bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on Shear Behavior of Combined Aggregate Concrete Beams
Authors: Zhang Yan Kun , Liu Hui , Song Ze Zao
Published: June 2012

Based on the test，the shear behavior of combined aggregate concrete beams is studied. The results show that combined aggregate concrete beam have similar behavior with ordinary concrete beams, and the shear capacity reduces with the increase of lightweight aggregate. And design formula of the combined aggregate concrete shear capacity is suggested.
Model of Identifying Deflexion of Oil Storage Tank
Authors: Liu Wen Bin
Published: June 2012

In the issue of oil storage tank, the method of corresponding oil volume is solved in different height of oil by differential coefficient.In actual oil storage amount in tank and height of oil, deflexion issue in three dimension is transformed to equal area issue in two dimension.The function relation is set in different variable quantity.
Elasticity Damage and Plastic Analyses of Masonry
Authors: Zhang Wen Fang , Wang Huan
Published: June 2012

The relation between stress and strain of masonry material under uniaxial monotonic condition is analyzed and the initial elastic stage is proposed for elastoplastic analyses. Furthermore, plastic damage model and elastic module degradation with plastic strain are investigated. The model describes the effects of irreversible damage: elastic module is fully determined by accumulated plastic strain; compressive stiffness may be recovered during cyclic loading. Based on the model, elastic module degradation and incremental stress-strain equations under multiaxial loading are discussed. Finally masonry shearwall under invariable compressive loading and monotonic shear loading is calculated, and plastic tensional strain before crushing is shown.
Research on Fault Diagnosis Method of the Aircraft Flap System Based on Weighted Fuzzy Petri Net
Authors: Xu Qing Hong , Jing Cai , Xu Yi Ming
Published: June 2012

Accordingly to the problem that during the fault diagnosis of the flap system, the existing experience and knowledge are always uncertainty, inconsistency, incompleteness, what’s more, the different fault cause has different effect on the fault. So the Weighted Fuzzy Petri Net is adopted, and fuzzy Petri net and matrix operations are combined, then the formal process of fuzzy inference reasoning algorithm is researched in order to obtain the fault probability of each event in the fault tree of flap system. The presented method effectively makes up the deficiency of the traditional FTA and FMEA, and provides a new fault diagnosis method for complex systems, so the fault diagnosis method based on Weighted Fuzzy Petri Net has a great practical value.
Temperature Forecasting System of Cement Decomposing Furnace Based on Grey System Theory
Authors: Liu Xiao Lin , Kun Yuan
Published: June 2012

Decomposing furnace, Temperature forecasting, Grey system theory
Dynamic Analysis of Gravity Platform's Marine Riser under Wave Load
Authors: Wang Xin , Wang Yin Bang , Liu Nan
Published: June 2012

Gravity platform was widely used in marginal oilfield, so the strength and the stability of its marine riser under wave load became very important. By simplifying the Morison equation, the paper made the dynamic analysis of the riser come down to solving the fourth order non-homogeneous linear differential equation, thus got the analytical solution of its deflection, shear force and bending moment. And the comparison with Ansys simulation showed that this simplified method was feasible.
Study on the Damage Law of SRC Frame-RC Core Wall Hybrid Structure Storey Affected by Component Damage
Authors: Zheng Shan Suo , Sun Long Fei , Tao Qing Lin , Hu Yi
Published: June 2012

Based on the general finite element software ABAQUS, the FE model of 30-story SRC frame-RC core wall hybrid structure is established and the simulation analysis is conducted to the evolution of storey damage under cyclic loading, then the law of storey damage evolution affected by component damage is revealed. The analysis results show that the storey damage evolution is affected more by the damage of SRC column and RC shear wall than by the SRC beam's, when the single component has similar damage; and also is affected greatly by the damage of RC shear wall, when the two different types of components have similar damage. Based on the results of numerical simulation, the mathematical relations between the component damage and the storey damage are established, which would provide theoretical support to the hybrid structure damage model under earthquake excitation.
Nonlinear Analysis of R.C Beams Strengthened with CFRP
Authors: Li Wen Sheng , Wang Kai
Published: June 2012

In order to study on the flexural performances of beams strengthened with external bonded carbon fiber reinforced polymer（CFRP）sheets, nonlinear analysis is carried out by using software ANSYS. The results show that a reasonable finite element model, using a reasonable solution strategy can be a good simulation of CFRP flexural performance of reinforced concrete beams, and finite element analysis results with the experimental results have good consistency .The beams reinforced by carbon fiber polymer，the capacity of flexural resistance increased with the numbers of carbon fiber paste sheets, reinforced components of flexural capacity significantly improved, but the extent of its increase is not proportional with the numbers of carbon fiber paste sheets.
Fatigue Life Prediction of Corroded RC Beams Strengthened with CFRP under Repeated Loads
Authors: Song Li , Yu Zhi Wu
Published: June 2012

