bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure and Property of Wear-Resistant Coating Layer by High-Frequency Induction Cladding on Mild Steel Surface
Authors: Yang Li , Li Gang
Published: May 2011

In order to improve the wear resistance of mild steel products, the Fe-based alloy layer was melted on the surface of mild steel by high-frequency induction cladding. Using scanning electron microscopy, energy dispersive spectroscopy and x-ray diffraction observation of microstructure of the alloy coating, wear resistance of the coating was evaluated. The results showed that: between the coating and the substrate is metallurgical bonded; The microstructure of coating layer was compact actinomorphous structure with plentiful nubby and strip eutectics; Actinomorphous structure was mixed structure of martensite and γ alloy solid solution covered with a large number floriform and dendrite eutectic; The coating has high hardness and good wear resistance.
Effect of Spew Fillets on Strength of Single-Lap Adhesive Composites Joints
Authors: Yang Yin Huan , Wu Lin Zhi , Guo Ying , Zhou Zhen Gong
Published: May 2011

Tension tests on T700/EXOPY unidirectional laminates single-lap joints of spew fillets at overlap ends under uniaxial tensile loading are performed in the presented paper. Two different types of joints are designed and analyzed in order to study effect of spew fillets and no spew fillets at overlap ends on strength and failure mode of single-lap adhesive joints. According to the results, failure mode of two joints are characterized and analyzed. Shear stress—strain curves are analyzed and compared. At the same time, a finite element simulation is carried out to analyze the peel/shear stress fields inside the joint interface. It is found that joint strength was much affected by spew fillets in overlap ends. Nerveless, joints strength is decreased with the increasing thickness of spew fillets in overlap ends. The computational results are in good agreement with the experimental values.
Optimal Design Method for Piezoelectric Sensors/Actuators Configuration
Authors: Yao Jun , Wu Yan Fei , Wang Huan
Published: May 2011

In the active vibration control field, the piezoelectric element was extensively researched with the advantages of wide response frequency band, light weight, big driving force and good linearity, but they were mainly focused on the vibration suppression for smart structure and the study on the piezoelectric element used as excitation source in the vibration test was still limited. First, according to the electromechanical coupling equation of the piezoelectric material, the piezoelectric equation when the piezoelectric ceramic applied on the one-dimensional structure like beam was derived. Then the transfer functions from piezoelectric actuator to the piezoelectric sensor were established in cases of micro-element and limited size. The quasi-independent modal control method for piezoelectric beam was studied, which made several step modals being controlled by one group of piezoelectric film simultaneously is possible. And based on this, an optimal design method for placement of sensors/actuators in the vibration test in which the piezoelectric element was used as excitation source is found.
Study on the Effect of Functional Monomer on the Binding Characteristics of Molecularly Imprinted Polymer
Authors: Rong Fei , Fu De Gang , Wu Wei
Published: May 2011

Three kinds of molecularly imprinted polymers (MIPs) were prepared with S-naproxen as template molecule, and methacrylic acid, acrylamide, 4-vinyl pyridine as functional monomers, respectively. The interaction between template molecule and different monomers were analyzed by UV spectra. Binding experiments and Scatchard analysis were adopted to compare the binding characteristics of MIPs. The results showed that the MIP based on 4-vinyl pyridine possessed the highest adsorption amount of 1.73 μmol for the template molecule, while the MIP based on methacrylic acid presented the lowest binding characteristic, which correlated positively with the interaction strength concluded by UV analysis.
Synthesis, Properties and Application in Optical Memory of a New Type Diarylethene with Benzene Ring
Authors: Yan Pei Jian , Cui Shi Qiang , Pu Shou Zhi
Published: May 2011

A new type photochromic diarylethene, 1-(2-ethylbenzo[b]thiophen-3-yl)-2- (2-methylphenyl)perfluorocyclopentene (1o), was synthesized, and its photochromic and fluorescent properties were investigated. This compound exhibited reversible photochromism and notable fluorescence photoswitches both in solution and in PMMA films. In addition, the fluorescence spectra of diarylethene 1o evidently depended on the concentration in hexane. Using diarylethene 1c/PMMA film as recording medium, optical recording was carried out successfully.
Research and Characterization of Water and Oil Repellent Finishing Auto Interior Materials
Authors: Du Zhao Fang , Cheng Xian Sheng , Huang Fu Rong
Published: May 2011

The treatment of resist water and oil by low-temperature plasma technology for recycled polyethylene terephthalate(PET)fiber automotive interior carpet was studied.The best process conditions were optimized:low-temperature plasma processing power was 150W,vacuum was 30Pa, time was 10 min,perfluorooctylsulfonyl amide(C8H2F17NO2S)monomer concentration was 15%.With angle measurement instrument,scanning electron microscopy and infrared spectroscopy,the performance of PET interior carpet on the condition of optimum process was tested and analysed.The result showed:there was cross-linked esterification between C8H2F17NO2S monomer and PET molecules,some C-F groups with low surface energy appeared on the fiber surface.Namely, C8H2F17NO2S monomer was effectively grafted onto the surface of PET fiber.The PET interior carpet had a better effect on resisting water and oil.
Effects of Thermomechanical Treatment Process on the Microstructure and Properties of Al-Zn-Mg Alloy
Authors: Cai Gang Yi , Yang Yu Yong , Li Xiao Hua
Published: May 2011

