bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced Equivalent Static Wind Loads for Tall Buildings with Tuned Liquid Dampers
Authors: Ross Andrew S. , El Damatty Ashraf A. , El Ansary Ayman M.
Published: November 2012

The tuned liquid damper (TLD) is a proven and an increasingly popular auxiliary device for mitigating the dynamic effects induced by wind loading on tall buildings. As buildings become taller, lighter, and more flexible, there is a greater contribution from the dynamic component. The most reliable tool for assessing the dynamic component is wind tunnel testing. A boundary layer wind tunnel is capable of accurately calculating an equivalent static wind load (ESWL) acting on a building. The current study investigates the reduction in the ESWL of a lateral-torsional coupled building with a TLD system installed. The building is sensitive to torsion in the first two vibration modes. The current investigation uses three unique multi-modal TLD systems designed specifically for a lateral-torsional coupled building. The building ESWL is evaluated with the TLD systems using measurements from tests conducted at the Boundary Layer Wind Tunnel Laboratory at Western University.
Tall Building Subsidence Data Regression Analysis Methods and the Final Settlement Value Prediction
Authors: Xu Zhong Yin , Liu Shan Jun , Wu Li Xin
Published: November 2012

In order to provide reference data for the safe construction and validation of the design method is correct, the subsidence monitoring for tall buildings (high-rise structures) which are being in the construction or completed. In this paper according to the actual settlement monitoring data, on basis of considering the construction stage, the settlement data were segmented regression analysis. The results show that in stage of load (in construction) uniform increasing, the settlement and load a linear regression analysis results are better than the results of settlement with time linear regression analysis, While in the building after the completion, the settlement with time were the logarithm function regression analysis, hyperbolic regression analysis and power function regression analysis. The regression analysis results show that hyperbola regression analysis method is of minimum variance and the regression analysis effect is best, the final settlement value was predicted and providing reference basis for construction and design.
Experimental Study on the Strength and Deformation Quality of Granite with Effect of High Temperature
Authors: Xu Xiao Li , Gao Feng
Published: November 2012

Experiments on granite under uniaxial compression at high temperature of 25~850°C and after high temperature of 25~1300°C were conducted to study the effect of temperature on rock strength and deformation quality. The results show that: (1) Fitting curves between temperature strain and thermal expansion coefficient with temperature are closely first order growth exponential function relation at high temperature. Temperature strain has mutagenicity after high temperature, which can not reflect rock deformation law at high temperature exactly. (2)Mechanical properties of granite weak continuously at high temperature. Compressive strength and elastic modulus show second order attenuation trend of exponential law. But mechanical properties show mutation state after high temperature, which is closely related to the alteration of rock crystal form and brittle-ductile transition. Regression curves between compressive strength and elastic modulus with temperature are closely polynomial curve. The results reflect the fundamental regulation of granite’s interior structure changing under the action of different temperature, which will provide some reference value to rock engineering involved in high temperature.
The Experiment to Research the Mudstone Interbeds which Affect the Mechanical Characters of the Layered Rock Salt
Authors: Jiang De Yi , Fan Xue Qin , Ren Tao , Chen Jie , Ren Song
Published: November 2012

Since mudstone interlayer has a big influence on the mechanic property of layered rock salt, and in order to research its law, the mudstone which strength is lower than pure rock is used as a interlayer to make the regular layer of salt formation, then both the uniaxial and triaxial compression test are carried out on the layer of salt formation. The result indicates: (1) As the thickness of interlayer increases the uniaxial compressive strength and elastic modulus of layer type salt decrease. (2) On the condition that the thickness of interlayer does not change, the more the interlayer number, the stronger the uniaxial compressive strength. (3) If the total thickness of interlayer is stable and the interlayer number is same, then as the distance of interlayer increases the uniaxial compressive strength and elastic modulus of layer type salt decrease. The result provides practical value and theoretic basis on the further research of the mechanic property of layered rock soil and on the analysis of the stability of Karst underground salt cavity reservoir.
Characteristic of Development of the Fractured Zone in Mining under Medium Hard Overburden Using Fully-Mechanized Top-Coal Caving Method
Authors: Zhu Wei , Teng Yong Hai
Published: November 2012

For the prediction of the height of the fractured zone developed in mining with fully-mechanized top-coal caving system, the traditional calculation method, if used, generally yield a value with a comparatively large error. Based on mining condition of 6206 face at Wangzhuang Coal Mine in Luan mining area, a comprehensive study is made in the paper of the characteristics of the development of the fractured zone in the medium hard overlying strata under such full-seam mining conditions by taking various means, including field measurement and numerical and physical simulation. Through comparison with the field measurement data available and regression analysis, it can be seen that the height of the fractured zone developed in the medium hard overlying strata in mining with fully-mechanized top-coal caving system is directly proportional to the total mining thickness. In comparison with the result obtained with the use of empirical formula, the method used in the paper can better bring to light the occurrence of the intensive failure of overlying strata under such a mining condition. The research-derived achievement can serve as a basis for reference for the prediction of the height of fractured zone in mining under medium hard cover by using fully-mechanized top-coal caving method, and for decision making in mining under a water body.
Study on Impact of Reservoir Leakage on the Proposed Tunnel Project in Metamorphic Region
Authors: Du Yi Han , Zhao Qi Hua
Published: November 2012