Structural deterioration is becoming a major problem when considering long-term performance of infrastructures. The actions of corrosive environment, repeated loading and concrete cracking lead to structural degradation, whereas externally bonded carbon fiber reinforced polymers (CFRP) may increases structural performance. In the present paper, a theoretical model based on fatigue performance of materials and stress analysis for cross-section is proposed in order to analyze the fatigue damage of corroded reinforced concrete beams strengthened with CFRP under repeated loads. Further, fatigue life is predicted by applying this method, and the method is evaluated by test results.
Analysis on Rationality of Deformation Resistance Structural Component Ring Beam
Authors: You Li Wen , Liu Wen Sheng
Published: June 2012

The ground surface above the gob appear movement and deformation after the coal seam was mined, the movement and deformation of the ground surface influence the buildings on different levels. The destructive effect of the subsidence area must be considered if building brick-concrete structure buildings in subsidence area. Setting the ring beam is a common rigidity protection measures, it can improve the integrity of the building, the ring beam usually combined with the structural columns to form the framework of the building so that the building still function properly when suffered with the subsidence and deformation of the ground surface. Through the study on cases, get the relationship between the ground surface deformation and the ring beam reinforcement and provide reference for the decision making and practice of new construction in mining area.
The Finite-Element Analysis for CFRP and Steel Bar Strain in the Strengthened Concrete Slab
Authors: Cui Xi Guang , Ding Jian Wei , Yang Yang , Liu Yong Fang
Published: June 2012

This paper studies the mechanical behavior of Carbon-fiber-reinforced polymer (CFRP) in one-way reinforced concrete slabs, and the relation of CFRP and steel bar strain under the uniformly distributed load. Based on the theoretical analysis of the constitutive relationship, the analysis calculation model was built by using the ABAQUS software. Data analysis demonstrates that under the same conditions the load-strain curves of CFRP and steel bar are similar, which indicates that the mechanical cooperation performance of CFRP and steel is mutually beneficial. The load-strain curve of CFRP and steel bar is linear before the steel bended, and the curve is approximately linear after the steel bended. In the reinforced stage, the curve is again linear and the strain rate of the CFRP and steel bar increases constantly with the increase of load. This result is valuable for related studies.
Rigidity Test Research of Rigid and Flexible Flange Connection in Substation Frameworks
Authors: Li Hong Bo , Yang Jun Fen , Peng Yi Liang , Han Xuan Min
Published: June 2012

Flange connection has been applied widely, and many researches have been done on flange connection both at home and abroad. But the existing research on flange focused on bearing capacity, and there were few reports on the rigidity of flange. In this paper, rigidity test was carried on for the connection of rigid flange and flexible flange in substation frameworks. According to the test results, the tensile rigidity, shear rigidity and flexural rigidity was compared. The results indicated that the tensile rigidity, shear rigidity and flexural rigidity of flexible flange connection was lower than those of rigid flange connection with high strength bolts.
The Study on Bond and Anchorage Behavior of RC Flexural Members with Inorganic Adhesive Powder
Authors: Zhou Xin Gang , Fang Hua , Yan Jun Yin , Zhu Peng
Published: June 2012

To study the anchorage performance of the inorganic post-installed RC flexural members in flexural test, this paper simulates the stress state of the inorganic post-installed RC flexural members in practical projects. Through cyclic loading test, the anchorage performance of the inorganic post-installed RC flexural members in the bending tensile conditions is checked. This paper studies the anchorage performance of the post-installed steel at the state of bending tension, such as: adhesion stress, bond-slip relationship, the load carrying capacity, deformation behavior of the flexural member, and compare with those of normal member. The result indicates that with anchorage length of 20D in flexure member, the load carrying capacity of the inorganic post-installed reinforced concrete is apparently worse to those of normal members under repeated loading test; In case that anchorage length is invariable, load carrying capacity can be significantly enhanced through improving the concrete strength level. The anchorage zone is easily damaged, and the steel is easily slipped, which result in the decrease of the load carrying capacity, so some measures must be taken if inorganic adhesive powder is used in practical projects.
Distributed Hybrid Vibration Absorbers for Shock and Forced Vibrations
Authors: Chen Lei
Published: June 2012

The control methods used for free/shock vibration suppression are normally different from those used for forced vibration cancellation, because shock vibration is regarded as a type of transient vibration that is different in nature from steady-state forced vibration. However, both steady-state and shock excitations may occur in flexible structures, so there is a need to control both types of vibrations. To show the integration of the two different vibration control strategies, a hybrid control system based on adhesive strain gauges and PZT patches is proposed to construct a distributed resonant absorber and shock absorber together. The hybrid system is governed by a control arbitrator that decides which absorber should be active according to the different excitation conditions. The effectiveness of the integrated system is shown through simulation and experimental studies.
Study on Stress Increment of Externally Strengthened Prestressed Box Beams
Authors: Wang Rong Xia , Chen Xiang Shang , Guo Rong , Li Qiao Ru
Published: June 2012

