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Sample records for box girders

  1. Stress and noises of steel box girders in Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Xue Tao; Chen Zhijian; Dong Xuewu

    2008-01-01

    Sutong Bridge is a cable-stayed bridge with a main span of 1 088 m.370 high-precision stress monitoring measured data show that in the process of hoisting the steel box girders,the stress of the main girders is in the fluctuant and complex state and many meteorological factors,such as sunshine radiation,temperature and wind,have important influence on the change of stress of the steel box girders.According to the real-time weather data,the stress data after the process of wavelet denoising from representative measuring points in different weather conditions is picked to estab-lish the stress response brought by meteorological factors with Layered Separation method,thereby basically eliminating the influence of meteorological factors on the stress of main girders,so that accurate and reliable stress data can be got for steel box girders adjustment and cable-tensioned construction control.

  2. Unconventional Bearing Capacity Analysis and Optimization of Multicell Box Girders

    Directory of Open Access Journals (Sweden)

    Jovan Tepic

    2014-01-01

    Full Text Available This study deals with unconventional bearing capacity analysis and the procedure of optimizing a two-cell box girder. The generalized model which enables the local stress-strain analysis of multicell girders was developed based on the principle of cross-sectional decomposition. The applied methodology is verified using the experimental data (Djelosevic et al., 2012 for traditionally formed box girders. The qualitative and quantitative evaluation of results obtained for the two-cell box girder is realized based on comparative analysis using the finite element method (FEM and the ANSYS v12 software. The deflection function obtained by analytical and numerical methods was found consistent provided that the maximum deviation does not exceed 4%. Multicell box girders are rationally designed support structures characterized by much lower susceptibility of their cross-sectional elements to buckling and higher specific capacity than traditionally formed box girders. The developed local stress model is applied for optimizing the cross section of a two-cell box carrier. The author points to the advantages of implementing the model of local stresses in the optimization process and concludes that the technological reserve of bearing capacity amounts to 20% at the same girder weight and constant load conditions.

  3. PARAMETRIC STUDY OF SKEW ANGLE ON BOX GIRDER BRIDGE DECK

    OpenAIRE

    Shrikant D. Bobade *, Dr. Valsson Varghese

    2016-01-01

    Box girder bridge deck, is the most common type of bridges in world and India, it consists of several Slab or girders. The span in the direction of the roadway and connected across their tops and bottoms by a thin continuous structural stab, the longitudinal box girders can be made of steel or concrete. The Simple supported single span concrete bridge deck is presented in present study. Skewed bridges are suitable in highway design when the geometry of straight bridges is not possible. The sk...

  4. Effect of material uncertainties on dynamic response of segmental box girder bridge

    OpenAIRE

    Suchart Limkatanyu; Kittisak Kuntiyawichai

    2007-01-01

    The main objective of this paper was to investigate the effect of material uncertainties on dynamic response of segmental box girder bridge subjected to a moving load, in this case a rapid passing trains. Literatures concerned with the design of segmental box girder bridge, the application of finite element analysis to model the segmental box girder bridge, and the minimum requirement for structural conditions of the bridge were described and discussed in detail. A series of finite element a...

  5. Design and test of box girder for a large wind turbine blade

    DEFF Research Database (Denmark)

    Nielsen, Per Hørlyk; Tesauro, Angelo; Bitsche, Robert;

    This report is covering the structural design and full scale test of a box girder as a part of the project “Demonstration of new blade design using manufacturing process simulations” supported by the EUDP program. A box girder with a predetermined outer geometry was designed using new inventions...... that the manufacturing process could include the new inventions. Subsequently the box girder was transported to the blade test facility at DTU Wind Energy. A series of test was performed with the blade to investigate the behaviour during loading, and finally the girder was loaded to ultimate failure. The report includes......, which create an inner structure in the box girder. With a combination of advanced FEM analysis and the inventions it was possible to reduce the material thickness of the cap by up to 40%. The new design of the box girder was manufactured at SSP Technology A/S, where it was demonstrated...

  6. Design and test of box girder for a large wind turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Per H.; Tesauro, A.; Bitsche, R. [Technical Univ. of Denmark. DTU Wind Energy, DTU Risoe Campus, Roskilde (Denmark)] [and others

    2012-09-15

    This report is covering the structural design and full scale test of a box girder as a part of the project ''Demonstration of new blade design using manufacturing process simulations'' supported by the EUDP program. A box girder with a predetermined outer geometry was designed using new inventions, which create an inner structure in the box girder. With a combination of advanced FEM analysis and the inventions it was possible to reduce the material thickness of the cap by up to 40%. The new design of the box girder was manufactured at SSP Technology A/S, where it was demonstrated that the manufacturing process could include the new inventions. Subsequently the box girder was transported to the blade test facility at DTU Wind Energy. A series of test was performed with the blade to investigate the behaviour during loading, and finally the girder was loaded to ultimate failure. The report includes the description of the test setup, the test and an overview over the results from the test performed on the box girder. During the final test the box girder failed at 58 % of the expected ultimate load. Unfortunately, no definite conclusion could be made concerning the failure mechanism. (Author)

  7. Study in the design and manufacture process of the elastic cable anchor box in steel box girder of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Gu Bifeng; Chen Ce; Ding Lei

    2011-01-01

    Taizhou Yangtze River Highway Bridge is a large span suspension bridge with three pylons. The elastic cables are installed to connect the steel tower and the steel box girder. The constraints can increase the safety coefficient of the middle saddle, and improve the stress conditions of the middle pylon and decrease the deflection in the middle of the main girder, as well as the longitudinal displacement of the main girder caused by live loads. The anchorage boxes of the elastic cable are installed in the wind fairing outside the vertical web plate of the box girder. Two anchor boxes form a pair and are arranged parallelly. Eight anchor boxes are installed in the bridge. In this paper, the design scheme and the technical difficulties in manufacturing are briefly discussed with the precision control techniques.

  8. Dynamic Magnification Factor in a Box-Shape Steel Girder

    Science.gov (United States)

    Rahbar-Ranji, A.

    2014-01-01

    The dynamic effect of moving loads on structures is treated as a dynamic magnification factor when resonant is not imminent. Studies have shown that the calculated magnification factors from field measurements could be higher than the values specified in design codes. It is the main aim of present paper to investigate the applicability and accuracy of a rule-based expression for calculation of dynamic magnification factor for lifting appliances used in marine industry. A steel box shape girder of a crane is considered and transient dynamic analysis using computer code ANSYS is implemented. Dynamic magnification factor is calculated for different loading conditions and compared with rule-based equation. The effects of lifting speeds, acceleration, damping ratio and position of cargo are examined. It is found that rule-based expression underestimate dynamic magnification factor.

  9. Design of steel box girder for Taizhou Yangtze River Highway Bridge

    Institute of Scientific and Technical Information of China (English)

    Ding Lei; Shan Hongwei; Zhou Qing; Zheng Benhui

    2011-01-01

    Taizhou Yangtze River Highway Bridge is the first three-pylon two-span suspension bridge in China. The maingirder adopts flat steamline steel closed box girder which has well wind-resistant capability and is technically mature besides beautiful appearance. Straight web plates of the steel box girder in longitudinal direction are proposed in order to ensure the integrity of the steel box girder, and to keep the stress of the steel box girder continuous in the middle pylon,as well as to reduce the gradient of the middle pylon columns. The cross section of the box girder has one box with three cells. Solid-web diaphragm plate with good integrity and high torsional stiffness is adopted. The lifting lugs are utilized in the anchors of suspender cable. In this paper, selection of the cross section of the steel box girder, the general structure design, local structure design and main structure calculation results of Taizhou Yangtze River Bridge are introduced emphatically.

  10. Research on the special lifting devices for steel box girders of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Chen Ming; Wu Qihe; Luo Chengbin; Zhou Hanfa

    2009-01-01

    Sutong Bridge is a cable-stayed bridge with a steel box girder and a main span of 1 088 m. The steel box girder of main span includes five portions: back span large unit, large block of pylon, standard girder, back span closure girder and middle span closure girder. Each back span large unit is fabricated by welding several deck segments together in factory, and is erected by floating crane. As navigational clearance of the main bridge is high, the traditional truss lifting device can' t satisfy the requirement of domestic lifting cranes for this kind of lifting height and weight. Hence, a kind of lighter lifting device for the erection of back span large units was accepted for this bridge. In this paper, the design and use of this lifting device is introduced.The upper structure used lifting gantry to install the standard girder segment by cantilever method. Because the bridge's navigation clearance is high, and the girder segment is wide and heavy, the meteorology and hydrology condition of the bridge district is abominable, and the requirements of long cable girder side pull-in, structure and performance propose high request to the lifting gantry. In this paper, the design and use key point of long cable pull-in angle adjustment device integrate into lifting gantry is introduced.

  11. Seismic response of skewed RC box-girder bridges

    Institute of Scientific and Technical Information of China (English)

    Ahmed Abdel-Mohti; Gokhan Pekcan

    2008-01-01

    It is critical to ensure the functionality of highway bridges after earthquakes to provide access to important facilities.Since the 1971 San Fernando earthquake,there has been a better understanding of the seismic performance of bridges.Nonetheless,there are no detailed guidelines addressing the performance of skewed highway bridges.Several parameters affect the response of skewed highway bridges under both service and seismic loads which makes their behavior complex.Therefore,there is a need for more research to study the effect of skew angle and other related factors on the performance of highway bridges.This paper examines the seismic performance of a three-span continuous concrete box girder bridge with skew angles from 0 to 60 degrees,analytically.Finite element (FE) and simplified beam-stick (BS) models of the bridge were developed using SAP2000.Different types of analysis were considered on both models such as:nonlinear static pushover,and linear and nonlinear time history analyses.A comparison was conducted between FE and BS,different skew angles,abutment support conditions,and time history and pushover analysis.It is shown that the BS model has the capability to capture the coupling due to skew and the significant modes for moderate skew angles.Boundary conditions and pushover load profile are determined to have a major effect on pushover analysis.Pushover analysis may be used to predict the maximum deformation and hinge formation adequately.

  12. Dynamic Analysis of Horizontally Curved Thin-Walled Box-Girder Bridge due to Moving Vehicle

    Directory of Open Access Journals (Sweden)

    K. Nallasivam

    2007-01-01

    Full Text Available The impact on curved box-girder bridges due to vehicle moving across rough bridge deck have been analyzed using bridge-vehicle coupled dynamics. The bridge deck unevenness has been assumed to be a homogeneous random process in space specified by a PSD function. The analysis incorporates the effect of centrifugal forces due to vehicle moving on curved bridge. The curved box-girder bridge has been numerically modeled using computationally efficient thin-walled box-beam finite elements which take into account the torsional warping, distortion and distortional warping, that are important features of thin-walled box girders. Rigid vehicle with longitudinal and transverse input to the wheels giving rise to heave-pitch-roll degrees of freedom has been considered. The theoretical bridge model used in simulation study has been validated by a free vibration experiment using impact excitation. The impact factors for several response parameters such as bending moment, shear force, torsional moment, torsional bi-moment, distortional moment, distortional bi-moment and vertical deflections have been obtained for various bridge-vehicle parameters. Both constant velocity and forward acceleration of the vehicle have been considered to examine impact factor. The results highlighted that the impact factors of a curved box girder bridge corresponding to torsion, distortion and their corresponding bimoments have been observed to be generally very high, while those of the other responses are also relatively higher than that of corresponding straight box girder bridge.

  13. Full Scale Test of a SSP 34m box girder 1. Data report

    DEFF Research Database (Denmark)

    Jensen, Find Mølholt; Branner, Kim; Nielsen, Per Hørlyk;

    This report presents the setup and result of a full-scale test of a reinforced glass fibre/epoxy box girder used in 34m wind turbine blade. The tests were performed at the Blaest test facility in August 2006. The test is an important part of a research project established in cooperation between R...

  14. Effect of material uncertainties on dynamic response of segmental box girder bridge

    Directory of Open Access Journals (Sweden)

    Suchart Limkatanyu

    2007-11-01

    Full Text Available The main objective of this paper was to investigate the effect of material uncertainties on dynamic response of segmental box girder bridge subjected to a moving load, in this case a rapid passing trains. Literatures concerned with the design of segmental box girder bridge, the application of finite element analysis to model the segmental box girder bridge, and the minimum requirement for structural conditions of the bridge were described and discussed in detail. A series of finite element analysis was carried out using SAP2000 Nonlinear software. The effect was investigated by varying the Modulus of Elasticity by 5%, 10% and 15%. The results were then compared with the case of assumed uniform property which had already been checked for model accuracy using the Standard prEN 1991-2. The results showed that, for the uniform case, the dynamic responses of the bridge gave the highest response at the resonance speed. When considering the non-uniform material properties (non-uniform case, the effect of material uncertainties appeared to have an effect on both displacement and acceleration responses. Nonetheless, the dynamic factor provided in the design code was sufficient for designing the segmental box girder bridge with either uniform or non-uniform material properties for the train speeds considered in this study.

  15. Computer Simulation of Dynamic Interactions Between Vehicle and Long Span Box Girder Bridges

    Institute of Scientific and Technical Information of China (English)

    Lei Gong; Moe S.Cheung

    2008-01-01

    Moving vehicle loads,associated with roadway traffic can induce significant dynamic effects on the structural behaviours of bridges,especially for long-span bridges.The main objective of current research is to study traffic induced dynamic responses of long-span box-girder bridges.The finite element method has been employed in this study to obtain a three-dimensional mathematical model for the bridge system.For vehicle-bridge dynamic interaction analysis,the vehicle is modeled as a more realistic three-axle,six-wheel system,and the corresponding dynamic interaction equations have been derived.The bridge-vehicle inter- action is affected by many factors.The current study has been focused on such factors as:vehicle speed, vehicle damping ratio,multiple traffic lanes,mass ratio of vehicle and bridge,and dynamic characteristics of bridge.Case studies have been conducted to investigate these factors by using several box girder bridge examples including Confederation Bridge,the longest box girder bridge in the world.