Taking into account the narrow terrain, the proposed highway has to be built near the reservoir in the study area of metamorphic rock. Furthermore, part of the tunnel elevation is lower than the reservoir of a hydropower station. If the horizontal distance between the reservoir and tunnel is far enough and the differential head is large enough, it is likely that the serious leakage of the hydropower station reservoir will occur. The interaction between highway construction and reservoir is to be the key point. Either the safety of tunnel construction and operation or the safety of reservoir storage is important. This paper use the Darcy’s law and the hydrogeological characteristics of metamorphic rock to estimate the lateral seepage and evaluate the line design.
Microvibration Model Development and Validation of a Cantilevered Reaction Wheel Assembly
Authors: Zhang Zhe , Aglietti Guglielmo S. , Ren Wei Jia
Published: November 2012

Reaction wheel assemblies are one of the most important microvibration sources on typical modern satellites. In this paper microvibrations induced by a cantilevered reaction wheel assembly are modelled and validated against microvibration test results. The disturbance model is developed using energy method. A microvibration measurement platform is designed to measure its disturbances. Disturbance test results are analyzed in detail. The peculiar dynamic characteristics such as nonlinearity and high damping of harmonic responses in the test results are discussed. Estimations of damping values used in the disturbance model are introduced. A new method developed to model harmonic excitations is discussed. Furthermore, novel methods to identify harmonics and extract model parameters from test results are presented. The empirical modeling method developed for broadband noise excitations are also introduced and validated.
Experimental Research on Failure Mode of Micro-Pile in Landslide Reinforcement
Authors: Wang Shu Feng , Fu Yong Peng , Zhao Xin
Published: November 2012

In recent years, micro-pile has been widely applied to landslide treatment engineering due to its advantages in application and construction, and the engineering effect is very evident. Large-scale physical model test was made for studying failure mode of micro-pile group in landslide, which indicated that numerical magnitudes between the displacement and the stress of the piles are better consistent along the load transfer direction. Concentrated destruction points locate on about three times the pile diameter up and down the slip surface. Failure mode of micro-pile in landslide treatment engineering is: pile of the loaded segment usually breaks for bending moment and shear force, and back of sliding side mainly exposes to the tension role, compared to role of tension of anchored segment in front of the micro-piles and compression behind of the piles.
Dynamic Response Simulation of SCR in TDZ Considering the Soil Property
Authors: Li Gan , Huang Xiao Ping
Published: November 2012

The pipe-soil interaction problem is a critical issue in the fatigue analysis of SCR. In this paper, investigation on the initial trench configuration in the touchdown zone (TDZ) of the steel catenary riser (SCR) and factors, which have influence on the trench configuration, such as the amplitude of top end motion were performed firstly. Then the bending moment variation at different points along the trench during the pull up and lay down, the trenches and dynamic response at the touchdown point (TDP) under different soil properties were also investigated. It should be noted that the pipe around the TDZ especially at the TDP, which bears the most drastic bending moment variation and stress variation, is the hot spot in the fatigue analysis of SCR, and the soil properties have big influence on the dynamic stress response amplitude.
Damage Identification Research of Cantilever Truss Based on the Principle of Strain Mode
Authors: Zhang Jun Hai , Du Nai Juan , Shen Yue Guo
Published: November 2012

This paper presents a method converting the modal distance of the node into elemental strain based on the special characteristic of two-force element .The strain change before and after damage is applied to the damage identification. The change rule of the relative strain for the same location of the truss occur the various damage extent and the various location of the truss occur the same damage extent, respectively, is obtained according to the strain modal simulation using APDL language. The simulation results show that the strain modal change ratio is sensitive to the cantilever truss damage detection. The damage location and damage extent will be identified. It is an effective nodestructive test way to identify the cantilever truss structural damage.
A Study on Micro-Seismic Monitoring of Rock Failure during the Excavation of Tunnel
Authors: Ding Dian Dian , Wu Shun Chuan
Published: November 2012

Yuan yanghui tunnel as the engineering background of this study, the layout of USTB micro-seismic monitoring system is introduced. The positioning accuracy of the system has been adjusted according to artificial fixed blasting tests. Combining with the relationship between activity rate and time of micro-seismic events, different types of micro-seismic events have been distinguished, which explain the emergence of those events. The results show that the design and implementation of micro-seismic monitoring system can meet the global monitoring of rock mass deformation during the construction of the tunnel. Imported with location condition, combining micro-seismic monitoring with conventional monitoring technique can find the concentration zone of rock failure more exactly and orientate the position of potential instable face, which has considerable engineering guiding significance and economic benefit.
Fracture Mechanics-Based Fatigue Behavior of Jointed Concrete Pavement
Authors: Wei Ya
Published: November 2012