With different original status including crack, controlled stretching stress and reinforcement ratio, five reinforced concrete box beams strengthened with external prestressed tendons were designed. The stress increment of external tendons was studied by indoor test and Finite Element Method analysis. The study shows that the less the controlled stretching stress is, the more rapidly the prestressed stress increment increases. There is no clear difference between the beam with original crack and without crack. In the test, the measured ultimate stress of external prestressed tendon agrees with the calculated result based on deflection method, and the stress in serviceability stage agees with the result based on structural mechanics method. In Finite Element model, the change of effective prestress, concrete strength, the area and depth of external tendons will result in a little change of stress in serviceability stage, but obvious change in ultimate status. the change of tendons lateral distance to the web results in litlle change of stress in the whole loading stage , no matter it is inside or outside the box at cross section.
Study on Bonding Properties of Bamboo-Steel Interface under Static Load
Authors: Zhang Jia Liang , Du Yong Fei , Yan Zhi Min , Li Yu Shun
Published: June 2012

Bamboo-steel composite structure is a new structure type, which has outstanding advantages of light weight, high strength, energy-saving and environmental protection. Components of this structure use bamboo plywood and cold-formed thin-walled steel as main materials, which are combined by structural adhesives. This paper presents an analysis approach of the bonding properties of bamboo-steel interface under static load.
Cement Based Material with Crystal-Growth Ability under Long Term Aggressive Medium Impact
Authors: Bohus Stepan , Drochytka Rostislav
Published: June 2012

This article describes test and results of long term effect by sulphate environment on new designed crystalline technology based material with fly-ash as partly cement substituent. At this article are presented results of new developed modification, which was the most effective and suitable for further commercial production during long term physical and mechanical tastings. Main aim of the experiment was to analyze ability of this new material to develop crystalline structure in capillary system and proof effectiveness of new developed crystalline structure in concrete pore system affected by long term sulfur medium attack.
Properties Research on Concrete Laminated Beam Combined with GRC Enhanced Reinforcement Template
Authors: Tian Jin Feng , Wang Qing Hua , Dong Jia Zhu
Published: June 2012

This paper introduces a stressed member which is composited of GRC enhanced reinforcement template combined with post-pouring concrete structure. The GRC template is as a permanent template combining with concrete into a composite beam. The surface of the template is respectively dealed in different ways. Through contrasting the results of stress performance experiment with ordinary beam,studing the cooperative performance between GRC templates and post-pouring concrete, as well as the effect of bearing stress of composite beams with templates in different treatment ways. The optimal size is diameter 15mm, depth 5mm from the experiment.
The Experimental Study on the Size Effects of Reinforced Concrete Members with Eccentrical Compression
Authors: Feng Fan , Zhao Jun , Lu Aizhen
Published: June 2012

The size effects of reinforced concrete members with eccentrical compression are experimentally studied, using two sizes of specimens which side lengths of cross-section are 200mm and 400mm, respectively, under the conditions in which e0/h0=0.6. It shows that, with the increase of the size of the specimen, the ultimate load capacity of the specimen decreases, relative to the calculated values; cross-sectional strain distribution of smaller specimens matches plane-section assumption better than larger-sized specimen’s.
Influence of Reinforcing Steel Post-Capping Strength Deterioration on Collapse Resistance Capacity of a Single-Storey RC Planar Frame
Authors: Han Jian Ping , Yang Jun Ping
Published: June 2012

Seismic analysis and design based on collapse probability under intense earthquakes is the main trend in the field of earthquake engineering. Accurate evaluation of collapse resistance capacity is necessary to achieve this target. Due to the accumulated deformation during seismic excitations, structural components would have different stiffness and strength deterioration characteristics. For evaluating the collapse capacity of the structure, it is important to take into account the deterioration characteristics in the analytical model. In this paper, the constitutive models for concrete and reinforcing steel, especially those adopted in OpenSees analytical software, are reviewed first. Then, a reinforced concrete single-storey planar frame structure with one bay is taken as case study and the effect of post-capping strength deterioration of reinforcing steel on evaluation results of global collapse resistance capacity is mainly investigated by incremental dynamic analysis (IDA) via OpenSees software. Analytical results show that global collapse resistance capacity will be significantly overestimated without considering the effect of post-capping strength deterioration of reinforcing steel.
Investigation of Effects of Baffle Configuration on the Performance of a Fixed-Cone Valve by Gas-Liquid Two-Phase Model
Authors: Wei W.L. , Lv B. , Liu Y.L. , Yang X.F.
Published: June 2012

Nested type Fixed-Cone Valve, numerical simulation, energy dissipating, turbulent flow Abstract: In this paper, In this paper, a new type of Fixed-Cone Valve was proposed by improving the conventional type Fixed-Cone Valve .The flow fields of the two kinds of Fixed-Cone Valves were studied by using numerical simulation method .The computed pressure fields and the velocity fields were analyzed ,which shows that under the same conditions ,and by using the nested Fixed-Cone valve, the pressure of the upstream pipe and the cone valve and the average velocity along the downstream pipeline are reduced ,but the rate of energy dissipation is increased.
Analytical Investigation of Progressive Collapse Resistance Mechanism in Steel Moment Frame with Fiber Model
Authors: Liu Chuan Qing , Mei Zuo Yun
Published: June 2012