  16. Field test on temperature field and thermal stress for prestressed concrete box-girder bridge

    Institute of Scientific and Technical Information of China (English)

    Baoguo CHEN; Rui DING; Junjie ZHENG; Shibiao ZHANG

    2009-01-01

    A field test was conducted to investigate the distribution of temperature field and the variation of thermal stress for a prestressed concrete (PC) box-girder bridge. The change of hydration heat temperature consists of four periods: temperature rising period, constant temperature period, rapid temperature fall period and stow temperature fall period. The peak value of hydration heat temperature increases with the increasing casting temperature of concrete; the relation between them is approximately linear. According to field tests, the thermal stress incurred by hydration heat may induce temperature cracks on the PC box-girder. Furthermore, the nonlinear distribution of temperature gradient and the fluctuation of thermal stress induced by exposure to sunlight were also obtained based on continuous in-situ monitoring. Such results show that the prevailing Chinese Code (2004) is insufficient since it does not take into account the temperature gradient of the bottom slab. Finally, some preventive measures against temperature cracks were proposed based on related studies. The conclusions can provide valuable reference for the design and construction of PC box-girder bridges.

  17. Research on overall assembling and welding process of steel box girder tuyere blocks of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Yan Shiguang; Li Hongtao; Wang Chao

    2012-01-01

    This article presents in detail the assembling and welding process technique of the steel box girder tuyere blocks of Taizhou Bridge. The application of this process technique effectively solves the problem of welding stress release in tuyere block assembling and welding without increasing the number of turns of the blocks and overhead welding, thus avoiding possible structural deformation due to excessive accumulation of internal welding stress, greatly reducing the repeated deformation and correction work during assembling and welding, and ensuring the weld seam quality and overall dimensions of tuvere blocks of Taizhou Bridze.

  18. Structural Health Monitoring of Precast Concrete Box Girders Using Selected Vibration-Based Damage Detection Methods

    Directory of Open Access Journals (Sweden)

    Zhengjie Zhou

    2010-01-01

    Full Text Available Precast, prestressed concrete box girders are commonly used as superstructure components for short and medium span bridges. Their configuration and typical side-by-side placement make large portions of these elements inaccessible for visual inspection or the application of nondestructive testing techniques. This paper demonstrates that vibration-based damage detection (VBDD is an effective alternative for monitoring their structural health. A box girder removed from a dismantled bridge was used to evaluate the ability of five different VBDD algorithms to detect and localize low levels of spalling damage, with a focus on using a small number of sensors and only the fundamental mode of vibration. All methods were capable of detecting and localizing damage to a region within approximately 1.6 times the longitudinal spacing between as few as six uniformly distributed accelerometers. Strain gauges configured to measure curvature were also effective, but tended to be susceptible to large errors in near support damage cases. Finite element analyses demonstrated that increasing the number of sensor locations leads to a proportional increase in localization accuracy, while the use of additional modes provides little advantage and can sometimes lead to a deterioration in the performance of the VBDD techniques.

  19. Free vibrations of multi-girder and multi-cell box bridges with transverse deformations effects

    Science.gov (United States)

    Hamed, E.; Frostig, Y.

    2005-01-01

    A general mathematical approach is developed for the free vibration behaviour analysis of multi-girder and multi-cell box bridges with a single or multi span, including the effects of the transverse deformations of the bridge cross-section. The governing equations of motion and the corresponding boundary and continuity conditions are derived via the variational principle of virtual work following Hamilton's principle. The model is general and valid for any boundary and continuity conditions, and is applicable for multi-girder bridges with longitudinal and cross beams and for multi-cell box bridges. The warping and the distortion of the bridge cross-section effects are included in the proposed model. Closed-form solutions of the governing equations are derived and the Newton-Raphson method is used to determine the eigenfrequencies. Numerical examples are presented to validate the proposed model, and are also used to examine the accuracy of other approximate models used in the analysis of bridges. The results of the proposed model are validated through comparison with three-dimensional finite element models. The results reveal that the transverse deformations decrease the magnitudes of the eigenfrequencies of the torsional mode shapes, as well as the high flexural modes.

  20. Fatigue stress monitoring and analyses for steel box girder of Runyang Suspension Bridge

    Institute of Scientific and Technical Information of China (English)

    Ying WANG; Zhaoxia LI; Baijian WU

    2008-01-01

    The monitoring of fatigue stress of steel bridge is a key issue of bridge health monitoring and safety assessment. This paper aims to find out the strain history features of the girder components of Runyang Suspension Bridge (RYSB) under vehicle and environmental loading during its first year of service based on the strain-history data recorded by structural health monitoring system installed in the bridge. The fatigue stress spectrums of steel box girders under normal traffic load, heavy trucks and typhoon loads were studied as well as the correlation between varying strain and temperature based on real-time monitoring of temperature histories. The results show that, monitoring on local strain in health monitoring systems of RYSB can effectively provide the information on fatigue stresses. The range of the equivalent fatigue stress on the monitoring location of the bridge is currently low, mainly due to varying traffic loading and temper-ature. There exists significant correlation between varying temperature and mean value of fatigue stress. Effect of the passing of heavy trucks on bridge fatigue is quite signifi-cant since the value of the cumulative fatigue damage generated by heavy trucks is 10 to 100 times larger than that by normal traffic. Therefore, the effect on fatigue cumulative damage due to heavy trucks or overloaded vehicles needs to be monitored and paid much attention to.

  1. Dynamic finite element model updating of prestressed concrete continuous box-girder bridge

    Institute of Scientific and Technical Information of China (English)

    Lin Xiankun; Zhang Lingmi; Guo Qintao; Zhang Yufeng

    2009-01-01

    The dynamic finite element model (FEM) of a prestressed concrete continuous box-girder bridge, called the Tongyang Canal Bridge, is built and updated based on the results of ambient vibration testing (AVT) using a real-coded accelerating genetic algorithm (RAGA). The objective functions are defined based on natural frequency and modal assurance criterion (MAC) metrics to evaluate the updated FEM. Two objective functions are defined to fully account for the relative errors and standard deviations of the natural frequencies and MAC between the AVT results and the updated FEM predictions. The dynamically updated FEM of the bridge can better represent its structural dynamics and serve as a baseline in long-term health monitoring, condition assessment and damage identification over the service life of the bridge.

  2. Finite element model updating of a prestressed concrete box girder bridge using subproblem approximation

    Science.gov (United States)

    Chen, G. W.; Omenzetter, P.

    2016-04-01

    This paper presents the implementation of an updating procedure for the finite element model (FEM) of a prestressed concrete continuous box-girder highway off-ramp bridge. Ambient vibration testing was conducted to excite the bridge, assisted by linear chirp sweepings induced by two small electrodynamic shakes deployed to enhance the excitation levels, since the bridge was closed to traffic. The data-driven stochastic subspace identification method was executed to recover the modal properties from measurement data. An initial FEM was developed and correlation between the experimental modal results and their analytical counterparts was studied. Modelling of the pier and abutment bearings was carefully adjusted to reflect the real operational conditions of the bridge. The subproblem approximation method was subsequently utilized to automatically update the FEM. For this purpose, the influences of bearing stiffness, and mass density and Young's modulus of materials were examined as uncertain parameters using sensitivity analysis. The updating objective function was defined based on a summation of squared values of relative errors of natural frequencies between the FEM and experimentation. All the identified modes were used as the target responses with the purpose of putting more constrains for the optimization process and decreasing the number of potentially feasible combinations for parameter changes. The updated FEM of the bridge was able to produce sufficient improvements in natural frequencies in most modes of interest, and can serve for a more precise dynamic response prediction or future investigation of the bridge health.

  3. Assessment of seismic performance of skew reinforced concrete box girder bridges

    Science.gov (United States)

    Abdel-Mohti, Ahmed; Pekcan, Gokhan

    2013-12-01

    The seismic vulnerability of highway bridges remains an important problem and has received increased attention as a consequence of unprecedented damage observed during several major earthquakes. A significant number of research studies have examined the performance of skew bridges under service and seismic loads. The results of these studies are particularly sensitive to modeling assumptions in view of the interacting parameters. In the present study, three-dimensional improved beam-stick models of two-span highway bridges with skew angles varying from 0° to 60° are developed to investigate the seismic response characteristics of skew box girder bridges. The relative accuracy of beam-stick models is verified against counterpart finite element models. The effect of various parameters and conditions on the overall seismic response was examined such as skew angle, ground motion intensity, soil condition, abutment support conditions, bridge aspect ratio, and foundation-base conditions. The study shows that the improved beam-stick models can be used to conduct accurate nonlinear time history analysis of skew bridges. Skew angle and interacting parameters were found to have significant effect on the behavior of skewed highway bridges. Furthermore, the performance of shear keys may have a predominant effect on the overall seismic response of the skew bridges.

  4. Full scale test of a SSP 34m box girder 1. Data report; Reinforced glass fiber/expoxy used in wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Find M.; Branner, K.; Nielsen, Per H. (and others)

    2008-03-15

    This report presents the setup and result of a full-scale test of a reinforced glass fibre/epoxy box girder used in 34m wind turbine blade. The tests were performed at the Blaest test facility in August 2006. The test is an important part of a research project established in cooperation between Risoe DTU, the National Laboratory for Sustainable Energy at the Technical University of Denmark -, SSP-Technology A/S and Blaest (Blade test centre A/S) and it has been performed as a part of Find Moelholt Jensen's PhD study. This report contains the complete test data for the final test, in which the box girder was loaded until failure. A comprehensive description of the test setup is given. This report deals only with tests and results. There are no conclusions on the data in this report, but references are given to publications, where the data are used and compared with FEM etc. Various kinds of measuring equipment have been used during these tests: acoustic emission, 330 strain gauges, 24 mechanical displacement devices and two optical deformation measuring systems. The mechanical displacement devices measured both global (absolute) and local (relative) deflection and the optical systems measured surface deformation. A prediction was made on the location of the failure of the girder. At this location the majority of the measuring equipment was concentrated. The prediction was proved to be correct and valuable information of the behaviour of the box girder prior to failure was obtained. The experimental investigation consisted of the following load configurations: -Flapwise bending -Torsion Ultrasonic scanning of the box girder was performed before, during and after the test the box girder. This was done to investigate whether the girder was damaged by the load or imperfection (productions defects) growth. (au)

  5. 预应力混凝土连续箱梁有限元损伤分析%Finite element failure analysis of continuous prestressed concrete box girders

    Institute of Scientific and Technical Information of China (English)

    张峰; 李术才; 李树忱; 叶见曙; 雷笑

    2009-01-01

    In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a finite failure analysis method for predicting behaviors of box girders is developed. A degenerated solid shell element is used to simulate box girders and material nonlinearity is considered. Since pre-stressed concrete box girders usually have a large number of curve pre-stressed tendons, a type of combined element is presented to simulate the prestressed tendons of box girders, and then the number of elements can be significantly reduced. The analytical results are compared with full-scale failure test results. The comparison shows that the presented method can be effectively applied to the failure analysis of in-situ continuous prestressed concrete box girders, and it also shows that the studied old bridge still has enough load carrying capacity.%为了确定预应力混凝土箱粱的极限承载能力,进行了预应力混凝土连续箱梁的破坏性试验,提出一种有限元损伤分析方法模拟箱梁结构行为.基于实体退化壳单元对箱梁进行模拟,并考虑了结构材料的非线性效应.由于预应力混凝土箱梁中通常存在大量曲线预应力钢筋,提出一种组合单元,并用该单元模拟箱梁中的预应力钢筋,该方法可使结构分析时单元数量大大降低.试验结果和理论分析对比表明:提出的方法能够有效地用于预应力混凝土连续箱梁的破坏性试验计算分析中;研究的旧桥依然存在较大的极限承载能力.

  6. Development of the applicability of simplified Henry's method for skewed multicell box-girder bridges under traffic loading conditions

    Institute of Scientific and Technical Information of China (English)

    Iman MOHSENI; A.R.Khalim RASHID

    2012-01-01

    Concrete precast multicell box-girder (MCB) bridges combine aesthetics with torsional stiffness perfectly.Previous analytical studies indicate that currently available specifications are unable to consider the effect of the twisting moment (torsional moment) on bridge actions.In straight bridges the effect of torsion is negligible and the transverse reinforced design is governed by other requirements.However,in the case of skewed bridges the effect of the twisting moment should be considered.Therefore,an in-depth study was performed on 90 concrete MCB bridges with skew angles ranging from 0° to 60°.For each girder the bridge actions were determined under the American Association of State Highway and Transportation Officials (AASHTO) live load conditions.The analytical results show that torsional stiffness and live load positions greatly affected the bridges' responses.In addition,based on a statistical analysis of the obtained results,several skew correction factors are proposed to improve the precision of the simplified Henry's method,which is widely used by bridge engineers to predict bridge actions.The relationship between the bending moment and secondary moments was also investigated and it was concluded that all secondary actions increase with an increase in skewness.