The mechanical properties of Al-Zn-Mg aluminum alloy were improved by deformation strengthening and transformations strengthening adopting thermomechanical treatment, whose process are solution treatment, preageing treatment, deformation treatment and ageing treatment in turn. The paper focuses on the influences of deforming degree and ageing process on microstructure and properties of Al-Zn-Mg aluminum alloy. The experimental results show that hardness increased with increasing deformation ratio, and the value are greatly higher than that of samples after solution treatment. The results of ageing after deformation show that the hardness enhanced with prolonging the ageing time, which reach the peak value at 16 hours. In addition, the microstructure became more homogeneous and the grain was refined obviously by metallography microscope observation. The second phase precipitate dispersedly to strengthen the alloy. Above all, in order to obtain the better mechanical properties, the optimal thermomechanical treatment processes are solution treatment at 470°C for 2h, preageing treatment at 140°C for 24h, deformation with ratio of 40% as well as ageing at 120°C for 16h.
Microstructure Control of Co-Base ODS Alloys
Authors: Takezawa Kazuhiro , Ukai Shigeharu , Hayashi Shigenari
Published: May 2011

As high-temperature metallic materials, Co-base ODS alloys were produced by means of mechanical alloying, spark plasma sintering and hot rolling. Co-3wt%Al-1.2wt%Hf-ODS alloy was found to be an attractive composite like material, which is formed by spinodal like decomposition. The metastable phases were traced by hard phase containing dense oxide particles and soft one containing less oxide particles. Their tensile stress at 1,000 °C was improved by Hf addition that forms Y2Hf2O7 type oxide particles and shortens their space distance.
Facile Synthesis of Benzyl Alcohol Type Hypercrosslinked Resin
Authors: Jin Qiu , Xie Pu Hui , Zhao Lin Xiu , Bai Ling Ling , Yuan Si Guo
Published: May 2011

A kind of novel hypercrosslinked resin containing hydroxymethyl group was firstly synthesised via chloromethylation of benzyl alcohol monomer and succedent Friedel- Crafts alkylation polymerization. The structure and micromorphology of the resin was characterized with BET, IR and elemental analysis. The results indicated that the novel polar adsorption resin possess high specific surface area (525.00m2/g) and abundant micropore structure (average pore diameter: 1.123nm), and could be anticipated having a potential application in the fields of solid phase synthesis, separation and adsorption.
Study on Dynamic Heat-Moisture Comport Properties of Moisture Transported and Dry-Fast Fiber
Authors: Yang Kai , Jiao Ming Li , Hu Luo Yan
Published: May 2011

A series of experiments was performed on studying the dynamic heat and moisture transferring procedure and evaluating heat-moisture comfort properties of functional moisture transported and dry-fast fiber in wearing conditions that produce continued sweat. Experiments were performed in two different environmental conditions, which were the most comfortable condition and an extremely uncomfortable condition for humans. The real time changes of temperature and relative humidity in inner and outer surfaces of different fiber fabrics were measured using self-made textile-microclimate measuring instrument. Then, fabric’s comprehensive heat-moisture comfort properties were obtained. Results show that fine denier polypropylene fiber as a newly moisture transported and dry-fast functional fiber has better heat-moisture comfort properties than other conventional fibers, and it is more suitable for sportswear fabric.
Screening Test of Phosphoric Acid-BTA Slurries for Copper ECMP Based on Static Inhibition Efficiency
Authors: Zhai Wen Jie , Yang Yang Zhan
Published: May 2011

An ECMP slurry screening protocol is proposed based on inhibition efficiency of inhibitor in copper static corrosion test, aiming at enhancing the planarization efficiency of copper ECMP slurries. The elctrochemical properties of copper in electrolytes including H3PO4 and BTA with different concentrations are studied basing on Linear Sweep Voltammetry (LSV) and chronoamperometry under static corrosion states. According to analysis of the anodic current, material removal rate (MRR) and inhibition efficiency of BTA, an electrolyte formula of 30 wt% H3PO4+0.01M BTA is sort out and the anodic potential on copper should be set below 0.5 V.
Solid-State Polymerization of 2,5-Dibromothiophene Derivatives and Properties of Corresponding Conducting Polymers
Authors: Chen Shu Ai , Xu Jing Kun , Lu Bao Yang , Duan Xue Min , Kong Fang Fang
Published: May 2011

Conducting polymers poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-ethylenedithiathiophene) (PEDTT) have been synthesized by solid-state polymerization of 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) and 2,5-dibromo-3,4-ethylenedithiathiophene (DBEDTT) respectively in air and under vacuum. Both polymers were completely insoluble in common organic solvents and retained partial crystal structure of monomers as indicated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. Thermoelectric tests showed that PEDTT exhibited Seebeck coefficient about 120 µV K−1 at 170 K, which is higher than PEDOT, while the later exhibited higher electrical conductivity (0.1S cm-1 at 298 K) and better thermal stability indicated by the thermal analyses. These results showed that replacement of oxygen by sulfur in the monomer structure played an important role on the properties of polymers.
Study on Mechanism of NC Sheet Metal Incremental Forming
Authors: Zhou Liu Ru
Published: May 2011