Concrete experiences thermal and hygral deformations at early ages due to it intrinsic properties and the environmental effects. Micro-cracking results on the top surface of pavement if deformations are restrained. These micro-cracks propagate transversely and downwards over time under traffic loadings, especially during early ages. This situation can be severe if upward curling conditions exist in pavements. Estimation of the remaining fatigue life of pavements with such cracks is of significance for scheduling prompt maintenance. Conventional fatigue models established based on uncracked beam tests are no longer applicable for such cases. It is necessary to develop a fracture mechanics-based fatigue model for pavement with cracks. This study provides a new fatigue life prediction methodology for pavement with cracks. Both model prediction and experimental test results suggest that fatigue life is significantly reduced if concrete develops a partial depth crack at early ages. These results can explain the observed premature transverse cracking failure in jointed concrete pavement. Crack growth behavior can be characterized as three stages, in which the steady stage is the most important one when prompt maintenance is needed to avoid structural failure.
Study on the Method of Construction of Large Section Tunnel Crossing the Ancient Great Wall
Authors: Jin Ai Bing , Li Long Fu , Deng Fu Gen , Zhang Min Zhe
Published: November 2012

While the tunnel crossing the ancient Great Wall, we must take effective measures to control ground deformation, prevent ground deformation is too large, destroying the heritage. In order to study the effects of tunnel excavation types on strata deformation, a three-dimensional computational model is built to simulate surface settlement and horizontal displacement by three different excavation types which are both-side heading method, CRD method, and hole pile method. Following comparative analysis, in line with the realistic program is recommended. The results show that both-side heading method can better control the surface deformation, and has a high efficiency of construction, which was selected as the construction scheme of tunnel crossing the ancient great wall. The results of this study are expected to provide construction experience to the works of a similar background.
Research on the Bridge Safety Monitoring System Based on Wi-Fi Network Technology
Authors: Jiang Gen Mou , Song Jin Bo
Published: November 2012

This paper mainly discusses a method based on Wi-Fi network technology cluster bridge safety monitoring system. In bridge safety monitoring center can be displayed at the same time, analysis of many bridge safety monitoring status, is convenient for decision makers to different budgets, optimize regional bridge within cluster maintenance; through the cluster type bridge safety monitoring, can be realized on the spread over a larger area of bridge security state data comparison, unified management, completely changed the previous single bridge safety monitoring system to realize the information sharing between the" information island" situation, more convenient to the regional environment, similar to different bridge structure or different environment, similar to bridge structure safety status of the longitudinal, transverse analysis comparison and research, which is beneficial to promote the optimum design of bridge structure, and based on the bridge maintenance and reinforcement.
Galloping Characteristics of Conductor Accreted with Crescent-Shaped Ice
Authors: Dang Hui Xue , Yang Feng Li , Li Xin Min , Yang Jing Bo
Published: November 2012

Accounting for the disastrous phenomena of ice-accreted conductor galloping, wind tunnel tests of LGJ630/45 conductor accreted with crescent-shaped ice are conducted. Based on the test results, conductor galloping is simulated by employing the PCL language of ANSYS commercial software package and then the influences of span lengths as well as free-stream speeds on galloping characteristics are studied. The results indicate that, conductor galloping consists several different frequency components. With the increase of span length, galloping energy moves from low-frequency component to its high-frequency counterpart, and finally high-frequency component dominates the galloping phenomenon. And with the movement of energy, galloping traces transforms from ellipse to that similar to a butterfly. With the increase of span length, the maximum cable tension first increases, next decreases sharply, and then increases again.
Study on Model Experiment of Long-Span Steel Truss Arch Bridge
Authors: Jiang Xiang Lin , Zhang Dong Bing , Yi Han Bin
Published: November 2012

This paper based on the structural characteristics of thin-wall steel truss of JiuJiang Yangtze River Bridge, designs a distorted model that thickness ratio is 1/10 and the length ratio is 1/40.Through the static test model, the cross-section stress of hangers chord, diagonal and the deflection of corresponding test point is tested, and the result is compared with numerical simulation result. It shows that the result of the test and numerical simulation satisfy the similar relations, thus verifying that the design of scale model is reasonable and correct.
The Research of Road Profile Estimation Based on Acceleration Measurement
Authors: Qin Ye Chen , Guan Ji Fu , Gu Liang
Published: November 2012