  7. Matrix Analysis on Flexural Behavior of Thin-walled Box Girder%薄壁箱梁挠曲性能的矩阵分析

    Institute of Scientific and Technical Information of China (English)

    张元海; 林丽霞; 李乔

    2011-01-01

    On the basis of the shape function matrix which is established through assuming the homogeneous solution to the governing differential equation for shear lag of the thin-walled box girder as the element displacement function, the formula of the equivalent nodal force of the element under vertical concentrated loads is derived by applying the principle of virtual work. The reasonable warping displacement function of shear lag is proposed for the box girder with the twin-cell cross-section. The plexiglass model of the cantilever box girder with variable cross-sections is calculated, thus validating the effectiveness of the finite segment element in analysis of the box girder with variable cross-sections. The flexural behavior of the prestressed concrete continuous box girder with variable cross-sections is analyzed through a practical example. The results show as follows:The finite segment element has high computing efficiency for the box girder with variable cross-sections; under the action of vertical concentrated loads, the shear lag moment diagram of the box girder is a smooth curve and the absolute value of the shear lag moment is not greater than that of the bending moment at any cross-sections; the shear lag effect increases the mid-span deflection of the continuous box girder significantly, which shall be treated seriously in engineering practice.%在选取薄壁箱梁剪力滞控制微分方程的齐次解作为单元位移函数建立形函数矩阵基础上,运用虚功原理推导竖向集中荷载作用下单元等效节点力公式,提出双室箱梁的合理剪滞翘曲位移函数.通过对变截面悬臂箱梁有机玻璃模型进行计算,验证提出的梁段单元对分析变截面箱梁的有效性.结合实际箱梁算例,分析预应力混凝土变截面连续箱梁的挠曲性能.研究结果表明:所提出的梁段单元用于变截面箱梁分析时,具有较高的计算精度;在竖向集中荷载作用下,箱梁剪滞力矩图是一条

  8. 铁路混合梁钢混结合段钢箱梁关键施工技术%Key Construction Technology for Steel-box Girder of Steel-Concrete Joint Section of Railway Hybrid Girder

    Institute of Scientific and Technical Information of China (English)

    任世朋; 朱元元; 闫明赛; 孙小猛; 徐登云

    2015-01-01

    The main bridge of Yongjiang river is the first railway hybrid girder cable-stayed bridge in China. Taking account of construction, geology and environment, the paper analyzes the inapplicability of traditional construction methods and proposes the method of matching and slipping the modules of steel-box girder of the steel-concrete section, addresses the principle of slicing the steel-concrete joint section, the design of pile-pillar-girder support, the structure of self-balanced girder moving slide, the integrated formwork for sliding and concreting and the technology of matching and slipping the module of the steel-concrete section. The paper also summarizes the key points of construction control during matching and sliding processes.%甬江主桥为国内第一座铁路混合梁斜拉桥,在钢混结合段钢箱梁施工中,综合分析构造、地质、环境等因素,阐述传统施工方法的不适应性,提出钢混结合段钢箱梁模块组拼滑移方法。详细介绍结合段钢箱梁模块划分原则、桩柱梁式支架设计、自平衡移梁滑道构造、滑移浇筑一体式胎架及模块匹配滑移技术,总结钢混结合段钢箱梁模块组拼滑移施工控制要点。

  9. Structural health monitoring of an existing PC box girder bridge with distributed HCFRP sensors in a destructive test

    International Nuclear Information System (INIS)

    The application of hybrid carbon fiber reinforced polymer (HCFRP) sensors was addressed to monitor the structural health of an existing prestressed concrete (PC) box girder bridge in a destructive test. The novel HCFRP sensors were fabricated with three types of carbon tows in order to realize distributed and broad-based sensing, which is characterized by long-gauge length and low cost. The HCFRP sensors were bonded on the bottom and side surfaces of the existing bridge to monitor its structural health. The gauge lengths of the sensors bonded on the bottom and side surfaces were 1.5 m and 1.0 m, respectively. The HCFRP sensors were distributed on the bridge for two purposes. One was to detect damage and monitor the structural health of the bridge, such as the initiation and propagation of new cracks, strain distribution and yielding of steel reinforcements. The other purpose was to monitor the propagation of existing cracks. The good relationship between the change in electrical resistance and load indicates that the HCFRP sensors can provide actual infrastructures with a distributed damage detection and structural health monitoring system. Corrections were made to this article on 13 May 2008. The corrected electronic version is identical to the print version

  10. CFRP-Strengthening and Long-Term Performance of Fatigue Critical Welds of a Steel Box Girder

    Directory of Open Access Journals (Sweden)

    Roland E. Koller

    2014-02-01

    Full Text Available Empa’s research efforts in the 1990s provided evidence that a considerable increase of the fatigue strength of welded aluminum beams can be achieved by externally bonding pultruded carbon fiber reinforced polymer (CFRP laminates using rubber-toughened epoxies over the fatigue-weak welding zone on their tensile flange. The reinforcing effect obtained is determined by the stiffness of the unidirectional CFRP laminate which has twice the elastic modulus of aluminum. One can therefore easily follow that an unstressed CFRP laminate reinforcement of welded beams made of steel will not lead to a substantial increase in fatigue strength of the steel structure. This consideration led to the idea of prestressing an external reinforcement of the welded zone. The present investigation describes experimental studies to identify the adhesive system suitable for achieving high creep and fatigue strength of the prestressed CFRP patch. Experimental results (Wöhler-fields of shear-lap-specimens and welded steel beams reinforced with prestressed CFRP laminates are presented. The paper concludes by presenting a field application, the reinforcement of a steel pendulum by adhesively bonded prestressed CFRP laminates to the tensile flanges of the welded box girder. Inspections carried out periodically on this structure revealed neither prestress losses nor crack initiation after nine years of service.

  11. 桥面铺装与小箱梁的共同作用试验%Experiment of Coaction of Bridge Deck Pavement and Small Box Girder

    Institute of Scientific and Technical Information of China (English)

    钱寅泉; 周正茂; 袁桂芳; 王素娟

    2012-01-01

    Load tests on a single small box girder and a bridge were carried out to evaluate the effects of deck pavement by comparing the deflections of the girders before and after the pavement surfaced. The comprehensive elastic modulus was obtained from the test before pavement surfaced, and the coaction degree of the bridge deck pavement and the girders was obtained by comparing the flexural inertia moment corresponding to the deflection in the test after pavement surfaced with the theoretical flexural inertia moment corresponding to the supposed thickness of the pavement in work. The results from these tests show that (1) the rough interface could greatly improve the coaction degree of bridge deck pavement with girders, which could reach 100% ; (2) in general cases, the extent of the coaction of bridge deck pavement with girders could reach 70% , and for a pavement with thickness of 8 cm, the thickness of the pavement in coaction could be taken as 60% or 3 cm in thickness could be substracted from the pavement in design; (3 ) the pavement could improve the uniformity of the transverse load distribution. Load tests on a single small box girder and a bridge were carried out to evaluate the effects of deck pavement by comparing the deflections of the girders before and after the pavement surfaced. The comprehensive elastic modulus was obtained from the test before pavement surfaced, and the coaction degree of the bridge deck pavement and the girders was obtained by comparing the flexural inertia moment corresponding to the deflection in the test after pavement surfaced with the theoretical flexural inertia moment corresponding to the supposed thickness of the pavement in work. The results from these tests show that (1) the rough interface could greatly improve the coaction degree of bridge deck pavement with girders, which could reach 100% ; (2) in general cases, the extent of the coaction of bridge deck pavement with girders could reach 70% , and for a pavement with

  12. 箱梁钢筋定位自动检测装置%The automatic detection device for box girder reinforced positioning

    Institute of Scientific and Technical Information of China (English)

    邵云

    2014-01-01

    In order to reduce or eliminate the box girder quality oroblems caused by box girder reinforced orotection layer and ore-stressed oosi-tioning network reinforced deformation and installation not in olace,this oaoer researched the reinforced oositioning of reinforced orotective layer and ore-stressed oositioning network in oost tensioned ore-stressed box beam construction orocess,designed a set of automatic detection each ten-sioned oositioning detection ooint tensioned whether accuracy oositioning or not and disolayed the tensioned oositioning automatic detection de-vice,solved the oroblem of reinforced oositioning detection.%为了减少或消除因箱梁钢筋保护层及预应力定位网钢筋形变和安装不到位而引起箱梁质量问题,对后张法预应力箱梁施工工艺中的钢筋保护层及预应力定位网的钢筋定位进行了研究,设计了一套能自动检测各检测点钢筋是否定位准确并显示的钢筋定位自动检测装置,解决了钢筋定位检测的问题。

  13. 钢箱梁典型病害分析及其检测与维护技术研究%Research on Typical Defects Analysis of Steel Box Girder and Its Testing and Maintenance Technology

    Institute of Scientific and Technical Information of China (English)

    姜竹生; 瞿涛; 吕磊; 吉伯海

    2011-01-01

    基于对我国钢箱梁桥的钢箱梁病害调查,总结出我国钢箱粱典型病害的类型,分析各种钢箱梁典型病害产生的机理及导致其破坏的原因,提出了钢箱梁病害的日常检测与维护技术.针对钢箱梁的涂装劣化、钢材腐蚀、结构性损伤等病害,给出了日常检测与维护的主要项目,介绍了人工目视检测、超声波检测、磁粉检测及涡流检测等主要的检测方法的工作原理、优缺点和适用范围.%Based on the survey of China steel box girder bridges' steel box girder defects, summing up the typical defects of China steel box girder, we analyse every typical defect production mechanism and the reasons of leading to destruction of steel box girder, and propose steel box girder defects' daily testing and maintenance technology. According to coating for the deterioration, steel corrosion, structural damage and other defects of steel box girder, we give the main items of the daily testing and maintenance technology and the main detection methods including manual visual inspection, ultrasonic testing, magnetic particle testing and eddy current testing. Studying the working principle of above testing methods, advantages and disadvantages, and scope of application, should be selected based on the actual requirements in the project.

  14. Analysis of Grillage Method for Two-span 24-m Continuous Multi-chamber Irregular Box Girder Bridge%两跨24 m连续多室异型箱梁桥梁格法分析

    Institute of Scientific and Technical Information of China (English)

    钟国东

    2009-01-01

    该文通过对异型箱梁桥有限元模型的建立、输出数据的整理及分析,说明异型箱梁桥的空间分析方法,为类似桥梁的结构分析及设计提供了参考.%Through the establishment of finite element model for the irregular box girder bridge, and the sorting and analysis of the output data, the article explains the space analysis method of the irregular box girder bridge to provide the reference for the structural analysis and design of the similar bridges.

  15. 跨多股道钢箱梁天桥的结构设计%The Structural Design of Steel Box Girder Pedestrian Bridge Crossing Multiple Railways

    Institute of Scientific and Technical Information of China (English)

    沈耀海

    2011-01-01

    结合西部某新建火车站进站人行天桥工程实例,分析了设计和施工的多种控制条件,论证了主梁采用钢箱梁结构的合理性.通过有限元分析和动力特性计算可知,结构设计的控制因素为竖向自振频率,采用中墩与主梁固结的连接方式可以有效地调整结构竖向自振频率.%Based on the project case of one pedestrian bridge in one new constructed railway station at west China, many controlled conditions are analyzed about structural design and engineering construction, and the rationalitles of steel box girder bridge adopted in the design are also demonstrated. It is learned from finite - element analysis and dynamic characteristics calculation that the control factor of structural design is vertical vibration frequency, which can be improved effectively by means of fixed connection between central pier and steel box girder.

  16. Difference Solution for Shear Lag Effect of Twin-cell Box Girder%单箱双室箱梁剪力滞效应的差分解

    Institute of Scientific and Technical Information of China (English)

    刘勇; 张丽; 张元海; 张效军

    2012-01-01

    从满足剪力滞翘曲应力的轴向平衡条件出发,选取三次抛物线翘曲位移模式,考虑了悬臂板宽度及上下翼板至形心轴不同距离的影响,从而更合理反映箱形梁剪力滞翘曲应力.导出了剪力滞翘曲惯性矩、惯性积和面积等几何特性计算公式.根据最小势能原理,建立了薄壁箱梁挠曲剪力滞的控制微分方程.采用有限差分法推导出变截面悬臂葙梁剪力滞效应计算式和边界条件.运用Ansys有限元软件中的Shell63单元进行建模,分析单箱双室三跨连续箱梁剪力滞效应的分布规律.对比分析了翘曲位移模式及轴力平衡条件对剪力滞效应的影响.结果表明:二、三次抛物线均不是最合理的位移模式;连续箱梁的剪力滞效应受翘曲位移模式的影响很小;轴力平衡条件对应力分布的影响亦很小.%The warping displacement pattern of cubic parabolic curve is chosen on the axial force equilibrium condition. In order to reflect the stress distribution in the box girder more rationally,the width of the cantilever plate and the distance form the top and bottom flange plates to the centre axis are fully considered. Formulas of the moment of inertia, product of inertia and sectional area for shear lag warping geometrical properties are deduced. The equations of equilibrium with considering the shear lag for thin-walled box girders are established on the basis of the variation principle. The calculation formulas and bounding conditions of shear lag effect of the continuous box girder are deduced by adopting the finite difference solution. The Shell63 unit of Ansys program is used to analyze the distributions of shear lag effect for three-span continuous box girder. The influence of distributions by longitudinal warping displacement patterns and axial force equilibrium condition is analyzed. The results show that neither of the warping displacement patterns of quadratic nor cubic parabolic curve is the most

  17. Research on temperature effect on reinforced box girder in cold region%寒冷地区混凝土箱梁温度作用影响

    Institute of Scientific and Technical Information of China (English)

    李长凤; 王岚; 赵延林; 杜秋楠

    2013-01-01

    This paper is a response to the effect of low temperature environment on the performance of reinforced concrete box-girder in the north cold area of China, as happens in the box-girder of Harbin Songpu north approach bridge. The response consisting of allowing for the cold current effect, daily temperature changes, and deck pavement, simplifying scaled finite element, combined with temperature field, and performing a comparative analysis of three sections, such as finite element calculation of the influence of temperature effects on box beam, the experimental values, and the solution due to the elementary theory. The results show that the geographical position and environment temperature have a significant effect on the mechanical properties of reinforced box girder in cold region. Finite element analysis allowing for temperature influence produces a smaller engineering error than elementary theory analysis, which implies a necessary analysis of temperature effect in the case of the mechanical analysis of bridges.%针对北方寒冷地区的外界低温环境条件对混凝土箱梁受力性能的影响,以哈尔滨松浦大桥北引桥箱梁为背景,考虑寒流作用、日气温变化及桥面铺装,将其与有限元分析的温度场相结合,简化缩尺模型,将温度效应影响箱梁的有限元计算、实验值及初等理论求解的结果进行对比分析.结果表明:地理位置、环境温度对箱梁受力性能影响较明显,考虑温度影响的有限元分析工程误差在允许范围内,初等理论分析结果误差较大,因此,对桥梁进行力学分析时,温度效应不可忽视.