In order to investigate the resistance mechanism of steel frame structure in progressive collapse, an advanced finite element model(FEM) is presented based on fiber beam-column element. Using this FEM, non-linear static pushdown analysis of a ten-story structure was carried out by the alternate load path method, in the two cases that two different columns are removed respectively. Analytical results show that residual structure has the different resistance mechanism for the different column removal case. In the initial stage, bending resistance mechanism can provide dominate resistance capacity in the structural progressive collapse, after both middle and side columns are removed. However, when the bending resistance is out of work, the catenary action is induced in the case of the middle column removal only, which is not developed after the side column is removed. It can be seen that steel frame structure has higher collapse risk in the case of the side column removal than in the case of the middle column removal.
Research Progress and Prospect on Self-Drilling Screw Connection Shear Capacity
Authors: Lu Lin Feng , Zhang Ya Ping , Fang Wen Qi , Yang Dong Hua
Published: June 2012

Recently, self-drilling screw connection is the most primary connection way in the cold-formed thin-wall steel structure, many scholars have studied its stress mechanism and shear capacity. This paper begins with several self-drilling screw stress mechanism and shear failure mode, introduces the domestic and international calculation, then summarize and analyze the research progress on the self-drilling screw. At last, prospect on the self-drilling screw shear capacity and application.
Reliability Simulation Combining Kriging and Monte Carlo Radius-outside Importance Sampling in Space Structure Latch
Authors: Gong Qi , Zhang Jian Guo , Su Duo
Published: June 2012

Concerning the issue of high dimensions and low failure probabilities including implicit and highly non-linear limit state function (LSF), the approach of reliability simulation combing Kriging and Monte Carlo Radius-Outside Importance Sampling (MCROIS) is presented, and the Kriging model is to approximate the unknown LSF, then calculate the initial sampling radius of the sphere, and the optimal radius is gained through the iterative algorithm. As such, the joint probability density function of importance sampling is constructed, which ensures that sampling domain is restricted to values outside the sphere located in the design point, and the efficiency is improved. The numerical example of space structure latch demonstrates the efficiency, accuracy and robustness compared with Crude Mote Carlo (CMC), which is validated that the method is of particular interest in applications with a low failure probability of failure, and it realizes the comprehensive design of reliability and wear lifetime on-orbit, and makes contributions to the exploration of reliability and lifetime analysis for the complex aerospace equipment
Reliability Assessment on Pipeline with Axial Surface Crack
Authors: Wang Zhong Xian , Li Xiang , Zhang Rui Feng
Published: June 2012

Stress constraints have a significant impact on the stress-strain fields of the crack front. In this paper, the weight function method is used to calculate the stress intensity factor K and constraint parameter T-stress at the crack front of pressure pipeline with a axial semi-elliptical surface crack. Based on the R6 procedure and considering the influence of stress constraint on fracture toughness, a modified failure assessment curve(FAC) and a computational formula are proposed to predict the fracture probability. In the end, a typical numerical example is presented to illustrate the proposed methodology and analyze the influences of crack geometry and axial stress on the failure probability of pipeline,where the crack size, material property parameter and load follow certain probability distribution.
Aging Effect on Corrosion Damage Evolution Behavior of Fuse-Head Used for Electric Explosive Device
Authors: Zhang You Hong , Zhang Qian , Chang Xin Long , Yue Chun Guo , Zhang Shi Ying , Liu Wan Lei
Published: June 2012

Degradation of mechanical properties of electric explosive device fuse-head was serious in different temperature and humidity environments. The objective of this study was to examine the effects of temperature and humidity aging on the damage evolution behavior of fuse-head used for electric explosive device. In this paper, the experimental studies were presented to appreciate the influence of humidity and temperature on the corrosion damage and firing of electric explosive device. The damage mechanisms and failure modes were determined through nondestructive evaluation. The explosive broken and corrosion damage on lead induced by temperature and humidity aging were the main factors affecting the firing probability. At last, the evolution rule of corrosion damage in the environment of different relative humidity and temperature was discussed.
Mean Wind Pressure Field on the Typical Large-Span Roof Structures
Authors: Li Fang Hui , Gu Ming , Ni Zhen Hua , Shen Shi Zhao
Published: June 2012

The wind tunnel tests of some typical large roofs, including a saddle roof, pitched roof and domes, are carried out with various terrains which cover suburban and urban exposures. The wind pressure data of roofs are obtained by using the synchronous multi-pressure scanning technique. The wind pressure coefficient and local shape factors of the wind load was investigated. The effects of various terrains on wind pressures of roofs are discussed. From the results, we can see mean pressures of these roofs exposed to the mean pressures exposed to the suburban terrain are 2 or 3 times those exposed to the urban terrain. And the terrains are no directly influence to the wind pressure shape factors.
Characterization of Surface Crack Using Surface Waves
Authors: Her Shiuh Chuan , Lin Sheng Tung
Published: June 2012