The principle of NC incremental sheet metal forming process as well as the experiment of cone forming are presented. Because the deformation of sheet metal only occurs around the tool head and the deformed region is subjected to stretch deformation, the deformed region of sheet metal thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheet metal deformation. The experiment results show that in the case of the parallel line type tool path, a uniform thickness of the deformed region is maintained and in good accordance with that obtained by the sine law. It is found that success in the forming depends on the forming half-apex angleθof the truncated cone. It can be obtained that NC incremental sheet metal forming process is a plane deform process and conforms to the sine law, i.e.t=t0 sinQ.
The Wear Behavior of Electroless Ni-P/SiC Composite Coating
Authors: Yang Gui Rong , Song Wen Ming , Sun Xian Ming , Ma Ying , Lu Jin Jun , Hao Yuan
Published: May 2011

The Ni-P/SiC composite coating was prepared by chemical deposition technique. The micro-structure and wear behavior of electroless Ni-P/SiC composite coating was investigated. The results show that the composite coating was dense and no any defects at the interface between substrate and electroless composite coating. Its thickness could reach 40 μm. Wear resistance was increased with the increasing content of SiC particles for single composite coating when the SiC concentration was less than 6g/L, then decreased with the increased SiC concentration. The wear resistance of gradient composite coating was improved above 16% comparing with the single composite coating. The wear resistance of T1 gradient coating was best for all electroless Ni-P/SiC composite coatings because the bonding strength was improved owing to the gradient change of SiC content.
Investigation of Phase Composition and Microstructure of the FeAl/Al2O3 Composites Fabricated by Mechanical Alloying Process and Pressureless Sintering Process
Authors: Jiang Tao
Published: May 2011

The FeAl/Al2O3 composites were fabricated by pressureless sintering process. The FeAl intermetallics compounds powders were fabricated by mechanical alloying and heat treatment process. The FeAl intermetallics compounds powders and Al2O3 powders were mixed and the FeAl/Al2O3 composite powders were prepared. The FeAl/Al2O3 composites bulks were fabricated by pressureless sintering process at 1600°C for 2h. The phase composition and microstructure of FeAl intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition and microstructure of the FeAl/Al2O3 composites sintered bulks were investigated. The XRD patterns results showed that the Fe-Al intermetallics compounds powders were fabricated by mechanical alloying for 60h. The FeAl intermetallics compounds powders were fabricated by heat treatment at 800°C, 900°C and 1000°C. The microstructure showed that the mean particles size of the FeAl intermetallics compounds powders produced by mechanical alloying and heat treatment process was rather fine and about 4-5μm. The XRD patterns results showed that there existed the FeAl phase and Al2O3 phase in sintered composites. The FeAl/Al2O3 composites bulks exhibited the homogenous and compact microstructure. The mean particles size of FeAl was about 4-5μm and the mean particles size of Al2O3 was about 5-10μm. The density and relative density of the FeAl/Al2O3 composites increased gradually with the increase of FeAl content.
Characterization of Fe-C Alloy Film Optical Fiber Corrosion Sensors by Fractal
Authors: Cai Li Hua , Li Wei , Fang Hai Feng
Published: May 2011

The optical fiber corrosion sensor was applied to measure the steel corrosion based on Fe-C corrosion-sensitive metal film, the sensing principle of which was introduced. Because corrosion was a complex random phenomenon and the corrosion surface of Fe-C alloy film of the optical fiber corrosion sensor possessed fractal characteristics, the image fractal dimensions was as a quantitative index of the sensor corrosion degree. The experimental results showed that the complexity level of the sensor surface morphology increased and the optical output power increased along with the increase of fractal dimensions. Therefore, a new method was provided for the research of the optical fiber corrosion sensor.
Effect of ECAP on the Electrochemical Behavior of Chromium Bronze
Authors: Zhang Ya Ni , Xu Chang Zheng , Zheng Mao Sheng , Zhu Jie Wu
Published: May 2011

The effect of equal channel angular pressing (ECAP) process on the electrochemical behavior of chromium bronze in NaCl solution was investigated by three-electrode cell setup. The result shows the difference of electrochemical behavior between X plane and Y plane is still exist, and even in the unodd number passes for “route C” of ECAP process. ECAP process don’t change the corrosion nature of chromiun bronze, but the corrosion potential of 12 passes ultra-fine grain (UFG) chromium bronze is a little more positive than that of 0 pass chromium bronze. For better understanding the effect of ECAP on the electrochemical behavior of chromium bronze, we chose the cold-rolled materials with the same composition as reference materials. The result shows that ECAP process is more benefical to electrochemical behavior of chromium bronze than cold-rolled process. On the other hand, the result of EIS also shows that ECAP process is more benefical to form compacted corrosion layers on the surface of specimens.
Study of Anti-Aging Properties of Aerodrome Oil-Depots Camouflage Paint
Authors: Sun Shi An , Fei Yi Wei , Xiao Yun Peng , Yang Hong Wei , Zhang Shan Shan , Zong Zhi Min
Published: May 2011