To get the certain response of vehicle during the driving process, it’s necessary to measure the road irregularities. Existing method of gauging the roughness is based on physical measurements and the instrument is installed under the vehicle, which is expensive and will affect the vehicle dynamic responses. This paper shows an easier method to estimate the road roughness by measuring and calculating the power spectral density (PSD) of unsprung mass accelerations. This approach is possible due to the relationship between these two via a transfer function. By comparing the power spectral densities of estimated road and the standard classes, we can classify the current road classes easily. Besides, this paper also shows that it’s feasible to estimate the road profile by calculating the PSD of unsprung mass accelerations directly.
Sensitivity Analysis of 1000MW USC Units Shafting Torsional Vibration Based on ANSYS
Authors: Liu Shi , Wang Cong , Li Bing , Chen Chang , Xie Dan Mei
Published: November 2012

To calculate a shaftings natural frequency of torsional vibration is one of the most important tasks in turbo-generators design, manufacture and frequency adjusting process. The sensitivity analysis of shafting structural parameters impact on the torsional vibration characteristics has important significance in reducing the amplitude of torsional vibration and ensuring the turbo-generators safe operation. In this paper, a 1000MW USC unit was taken as a research object to analyze the shaftings sensitivity to moment of inertia.
Identification of Loads on Suspenders in Bridges Based on Measured Response Data in Time Domain
Authors: Zhang Li Tao , Zhang Yu Feng
Published: November 2012

The purpose of this paper is to deal with identification of loads on suspenders. Values of the load at every moment were chose as identification parameters, and the objective function was established using measured data of responses and corresponding simulated ones. The vibration differential equation of suspenders was adopted to obtain the formula of relationship between the load and acceleration responses with superposition method. Furthermore, a regularization technique was applied in identification calculations to improve ill-posedness of the problem to be solved. With a tied arch bridge as the real example, the load on one of its suspenders was identified. Results of identification showed that the simulated data of acceleration response were almost identical to measured ones, which indicated validity of the proposed method.
Comparison and Analysis of Permafrost Railway Subgrade Settlement Deformation Monitoring
Authors: Tan Qu Lin , Xie Chou
Published: November 2012

Under inclement Qinghai-Tibet plateau environment, monitoring and analysis of railway subgrade deformation in plateau permafrost region has very important engineering significance for stability evaluation and safety management. In the paper, satellite interferometry was applied to measure subgrade deformation in the Beiluhe test site along the Qinghai-Tibet railway with gathered satellite interferometric SAR images. Based on the satellite-interferometry-derived data, the deformation characteristics of six points in different permafrost subgrades (the sliced rock embankment, the crushed rock embankment and railway bridge) along the Qinghai-Tibet railway were analyzed and compared. The analysis results show that settlement is the main behavior of railway subgrade deformation and the deformation amount of railway bridge is less than the sliced or the crushed rock embankment along the Qinghai-Tibet railway in permafrost regions.
Damage Identification of Multi-Box Steel-Concrete Composite Bridges Based on Modal Curvature Difference Method
Authors: Xiang Yi Qiang , Liu Li Si , He Yu Liang
Published: November 2012

Based on the data from dynamic analysis of a 40m-span multi-box steel-concrete composite bridge and the difference value of its modal curvature before and after the structural damage, this paper detects the damage locations in steel-concrete composite bridge by modal curvature difference method (MCDM). Here we adopt the updated finite element model in last work as analytical model, taking concrete density and elastic modulus as updating parameters and modal frequency+MAC as reference data. The results indicate that the modal curvature difference method can well locate the damages in steel-concrete composite bridge, especially the damage in concrete. But the change rate of frequency as damage index is insensitive to the bridge damage and the method can’t be applied solely for practical.
Experimental Study on Seismic Isolation Bearing of Large Aqueduct
Authors: Jiang Yin Jun , Zhou Yan Guo , Song Yi Le
Published: November 2012

Though seismic isolation technology has been applied widely in civil engineering and proved effective, it is not used in large aqueduct. Shaking table test experiment was made on anti-seismic problem of a large aqueduct in South-to-north Water Transfer Project. First, a single span aqueduct model is designed and made. Then, several isolation bearings are designed for experiment. At last, the structure system dynamic responses were presented with isolation bearing mounted and not under different period earthquake loads for different working conditions. The results show that by using isolation bearings, which can play an important role in large aqueduct anti-seismic problem, the structure dynamic response can be reduced effectively.
The Influence on High-Temperature Mechanical Properties of Hybrid-Fiber-Reinforced High-Performance Concrete and Microscopic Analysis
Authors: Yan Lan , Xing Y.M. , Li Ji Jun
Published: November 2012

