reinforcement ratio. Based on test results and a data analysis, conclusions regarding the influence of beam depth and longitudinal reinforcement ratio on shear strength of reinforced concrete beams are presented herein.
Experimental and Nonlinear Finite Element Analysis on Seismic Behavior of SRC Column and Steel Beam Planar Frame
Authors: Li Feng Ge , Zhao Gen Tian , Li Feng Yun
Published: December 2010

Based on experiment of two mixed frame with SRC columns and steel beam under low-reversed cyclic loading, hysteresis behavior, ductility, energy dissipation are studied. The test results show that the mixed frame with SRC columns has better seismic performance. The nonlinear finite element analysis on the seismic behavior of the frame specimen was conducted using Openness developed by the Pacific Earthquake Engineering Research (PEER) Center. The calculated results are much coincided with the tested results.
Numerical Analysis of Lining Temperature Field of Hydraulic Tunnel under the Highway
Authors: Jia Xiao Yun , Lin Bao Long
Published: December 2010

Based on the geological conditions of culvert of the South to North Water Transfer Project, lining temperature field of hydraulic tunnel for crack control is simulated by finite element software—ANSYS. According to numerical analysis results of lining temperature field, considering terrain condition, structural characteristics and climate, some engineering measures are taken during construction. Internal temperature of concrete is controlled effectively, concrete crack caused by temperature changes is solved successfully, and construction quality is assured. The difference of measuring data in-situ and calculating data is very small, which illustrate that calculated model is correct and parameters are reasonable. The results can act as reference for the design and construction of similar projects later.
A Study on the Use of Construction Wastes as Coarse Aggregates on High Performance Concrete
Authors: Ho Chung Ming , Tsai Wei Tsung
Published: December 2010

In recent years, because of rising consciousness on environmental protection and the lacking of construction waste dumping yards, recycling of construction wastes has been promoted extensively. The purpose of this study is to ascertain the effect on properties of the fresh and harden concrete replacing coarse aggregates by construction wastes under ambient and enhanced temperatures exposure. This research mainly concentrates on high performance recycled concrete (HPRC); by adding different amount of superplasticizer into the HPRC and to test and compare its mechanical and thermal properties with general high performance concrete (HPC). Thereafter, tests are carried out determine its compressive strength, residual strength after high temperature and the loss on ignition of the HPRC mixed with two water-to-cement ratios and different replacement proportions of recycled aggregates. Similar tests, such as the slump test and slump flow test, are carried out both on the HPRC and HPC. When the water-to-cement ratio is 0.3 and the amount of superplasticizer added is 1.2%, HPRC has the best performance. The specimens with 100% recycled aggregates were 31% below the control concrete sample in compressive strength at age of 28 days. By the way of adding admixture, the recycled concrete could reach the demand strength of the HPC. The results show that it is feasible to allow a higher replacement percentage of construction wastes for producing concrete products.