Two camouflage paints were developed respectively on the surface of concrete and metal surface for getting high weather resistance. Different materials and their ratios especially those used in anti-aging agents, pigments and fillers were studied. Results indicated the prepared compound formula could significantly improve the properties of camouflage paints. The useful lives of products were extended and could meet the requirement of military.
Study on the Wear Resistance of Cast-Oozing Different Content of WC
Authors: Wang Ai Qin , Wang Shu Li , Xie Jing Pei
Published: May 2011

In this paper, the WC and high-Cr Cast Iron layer were obtained on the surface of ZG30Cr steel by casting-penetrating process, the organization and wear properties of penetrating layer were studied. The results show that the layer is dense, without pores, slag and other defects, the penetrating layer and substrate are metallurgical bonding. When 20 %WC and 80 % Cr-Fe with are added to permeability agent, the penetrating layer has the best wear resistance, is 11.3 times the matrix materials.
Sintering Temperature Effect on Ferroelectric and Piezoelectric Properties of Lead-Free Piezoelectric (K0.5Na0.5)NbO3 Ceramics
Authors: Cheng Chien Min , Kuan Ming Chang , Chen Kai Huang , Shih Chia Chi , Jiang Jiann Sheng
Published: May 2011

Lead-free potassium sodium niobate ceramic, with the nominal composition of K0.5Na0.5NbO3, were synthesized by conventional solid state sintering, and its dielectric, ferroelectric, and piezoelectric properties were characterized as a function of sintering temperature. The orthorhombic to tetragonal phase transition (TO-T) temperature of K0.5Na0.5NbO3 ceramic sample was about 220°C, and its Curie temperature was about 420°C. The high bulk density was obtained for all compositions by solid state sintering in air. Bulk density was increased with temperature and it reached to 4.4 g/cm3. The K0.5Na0.5NbO3 ceramic sample sintered at 1100°C was optimized densification properties. In addition, the ferroelectric loop and dielectric characteristics dependence of different sintering temperature for K0.5Na0.5NbO3 ceramic sample was obtained. Finally, we found that the piezoelectric constant (d33) was 160 pC/N, high remanent polarization (Pr) was 33mC/cm2, and high electromechanical coupling coefficients (kP) was about of 45%.
Optimal Design for Prestressed Structures Based on Continuous and Discrete Variables
Authors: Yang Yong Hua , Wu Jie
Published: May 2011

The mathematical model of optimal design for prestressed structures is established and a two-level algorithm based on hybrid variables is proposed. At the first level, the prestressed forces are chosen to be the design variables and the optimal design for prestressed forces based on continuous variable is carried out. At the second level, the cross-sectional areas are chosen to be the design variables and the discrete sizing optimization is carried out under fixed prestressed forces, the local constrains are satisfied with one-dimensional search algorithm, the integral constrains are satisfied with the relative difference quotient algorithm, and the efficiency of the relative difference quotient algorithm is greatly improved by introducing the assumption of statically determinant structures. The numerical example shows the correctness and effectiveness of the method.
An Investigation on Flexural Behavior of Reinforced Concrete Beam with Textile
Authors: Yin Shi Ping , Xu Shi Lang
Published: May 2011

The textile reinforced concrete (TRC) member has no distinct failure symptom when it arrives at its ultimate load. At the same time, ordinary steel-reinforced concrete (RC) elements have large dead weight and can not efficiently restrict the expansion of the main crack of structures. In order to overcome the above disadvantages, a new architecture reinforced with a combination of the textile and steel bar was presented in this study. The analytical formulae of the proper beam using this new structure were derived, including the load-carrying capacity at different stages and load vs. mid- span deflection relationship during the entire loading process. The theoretical values were compared with the experimental values. It is shown that the theoretical values coincide with the experimental values well and the feasibility of the formulae is verified.
Nonlinear Finite Element Stress Analysis on the Interior Steel-Concrete Composite Beam Joints
Authors: Shi Qi Yin , Wen Long Wei , Mao Peng Fei
Published: May 2011

Nonlinear 3D finite element models (FEM) of the two kinds of joints, namely steel bars headed through the pipe joint and steel bars welded with the upper strengthened ring joint, are established by using the ANSYS program. By choosing the suitable element type, boundary condition and loading regime, the author made intensive study on the stress distribution of the steel tubular, the concrete, the strengthened ring and the bar. The result shows that the finite element model accords with the actual stress situation of the joint. Holes on the steel tubular have little effect on the bearing capacity of the axial load of the joint, but the greater impact on the shear transfer.
The Seismic Performance of Single Beam String Structure
Authors: Nie Yun Jing , Li Tie Ying
Published: May 2011