Surface cracks are the most common defects in structures. Ultrasonic has been widely used as a non-destructive evaluation technology in the case of crack characterization. In this investigation, surface waves are applied to a steel block with artificial slots to characterize the crack depth. A series of test specimen with different depths of surface crack ranging from 4mm to 10mm was fabricated. The depth of the surface crack was evaluated using the pitch-catch ultrasonic technology. In this work, 2.25 MHz, 5 MHz and 10 MHz of incident waves were employed to investigate the effect of frequency on the crack depth detection. Experimental test results show that the accuracy of crack depth detection is increasing with the increase of frequency.
Influence of Boundary and Initial Condition on Durability of Concrete Structures Exposed to Chloride Environment
Authors: Zhou Xin Gang , Zhao Fang
Published: June 2012

According to investigations of apparent surface chloride contents and chloride penetration profile of concrete structures exposed to chloride environment, the influences of boundary and initial conditions, geometry parameters such as the geometry dimension and section shape, etc. were discussed. Based on the Fick’s second law of diffusion and different boundary and initial conditions, different analytical models to predict the chloride penetration profile in concrete structural members with different boundary and initial conditions were derived. Some calculations examples were made using those analytical models. Computational results show that the boundary and initial conditions have remarkable influences on chloride penetration profile and service life time of concrete structures. Using prevailing error-function solution model based on the semi-infinite assumption of chloride ingress, the prediction of service life time of concrete structures are over evaluated, in particular for the steel reinforcement in corner of the section. Some modify coefficients should be taken into consideration, concerning the influences of boundary and initial conditions.
Reliability Analysis of Different Concrete Strength RC Beams Reinforced by CFRP
Authors: Chen Shuang , Tao Yan , Zhao Sheng Hua
Published: June 2012

This paper analyzes the cause and effect of the influence which the change of concrete strength have on the reliability through carrying capacity test of six CFRP repaired and strengthened beams that are different in concrete strength grade. The reliability of CFRP reinforced RC beams increase gradually along with the enhancement of the concrete strength, , and this trend becoming more apparent when the concrete strength grade raise.
Corrosion Properties of Rebar Welded Joints
Authors: Tang Li Yun , Xiao Qian Hui , Zhang Shu Yun
Published: June 2012

The main reason that causes the premature failure of concrete structure is rebar corrosion damage. Furthermore, the chloride ion penetration is the main reason of rebar corrosion damage. Stress corrosion in welding joint of rebar is studied. Separate rebar into 5 groups, each group have 3 pieces. Grouping experimental method is used to make welded joints soaked, compare the variation law of mechanical properties of flush welded joint under the influence of corrosive environment. Combining with Finite Element Analysis shows that a higher stress concentration during welding process is the important reason to the performance degradation of rebar in corrosive environments. Comparative tests have shown that stress corrosion cracking more likely occur in the welding zone and welding clamping position. The results show that the rebar production process must be strictly controlled, and effectively prevent the erosion of the corrosive medium to ensure the long-term safety of the building.
An Experimental Corrosion Investigation of Coupling Chloride Ions with Stray Current for Reinforced Concrete
Authors: Chen Mengcheng , Wang Kai , Wu Quanshui , Qin Zhen
Published: June 2012

According to the service environment of light rail transit and subway structures, in this paper experiments on the corrosion characteristics of reinforced concrete under single corrosion environment of stray current, single corrosion environment of chloride ions and joint corrosion environment of stray current and chloride ions were respectively carried out. Loading direct current electric field was used to simulate the stray current. The experimental results showed that, the corrosion growth process of the rebar in reinforced concrete under single environment of chloride ions was slow and stable, while that under single environment of stray current being separated two stages, i.e., rapidly increasing stage and stably varying stage. In addition, the rebar of reinforced concrete in stray current alone environment was corroded faster than that in chloride ion alone environment did; when stray current and chloride ion coexist, the stray current speeded up the chloride ion transportation, which gave rise to the increase of the corrosion rate of the rebar of reinforced concrete; the corrosion degree of the rebar depended on the chloride ion concentration, stray current strength and test time. The stronger the stray current strength, the longer the stray current corrosion period and the heavier the chloride ion concentration, the more the corrosion products of the rebar and thus the more serious the reinforced concrete deterioration.
Discussion on the Accuracy of Approximate Spring-Dashpot Artificial Boundary in Fluid-Saturated Porous Media
Authors: Wang Zhi Hui , Gai Yan Mei , Zhao Cheng Gang
Published: June 2012