  18. Discuss the Full Framing Construction of Cast-in-place Box Girder%浅谈现浇箱粱满堂支架搭设施工

    Institute of Scientific and Technical Information of China (English)

    黄亮

    2013-01-01

    在进行桥梁上部结构的箱梁现浇施工时,满堂支架法的应用已经非常普遍。但是在进行满堂支架法施工时,其施工事故发生的频率也比较高。如何有效提高满堂支架法的施工安全,是值得去深入探究的问题。%During conduct the box girder cast-in-place const-ruction of upper structure in bridge, the application of ful fra-ming method has become so common. But when making ful framing construction method, its construction has a high acide-nt frequency. It is worth to delve into the problem of how to i-mprove the method of ful framing construction safety.

  19. Surveying Technique in Steel Box Girders Construction of Long- span Steel Pylon Cable- stayed Bridge%大跨径钢索塔斜拉桥钢箱梁施工测量技术

    Institute of Scientific and Technical Information of China (English)

    孙景领; 赵显富; 王新志

    2012-01-01

    Nanjing Third Yangzi River Bridge with its orthotropic plate streamlined fiat steel girder box is the first supergiant cable - stayed bridge in china whose main tower is of steel structure. This paper introduces the accuracy requirement of the steel box girder installation and the way to establish construction control network step by step. It also elaborates on the methods and techniques adopted in the construction and measurement of different sections of the girders. The result shows that the line type of steel box girder accords with the requirement of design.%南京长江三桥是我国首座主塔采用钢结构形式的特大型斜拉桥,主梁为正交异性板流线型扁平式钢箱梁。文章介绍了钢箱粱安装的精度要求,以及分步骤建立施工控制网的方法,并详细阐述了不同梁段施工测量的技术和方法,结果表明成桥后的钢箱梁线型符合设计要求。

  20. Finite Element and Experimental Analysis and Evaluation of Static and Dynamic Responses of Oblique Pre-stressed Concrete Box Girder Bridge

    Directory of Open Access Journals (Sweden)

    Ali Fadhil Naser

    2013-10-01

    Full Text Available Hashuang bridge is type of prestressed concrete box girder oblique bridge and it is located in Harbin City within Heilongjiang province in the east north of China. The objectives of this study are to investigate the appearance of the bridge structure and identify all the damages in the bridge structural members and to evaluate the structural performance of the bridge structure under dead and live loads. Finite element analysis is used to analyze the static designed internal forces and dynamic responses by adopting SAP200 software Ver. 14.2.0. Static and dynamic load test are adopted to evaluate the structural performance of the bridge structure. The results of field investigation process of the bridge appearance show that the bridge suffers from serious damages. The web of box girder of the second span near pier No.2 (in the quarter of middle span at 39m on the bridge length suffers from serious shear cracks. The state of abutments, piers and sidewalks is good, but the bearing, drainage holes, steel rail and expansion joints are not good and they suffer from much damage. The steel rail is corroded and the expansion joint loses the material which fills the joint. There are many dusts and debris is collected on the bridge deck in the location near sidewalk. The analysis results of finite element and load tests show that there are high tensile stresses in the quarter of middle span at distance 39 m of the bridge length and the state of the bridge structure is not good and the main problem of the bridge structure in the original design of prestressed tendons. Therefore, this study recommends for repairing and strengthening the bridge structure to increase the stiffness and strength and to improve the bearing capacity of the bridge structural members to increase the service live of the bridge structure.

  1. 大跨度斜拉桥钢箱梁非对称安装技术%Asymmetric Mounting Technology for Steel Box Girder of Large - span Cable - stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    黄中华

    2012-01-01

    介绍了辽宁滨海公路辽河特大桥斜拉桥钢箱梁非对称悬臂安装技术,通过对本桥方案箱梁非对称悬臂安装方案—边跨钢梁高支架上直接滑移就位连接、主跨钢梁逐段悬臂安装的方案可行性研究与实施,为同类型桥梁施工提供了很好的借鉴作用。%Asymmetric cantilever - type mounting technology of steel box girder of cable - stayed bridge of Li- aohe Bridge across Liaoning Coastal Highway is introduced; through the feasibility study and implementation of asymmetric cantilever - type mounting scheme of steel box girder of the bridge - scheme of direct slip in place con- nection on high bracket of side - span steel girder and section by section cantilever - type mounting of main span steel girder, a good reference is provided for the bridge construction of the same type.

  2. Space Mechanical Characteristics of Continuous Box Girder Bridge with Variable Width%变宽度连续箱梁桥空间力学性能分析

    Institute of Scientific and Technical Information of China (English)

    孙峰伟

    2016-01-01

    Continuous box⁃girder bridge with variable⁃width is widely used in transportation construction. However, there is few study about the special structure. Taking a multi⁃span continuous box bridge with variable width of the intercity railway between Zhengzhou and Xinzheng international airport as an example, the influence of variable width section on the space me⁃chanical properties of continuous girder bridge was studied, taking into account of transverse effect of girder. Based on spatial beam element model, the feature of internal force, stress as well as displacement was obtained under dead load, prestressed load, temperature load and live load. The results indicated that torsion, reaching its maximum at bearing of the first span, was greatly influenced by the width of the cross section. And bearing bending moment and shearing force increased with wider beam under the action of self weight. The analysis results had reference value for the design of similar bridges.%横向变宽度桥梁在交通建设中被广泛采用,但对这种特殊结构的分析研究较少。本文以郑机城际铁路多跨变宽度连续箱梁桥为例,考虑主梁横向协同工作效应,研究截面宽度变化对连续梁桥空间受力特性的影响规律。通过建立空间梁单元模型,得到恒载、预应力荷载、温度作用和列车活载等荷载作用下箱梁的内力、正应力和位移分布特征。结果表明:变截面宽度对扭矩影响较大,在宽度较大的第一跨支座处达到最大扭矩值;自重作用下,支座处弯矩及剪力随着梁宽度变大而增大。分析结果对设计同类桥梁有参考价值。

  3. 箱型梁附加挠度与剪力滞效应的一维有限元分析%One-dimensional finite element analysis on additional deflection and shear-lag effect of box-girders

    Institute of Scientific and Technical Information of China (English)

    杨绿峰; 周月娥; 曾有凤

    2013-01-01

    当前箱型梁剪力滞效应分析的一维离散有限元法对剪力滞函数的处理存在局限性,而且剪力滞系数难以准确反映翼缘截面剪力滞效应及其变化规律.为此,利用箱梁附加挠度代替剪力滞函数建立箱梁翼缘的纵向位移函数,并根据能量变分原理建立控制微分方程并识别了其中的待定参数.以箱梁挠度、附加挠度及其一阶导数作为单元节点位移参数,提出了箱型梁剪力滞效应分析的一维离散有限元法,给出了箱梁的自然边界条件和强迫边界条件.基于箱梁挠度和附加挠度定义了新的剪力滞系数,分析了不同支撑条件对箱型梁剪力滞效应的影响.算例分析证明了该方法的有效性,且具有较高的计算精度;与传统的基于应力的剪力滞系数相比,基于挠度的剪力滞系数能够更加准确地反映箱型梁截面的剪力滞效应及其分布规律.%The shear-lag function in one-dimensional finite element method for box-girders has no definite physical interpretation, and moreover the shear-lag coefficient can not reflect correctly the shear-lag effect and its variation along the axis of box girder. In order to circumvent these problems, the additional deflection function instead of the shear-lag function is incorporated in the longitudinal displacement of the flange of the box girder. The variational principle is employed to identify the undetermined constants in the longitudinal displacement function. Furthermore, the deflection, additional deflection and their first derivatives are adopted as nodal displacement parameters in the discreted finite elements of box-girder, leading to one-dimensional finite element method for the shear-lag effect of box girders. A new shear-lag coefficient is defined in terms of the deflection of the box-girder, based on which the shear-lag effect on box girders is analysed with different boundary conditions considered. Examples show that the shear

  4. Ansys -based research on fatigue crack of welded box girder for overhead travelling crane%基于Ansys的桥式起重机焊接箱形梁疲劳裂纹研究

    Institute of Scientific and Technical Information of China (English)

    殷玉枫; 曾光; 吕西波; 张孟辉

    2012-01-01

    The box girder of overhead travelling crane features typical thin-wall structure, in which fatigue crack can appear easily due to load situation and weld defects of the crane, etc. Considering such case, the Ansys finite element software is adopted for load analysis of typical working conditions of the box girder in order to figure out the position and causes of any crack, and the fracture mechanics and Ansys software are adopted for analysis and simulation of the stress field, displacement field of the fatigue crack in box girder, as well as the size of stress field, which is significant to estimate the fatigue crack expansion and remaining life of the crane box girder.%桥式起重机箱形梁是典型的薄壁结构,由于起重机受载情况及本身结构焊接缺陷等因素,在箱形梁上很容易出现疲劳裂纹.针对桥式起重机箱形梁疲劳裂纹现象,借助Ansys有限元软件,对箱形梁典型工况进行受载分析,判断出裂纹的位置及其产生原因;运用断裂力学和Ansys软件分析模拟出箱形梁疲劳裂纹的应力场、位移场以及应力场区域的大小,对起重机箱形梁进行疲劳裂纹扩展以及剩余寿命的预估都有意义.

  5. Experimental Modal Anlysis of Pedestrian Steel Box Girder Bridge%人行钢箱梁桥模态试验研究

    Institute of Scientific and Technical Information of China (English)

    申杨凡; 杨斌; 何钰龙; 郭凯强; 续琦峰; 王艳琪; 贾艳敏

    2016-01-01

    为了了解人行钢桥的自振特性,运用东华测试系统对某人行钢箱梁桥进行模态测试,得到桥梁的动力特性参数,并将试验测得的固有频率、模态振型与 ANSYS 有限元模型中的模态数据进行对比分析。分析结果表明:该人行钢箱梁桥的基频的试验值与理论值的误差为3.8%,行人的附加模态质量是对试验产生误差的原因之一,但对结构基频的影响不大,这也就证明了采用峰值拾取法处理时域数据是合理的,同时结合模态判定准则所得模态数据也是可信的,通过该模态测试系统可有效地测得模态参数(固有频率、模态振型及阻尼比)。%In order to study the natural vibration characteristics of the pedestrian bridge steel,a pedestrian steel box girder bridge’s model experiment is carried out with Donghua Test System to get the dynamic characteristics of bridge,and comparing Natural frequency and mode shapes with modal data a-nalysis of ANSYS finite element model.The analysis results indicate that the error between the fundamen-tal frequency experiment value and the theoretical value of the pedestrian steel box girder bridge is 3.8%.And the additional modal mass of pedestrian is one of the reasons why the experiment have error,it’s in-fluence is little.What proved that using the Peak Picking Method to manipulation time domain data is rea-sonable.At the same time,the modal date that obtained by combining with the modal criterion is credi-ble.That modal parameters(natural frequency,modal vibration mode and damping ratio)can be measured effectively by the modal testing system.

  6. 预应力混凝土悬浇箱梁裂缝问题的探讨%Discussion on Prestressed Suspension Casting Box Girder Structure

    Institute of Scientific and Technical Information of China (English)

    梁岩

    2014-01-01

    With the widely use of prestressed box girder bridge structure with suspension casting popularization in the transportation construction, some structure due to the occurrence of cracks, affect the use of bridge in further. This article takes two typical bridges for practical cases which are Shenzhang highway bridge, between Baidun harbour bridge and Xiangshan harbour bridge connecting. Through theory and calculation analysis of root cause of structure bridge seam, it infers the cause of cracks which leads to the formation of prestressed suspension casting box girder structure. By optimizing the structure of prestressed tendon, reinforcing transverse rebar , increasing shear effect and other measures, it reduce the bad influence of external factors on the structure during the period of construction and operation stages, and prevent the happening of the similar structure disease.%随着悬浇预应力箱梁结构桥梁在交通建设项目中的普及,一些结构由于裂缝的出现,影响到桥梁的进一步应用。本文以沈彰高速公路大转弯桥、宁波市象山港大桥接线工程白墩港大桥两座典型桥梁为实际案例,通过对发生病害结构桥梁裂缝成因的理论及计算分析,推测出导致悬浇预应力箱梁结构形成裂缝的成因,提出设计过程中,通过优化预应力结构配束,增加横向钢筋加大抗剪作用等措施,减少施工期间及运营阶段外部因素对结构的不良影响,防止类似结构病害的发生。

  7. Pedestrian bridge steel box girder with steel truss mechanics performance comparison and analysis%钢箱梁与钢桁架人行天桥力学性能对比分析

    Institute of Scientific and Technical Information of China (English)

    申杨凡; 续琦峰; 杨斌; 王绍全; 郭凯强; 王艳琪; 贾艳敏

    2015-01-01

    为了分析并对比钢箱梁与钢桁架人行天桥的力学性能,建立了两者的ANSYS有限元计算模型,通过静力分析,得出钢桁架人行天桥的承载力更大,通过动力特性分析,钢桁架人行天桥较钢箱梁人行天桥更易产生扭转,且钢箱梁的自振频率较钢桁架的自振频率要大。%In order to analyze and contrast the steel box girder and steel truss pedestrian bridge mechanical properties,the ANSYS finite element calculation model is established,by static analysis,we can draw the steel truss of pedestrian bridge bearing capacity is larger,through the analy-sis of the dynamic characteristics of the pedestrian steel truss bridge with steel box girder footbridge reverse easier to be produced,and the natural frequency of vibration of the steel box girders for bigger than the natural frequency of vibration of steel truss.