The modal analysis is performed on the single beam string structure in a practical project in this paper. Then the response history analyses, under the four different earthquake-induced ground motions in the single direction, are implemented on the structure. The analysis results indicate that it is very necessary to install out-of-plane bracings for the single beam string structure. In the design of similar structures, the section dimensions of the struts can be appropriately reduced due to the average stresses of the struts being smaller, and cross beams near the middle of structures are be given attention. And the analysis results provide a reference for the seismic analysis and design of similar structures.
Simulation of Electric Heating Prestressed Concrete Component
Authors: Jiang Yin Jun , Zhu Yong Hua
Published: May 2011

Because channel quality defects of post-tensioned prestressed concrete construction cannot be discovered on time, an electric heating method is put forward to produce effective detection. The results of the numeric simulation on the temperature field of a prestressed concrete component show that the electric heating infrared detection method, for its energy consumption, efficiency and safety, is feasible for detecting the channel quality of prestressed concrete component, but the electric current needs to be controlled to avoid high temperature which affects the physical and mechanical properties of the strand and the concrete.
A Caculation Method Discussion of Vertical Bearing Capacity on End Post-Grouted Drilled Piles
Authors: Liu Jie , Zhang Yan Yan
Published: May 2011

This article establishes a circular truncated cone model of the post-grouted induration end,brings forward a integrative influence coefficient and edtablishes a simple vertical bearing capacity caculation formula of post-grouted piles with the broaden diameter caculating the end resistance of the pile, which has considered the influence of mortar volumn.According to a certain number of engineering experiment,the tesults derived from this formula can fit the static loading test bearing capacity of the post-grouted drilled piles well,which can provides a certain engineering practical reference value.
FEM Research on Static Mechanical Performance of Twice Prestressed Composite Curved Beam
Authors: Wei Fang Fang , Wang Jin Bo , Zou Ben Wei , Sun Hao
Published: May 2011

The conception of twice prestressed composite structures (TPCS) was proposed in order to solve great distortion problems in prestressed concrete structures. Through decomposition of the total prestress, we define the 1st stage as one part of the prestress acting on a prefabricated beam, and the 2nd as the other part on a post-pouring structure. This kind of structure could substantially decrease its distortion and enhance the efficiency of prestress, at the same time contributing to flexibly laying the prefabricated concrete. A continuous curved prestressed concrete box girder bridge was modeled with the FEM software ANSYS, taking into account the ordinary steel and prestressed losses. The aim is to analyze the deformation, stress performance, the impacts of the primary prestressed force value on the anti-deforming performance as well as bearing load performance of the twice prestressed composite curved beam. The conclusion could provide a basis for the application and promotion of the structure.
Mechanical Properties of Reinforcement Construction Waste in Base Cource
Authors: Zhang Tie Zhi , Wang Li Jiu , Sun Dan
Published: May 2011

Waste concrete, broken bricks, mortar were very good renewable resources. 6 mix proportions were designed with construction waste after sieved and broken, and fiber was added to increase its crack-resistance. It was examined that the mechanics indexes of the cement stable construction waste mixture would change under different aggregates combination and different the proportion by experiment. it was found that the mechanical characteristics and functions varied because of various aggregates, and the regular pattern was also found different aggregates combination and different proportion influence mechanical characteristics of cement stabilized construction waste mixture.
Experiment on the Crack and Deflection of Basalt Fiber Reinforced Concrete Beams
Authors: Wang Jun , Ye Huan Jun , Sun Zhi Wei , Chen Wei
Published: May 2011

In order to research the influence of basalt fiber on the crack and deflection of the reinforced concrete beams, four basalt fiber reinforced concrete beams with the key parameters of length which were 12mm and 30mm and volume ratio which were 0.1% and 0.2% were designed and made. The test data was obtained through the bending experiment and the comparison with the common reinforced concrete beam. The result shows that it is obvious to control the crack and deflection of the test beams with the increasing of basalt fiber characteristic parameters. The calculation method of the maximum crack width of the basalt fiber reinforced concrete beams were presented based on the method of common concrete beam, which can provide the theoretical basis for the engineering practice.
Experimental Study of Deep Alluvium Boring Shaft Lining Used Super Strength Steel Fiber Concrete and Double Steel Plate
Authors: Wang Xiao Jian , Cheng Hua , Yao Zhi Shu , Cai Hai Bin
Published: May 2011

The article proposes boring shaft lining used super strength steel fiber concrete and double steel cylinder to solve the problem of the construction of shaft lining in deep alluvium of 700~800m, and studies the mechanical characteristics and failure of the shaft lining structure based on the model testing. The studies indicates that boring shaft lining structure used super strength steel fiber concrete and double steel cylinder may greatly improve the capacity of the shaft lining, the ductility of common high strength concrete shaft lining, obtains good plastic characteristics and upgrades the reliability of the shaft lining structure. In addition, strengthening coefficient of super strength steel fiber concrete based on theoretical analysis and experimental results, providing the design references for the engineering application of the new type shaft lining structure.
Finite Element Analysis for Cyclic Behavior of Exposed Type of Column Bases Subjected to Tensile Force
Authors: Jin Gui Yan
Published: May 2011