This paper investigated the high temperature mechanical properties of the hybrid fiber reinforced high performance concrete (HFHPC) and normal concrete (NC) .After being subjected to different elevated heating temperatures, two kinds of concretes have been tested for the compressive strength, splitting tensile strength and flexural strength of test specimen at room temperature and 200 °C,400 °C,600 °C,800 °C.Microstructure changes of concrete were also observed by using Scanning Electron Microscopy (SEM) after high temperature. The results show that the hybrid fiber can significantly increase mechanical properties of the concrete at room temperature and high temperature. SEM and XRD analysis shows that there is a permeable diffusion layer in the steel fiber surface because of solid state reaction in the Interfacial Transition Zone of steel fiber and concrete. This permeable diffusion layer is white, bright, serrated and mainly consist of FeSi2 and the complex hydrated calcium silicate. The compounds of this layer change the Interfacial Transition Zone structure, enhance bonding capacity of the steel fiber and matrix, and increase the high temperature mechanical properties of concrete.
Adsorption of Naphthalene-Based Water Reducer on Alkali-Activated Slag Cement
Authors: Yang Chang Hui , Pan Qun , Zhu Jiong
Published: November 2012

In this work, the adsorption of naphthalene-based water reducer (FDN) on slag ground with or without the composite retarder YP-3 and PN (YP) in alkali-activated slag cement (AASC) activated by water glass (WG) has been studied in detail. The results show that the effect of the adsorption of water reducer on AASC depends directly on the dosage of the water reducer and on the composite retarder used. For example, mixed slag particles adsorb thrice as much water reducer FDN than pure slag particles at 1% mass of the slag, and the absolute value increment of the zeta potential of the AASC suspension containing the composite retarder is 8.61 mV, compared with 1.99 mV in the system without the composite retarder. Moreover, the AASC pastes activated by WG containing the retarder YP show better rheological properties and lower fluidity loss over time.
Experimental Study on Mixed-Mode Fracture for Concrete
Authors: Luo Zhang
Published: November 2012

A new criterion (failure stress criterion) is presented for the mixed-mode fracture of concrete by comprehensively evaluating several mixed-mode crack criteria. The new criterion absorbs some results fitting in with concrete from G.C.Sih and Erdogen’s maximum circumference stress criterion and G.C.Sih’s minimum strain energy intensity factor criterion. It combines concrete material fracture property with the condition of loads at the moment of concrete fracture by Weibull theory. It is concluded that concrete crack expands neither along the direction of maximum circumference stress nor along minimum strain energy factor S. The crack extends along the direction limited in the area controlled by two criteria. The accurate crack position is determined by failure probability of the strength of concrete structure. The experimental results indicate that the new criterion has better precision and adaptability comparing with other criteria and it can be applied to engineering very well.
Fractal Characteristics of Sandstone Cutting Fracture under Mechanical Shock Loading Conditions
Authors: Wang Shu Ren , Hagan Paul , Cheng Yan
Published: November 2012

It is the key to guide rock-breaking design and engineering practice for how to obtain a reasonable test indicator to assess the cuttability of the rock. Some sandstone samples were tested by using the linear rock cutting machine in the school of mining engineering, University of New South Wales (UNSW), Australia. The curves characteristics for the weight percent of the broken debris with the mesh size distribution were obtained through the screening statistics. Furthermore, the fractal dimension of the specimen broken debris was derived through theoretical calculations and statistical analysis. The results showed that the rock cutting fragmentation is of significant fractal features under the mechanical shock loads. The broken debris fractal dimension of the structural integrity specimens is bigger, the range of the fractal dimension is smaller and the broken debris size distribution is more even than that of the poor structural integrity specimens. The fractal dimension is the ideal test indicator to assess and analysis the rock-breaking degree.
Load Stress Analysis on BFRC-RCC Composite Pavement
Authors: He Dong Qing , Wang Yi Ming , Lu Chang
Published: November 2012

The finite element model for the basalt fiber reinforced concrete(BFRC)-roller compacted concrete(RCC) composite pavement structure is formed, by the model the influence of the BFRC and RCC panel thickness, elasticity modulus and foundation Equivalent Resilient Modulus on the complex road load stress can be summarized as: with the increasing of the composite pavement slab thickness, the stress at the end of the below plate shows decreasing trend, but the above end of the plate stress increased with the increasing of relative thickness of laminates; the increasing of concrete elastic modulus will make the stress in the end of this laminate increase, while the end of the adjacent laminates stress will reduce; with the increasing of the equivalent modulus of elasticity of roadbed top, the stress of laminates decreases. The results of the analysis are available as the reference to optimize the design of BFRC-RCC composite pavement.
Research on Precision Measurement and Fitting Method for Sliding-Shoe’s Inferior Concave Spherical Surface
Authors: Zheng Wei Gang , Tang Chao , Dai Ming , Huang Hai Bo , Ma Xiao Xiao
Published: November 2012