  8. Full scale test of a SSP 34m box girder 2. Data report; Reinforced glass fiber/epoxy used in wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Find M.; Branner, K.; Nielsen, Per H. (and others)

    2008-05-15

    This report presents the setup and result from three static full-scale tests of the reinforced glass fiber/epoxy box girder used in a 34m wind turbine blade. One test was without reinforcement one with cap reinforcement and the final test was with rib reinforcement. The cap reinforcement test was part of a proof of concept investigation for a patent. The tests were performed at the Blaest test facility in August 2007. The tests are an important part of a research project established in cooperation between Risoe National Laboratory for sustainable energy--Technical university of Denmark, SSP-Technology A/S and Blaest (Blade test centre A/S) and it has been performed as a part of Find Moelholt Jensen's PhD thesis. This report is the second data report containing the complete test data for the three full-scale tests. This report deals only with the test methods and the obtained results, no conclusions are drawn. These can be found in papers and patent referenced in the data report. Various kinds of measuring equipment have been used during these tests: acoustic emission, force transducers, strain gauges and optical deformation measuring system (DIC). The experimental investigation consisted of the following tests: 1) Flapwise bending with no reinforcement 2) Flapwise bending with wire reinforcements 3) Flapwise bending with rib reinforcements. (au)

  9. Application of TMD in Large Span Steel Box Girder Footbridge%TMD在大跨径钢箱梁人行桥上的应用分析

    Institute of Scientific and Technical Information of China (English)

    苑翔

    2013-01-01

    This paper introduces the Tuned Mass Damper (TMD) composition and operation principle of the structure, comparison of advantages and disadvantages of TMD and other control of steel box girder footbridge vibration methods, and combined with the Mianyang No.1 bridge footbridge of Sichuan Province as an example, through the use of text and graph-table combination method, describes vividly the practical application of TMD in large span footbridge.%  介绍了质量调谐阻尼器(TMD)的结构组成以及工作原理,比较了TMD与其它控制钢箱梁人行桥振动方法的优缺点,并结合四川省绵阳市一号桥人行桥为工程实例,通过采用文字与图、表相结合的方式,形象地阐述了TMD在大跨径人行桥中的实际应用。

  10. 扁平钢箱梁剪力滞效应分析%Shear lag effect analysis of flat steel box girder

    Institute of Scientific and Technical Information of China (English)

    乔朋; 周绪红; 狄谨

    2014-01-01

    The shear lag effects of flat steel box girder under concentrated and uniform loads were studied by using finite element method.Considering the reasonable ranges of design parameters of flat steel box girder,the influences of some parameters including the width and height of cross section,the thicknesses of top and bottom slabs,the thicknesses and spacings of longitudinal and transverse diaphragms on shear lag effects were analyzed.Based on the result of theoretical analysis,the practical formula was proposed to calculate the shear lag coefficient of flat steel box girder by using mathematical regression analysis,and the calculation result of practical formula was compared with the result of finite element method.Analysis result indicates that span-width ratio has the most significant influence on shear lag effects,when the span-width ratio increases from 1.786 to 8.926,the shear lag coefficients of top and bottom slabs decrease from 1. 40 and 1. 32 to 1.07 and 1. 06,and decrease by about 20%.When the thickness of longitudinal diaphragm increases from 10 mm to 30 mm,the shear lag coefficient of side web decrease by 7%, while the coefficients at other positions change by less than 1%.When the ratio of longitudinal diaphragm spacing to girder width increases from 0.430 to 0.582,the shear lag coefficient increases by 9%.Other parameters have negligible effect on shear lag coefficient.The relative error between the results of proposed practical formula and finite element method is less than 1%,which conforms the formula has higher calculation precision, and meets the need of engineering calculation.4 tabs,14 figs,18 refs.%利用有限元法研究了扁平钢箱梁在集中荷载和均布荷载作用下的剪力滞效应。结合扁平钢箱梁设计参数的合理取值范围,分析了截面宽度和高度、顶板和底板厚度、纵隔板与横隔板的厚度和间距等参数对剪力滞效应的影响。根据理论分析结果,应用回归分析法提出了

  11. A case study of interior low-frequency noise from box-shaped bridge girders induced by running trains: Its mechanism, prediction and countermeasures

    Science.gov (United States)

    Zhang, Xun; Li, Xiaozhen; Hao, Hong; Wang, Dangxiong; Li, Yadong

    2016-04-01

    A side effect of high-speed railway and urban rail transit systems is the associated vibration and noise. Since the use of concrete viaducts is predominant in railway construction due to scarce land resources, low-frequency (20-200 Hz) structure-radiated noise from concrete bridges is a principal concern. Although it is the most commonly used bridge type, the mechanism of noise emission from box-shaped bridge girders when subjected to impact forces from moving trains, which sounds like beating a drum, has not been well studied. In this study, a field measurement was first made on a simply-supported box-shaped bridge to record the acceleration of the slabs and the associated sound pressures induced by running trains. These data indicated that a significant beat-wave noise occurred in the box-shaped cavity when the train speed was around 340 km/h, which arose from the interference between two sound waves of 75.0 Hz and 78.8 Hz. The noise leakage from the bridge expansion joint was serious and resulted in obvious noise pollution near the bridge once the beat-wave noise was generated in the cavity. The dominant frequency of the interior noise at 75.0 Hz was confirmed from the spectrum of the data and the modal analysis results, and originated from the peak vibration of the top slab due to resonance and the first-order vertical acoustic mode, which led to cavity resonance, amplifying the corresponding noise. The three-dimensional acoustic modes and local vibration modes of the slab were calculated by using the finite element method. A simplified vehicle-track-bridge coupling vibration model was then developed to calculate the wheel-rail interaction force in a frequency range of 20-200 Hz. Numerical simulations using the boundary element method confirmed the cavity resonance effect and the numerical results agreed well with the data. Based on the calibrated numerical model, three noise reduction measures, i.e., adding a horizontal baffle in the interior cavity, narrowing

  12. Full scale model test of segmental precast concrete box girder with external and internal tendons%体内-体外混合配束节段预制拼装箱梁足尺模型试验研究

    Institute of Scientific and Technical Information of China (English)

    郑开启; 卜红旗; 刘钊; 惠卓; 吕志涛

    2013-01-01

    To investigate the structural behavior of segmental precast prestressed concrete box girder un-der the regular service stage and the construction state,a span of 48 m full scale box girder model of this type was tested for the Fourth Nanjing Yangtze River Bridge approach. The assembling and loading plans were de-termined according to the geometric parameters as well as the actual constraints of the girder. This paper focuses on the static performance,such as stress and displacement changes of the girder during segment loading and transporting. Comparative finite element method analysis was also performed for checking. The model test results show that at the regular service stage,the residual deformation of the girder after unloading is small,which demonstrates that the girder keeps in elastic during loading. The tooth joints of segments work well with each other and have no relative slip;the global performance of the girder is good as monotonous. The vertical distribution of longitudinal strain at joint and between joints basically accords with hypothesis of plane section. Also,the stress increment of prestress tendons is linear to the mid-span moment change. Finally,during the segment trans-port stage,it shows that there is sufficient compressive stress of the lower flange of the girder to meet the security requirements of transporting girder.%  以南京长江第四大桥引桥为背景,开展了一孔48 m跨径体内-体外混合配束节段预制拼装箱梁的足尺模型试验,以研究该类箱梁在正常使用阶段和施工状态下的结构行为。根据试验箱梁的尺寸参数以及实际约束条件确定了拼装与加载方案。本文重点研究正常使用荷载和梁上运梁两种工况下梁体应力状况与位移变化等结构静力性能,并与试验梁实体有限元模型进行对比分析。研究结果表明:在正常使用阶段,加、卸载后拼装梁体残余变形较小,基本处于弹性工作状态,整体

  13. 体内-体外混合配束节段预制拼装箱梁足尺模型试验研究%Full scale model test of segmental precast concrete box girder with external and internal tendons

    Institute of Scientific and Technical Information of China (English)

    郑开启; 卜红旗; 刘钊; 惠卓; 吕志涛

    2013-01-01

    To investigate the structural behavior of segmental precast prestressed concrete box girder un-der the regular service stage and the construction state,a span of 48 m full scale box girder model of this type was tested for the Fourth Nanjing Yangtze River Bridge approach. The assembling and loading plans were de-termined according to the geometric parameters as well as the actual constraints of the girder. This paper focuses on the static performance,such as stress and displacement changes of the girder during segment loading and transporting. Comparative finite element method analysis was also performed for checking. The model test results show that at the regular service stage,the residual deformation of the girder after unloading is small,which demonstrates that the girder keeps in elastic during loading. The tooth joints of segments work well with each other and have no relative slip;the global performance of the girder is good as monotonous. The vertical distribution of longitudinal strain at joint and between joints basically accords with hypothesis of plane section. Also,the stress increment of prestress tendons is linear to the mid-span moment change. Finally,during the segment trans-port stage,it shows that there is sufficient compressive stress of the lower flange of the girder to meet the security requirements of transporting girder.%  以南京长江第四大桥引桥为背景,开展了一孔48 m跨径体内-体外混合配束节段预制拼装箱梁的足尺模型试验,以研究该类箱梁在正常使用阶段和施工状态下的结构行为。根据试验箱梁的尺寸参数以及实际约束条件确定了拼装与加载方案。本文重点研究正常使用荷载和梁上运梁两种工况下梁体应力状况与位移变化等结构静力性能,并与试验梁实体有限元模型进行对比分析。研究结果表明:在正常使用阶段,加、卸载后拼装梁体残余变形较小,基本处于弹性工作状态,整体

  14. 基于WIM数据的上海长江大桥钢箱梁的寿命评估%Life Evaluation of Box Girder of Shanghai Yangtze River Bridge Based on WIM Data

    Institute of Scientific and Technical Information of China (English)

    廖霞霞; 胡明敏; 徐昊

    2014-01-01

    Evaluation of the box girder details of Shanghai Yangtze river can provide the basis for the bridge ’ s maintenance and repairment .The research result of “Fatigue stress spectrum study of the steel box girder of Shanghai Yangtze River Bridge ,based on the analysis of WIM data” was used to get all the details of the stress spectrum of steel box girder .Then according to BS 5400 the tenth part ,confirming S-N curve which can reflect the details quality of fatigue .Finally ,estimating the steel box girder’s life with the combination of the Miner fatigue cumulative damage rule .According to the result ,we can know that during the current oper-ating process ,the box girder details have small stress amplitude ,high cycles and small damage magnitude . These details will not bring about fatigue damage .During the current operation ,the structure will keep high safety performance and reliability .Determine the damage point and the size of the damage value is unique in this article .%通过对上海长江大桥细节寿命的估算为大桥的维护和修复提供依据。基于论文“基于WIM数据的上海长江大桥钢箱梁应力谱研究”的研究结果,得到钢箱梁各细节的应力谱,同时参考英国桥梁规范BS 5400第十部分,确定了能够体现细节疲劳性能的 S-N曲线,并结合M iner疲劳累积损伤准则,对大桥钢箱梁细节寿命进行评估。研究结果表明,在现行日常运营过程中,钢箱梁各细节应力幅值较小,循环次数多,损伤量级很小,故细节不会发生疲劳破坏,即结构在现行运营期间保持了很高的安全性和可靠度。

  15. Stress analysis of deck pavement of continuous steel box girder%连续钢箱梁桥面铺装层结构应力分析

    Institute of Scientific and Technical Information of China (English)

    李国芬; 曹牧; 王宏畅; 朱华平

    2013-01-01

      正交异性钢桥面的构造复杂,用理论算法对铺装层进行力学计算,较难得到精确的计算结果。本文利用有限元通用软件对曲线钢箱梁桥浇筑式沥青铺装层进行受力分析,将正交异性钢桥面板、铺装层作为整体,建立有限元模型,研究铺装层受力变形特点。根据钢桥面铺装层常出现的病害,并结合超载及刹车产生的水平荷载对铺装层受力的影响,提出相应的桥面铺装层破坏的综合控制指标。%The geometric structure of steel deck plates is complex. So it is difficult to get precise results in the mechanics calculation of deck pavement with traditional methods. This paper adopts the finite element meth-od for the mechanics analysis of the composite guss asphalt surfacing layer of curved steel box girder bridges. By taking the orthotropic steel deck and the pavement as a whole,a reasonable finite element model which estab-lished can be used to study the stress and deformation features of the surfacing layer. According to the common diseases in steel deck pavements and the effect of the overload and the horizontal load in braking to the pave-ment,this paper puts forward the comprehensive control indicators for pavement failures.