This paper presents the results of analytical studies on exposed type of column bases, which were carried out to investigate the effect of tensile force on cyclic behavior of column bases. The cyclic behavior of the column bases subjected to tensile force ratio n > -0.4 is stable. While, in the column bases subjected to tensile force ratio n < -0.6, the deformation of base columns progresses with increasing severely under a constant amplitude.
Slipping Effects of Simple Combination Beam under the Action of Negative Bending Moment
Authors: Zhang Xu Hong , Wu He , Cao Jian Ping
Published: May 2011

A numerical study on slip effect of simply supported composite beams under negative bending moment is conducted by means of finite element program of ANSYS based on the feasibility verification of ANSYS. The research contents include: slip distribution rules; slip effect on deflection in service stage and ultimate bearing capacity; relationship between slip effect and shear connection、lognitudinal percentage of reinforcement and working behavior of composite beams with partial shear connection under negative bending moment .
Finite Element Model Updating of Space Grid Structures
Authors: Xiao Tian Yin , Han Jian Gang , Gao Hong Bo
Published: May 2011

The aim of updating models is to generate improved numerical models which may be applied in order to predict actual dynamic behaviors of the structure. The approach of numerical predictions to the behavior of a physical system is limited by the assumptions used in the development of the mathematical model. Model updating is about correcting invalid assumptions by processing vibration test results. Updating by improving the physical meaning of the model requires the application of considerable physical insight in the choice of parameters to update and the arrangement of constraints, force inputs and response measurements in the vibration test. The choice of updating parameters is the most important and the numerical predictions should be sensitive to small changes in the parameters. So methods used in model updating places a demand that the mass, stiffness and damping terms should be based on physically meaningful parameters. Using the structure frequency and local modal shape acquired from structural time-history responses, a model updating method of space grid structures was established in this paper. A numerical example is provided to prove the accuracy of this method. The results show that the method can be effectively used to correct the finite element model of space grid structures.
The Combined Application of Intermittent Strengthening Strip and After-Irrigation-Strip in Certain Long Concrete Structure
Authors: Yang Shu Juan , Ji Sheng Min , Ding Lu Yao , Yu De Hu , Sui Tao , Du Ying Hao
Published: May 2011

Long concrete structure is frequently used in modern buildings or structures. As the main measures of achieving seamless construction and crack control of long concrete structure, strengthening strip and after-irrigation-strip have been widely applied. However, compared with after-irrigation-strip, the clear advantage of strengthening strip is closure ahead. Therefore, this paper from aspects of theoretical analysis and engineering application replace the after-irrigation-strip with intermittent strengthening strip in one original design of a project. Since the completion of construction, there are no harmful cracks in the structure. This article also describes the project quality control measures and technical and economic analysis for the design and construction of similar projects.
Effects of Residual Stress on Bearing Capacity of Cold-Formed Thin-Walled Steel Members with “л” Section under Axial Compressive Force
Authors: Gong Wan Ting , Yang Rong , Liang Zong Min
Published: May 2011

In order to enhance the pertinence of agriculture building design, the experiment and numerical simulation on cold-formed thin-walled steel members with “л” section under axial compressive force were conducted to investigate the effects of residual stress on bearing capacity of them. For the members, there are inevitably initial defects, such as initial bending, initial eccentricity and residual stress due to the manufacturing error. In the numerical simulation, initial bending and initial eccentricity of the members were considered. The results show that the residual stress affects instability forms of the members. And as the member slenderness ratio increases from 69 to 200, the bearing capacity of member with residual stress decreases from 12.8% to 84.9% of that without residual stress.
Consideration of Improving Earthquake Resistant Capacity of Earth Buildings
Authors: Zhang Bo
Published: May 2011

Earth building is one kind of residential buildings with typical characteristics of materials used locally, natural existence, reasonable construction and low cost in Hanzhong country, and it includes wisdom of working people, and contains plentiful ecological concept, previous architecture experience. The major defect is its low anti-seismic performance, suggestions improving the earthquake resistant capacity of raw-soil structures are put forward from the aspects of enhancing strength and connection, and the preferences for the socialist new rural construction after seismic disasters are provided in the end.
Stiffness Analysis on Semi-Rigid Joints in Gabled Frames
Authors: Wang Yu , Liu Yong Jun , Xu Ya Feng
Published: May 2011

At present, the structure of gabled frames is the most extensively-applied structure in the single-storey industrial building and long-span single-storey buildings. The joints of corner are main connecting part of gabled frames, of which the performance directly affects the integral behavior of its structure subject to load. At the same time, the construction of joints also determines its features of the semi-rigid stiffness. In this article, numerical simulation and experimental research are conducted to investigate semi-rigid connection of corner joints in gabled frames with different height-thickness ratios of beam-column web, width-thickness ratios of flange, and height-width ratios in corner joints. The three-folder-line moment-rotation relation model has been established and the expression concerning moment-rotation relation obtained.
Dynamic Response of Damped Outrigger System for Frame-Core Tube Structure under Earthquake Loads
Authors: Xu Ze Yao , Lin Qian , Zhang Jian Lin
Published: May 2011