The accuracy of artificial boundary conditions plays an important role in the dynamic finite element analysis of unbounded media. By loading the solid skeleton an uniformly distributed triangular pulse on the approximate stress boundary and the original stress boundary respectively, the accuracy of the approximate artificial boundary is analysed. The calculation difference of radial displacement decreases with the increase of distance from artifical boundary to the scattering center, i.e. only when the artificial boundary are far enough can the accuracy be satisfied.
The Theoretical Solutions of Several Integrations in Relation with the Plane Wave Functions
Authors: Shi Wen Pu , Li Cui Hua
Published: June 2012

Several integrations of the plane wave functions frequently appearing in the scattering problems of elastic waves are considered in this study. In conjunction with the principle of superposition and the stationary wave function expansion, the exact solutions are obtained. As in the scattering problems of elastic waves and plane waves, the theoretical solutions can improve the convergence speed of the arithmetic and the computation precision. The analysis method and the analytical solutions can also be very helpful to solving other complex integrations in relation with the cylinder functions and plane functions.
Information Entropy Method for Evaluating Regional Earthquake Relative Disaster-Carrying Capability
Authors: Liu Juan , Su Jing Yu , Wang Wei , Ma Dong Hui
Published: June 2012

In order to enhance the accuracy of regional disaster-carrying capability assessment, the dissipative structure of the regional urban earthquake relative disaster-carrying system is highly complicated and nonlinear. Moreover, the problem is multi-attribute, multi-index and multilevel. Based on the evaluation index system of regional relative disaster-carrying capability, This paper used the entropy weight assignment method to work out each index’s objective weight, quantitatively researched the 29 cities’ earthquake relative disaster-carrying capability, worked out every city’s relative disaster-carrying capability and divided its grades using the mean deviation method. The research results showed that the earthquake relative disaster-carrying capability of our country was much unbalanced. It was positively correlation with the economic performance, the eastern, central and western cities’ earthquake relative disaster-carrying capabilities were mainly distributed in the shape of the ladder. The eastern cities’ capabilities were much higher than the western cities’. So, we suggested that the eastern cities should further improve its earthquake disaster-carrying capability and the central and western cities should spend more efforts to develop its earthquake disaster-carrying capability. Only in this way, our country’s urban earthquake disaster reduction can develop evenly.
Analysis on the Mechanism for Baseline Drift of near-Fault Accelerograms
Authors: Wang Yu Shi , Li Xiao Jun
Published: June 2012

Accelerograms recorded by accelerographs are of fundamental importance in seismic engineering, forming the basis of ground shaking employed for anti-seismic design. By analysis on the general solution of wave equation, this article demonstrated that the ground tilting is related with the ground velocity and displacement histories. For accelerograms with co-seismic permanent displacement, this ground tilting would be presented continuously with a tiny constant value after severe shock terminated. The co-seismic permanent displacement might be the reason of baseline drift, which caused that the real velocity and displacement histories could not be achieved by the direct integration of accelerograms. A baseline correction method was also proposed based on this finding, with which the ground velocity and displacement histories of several near-fault stations were given. But this proposed method still needed improvement because of the divergence in its iterative process.
Seismic Response Research on Oil Pipeline with Corrosion Defects
Authors: Qi Han Bing , Wang Qiu Shi , Wang Li Li , Wu Xiao Dan
Published: June 2012

The finite element analysis method was used to analyze the seismic response of two oil pipelines, which have corrosion defects and no defects correspondingly. The velocity, displacement and acceleration time history of the two pipelines and the contrastive analysis of the maximum stress of two pipelines were obtained. The results show that the displacement, velocity and acceleration of the pipeline with corrosion defects are larger than those of the pipeline without corrosion defects, the corrosion has great influence on the bottom of the pipeline, and the influence also has certain wide, the farther away from the corrosion, the smaller the influence is.
In Situ Test Methods in Bachu-Jiashi Earthquake Liquefied Evaluation
Authors: Li Zhao Yan , Li Yu Run , Chen Long Wei
Published: June 2012

The serious soil liquefaction phenomenon in Bachu-Jiashi earthquake on 24th February, 2003, which is the most prominent phenomena of sand liquefaction since the Tangshan Great Earthquake in 1976. Based on the earthquake liquefied investigation, inspect SPT and CPT applicability in situ tests. The results show that our country SPT specification and CPT specification of non-liquefied sites evaluation rate is higher than liquefied sites evaluation success rate, the liquefied sites evaluation rate are 88% and 88% respectively, but for liquefied sites evaluation rate are 38% and 55%. The result is tends to danger and the reason need further investigation, so establish a suitable liquefied prediction method should be to the future work in the local area.
Lateral Seismic Action on Gravity Retaining Wall along the Height
Authors: Liu Hai Ming , Tao Xia Xin , Zhou Xiao Yan
Published: June 2012

Lateral seismic action on retaining wall along the height is a key parameter in the design of the wall against earthquake. Seismic responses of 6 gravity retaining walls with heights from 7 to 25 meters are analyzed by finite element method with considering the soil-structure interaction. A formula of the action on retaining wall is summarized from the response results with input acceleration time histories simulated for Intensity Ⅵ, Ⅶ, Ⅷ and Ⅸ.
Test on Hybrid Connection for Steel Bars in Concrete
Authors: Tian Ye , Feng Peng , Zhou Zheng Hai , Ye Lie Ping , Wan Bao Lin
Published: June 2012