Due to the presence of nonlinear springback deformation, when the aviation piston hydraulic pump which is usually called sliding-shoe is formed by cold extrusion method, the surface of the sliding-shoe’s ball-socket becomes non-analytic curved surface. And this brings many difficulties to the measurement. In this paper, the precision measurement and fitting method to the inferior concave spherical surface of the sliding-shoe is discussed. And according to the deformation characteristics of the sliding-shoe, a meridian measurement method is established for the measurement. To a large number of discrete data, we fit it by least squares method and calculate it by VC++ Language program. Then we get the ball-socket’s center and radius. And fitting the sliding-shoe’s ball-socket to find out the contour error. It provides a reliable basis for the inspection of sliding-shoe.
A Passive Ranging Algorithm Based on Imaging Detection
Authors: Chen Xiao Min , Fu Xiao Ning
Published: November 2012

It investigated in an algorithm for passive ranging algorithm based on the target’s image information along with direction information. It aimed at to avoid the sick solution of the quadratic equation for distance estimation, such as the complex solution, or the negative solution, a novel one variable quadratic equation is proposed for distance estimation. In our method, the distance ratio between two sampling times could be obtained from image matching based on feature points, and combined both the space coordinate of the observer itself and direction cosine parameters of the target to the observer, a passive distance ranging equation is settled. Theoretical analysis shows that when the observer with non-zero displacement in the adjacent sampling times, this passive ranging equation could always be solvable. It illustrated by our reduced mode experiment that the proposed algorithm is simple and feasible, relative ranging error is smaller than the former quadratic equation. It confirmed that under the same observation model, if the observer itself is moving, the distance estimation would be in much simpler mathematical form.
A Scheme for Excavation Displacement Monitoring Based on Image Processing
Authors: Sun Mao Heng , Zhao Yi Xin , Jiang Wei , Feng Tian Tian
Published: November 2012

Geotechnical monitoring is integral part of each excavation project and usually done with manual manner. This study proposes a new monitoring method, which combines with image processing and wireless communication to break traditional one. The scheme uses image sensors to capture the images of the cooperative boards. The camera system is calibrated by Zhang Zhengyou calibration method beforehand. Digital signal processors in the image acquisition module generate the undistorted version of the images by the calibration results and utilize Harris corner detection algorithm to extract grid corners’ coordinates. Then these coordinates are sent to the data processing center through wireless sensor network. In the data processing center, the computer calculates the real displacement of the target by the extrinsic parameters of the camera. The experiment in this paper proves that the systematic accuracy satisfies the national standard. The system realizes the automatic real-time monitoring to excavation works.
Local Quasi-Geoid Refinement Based on Spherical Cap Harmonic Model
Authors: Guo Jin Yun , Wang Shu Yang , Li Guo Wei , Mao Wei Hua , Ji Yuan Ming
Published: November 2012

The local quasi-geoid model up to centimeter precision has became the basic requirement for the development of modern surveying and mapping science. There are a variety of models can be used for the quasi-geoid refinement, including the spherical cap harmonic model (SCH). This paper studies the theory of SCH to get the spherical cap harmonic expression to fit the height anomaly in the least squares sense, which is to achieve the transformation between the geodetic height and the normal height. We also discuss the selection of the maximum model degree in local region. The practical case is studied to refine the local quasi-geoid model with SCH using GPS/leveling data at 85 points. The results indicate that the local quasi-geoid model can reach 3 centimeter-level at the internal and external fitting precision.
Non-Intrusive Measurement of the Temperature and Size Distribution of Water Droplets in a Flat Fan Spray
Authors: Pan Qi , Zhang Zi Jia
Published: November 2012

The measurement of spray characteristics especially the droplets thermal and hydrodynamic properties is very important for many industrial applications. In this paper, a developed global rainbow thermometry method is applied to measure droplets temperature and size distribution in a flat fan air-blast atomizer spray. The spray droplets is illuminated by a continuum laser with the wavelength of 532nm and power of 14mW, and the rainbow light formed by the droplets is received by a linear CCD. To get accurate result, a calibration method for the relation of scattering angle and CCD pixels is designed, which can effectively reduce the error of the measured temperature. Experiment is taken under different temperature at a fixed gas-liquid ratio conditions, and results shows the method is feasible and has a relatively good precision.
Sound Transmission Control of a Cylindrical Structure Using Acoustic Resonators
Authors: Li De Yu , Ou Li Jian
Published: November 2012

This paper presents a passive method to control low-frequency noise in a cylindrical structure by using multi-modal T-shaped acoustic resonators. The feasibility of noise transmission control on the cylindrical structure is investigated, including a detailed experimental evaluation of the control performance using a single resonator and a resonator array consisted of different resonators. Finally, six long T-shaped acoustic resonators are used to target the first four lowest cylindrical cavity resonances, and up to 9 dB noise reduction is achieved, and broadband improvement of noise reduction is also observed.
The Diagnostic Method of Concrete Dam Monitoring Information Valid Interval
Authors: Qin Dong , Zheng Xue Qin , Wang Fa Meng , Liu He Zhi
Published: November 2012