The novel passive energy dissipation system named Damped Outrigger System for frame-core tube structure is introduced in recent years, in which the outrigger and perimeter columns are separate, and the vertically acting fluid-viscous dampers connect the end of each of the outrigger walls to the adjacent perimeter column. In this paper, a new simplified model of this structure is studied by considering the damping force and shear stiffness of the core tube and lateral stiffness of the frame with finite element method. The shear correction factor is also employed to consider the shape of the core tube cross section. The numerical example shows that the displacement and the inter-story drift of the structure are reduced effectively under earthquake loads. It means that the damped outrigger is an innovative solution to resisting earthquake loads for frame-core tube structure.
Beam-to-Beam Impact Behavior of Reinforced Concrete Frames under Severe Ground Motions
Authors: Huang Guo Hui , He Zheng
Published: May 2011

The beam-to-beam impact behavior during the progressive collapse progress of reinforced concrete frame structures under severe ground motions is studied in which three types of impact are included, i.e. 1) contact-impact between one-end failed active beam and intact passive beam; 2) contact-impact between two-end failed active beam and intact passive beam, and 3) contact-impact of one-end failed active beam and one-end failed passive beam. As the first step, the initial impact conditions are established based on the principles of the kinematics and the structural dynamics. Then, the velocities of the beams at the impact instant and the locations of the impact would occur are derived. A so-called impact mass factor is introduced in the paper and determined through the principle of equivalent energy. The history of contact force between the beams involved in the impact is evaluated by the Hertz-damp model. The responses of the passive beam are calculated by solving the equation of motion of a generalized single degree of freedom system.
Research on Behaviour of a Pre-Stressed Suspended Lattice Shells Subjected to Fire Load
Authors: Xie Zhi Guo , Wang Xin Tang , Zhou Ming , Yin Jie
Published: May 2011

Numerical analysis of thermal response and structural response of a suspended pre-stressed steel reticulated lattice shell are conducted for the key nodes of the structure of a gymnasium on software FDS. Two different location of fire source are considered for analysis of response displacements and stresses of the nodes of the pre-stressed lattice shell and three cables. It is shown that the response temperatures of three cables set in the structure have similar variation trend for the fire scene presented here and the fire temperature near inner cable is highest among the three cables. It is concluded that the shell element of center of the structure has largest response stress, and the element above the side cable has larger stress than the shell element above the middle cable when the fire source is located at center of the gymnasium. It is shown that decrease of the pre-stress of the outer cable far away from the fire source is smallest among the three cables set in the structure.
Research on Fire Behavior of a Suspended Pre-Stressed Steel Reticulated Shell with Large Span
Authors: Wang Xin Tang , Zhou Ming , Xie Zhi Guo , Yu Feng Bo
Published: May 2011

In order to study the fire-resistance behavior of the spatial pre-stressed steel structures with large span, the model of numerical analysis of a suspended pre-stressed steel reticulated shell subjected to fire load is established with using the software Marc. Based on the model presented here, numerical analysis of thermal response and structural response of the pre-stressed steel structure are computed for the key nodes of the structure. For comparison, the air temperatures near the key nodes are also calculated based on the practical formula of large space air temperature rise. The different location of fire source is considered for analysis of response temperature, displacements and stresses of the nodes of the pre-stressed lattice shell. It is shown that the air temperatures was much higher than the response temperatures of the nodes of the lattice shell during a quite period of time after a fire takes place, and the temperature of the cable nodes are also less than the air temperature near the nodes. It is also concluded that not the cable nearest the fire source but the other cables around the cable fail to work first in the fire.
Finite Element Modeling and Analysis of FRP Composite Trough
Authors: Shan Lu Yang , Qiao Pi Zhong
Published: May 2011

A composite FRP trough is analyzed by finite element (FE) method. A modeling of FRP composite trough, which meets the performance requirements, is build in the commercial finite element software ANSYS. The deflection and stresses contours of the FRP trough for the intended application are obtained and discussed.
Preliminary Research on Mechanical Properties of FRP-Reinforced Bamboo Beams
Authors: Wei Yang , Li Guo Fen , Jiang Shen Xue , Zhang Qi Sheng , Lv Qing Fang
Published: May 2011

FRP bars were used to improve the mechanical properties of bamboo beams for civil engineering without changing the existing bamboo processing technology in this paper. Three bamboo beams, including one control beam and two FRP-reinforced beams were tested. The effects of various types of FRP bars were compared, including CFRP and BFRP. The results show that the ultimate displacements of reinforced specimens are less than the control specimen. The FRP bars can enhance effectively the cross-section stiffness of bamboo beams. CFRP bars can reduce about 30% strain and BFRP bars can also reduce about 10% strain for the tensile bamboo fiber. The FRP bars in the tension zone can share tensile stress of bamboo fiber. The cross-section stiffness still controls the structure design for the FRP bars reinforced bamboo beams.
The Bearing Behaviors of Concrete Quadratic Transfer Beam under Seismic Action
Authors: Liu Ying Li , Yan Te Liang , Zhang Shu Qing
Published: May 2011