  16. Slanted Pylon Construction Technology of a Cable Stayed Bridge with Box Girder of Corrugated Steel Webs and Without Back Stays%波形钢腹板箱梁无背索斜拉桥斜塔施工技术

    Institute of Scientific and Technical Information of China (English)

    贾贯乾

    2015-01-01

    The original structural single tower cable stayed bridge without back stays is used in the main bridge on Zhens-hui Road in Xinmi City.The main girder is box girder with corrugated steel webs.Pier,tower and girder of the main bridge are consolidated together.The dip angle of the main tower is 59 degrees.Construction of the main girder is very difficult. Based on the design,segmental division is made of the main tower construction.To overcome the difficulties of construc-tion,comparison and study were made on the construction scheme which was explained in details.%新密市溱水路大桥主桥采用新型的钢-混组合结构梁独塔无背索斜拉桥桥型,主梁主塔为波形钢腹板混凝土箱梁。主桥为墩塔梁固结体系,塔身倾斜,斜塔倾角59°,主塔施工难度非常大,质量控制困难。依据设计特点,对斜塔施工进行了合理的节段划分,为克服斜塔实心混凝土结构施工困难,对施工方案进行详细的比选和研究,并对方案实施进行了详细阐述。

  17. CALCULATION AND ANALYSIS ON FLEXURAL CAPACITY OF PRESTRESSED COMPOSITE BOX GIRDER%预应力组合箱梁抗弯能力计算分析

    Institute of Scientific and Technical Information of China (English)

    胡少伟; 胡汉林

    2012-01-01

    The prestressed steel and concrete composite beams having been widely used in engineering as a new transverse bearing component.The bending capacity is one of the most fundamental and important behaviors.The calculation formulas of elastic bearing capacity and deflection were derived considering the slip at the steel-concrete interface and the stress increments of prestressed tendons on the base of the elastic theory;and on the premise of plane section and complete composite action,the expressions of prestressed composite beam's ultimate plastic capability which consider the stress increments of prestressed tendons were deduced,based on the simplified plastic theory.These foumulas can reflect the characteristics of the prestressed composite box girder.It turns out that the calculation values are in good agreement with the experimental results,which meet the engineering accuracy.%预应力钢-混凝土组合梁作为一种新型的横向承重构件,在工程中得到了广泛的使用,准确计算其抗弯承载能力是工程上最为基本也是最重要的要求。该文以弹性分析理论为基础,推导了考虑交界面相对滑移和预应力增量的预应力组合梁弹性承载能力和挠度计算公式;以完全协同作用和平截面假定为前提,采用简化的塑性理论,推导了考虑预应力增量的极限抗弯承载能力计算公式。公式能够反映预应力组合梁的受力特点,计算结果与试验值吻合良好,满足工程精度。

  18. Design of Prestressed Concrete Box Girder Based on Life Cycle%基于全寿命周期的预应力砼小箱梁设计

    Institute of Scientific and Technical Information of China (English)

    余少华

    2013-01-01

    With the increasing age of bridge girders,performance degradation is an unavoidable phenomenon. In addition to the natural aging,the bridge performance degradation can be attributed to many factors,such as the bridge construction speed,short design cycle,the outdated design concepts,serious overload,lack of mainte-nance and so on. Therefore,it is significant to take into consideration the whole bridge life cycle in the scientific design of bridges. This study first collected the road area data of a newly built bridge,including environmental data,traffic data and other basic structure data,then divided the life cycle with reference to the bridge mainte-nance specification provisions of the management and maintenance unit,and finally analyzed the cycle cost. This preliminary study on the cycle life of commonly-used prestressed concrete box beam tries to provide some reference for the bridge design.%随着桥龄的增加,主梁性能老化是无法避免的现象。然而桥梁性能退化除了自然老化外,还与桥梁建设速度过快、设计周期短、理念陈旧、超载超限严重、疏于管养等因素有关。因此,科学的设计应把桥梁纳入全寿命周期考虑,本研究先搜集了新建桥梁公路干线所在地区的相关数据,如环境数据、交通量、基本及已建桥梁的结构数据,再结合管养单位执行的桥梁养护规范规定划分生命周期,进行周期成本分析,对常用的预应力砼小箱梁进行了全寿命周期设计的初步研究,以供同道参考。

  19. The Compare Between Steel Box Girder And Steel Truss In City Overpass%钢箱梁及钢桁架城市人行天桥对比分析

    Institute of Scientific and Technical Information of China (English)

    范旭辉

    2012-01-01

    Steel box girder bridges are widely used in our city pedestrian bridge and it has the characteristic such as linear appearance and easy factory prefabricated construction. However, due to the need to control the vertical nat- ural vibration frequency, the box girder general beam steel is too high. As a result the steel truss bridge in the city pedestrian bridge is also a widely the popularity of the bridge type. The particle compares among the same span of two bridge type comprehensive comparison of the amount of structural steel, vertical natural frequency, constructa- bility, stairways climbed higher.%钢箱梁桥在我国城市人行天桥中应用广泛,其优点是线型美观,工厂预制装配式施工方便等。然而由于需要控制竖向自振频率,钢箱梁一般梁高过高,造成压抑感强,两侧梯道过长等缺点也不容忽视,因此钢桁架桥在城市人行桥中也是一种可以广泛普及的桥型,本文对相同跨径的两种桥型就结构用钢量、竖向自振频率、施工性、梯道爬高等方面进行了综合对比。

  20. 用体单元分析薄壁箱梁剪力滞效应的新方法%On new method for analyzing thin-wall box girder shear lag effect with body element

    Institute of Scientific and Technical Information of China (English)

    王延华

    2012-01-01

    In order to analyze the shear lag effect of the thin-wall box section in a more accurate way,the paper points out tetrahedral body element is a more effective method,indicates that the finite element software is used to analyze the box girder modeling,and proves the accuracy of the calculation method by experiment,so as to provide certain reference for relative personnel.%为了更精确地分析薄壁箱形截面的剪力滞效应,提出了用四面体单元分析是一种比较有效的方法,利用有限元软件对箱梁建模分析,并经实例验证了本算法的准确性,可供相关人员参考。

  1. Force Analysis and Experimental Study of Steel Anchor Box in Girder of Railway Hybrid Girder Cable-Stayed Bridge%铁路混合梁斜拉桥索梁钢锚箱受力分析与试验研究

    Institute of Scientific and Technical Information of China (English)

    刘振标; 施洲; 罗世东; 么超逸; 曾甲华

    2015-01-01

    The Yongjiang River Bridge on the North Ring Link of the Ningbo Railway Termi‐nal is a hybrid girder cable‐stayed bridge with a main span of 468 m .In view of the characteristics of the heavy double‐track railway live load and narrow deck on the bridge and the strict require‐ments for the train traveling safety and passenger riding comfort ,a new type of the double‐cantile‐ver steel anchor box in girder has been developed .Integrating both the functions of the structure itself and the wind fairings ,the new steel anchor box has advantages of great bending ,torsional stiffness and good fatigue performance as compared to the traditional single‐cantilever steel anchor box .To systematically analyze the force characteristics of the new type of the anchor box ,the fi‐nite element model was established and the force and force transfer characteristics of the anchor box were analyzed .The local model in full scale of 1∶1 for the anchor box was fabricated and the fatigue checking test of 2 million time cycling and the fatigue failure test of 1 million time cycling were carried out .The results of the tests show that the stress and load of the new anchor box ex‐hibit linear relationship and no cracks are found in the model ,verifying that the structural design of the anchor box is rational and safe and the anchor box is the rational steel anchor box type in girder that is applicable to long span double‐track railw ay cable‐stayed bridges .%宁波铁路枢纽北环线甬江特大桥为主跨468 m的混合梁斜拉桥,基于双线铁路活载重、桥面窄、列车运营安全性和旅客乘坐舒适度要求高,研究采用了一种新型双挑式索梁钢锚箱,集结构功能与风嘴功能于一体,相比传统单挑式锚箱具有抗弯抗扭刚度大、疲劳性能优良的特点。为系统分析新锚箱结构受力特性,通过建立有限元模型,分析索梁钢锚箱的受力特点与传力特性,并制作1∶1足尺

  2. 混凝土薄壁箱梁剪力滞效应的空间分析%Spatial Analysis on Shear Lag Effect of Concrete Thin-Walled Box Girder

    Institute of Scientific and Technical Information of China (English)

    林志春; 魏保立; 邓苗毅

    2011-01-01

    通过对预应力混凝土薄壁箱梁剪力滞效应的理论分析,重点阐述了有限元法理论在剪力滞分析中应用,介绍了规范考虑剪力滞效应的有效分布宽度方法.利用一实际混凝土箱梁桥进行有限元建模计算,对于箱梁在受到不同荷载作用时表现的剪力滞效应进行了分析,指出箱梁在对称荷载作用情况下仍然表现出剪力滞效应.通过箱梁有限元模型计算指出了初等梁理论的适用范围,可为箱型截面桥梁设计提供借鉴意义.%In this article, through analyzing thin-walled box girder of prestressed concrete shear lag effect in theory,it was focused on the theory of finite element analysis of shear lag in the application. And briefly describes the specifications for effective width considering of shear lag effect. By analyzing the actual concrete box girder bridge with FEM, the stress and deflection of box under different load conditions were calculated. Analyzing shear lag effect of the box in different loads conditions, it was pointed that box still showed shear lag effect in the case of symmetrical load condition. For the effective distribution width about the top and bottom plate of the box has been studied, it was indicated that shear lag effect can be considered with the effective distribution width. By calculating stress and deflection of the box with FEM, it was identified that the application of general beam theory. This article could provide reference for design of the box bridge.

  3. Load transverse distribution of single box multi-cell girder with corrugated steel webs%单箱多室波形钢腹板箱梁荷载横向分布

    Institute of Scientific and Technical Information of China (English)

    马磊; 万水; 蒋正文; 李明鸿

    2014-01-01

    A formula for calculating the load transverse distribution coefficient of single box multi-cell girder with corrugated steel webs was deduced by the rigid connected beam method on the basis of the equivalent plane plate-girder model.Then,a test on a single box double-cell girder with cor-rugated steel webs was carried out to research its load transverse distribution.The research results show that the error between the load transverse distribution coefficient calculating with rigid connect-ed beam method and that obtained from test and finite element analysis is less than 7%.Compared with the finite element analysis result of the girder with midspan diaphragm,the load transverse dis-tribution coefficient calculated by the rigid connected beam method is relatively safe.Thus the rigid connected beam method can be used to calculate the load transverse distribution coefficient of the sin-gle box double-cell girder with corrugated steel webs where or not there is a diaphragm in the mids-pan of the girder.The distribution law of the load transverse distribution coefficient along the longi-tudinal of single box multi-cell girder with corrugated steel webs was suggested according to the ex-perimental results.The moment transverse distribution coefficients are mc ,where mc is the load trans-verse distribution coefficient at the middle span calculated by the rigid beam method.For the support reaction transverse distribution coefficients of the middle girder,0.6m0 is used at the end,where m0 is the load transverse distribution coefficient at the end calculated by the level principle method;mc is applicable from L/4 to L;and the transition from the end to L/4 is linear.The support reaction transverse distribution coefficients of the side girder are 0.9m0.%将单箱多室波形钢腹板箱梁等效为平面板梁模型,用刚接梁法推导了单箱多室波形钢腹板箱梁荷载横向分布系数的计算公式,并对1根单箱双室波形钢腹板箱梁进行了荷

  4. Technology for Erecting Box Girder with Bridge Erecting Machine and Tow Beam Under Low Clearance%低净空架桥机结合扁担梁架设箱梁技术研究

    Institute of Scientific and Technical Information of China (English)

    郭富君

    2015-01-01

    高速公路连接线桥梁工程设计采用先简支后连续小箱梁施工,在穿越高铁时,由于高铁桥梁底部距新建公路桥梁桥面净空只有5.823 m,架桥机无法采取正常的工艺架设施工。通过方案优化,提出了架桥机结合自制扁担梁架设箱梁的施工技术,在不影响高铁运行的情况下,解决了净空不足情况下的小箱梁架设施工难题。%The design of bridge engineering for expressway connecting line uses simply-supported to continuous casket gird-er construction.During the crossing of the high-speed railway,due to the clearance between the bottom of the high-speed railway bridge and the newly built highway bridge deck is only 5.823 m,the bridge erecting machine cannot take normal process erection.Through the scheme optimization,the construction technology for erecting box girder with bridge erecting machine and self-made tow beam is proposed.It solves the problems for erecting casket beam under insufficient clearance without affecting the operation of high-speed railway.