On the basis of the analysis of the displacement of concrete dam and its related influential factors, based on the evolvement of nonlinear dynamics of concrete dam, it can effectively identify the mutations position of measured value and the attribute interval of dynamical system applied with the wavelet analysis, dynamic structural mutation theory and other numerical analysis methods. When detecting after separating structural mutation sequence, it can finally get the relative stable displacement time series of dynamical structure, so it can realize the diagnostic separation of the monitoring information effective interval. At the end of the paper, through applying a certain concrete arch dam, it is proved that the proposed method of concrete dam mutations diagnosis of is of great significance for the real-time monitoring of the workability state of a dam.
Application Research of Geological Radar in Volcanic Lava in the Geological Survey
Authors: Xiao Qiao Lin , Lü Fen
Published: November 2012

Aiming at the Hainan volcanic lava the geological characteristics, the application of geological radar detection technology in the geological environment of signal respond, combined with the added drilling data is compared, established the goal of geological radar image characteristics of geology, summarized the poor geological conditions in the area of geological radar signal response law. Field test shows that the radar reflected wave group of wave characteristic in volcanic lava can distinguish different geological layer reflection wave group, and via studying their relationship and change trend, to achieve the purpose of geological interpretation, and determine the adverse lava geology development stages , for design and construction to provide the reliable foundation material, effective use of survey for the design and construction of the guidance function.
Optimal Design and Test of Ultrasonic Vibration System
Authors: Miao Xin Lei , Zhu Yong Wei
Published: November 2012

Ultrasonic vibration system is the chief component of USM machine tool. Whether products are precisely machined is lie on the performance of the system. To design good performance of ultrasonic vibration system, finite element method is used to analyse the dynamic performance of the system based on theoretic calculation. The dynamic performance of transformer and transformer with tool is analysed respectively, including natural vibration characteristic and harmonic characteristic. The result of FEA is compared with theoretic calculation. The parametric optimization design technique of the finite element analysis package ANSYS is applied to optimize the structure dimension of the piezoelectric transducer and transformer with tool. Then amplitude of the optimized system and the previous system is compared based on laser-CCD sensor for micro-displacement. The optimized system is more superior and has larger amplitude. Last some round holes are machined on kentanium YG8, monocrystalline silicon, PZT. And machining effect of single Micro-USM is got by the test.
Stress Real-Time Monitoring of Marine Derrick Based on Environmental Loads
Authors: Huang Tao , Wang Jun Pu , Wan Fu , Chen Shao Wei , Dong Yao
Published: November 2012

Aiming at the design feature and the operating of K-type derrick, an effective method used to stress real-time monitoring consider environmental loading is proposed. The challenge to the South China Sea offshore drilling derrick is a illustration. The derrick corrosion and wall thinning conditions is be considered, then using finite element software analyze derrick structure of static analysis, get the higher force about main member of derrick. Based on finite element analysis, select the key parts layout of measuring points, then monitor derrick stress under nine storms environmental loading and extreme work condition. The measured data results show that: the nine storms environmental load affect capacity of drilling significantly, the different parts of the main member stress have the different degrees of influence by environmental load, the maximum can reach 50.8%. This real-time monitoring method of stress, can protect the safety of marine operations, has a certain value of engineering application.
Effect of Mesh Size on Structure Vibration and Acoustic Radiation
Authors: Xie Zhi Yong , Zhou Qi Dou , Lv Xiao Jun , Duan Jia Xi
Published: November 2012

The cylinder for experiment has been excited by steady sinusoidal and random white noise excitation forces and the acceleration responses are measured. The frequency response functions of two excitation ways agree well. The reciprocity law and the linearity are certified by exchanging the excitation and measurement spots and increasing input voltage continuously respectively. The influence of mesh size to calculated time and precision of vacuum vibration mean square velocity and underwater vibration mean square velocity and acoustic radiation are investigated. Results show that time consumed mounts with the mesh size gets smaller, and the vibroacoustic results is less influenced at lower frequencies but much more at higher frequencies.
Numerical Simulation of the Impact between the Front-End-Coated Projectile and the Substrate Coated by Ceramic Film
Authors: Wu Zhi Lin , Wang Xiao Mei
Published: November 2012

The propagation of the stress wave in axial direction during the impact between the front-end-coated projectile and the substrate coated by ceramic films is described by the stress wave theorem. The impact process is numerically simulated by ANSYS/LS-DYNA, where the shell unit is used for precision. The effects of thickness of the front-end coating on the interfacial stress are discussed in detail. Dependence of different ceramic films are also considered. Simulation results show that interfacial normal stress is much greater than tangential stress. The interfacial normal stress is greatest when the thickness of the projectile coating is 0.2 mm. The interfacial tangential stress increases slightly as the thickness of coating increases. Similar stress history in the interface occurs when the acoustic impedance of the films are close. Greater acoustic impedance results in smaller stress.
Sound Radiation of Underwater Structure Based on the Arithmetic of Coupled Acoustic-Structural Analysis with ABAQUS
Authors: Qian De Jin , Miao Xu Hong , Wang Xue Ren
Published: November 2012