The steel bar connection is an important and inevitable work in civil engineering. The traditional overlapped connection method usually needs to place the transversal rebars in the overlapped splicing area to restrict the splitting cracks in concrete. The steel usage and labor cost are increased. An improved splice, which is the hybrid connection of welding and overlapping, was developed for mid-diameter bars, which is easy to install and has commendable mechanical behavior. A series of reinforcing rebar splice tests with steel-concrete interaction were conducted. The failure model of hybrid connection and the ultimate strength were acquired. Based on the tests, the failure mechanism of hybrid connections was analyzed. The results show that the ultimate load of the new splice is sufficient for the engineering application and the failure model is reasonable. The hybrid connection could be used in the engineering practice.
Analysis of the Seismic Performance of RC Frame Structures with Different Types of Bracings
Authors: Wang Zhi Xin , Fan Hai Tao , Zhao Huang Juan
Published: June 2012

Finite element models of frames with steel-bracings and with concrete filled steel tube struts are built in ETABS. Seismic performance of these models is analyzed with base-shear method, superposition of modal responses method and time history method respectively. The results show that the steel-bracings or concrete filled steel tube struts are efficient to increase the story-stiffness, and the top displacement of the frame structure decreases significantly.
Dynamic Response of Ceiling System with Light Steel Furring and Gypsum Board under Severe Earthquake
Authors: Wang Duo Zhi , Dai Jun Wu
Published: June 2012

In order to make sure reliability of ceiling system according to the current code, response acceleration of ceiling suspension points are obtained by seismic model developed by ANSYS/LS-DYNA. Then the FE model of ceiling system according to the current code is also developed in ANSYS/LS-DYNA. The input acceleration is added on ceiling suspension point. The following features are obtained from ceiling system with light steel furring and gypsum board under severe earthquake. These are: 1 Many gypsum boards which are designed according to the current code are failed and drop down，that may result in casualties. 2 The furrings are failed and did not drop down, then may drop for higher peak acceleration. 3 The ceiling system according to the current code is not safe under severe earthquake.
Review of Anti-Seismic Capability Study of Storey-Adding Structure
Authors: Xi Xin , Qu Shu Ying , Sun Chen
Published: June 2012

The forms of storey-adding structure include direct, separating, unitary, cooperating with vibration reduction and so on. The characteristic and anti-seismic capability are different for each form, and the homologous application are distinct. The paper summarises the research process of anti-seismic capability of the above four forms, and makes suggestions in some ways, such as strenghening experimental study, combining with advanced new technics on seismic isolation and absorption.
Comparative Analysis of Several Common Quasi-Statics Methods for Tunnel Seismic Soil Pressure Calculation
Authors: Deng Tong Fa , Gui Yong , Nie Fu Sheng
Published: June 2012

The current underground structure seismic soil pressure was stated briefly in this paper first, as well as several commonly used quasi-statics calculation methods, and then based on the calculation mentioned above, various simplified calculation methods were applied to calculate the seismic pressure of tunnel structure, offering reference for future improvement of seismic pressure calculation methods and seismic design level of tunnel structure.
A Simplified Prediction on Deflection of Web-Core Sandwich Beam in Weak Direction
Authors: Shao Yong Bo
Published: June 2012

Through theoretical analysis of a simplified model for web-core sandwich beam, a simple equation for predicting the deflection of such beam in the weak direction is deduced. The obtained equation is verifed by comparing the predicted deflection of a web-core sandwich beam with reported finite element result. It is found that the presented equation can provide reasonably accurate estimation in analyzing the static behaviour of web-core sandwich beam in weak direction. Additionally, it is also found that the deformation of a web-core sandwich beam is caused mainly by shear deformation while the flexural deflection is much smaller compared to the shear deformation
Influence of Ground Motion Spectral Shape on Nonlinear Responses of a 3-Storey RC Frame
Authors: Han Jian Ping , Luo Yi
Published: June 2012

Selection and modification of recorded earthquake ground motions is one of the most important issues for reliable seismic performance evaluation of the structure. In order to investigate the influence of ground motion spectral shape on nonlinear seismic response and to find the implication for ground motion selection and modification, a 3-storey RC planar frame is taken as case study in this paper. 15 ground motion records are chosen from PEER Ground Motion Database and Wenchuan Great Earthquake as dynamic analysis inputs.
Study of Bearing Capacity for Vertical Stiffener Joint with Concrete-Filled Square Steel Tube and Steel Beam
Authors: Wang Su , Zhu Qian , Zhao Jun Hai , Zhang Dong Fang
Published: June 2012