  5. On construction of post-tensioning method precast prestressed concrete continuous box girder%后张法预制预应力混凝土连续箱梁施工

    Institute of Scientific and Technical Information of China (English)

    王迎春

    2011-01-01

    Combining with the recent work experience,the paper sums up the construction points and the craft procedures of the post-tensioning method precast prestressed concrete continuous box girder,and points out some precautions and the technical measures,so as to improve the engineering quality and to create better economic and social benefits.%结合近年来的工作经验,对后张法预制预应力混凝土连续箱梁施工要点和工艺流程进行了归纳,并提出了一些施工注意事项和技术措施,以提高工程质量,创造更好的经济效益和社会效益。

  6. Design of Curve Cable-Stayed Bridge with Steel-Box Hybrid Girder for Four-Track Railway%四线铁路钢箱混合梁弯斜拉桥设计研究

    Institute of Scientific and Technical Information of China (English)

    罗世东; 饶少臣

    2011-01-01

    According to the mechanical characteristics of the curve cable-stayed bridge of four-track railway, the structure design and research on the cable, girder, bridge towers and foundation construction were launched by space bar finite element static analysis method in terms of the cable-stayed bridge architecture, the bridge stiffness, shrinkage and creep, and geometric nonlinearity etc. FEM analysis was used to study the stress distribution of the orthotropic steel box decks under the combined effect of the vertical and horizontal bending, shear lag and torsion warping. With FEM simulation, the local stress analysis and structure research were carried out on several aspects, such as the joint section of steel box girder and the prestressed concrete beam, the consolidation area between the main girder and the crossbeam of the bridge tower as well as the upper and lower steel anchor boxes for stay cable. Vehicle-bridge coupled time-varying analysis method was adopted to study the train running dynamic performance. Response spectrum method and seismic time history analysis method were used to study and analyze the seismic performance and seismic measures of the structure. Analyses show that about 3 m distance between the diaphragm and the web plates adopted for the steel box girder plays important role in improving the main beam structure in the curve cable-stayed bridge of four-track railway. Good train operation performance indicates that 1/900 deflection-span ratio adopted for the bridge to control the structural stiffness is more reasonable. E-type steel damping bearing has improved the seismic performance of the bridge.%根据四线铁路弯斜拉桥的受力特点,采用空间杆系有限元静力分析方法,围绕斜拉桥结构体系、桥梁整体刚度、收缩徐变、几何非线性等方面对其展开拉索、主梁、桥塔、基础的构造设计与研究.采用有限元仿真分析技术,研究正交异性桥面板的弯钢箱梁在受纵横向弯曲

  7. 现浇箱梁满堂式支架搭设与设计方案%The erection and design scheme of cast-in-situ box girder full timbering

    Institute of Scientific and Technical Information of China (English)

    孙保华

    2015-01-01

    Combining with the engineering example,this paper introduced the design parameters and compilation basis of cast-in-situ box girder full timbering erection,discussed the foundation treatment scheme in full timbering erection,and elaborated the load calculation process,re-searched the specific measures of timbering configuration,to ensure the stability of timbering and the quality of beam body.%结合工程实例,介绍了现浇箱梁满堂式支架搭设的设计参数及编制依据,探讨了满堂式支架搭设中的基础处理方案,并对荷载的计算过程进行了阐述,同时研究了支架配置的具体措施,以保证支架的稳定性和梁体的质量。

  8. An improved approach for analyzing shear lag effect of box girders%箱形梁剪力滞效应的改进分析方法研究

    Institute of Scientific and Technical Information of China (English)

    张元海; 白昕; 林丽霞

    2012-01-01

    以薄壁箱梁的弯曲理论为基础,从分析翼缘板的面内剪切变形和弯曲剪力流的分布规律入手,从理论上证明二次抛物线是箱形梁剪力滞效应分析中的合理翘曲位移函数。选取剪力滞翘曲位移函数时,对悬臂板和底板引入修正系数,并考虑翘曲正应力的平衡条件。对箱形梁横截面上新出现的广义内力给出明确定义并称之为剪滞力矩,从分析正应力在翘曲虚位移上的虚功出发,揭示所定义的剪滞力矩即为相应于剪力滞广义位移的广义内力。对简支箱梁和连续箱梁模型的应力计算表明,计算值与实测值吻合良好,从而证实该文的分析方法和建立的公式是正确的。挠度计算表明:剪力滞效应使简支箱梁和连续箱梁算例的跨中挠度分别增大12%和19%,工程实践中必须认真对待。%Based on the flexural theory for thin-walled box girders, quadratic parabola is proved to be reasonable as the warping displacement function in shear lag effect analysis of a box girder through investigating the in-plane shear deformation and the shear flow in the flanges. Modified factors for the cantilever and bottom slabs are introduced in the warping displacement function for shear lag and the equilibrium condition for warping stresses is also considered. The new generalized internal force is defined explicitly and named as shear lag moment, which is proved to be the generalized moment corresponding to the generalized displacement for shear lag, through analyzing the virtual work done by the normal stress on the virtual warping displacement. Simply supported and continuous box girder models are analyzed and the calculated results are in good agreement with the test results, which validates the proposed method and formulas. For the simply supported and continuous box girder models, shear lag effect increases the mid-span deflections by 12% and 19%, respectively, which should be treated

  9. Innovative Design and Application of Assembled Bridge Erection Machine Used for Segmental Box Girder%拼装式节段箱梁造桥机的创新设计与应用

    Institute of Scientific and Technical Information of China (English)

    张耀辉; 赵振宇; 鲍存坤

    2013-01-01

    为了解决新建兰新二线红柳河特大桥在特殊条件下的节段箱梁施工难题,在总结吸收以往造桥机施工技术的基础上,对采用八七梁杆件为主要材料的拼装式造桥机进行了大胆的创新设计.特殊设计了不同以往造桥机的前、中、后支腿等特殊支撑结构,并采用了独特的造桥机过孔模式和安全保护措施,很好地实现了特殊条件下的高速铁路箱梁节段拼装施工要求,供其他类似工程的施工参考借鉴.%To solve the construction problems in segmental box girder of Hongliu River Bridge on the new second line of Lanzhou - Xinjiang Railway under the special conditions, this assembled bridge erection machine, which was mainly composed of the 87-type railway emergency steel beams, was designed boldly with technical innovation based on the construction technologies of former bridge erection machines. For this machine, some special supporting structures were designed, such as the front leg, middle leg and the rear leg, which were different from the previous similar machines. In addition, the unique models were adopted for this machine passing through the bridge spans and for the security measures, so that it can meet the requirements of segmental method for box girder of high-speed railway under the special condition, and can also provide good reference for the bridge erection of similar projects.

  10. 曲线薄壁箱梁侧向静力分析的能量变分法%ENERGY-VARIATIONAL METHOD OF LATERAL STATIC ANALYSIS OF THIN-WALLED CURVED BOX GIRDERS

    Institute of Scientific and Technical Information of China (English)

    甘亚南; 周广春; 吴亚平

    2011-01-01

    以能量变分原理为基础,在曲线箱梁侧向综合考虑了剪力滞后和剪切变形效应的影响,建立了薄壁曲线箱梁的侧向弹性控制微分方程和自然边界条件,获得了相应广义位移的闭合解.论文提出了一种曲线箱梁侧向静力学特性分析的解析法,揭示了各参数之间的内在联系.算例中论文解析解与板壳有限元结果吻合较好,证明了本文方法的有效性,因而更具理论价值和工程实际意义.%Based on the energy variation principle, this paper proposes an approach of analyzing the effect of shear lag,shear deformation on the lateral static characteristic of curved thin-walled box girders generally applied in engineering. The minimum potential principle is applied to establish the lateral governing differential equations and the corresponding natural boundary conditions. The closed-form solutions of generalized displacements are obtained. The variations of shear lag effects of curved box girders,caused by the change of factors such as span-height ratio,types of loading and natural boundary conditions,are discussed. The results are compared with finite shell element solutions to verify the validity of the proposed approach.

  11. 钢-混组合箱梁的车桥耦合振动影响分析%Analysis on Coupling Reaction of Steel-Concrete Composed Box Girder Vibration

    Institute of Scientific and Technical Information of China (English)

    汪家正

    2011-01-01

    随着对于钢-混组合箱梁结构研究的深入开展,其在车辆荷载作用下的车桥振动响应问题也备受关注。不同截面形式对其车-桥相互作用性能有着较大影响。文章基于模态综合法的原理,建立两种不同截面形式的钢-混组合箱梁的动力计算模型,并对其动力特性进行了比较分析,结果表明:双车响应大致为单车响应的两倍,说明不同车辆荷载作用下桥梁的反应是线性的,为以后此类桥梁的设计提供参考。%As the development of study on steel-concrete composed box girder,its natural vibration under vehicle loading draws more and more attentions.Different types of cross sections have different influence on the interaction between vehicle and bridge.Based on the component mode synthesis principle,the article builds two different types of steel-concrete composed box girder model and performs comparison analysis on its dynamic property.The result shows that the coupling reactions for two vehicles are bigger than that for one vehicle.This indicates that the relationship between them is linear,which provides reference for future bridge design.

  12. Calculation of Flexural Capacity for Prestressed Box Girder with Corrugated Steel Webs Considering Shear Slip%考虑剪切滑移的波纹钢腹板预应力箱梁抗弯承载力计算

    Institute of Scientific and Technical Information of China (English)

    任红伟; 刘保东; 李鹏飞

    2012-01-01

    In order to calculate the ultimate flexural capacity for externally prestressed box girder with corrugated steel webs, in view of its structural characteristics, considered the shear slip of shear key between the corrugated steel webs and the roof and floor concrete, the formulas of the ultimate flexural capacity of the externally prestressed box girder with corrugated steel webs were derived. As the slip strains increased the strain of the roof and floor and the sectional curvature, the influence of the interfacial slip on the ultimate flexural capacity were taken into account by the additional moment. Based on the analysis of the compatibility relation between externally prestressed tendons and the beam deformation, the stress increment of the external prestressing tendons was derived, the calculating steps of the ultimate flexural capacity of the externally prestressed box girder with corrugated steel webs by the plastic hinge method were derived and summarized, and the method was verified by model tests. The comparison of the experimental and theoretical results indicate that (1) the ultimate flexural capacity will be reduced when considering shear slip of the shear key; (2) the results obtained using the derived formulas are better than those from existing methods, which are close to the measured values and can give a reference to the calculation of the same type of girders.%为了计算体外预应力波纹钢腹板组合箱梁桥的极限抗弯承载力,针对其构造特点,考虑波纹钢腹板与顶底板混凝土剪力连接键剪切滑移的影响,推导了波纹钢腹板预应力箱梁极限抗弯承载力计算公式.滑移应变增大了项底板的应变和截面曲率,可以通过附加弯矩考虑界面滑移对极限抗弯承载力的影响;在分析体外预应力钢筋与梁体变形协调关系的基础上,得到了体外预应力筋的应力增量,推导并总结了应用塑性铰法计算波纹钢腹板体外预应力组合箱梁极限抗

  13. Comparison of Temperature Loadings of Bridge Girders

    Directory of Open Access Journals (Sweden)

    J. Římal

    2008-01-01

    Full Text Available This paper compares the effect of temperature changes on the superstructure of bridges, above all the effect of non-uniform temperature. Loadings according to standards ESN 73 6203, ENV 1991-1-5 and DIN 1072 are compared here. The paper shows a short summary of temperature loading according to each standard and shows the comparison of bending moments arisen from these temperature loadings on superstructure made from continuous girder from a steel-concrete box girder with a composite concrete slab. With respect to a variety of design processes, the comparison is made without any coefficient of loading, combination or material. 

  14. 一种计入桥面铺装非完善接触效应的箱梁结构计算方法%Application of Deck Pavement into Box Girder Structure

    Institute of Scientific and Technical Information of China (English)

    董建兴

    2013-01-01

    The local simulation analysis is carried out for the imperfect contact between the bridge deck pavement and the box girder structure.Then the shear stiffness is obtained from load-slip curves.And a 3-D model for a real bridge structure is built and analyzed in which Spring elements are adopted to simulate the interface shear stiffness.By this calculation model the structural responses under some loads are acquired to explore the effect of considering interface slip between the concrete box deck and the pavement on the structural behavior of the bridge.The results indicate that the cracking load and ultimate bearing capacity of structure are advanced by the affect of the pavement.By comparing the data,the advice of analyzing the box girder with deck overlays is proposed,which has definite social and economic benefit.%采用有限元软件对桥面铺装与箱梁结构桥面板之间的非完善接触进行局部仿真分析,提取荷载一滑移曲线获得界面之间的剪切刚度,并在整体模型中用弹簧单元模拟界面之间的剪切刚度,对猫铺大桥结构进行三维空间分析.通过这种计算模式分析结构在荷载作用下的的整体响应,探讨比较了考虑混凝土与桥面铺装界面滑移对箱梁结构受力性能的影响.研究得出了考虑铺装层参与截面受力能提高结构开裂荷载和极限承载能力、增大结构刚度的结论.计算结果对考虑铺装层作用时箱梁计算提出合理建议,具有一定的经济和社会效益.

  15. Experiment Research on Vertical Mechanical Performance of Web Plate of 32 m Simply-surpported Prestressed Concrete Box Girder on Chengdu-Dujiangyan Railway%成灌铁路跨度32 m预应力混凝土简支箱梁腹板竖向受力性能试验研究

    Institute of Scientific and Technical Information of China (English)

    苏永华; 马林

    2014-01-01

    我国客运专线各种标准梁型在实际应用之初均进行了实体箱梁的试验研究工作,以掌握结构的实际受力性能,对于保证箱梁的正常、安全使用起到了重要作用。以新建成灌铁路跨度32m预应力混凝土简支箱梁为研究对象,对梁端变截面处腹板在预施应力条件下的受力状态进行了计算分析和测试,对跨中等截面段腹板在模拟运梁车运梁通过工况下的受力性能进行了计算分析和静载试验。根据箱梁腹板受力性能试验研究结果,对箱梁的截面构造和预应力束布置进行了设计优化、完善,改善了腹板的竖向受力性能,静载试验结果表明在运梁、运营工况下箱梁能满足正常使用要求。%In China, experiment research on a new box girder structure is always carried out at the beginning of its practical application, so as to ascertain the actual mechanical performances of various standard girder types used on passenger dedicated lines; and this practice plays a important role in ensuring normal and safe use of the box girders. This article took the 32m simply-supported prestressed concrete box girder on newly-built Chengdu-Dujiangyan Railway as the research object. And then the calculation analysis and mechanical performance test of the web plate of variable cross-section at the girder end were conducted under the pre-stressing condition. Furthermore, calculation analysis and static load test of the mechanical performance of the web plate of uniform cross-section at the mid-span were also conducted when simulating the girder transporter passing through. Subsequently, according to the results of experiment research of vertical performance of box girder web plate, the box cross-section structure design and the layout design of prestressed steel tendon were optimized and perfected, so that the vertical performance of the web plate was able to be improved. The result of static load test indicates that

  16. Aerodynamic hysteresis of thin airfoil and streamline box girder under large amplitude oscillation%大振幅下薄翼和流线型箱梁的气动迟滞研究

    Institute of Scientific and Technical Information of China (English)

    王骑; 廖海黎; 李明水; 马存明

    2013-01-01

    回顾了机翼和箱梁的气动迟滞效应研究现状,介绍了大振幅下获取薄翼和流线型箱梁自激气动力的风洞试验.研究结果表明:薄翼在超过失速角的振幅条件下,升力并没有出现明显的失速现象,但气动力的高阶谐波分量显著增加;大振幅条件下,流线型箱梁的气动力高阶谐波分量也比较显著,并以第2和第3阶谐波分量为主.此外,在大振幅条件下,流线型箱梁的气动力矩迟滞曲线可出现“8字环”,即气动力在一个振动周期内既做了正功也做了负功;其中,迟滞曲线“8字环”的气动正功部分随着振幅和折算风速的增大而增加.该现象可导致桥梁也出现类似于失速机翼的极限环震荡.最后,基于不同振幅下流线型箱梁的力矩迟滞曲线,简要讨论了大跨度桥梁在颤振后状态可能出现的振动形式和气动稳定性.%The state-of-the-art of aerodynamic hysteresis of airfoil and box girder is reviewed briefly. A detailed introduction is given to the wind tunnel tests of motion-induced aerodynamic force measurements of thin airfoil and streamline box girder under large amplitude oscillation. The test results show that the lift stall didn't occur while the torsional amplitude exceeds the stall incidence angle, and the higher order harmonic components are remarkable in the aerodynamic force. The aerodynamic hysteresis curve of pitching moment for streamline box girder can take on "8-shape" loop, which means that the aerodynamic forces can provide both the positive and negative works within one vibration period. The limited cycle oscillation may also occur for bridge deck, which is usually observed in the stall airfoil. Based on the aerodynamic hysteresis curve of pitching moment under different amplitudes, the possible vibration pattern and aerodynamic instability are discussed for the post-flutter state of long span bridge.