Finite cylindrical shells with stiffened ribs are major structure of cabin on the submerged or underwater vehicles. This paper aims to probe into the feasibility of sound radiation simulation of underwater structure based on ABAQUS. ABAQUS is used to compute and analysis the underwater sound radiation rule of double cylindrical shell structure. And the computation data agrees with the experimental data basically. Adopting boundary impedance technique and acoustics IEM technique to simulation infinite flow field is feasible, and adopting acoustics IEM technique has much better performance. Boundary impedance technique is promoted for the concerning of accuracy. The results indicate that ABAQUS is appropriate to solve underwater sound radiation problem and it can satisfy the requirement of project application, which provides a new analysis method.
External Factors Influencing the Ethical Responsibility of Construction Project
Authors: Wang Li Fei , Mao Peng
Published: November 2012

The implementation of ethical responsibility of construction projects is impacted by many external factors. According to resource dependence theory, this paper constructs the indicator system of external factors influencing the ethical responsibility of construction projects, conducts quantitative analysis on it by means of Analytic Hierarchy Process (AHP), defines the five indicators (namely the perfect degree of laws and regulations, information symmetry, equality in status of project stakeholders, governmental supervision degree, and justice degree of contracts) as key influencing factors, and sets forth corresponding measures from three aspects aiming at the impact of the abovementioned key factors on the ethical responsibility of projects, in order to form an external restriction system for the ethical responsibility of projects, to realize the unification of self-discipline and heteronomy of project organizations, and to promote the realization of ethical responsibility objective of projects.
Study on Critical Conditions of Scour-and-Siltation in Flood Seasons of Ningmeng Reach in the Upper Yellow River
Authors: Zheng Yan Shuang , Zhang Xiao Hua , Peng Hong
Published: November 2012

Based on the actual measurement datum in flood seasons in the Ningmeng Reach of the Upper Yellow River Reach, Authors search the law of erosion and deposition and sediment transport characteristics with built the quantitative correlation of erosion and deposition efficiency and water and sediment combination (sediment coming coefficient, sediment concentration/discharge)of the flood season. When the sediment coming coefficients of flood season is0.0038kg.s/m6 the Ningmeng reach in relative equilibrium state. The Ningmeng reach has the characteristic of “the more sediment coming, the more depositing, the more sediment transporting”, the sediment discharge increases with sediment concentration of coming flow increasing. The result of these research can be used in the Yellow River management and alluvial channel regulation.
The Riverbed Evolution and its Influence on Channel in Tunaozi Reach after Three Gorges Water Storage
Authors: Fu Hua , He Xu , Ma Yao Chang , Yang Yun Yun
Published: November 2012

Tunaozi reach is one of the three famous sediment depositing reach on the Sichuan section of Yangtze River. It’s on the fluctuation backwater area when the Three Gorges Project is operated at the level of 135 m. According to the measured data before and after impoundment, this paper analyzes and calculates the sediment of the reach, and discusses the variation of silting and scouring of the reach after impoundment. Thus, this paper will have a study on the reason that silting and scouring lead to channel condition change. The result as follow: after impoundment, the bank-up water level of the reach has been head up 2 m during the flood season, sediment deposition becomes heavier than before impoundment; in post-flood season, the water level is 139m in November, it has been head up 7 m, compared with low water level in natural, current slowly flow further, the silt lack of enough scour in flood season, it leads to cumulative deposition. Until December 2005, thalweg plane position move left 200 m after impoundment. The maximum silting height of the thalweg longitudinal section is 30 m. The prime channel has been basically silted flat, year. Since the Three Gorges reservoir began to store water for three years, in low water level periods, ship tank is out of shallow, some timely dredging measure should be taken and make sure the smooth channel.
Load Dependent Hysteresis Model for GMM and its Parameter Identification
Authors: Chang Guang Hui , Zhu Shi Jian , Lou Jing Jun
Published: November 2012

This paper focuses on the development of load-dependent hysteresis model for Giant magnetostrictive materials (GMM). GMM are a class of smart materials and which are used mostly as actuators for active vibration control. Magnetostrictive actuators can deliver high ouput forces and relatively high displacements. Here, Terfenol-D, a magnetostrictive material is studied. Unlike the hysteresis seen in magnetic materials, The shape of Terfenol-D hysteresis curve changes significantly if the load is changed. To meet performance requirements for active vibration control, an accurate hysteresis model is needed. By modeling the Gibbs energy for each dipole and the equilibrium states, load-dependent hysteresis of GMM is modeled. Then a new PSO-LSM algorithm is brought forward by combing the Particle Swarm Optimization (PSO) with the least square method (LSM).Throughout this algorithm the model parameters were identified. The model results and experimental data were compared at different loads. The simulation results show that the load-dependent hysteresis model optimized by PSO-LSM yields outstanding performance and perfect accuracy.