Based on the limit equilibrium method and assumptions of vertical stiffener joint model, the stress mechanism of vertical stiffener joint model is analyzed for concrete-filled square steel tube and steel beam. The formula of bearing capacity for vertical stiffener joint of concrete-filled square steel tube and steel beam is established. The rationality of proposed formula is validated by comparing analytical results with experimental data. Moreover, some factors involved in the proposed bearing capacity formula of connection joints are discussed. The results can provide some theoretical references for the study of bearing capacity of annular plate joint.
Seismic Fragility Analysis of Reinforced Concrete Frames within Service Life
Authors: Wang Neng Jun , Wang Jian Min , Jiang Wen Ting
Published: June 2012

An analytical method was proposed to obtain the seismic fragility curve of reinforced concrete frames within the service life. Considering the variation law of nonlinear mechanical characteristics of un-carbonated concrete within service life, the seismic fragility curve of frames was developed based on the inter-storey drift corner in the weak storey of frame structures. According to the defined frame damage states, each seismic fragility curve reflects the probability change tendency of the defined damage state in frames within service life. A numerical example was modeled to illustrate the variation characteristic of seismic fragility within the service life.
Study on Performance-Based Seismic Evaluation and Strengthening for RC Damaged Structures
Authors: Gao Qiu Mei , Wang Bao
Published: June 2012

After the earthquake, the extent of the destruction of the structure will directly influence the ability to resist the after-shock and the carryout of rehabilitation, the study on the damaged structures’ seismic performance is very important and complex. The seismic evaluation and strengthening of RC damaged structures must not only ensure the safety of structures, but also have enough ability to resist the earthquake in the last life-span. While a performance-based criterion, both for the design of new construction and the retrofit of existing construction, is very desirable, the process of developing such a guideline can be formidable. In this paper, basic idea and design process of performance-based design is discussed firstly. Then story drift ratio and deformation of component are used as performance targets to solve the problems of seismic evaluation and strengthening for damaged reinforced concrete structures under different performance levels ， the specific performance-based design method is listed to provide theoretical basis of strengthening of damaged structures.
The Seismic Performance Analysis of Steel Frame Adding the Viscoelastic Dampers
Authors: Wang Ya Li , Lei Jin Song , Zheng Fei Hua , Zhai Kang Lan
Published: June 2012

Based on the mechanics characteristics of the viscoelastic dampers, the seismic performance of a 5 layers steel frame structure with viscoelastic dampers or not was researched. In under the action of the rarely met earthquake, the finite element analysis software MIDAS was used to analyses two of the models of displacements, interlayer shear and ductility of structure. The results showed that: after the installation of viscoelastic dampers, the displacements and interlayer shear of the structure reduced significantly, and ductility increases, the earthquake response can be cut down obviously, it shows better seismic performance.
Research on Numerical Simulation of Smart Base Isolation System with MR Damper (I)
Authors: Fu Wei Qing , Chen Fei , Yu De Hu , An Ying Hao
Published: June 2012

Rubber bearing base-isolation is well-developed vibration reduction technique and is applied in practical engineering broadly. The nature period of the base-isolation structure applied with rubber bearing is extended. Meanwhile the response of the superstructure is also reduced. But it is noticed that the displacement of isolation layer is too large. So it is required to find a suitable damper to reduce the displacement of isolation layer. Magnetorheological damper has good smart performances- broad controlled band, fast response and demand a little energy. In this paper smart base isolation system, which is combined with rubber bearing and MR damper is applied to structural vibration control, and have numerical simulation e of structure employing RB isolation and smart isolation in different kind and magnitude of earthquake waves. The result indicates the control system is effective.
Near-Fault Baseline Correction Method and Appliction in Wenchuan Earthquake
Authors: Peng Xiao Bo , Peng Xiao Jun , Yang Wei Lin
Published: June 2012

To eliminate the drifting in recordings from Ms8.0 Wenchuan earthquake, a modified two segments baseline correction method is brought up and systematic acceptance standard is presented. The method is applied to recordings from Qingping station and Bajiao station, which are closest stations to surface rupture traces. The effect of baseline correction on acceleration time history, Fourier amplitude spectrum and 5% damped relative displacement response spectrum is analyzed.
Effects of Water and Thermal Contact Resistance on the Temperature Field of Concrete Filled Steel Tubular Columns
Authors: Han Jin Sheng , Wang Xiao Ting , Sun Qi Wo
Published: June 2012

The water separated from concrete and the thermal contact resistance between steel tube and concrete have important effects on the temperature field of concrete filled steel tubular columns subjected to fire. Therefore, it is necessary to consider these effects in many cases to obtain accurate results of temperature field. The actual influences of water and thermal contact resistance on the temperature field of concrete filled steel tubular columns are analyzed in this paper, and the corresponding simplified methods are presented to take into account these effects in numerical analysis. A numerical program using these simplified methods is developed to calculate the temperature field of concrete filled steel tubular columns under fire. It can be shown by the comparison with the test results that the methods adopted in this paper have good accuracy and feasibility, and can obviously improve the calculation precision of temperature field.