Concrete quadratic transfer beam is definite completely based on the specifications. It is using ANSYS finite element software to optimize models rationally and calculate the structure with quadratic transfer beam under seismic action. Compared the mechanical characteristics of the two models of quadratic transfer beam, we can know that the wall on quadratic transfer beam played an important role in the mechanical characteristics. When there is no wall on quadratic transfer beam, the conclusions are banned used. It can provide a reference for design of engineering with quadratic transfer beam.
Bearing Capacity of Concrete Filled Square Steel Tube Short Columns with Inner CFRP Circular Tube under Eccentric Compression
Authors: Li Tian Hua , Zhao Jun Hai , Wei Xue Ying , Kong Wei , Dong Xiao Ming
Published: May 2011

Based on the unified strength theory, the bearing capacity of the concrete filled square steel tube short columns with inner CFRP circular tube under eccentric compression was analyzed. The restriction effect of the inner CFRP circular tube upon the core concrete, strength reduction factor for eccentricity ratio and the equivalent reduction factor, which considered the ratio of thickness to side effect, were taken into account in the theoretical analysis. The axial bearing capacity formula of the square steel tube short columns filled with inner CFRP circular tube was deduced. By introducing the strength reduction factor for eccentricity ratio, the eccentric bearing capacity formula on the basis of the axial bearing capacity formula was obtained. Parametric studies were carried out to evaluate the effects of intermediate principal stress, different CFRP deployment ratios, eccentricity ratios and the tension-compression ratio on the eccentric bearing capacity of the column. The formula was verified by the comparison of the theoretical results with the experimental data. The results show that inner CFRP circular tube can effectively restrain the core concrete.
Discussion of Criteria of Shear Strength Reduction FEM
Authors: Chen Li Hong , Yu Shu , Zhang Hong Tao
Published: May 2011

Shear strength reduction finite element method (SSRFEM) has been a main technique for stability analysis of slope. Although SSRFEM has advantages to deal with complex geometry and nonlinear material, the criteria for failure is still argued. Ideal elastoplastic model and rheological model were both adopted, and the results of computation showed that using the intersection of two straight lines as failure point was more appropriate. The usage and advantage of two different material models was compared.
Experimental Study on Concrete Slab Combined with Permanent Cement Formwork with Joints
Authors: Song Xiao Ruan , Liu Pei Ge , Zhang Xiao Yun , Qu Yu Ting , Xu Ji Min
Published: May 2011

In this research, a kind of composite cement plates are utilized as permanent formworks, and poured concrete together to form composite slabs. Through static test of composite slabs with different bonding modes of interface between formwork and concrete, bearing capacity, deformability and cooperation states of concrete and composite formwork are studied. Through static test of composite slabs with splicing joints formworks at different positions, bond quality near the splicing joints are observed visually, stress nature and deformability variations resulted from different splicing joint positions of formwork are analyzed. And meanwhile, stress and deformability of the ordinary concrete slab without formwork is researched under the same conditions. Through above experiments, acting as a part of the slab, how composite formwork influence bearing capacity and deformability of the combined slab is investigated.
Study on Effects of Infill Walls on Seismic Performance of RC Slab-Column Structure
Authors: Lu Yi Yan , Yin Xiao San , Li Liang Yi , Zhang Xue Peng
Published: May 2011

The research focused on the effects of infill walls on the RC slab-column structural system. In order to accomplish this, the elastic-plastic time-history analysis of RC slab-column structure was performed. Based on the test results of a full-scale three-story RC structure repaired and strength with masonry infill walls, the four optional analysis models were analyzed. The first was the pure RC slab-column structure without infill walls, the second was the RC slab-column structure added with half-height infill walls, which was equivalent to open holes inside infill walls, the third was the RC slab-column structure added with infill walls arranged symmetrically along the plane symmetric axis, and the fourth was the RC slab-column structure added with infill walls arranged around the plane geometry center. Analysis results indicated that addition of infill walls could increase the seismic performance of the structural system, configurations and amounts of infill walls, and the hole positions and sizes inside infill walls had effects on the structural system.
Probing into Study on Relevant Factors of BRBs’ Ultimate Bearing Capacity
Authors: Liu Guo Qi , Song Jian , Yan Bing
Published: May 2011

This paper presents a suitable solution of studying methods on BRBs’ critical load with finite element software．The effects of the relevant factors on the BRBs’ ultimate bearing capacity are investigated, and some practical suggestions for the design and production are provided．
Flexural Behavior of Concrete-Filled FRP-Steel Composite Circular Tubes
Authors: Wei Yang , Wu Gang , Wu Zhi Shen , Gu Dong Sheng
Published: May 2011

Three large-scale concrete-filled FRP-steel composite circular tubes and a control steel tube were tested to investigate flexural behavior. The effects of FRP and composite with different types of FRP with various ultimate strains were investigated. The study demonstrated the important effect of FRP, and showed that the load-displacement curves of FRP-steel composite tube beams could be divided into four stages: elastic stage, plastic stage, hardening stage and residual stage. An additional decline stage was gained for multi-fiber with different ultimate strains and steel composite tube concrete beams. FRP could increase the ultimate bearing capacity and bring the hardening stage after steel tube yielding, and a certain degree of stiffness would be achieved to avoid the “zero stiffness”. The composite of a variety of FRP could relax fracture failure for the FRP-steel composite steel concrete beams, realized the successive rupture of fiber in batches and changed the failure modes.