  17. Joint design and model tests of extra-long-span continuous box girder bridge composed of UHPC%超大跨径UHPC连续箱梁桥接缝设计及模型试验

    Institute of Scientific and Technical Information of China (English)

    张策; 邵旭东; 张阳

    2015-01-01

    With the precast segment cantilever method,a bracket joint between segments is proposed for the extra-long-span continuous box girder bridge composed of ultra-high performance concrete (UHPC ). The optimization analysis is conducted based on some parameters,such as the horizontal angle of bracket joint,the ratio of joint tooth block depth and height,and the ratio of joint tooth block height to beam height. The optimal ones are less than 45 ,great than 1/10, and 1/3 ~ 2/3 correspondingly. A double cantilever box girder with bracket joint is designed according to the optimization results. Combining with model tests and numerical analysis,the shear behavior of web ’s joint and the influence of diaphragm plates on the joint performance are studied. The results demonstrate that the shear behavior of web’s joint is strong,and the shear capacity of joint can be increased by intensive diaphragm plates in thin-walled box girder. The cracking strain in joint’s corner is up to 455με,and the corresponding stress is about 9. 23MPa. The results are much greater than those of the ordinary concrete joint,and the resistance cracking degree of safety approaches 1. 63.%针对超大跨径UHPC连续箱梁桥,提出悬臂拼装法施工的牛腿式UHPC节段间接缝,并对其倾角、深高比、齿梁高之比进行优化设计,得到接缝牛腿最优水平倾角为0°~45°,深高比≥1/10,齿梁高比为1/3~2/3。利用优化结果设计制作一个双悬臂梁接缝模型,采用模型试验与数值分析相结合的方法,研究薄壁箱梁拼装节段腹板接缝的抗剪性能及横隔板对腹板接缝性能的影响。静力试验的结果与数值模拟分析的结果都表明:薄壁箱梁腹板接缝抗剪性能强,密集横隔板能提高接缝抗剪承载力,接缝角趾开裂应变达到455με,相应计算应力达14.71MPa,远大于普通混凝土的接缝强度,抗裂安全度可达1.63。

  18. 重复荷载下高铁24 m箱梁模型试验研究%Experimental Research on the Static Performance of High-speed Railway Box Girder Model Under Repeated Loading

    Institute of Scientific and Technical Information of China (English)

    葛继平; 王志强; 彭大文; 严平

    2013-01-01

    对高速铁路中广泛应用的预应力混凝土简支箱梁进行了多级重复荷载下的模型试验.试验的主要测试结果包括2种加载方式下梁的裂缝宽度和裂缝分布展开情况,荷载-挠度曲线和弯矩-转角曲线,混凝土和普通钢筋的应变分布等.研究结果表明:混凝土首先在跨中底板出现裂缝,然后慢慢向腹板扩展.在纯弯段,裂缝间距分布比较均匀.在施加荷载超过开裂荷载不多的情况下卸载,裂缝在预应力筋的作用下能够闭合.箱梁的最终破坏现象是混凝土顶板的压溃爆裂,跨中极限位移为跨径的1/55.重复加载下的荷载位移曲线的包络线有3个拐点,分别对应于混凝土开裂,钢筋屈服,预应力筋屈服;而重复荷载下的弯矩转角曲线在整个过程中有一个拐点,对应于预应力筋的屈服.%The simply supported prestressed concrete box model of widely applied high-speed railway girder under repeated loading is tested.Two cases,including larger loading space and smaller loading space are included in the three-point bending tests.The experiment is focus on the width and distribution of cracks,the load-deflection curve and moment-rotation curve,and strain distribution of concrete and steel.The test results show that the concrete cracks first appear in the bottom plate of the box girder,and then slowly extend to the web.In the area of pure bending,spacing distribution of cracks is relatively uniform.When the load is little bigger than the cracking load,cracks can be closed under the action of the prestressed tendons.The final damage phenomenon of box girder is crush and hurst in the concrete roof plate and the ratio of limit displacement to span is about 1/55.Under the repeated loading,the envelope of load-displacement curve has three inflection points,respectively corresponding to the cracking of concrete,the yield of reinforcement,and the yield of prestressed strand wires; while the envelope of moment

  19. Integrated Construction Technology of Fish-Belled Box Girder Bridge with Variable Cross-Section%鱼腹式变截面箱梁桥综合施工技术

    Institute of Scientific and Technical Information of China (English)

    孔德法

    2012-01-01

    鱼腹式变截面箱梁桥具有造型美观的特点,符合桥梁美学设计,但施工难度大;结合工程实例,通过建立空间直角坐标系,“从点到线、从线到面、从面到体”进行控制,思路清晰,工艺明确,较好的解决了变截面箱梁的施工难题.桥梁施工范围内淤泥深度为3.49~8.86 m,无明水,施工过程中,根据淤泥深度不同,分别采用“钻孔桩、贝雷梁”和“清淤换填、戗灰处理”两种方式对支架基础进行处理:经过施工检验,基础沉降量控制在允许范围内.%Fish-bellied box girder bridges with variable cross-section have attractive characteristics which comply with the idea of aesthetic design of bridge, but the construction is difficult. The author, in combination with actual project, established the space rectangular coordinate system to control the construction "from point to line, from line to surface, and from surface to body" with clear technological meanings and processes, therefore the construction puzzle of variable cross-section box girder was well solved. In addition, because the depth of silt within construction range is 3. 49 .8. 86 m without visible water, two ways of "bored piles plus bailey beam" and "dredging for filling, treating with ash" were adopted to deal with the support foundation during construction based on different depth of silt. The results of construction inspection show that the settlement of the foundation is within the allowed range.

  20. 超宽箱梁抗裂混凝土配合比试验研究%Experimental Study of Mix Proportioning of Cracking Resistance Concrete for Very Wide Box Girder

    Institute of Scientific and Technical Information of China (English)

    王运金; 李北星; 唐凯; 胡峰强; 张剑峰

    2012-01-01

    为防止九江长江公路大桥主桥超宽箱梁混凝土的早期开裂,进行专门的抗裂混凝土配合比优化设计试验.通过水化热、绝热温升、平板法塑性收缩开裂、温度~应力试验机开裂等试验方法,研究了胶凝材料组成对混凝土早期抗裂性的影响,配制出抗裂性能良好的C55混凝土.该混凝土采用42.5级p·Ⅱ水泥掺入25%的Ⅰ级粉煤灰、缓凝型聚羧酸盐高性能减水剂配制,绝热温升55.8℃,塑性收缩抗裂等级Ⅱ级,开裂温度8.7℃,应力储备37.3%,实际应用效果良好.%To prevent the concrete for the very wide box girder of the main bridge of Jiujiang Changjiang River Highway Bridge from early stage cracking, the optimal design and experiment for the mix proportioning of cracking resistance concrete for the box girder was specially carried out. By way of the hydration heat testing, adiabatic temperature rise testing, flat slab testing of plastic shrinkage cracking and cracking testing of temperatures-stress testing machine, the influence of the cementitious material compositions on the early stage cracking resistance of the concrete was studied and the C55 concrete having good cracking resistance was accordingly prepared. The concrete is used with the Grade 42. 5 P?II cement added with 25% of the Grade I flyash and high-range water reducer of retarding-type polycarboxylate. The adiabatic temperature rise of the concrete is 55. 8 ?, the level of the plastic shrinkage cracking resistance is grade II, the cracking temperature is 8. 7 ? and the stress reserve is 37. 3%. The practical application of the concrete proves that the effect of the concrete is sound.

  1. Load Test of a Continuous Box Girder Bridge%某连续箱梁桥荷载试验研究

    Institute of Scientific and Technical Information of China (English)

    王丽; 孙立; 霍立飞

    2014-01-01

    Through the static and dynamic load test of a reinforced concrete continuous girder bridge,the mechanical property indexes of the bridge structure under load were measured.According to the comparison of test results with those of theoretical calculation,and in accordance with the relevant norms,the overall performances of the bridge were evaluated.The analysis re-sults show that all the indexes of the bridge could meet the requirements of the code;the bridge was in elastic working state.The calculation of such bridge could provide reference for similar projects.%对某4跨连续箱梁桥进行静、动载试验,测得试验荷载作用下桥梁结构关键力学参数的各项指标。根据实测结果与理论计算值的比较,并按相关规范,对桥梁整体性能进行评价,分析结果表明该桥各项测量指标均满足规范要求,结构处于正常弹性工作状态。这对此类桥梁结构的计算分析方法在工程中有一定的借鉴意义。

  2. Box girder vertical displacement monitoring for Xujiawan continuous rigid aqueduct water filling test%徐家湾连续刚构渡槽充水试验箱梁竖向位移监测

    Institute of Scientific and Technical Information of China (English)

    张健; 钟伟

    2016-01-01

    为了检验徐家湾连续刚构渡槽箱梁的安全性能,经过近42天5级加载充水试验,监测结果表明:徐家湾渡槽箱梁竖向位移与设计理论值一致,渡槽施工质量良好,结构安全。其成果可供类似连续刚构渡槽充水试验参考。%In order to check the safety of box girder of Xujiawan continuous rigid aqueduct,5-grade loading water filling test was conducted for nearly 45 days. The results of monitoring demonstrate the vertical displacement is identical with the design value,the construction quality is good,and the structure is safe. The results also can be reference for water filling test of similar rigid aqueduct.

  3. Analysis of vibration test for the skew box girder bridge under human-induced excitation%人群荷载作用下斜箱梁桥振动试验分析

    Institute of Scientific and Technical Information of China (English)

    赵学; 王介修; 勾志硕; 贾艳敏

    2014-01-01

    By the actual test and theoretical analysis for vibration of the skew box girder bridge under human-induced excitation,the determina-tion of dynamic characteristic and the dynamic reaction under the effect of moving pedestrian,actual working state of the bridge under moving load have been studied,with safe bearing capacity and use condition of the whole structure determined.%通过对三跨预应力连续斜箱梁桥在人群荷载作用下的振动问题进行实桥测试和理论分析,测定其动态特性及在跑动的人群荷载作用下的动态响应,了解了该桥在动荷载作用下的实际工作状态,从而判断该桥整体结构的安全承载能力和使用条件。

  4. 超大跨径单向预应力UHPC连续箱梁桥概念设计与初步实验%Conceptual design and preliminary experiment of super-long-span continuous box-girder bridge composed of one-way prestressed UHPC

    Institute of Scientific and Technical Information of China (English)

    邵旭东; 詹豪; 雷薇; 张哲

    2013-01-01

    A novel super-long-span continuous box-girder bridge made from ultra-high-performance concrete (UHPC) was proposed.By combining UHPC,thin-walled box girder with dense diaphragm plates and partial external prestressing into the novel box-girder system,a traditional three-dimensional prestressed structure is transformed into a longitudinal one-way prestressed one.Hence,not only can the main span length of girder bridges be improved,but also the ever existing problems in long-span PC bridges,such as the cracking in concrete girders and the excessive deflection at midspan,may be eliminated.A trial-design for a continuous box-girder bridge built from UHPC with main span length of 400m is presented,and the results show that the thicknesses of its components can be decreased greatly,the transverse stress decreased effectively by using the dense diaphragms,and the self-weight of superstructure may be reduced about 50% so that a good economy may be achieved and the one-way prestressed structure is completely feasible.The model tests were carried out to evaluate the creep deformation and shear capability of UHPC beam,and the results show that the creep deformation of UHPC beam is only 20% of that of ordinary concrete beam,and the shear capability of web can be further enhanced by employing dense diaphragms.The novel super-long-span continuous box-girder bridge is a competitive candidate in the aspects of safety,economy and durability,implying that it is applicable to the continuous girder bridge with main span length of 400m.%提出一种超大跨径超高性能混凝土(UHPC)连续箱梁桥新体系.新体系梁桥将超高性能混凝土(UHPC)、密集横隔板薄壁箱梁和部分体外预应力有机结合,变传统三向预应力为纵向单向预应力结构,不仅提升了梁桥跨径,而且可消除传统大跨径PC梁桥的主梁过度下挠和梁体开裂两类病害,通过对跨径400m的UHPC连续箱梁桥试设计,结果表明,新体系箱梁桥各种板件

  5. Research on temperature field and temperature stress of prestressed concrete girders

    Directory of Open Access Journals (Sweden)

    Chen Cheng

    2011-02-01

    Full Text Available This paper introduces the establishment and simplification of the temperature field and the general calculation method of temperature stress of the prestressed concrete box girders. Three kinds of sunshine temperature gradient models were loaded to a real bridge respectively, and got stress and displacement curves. Research data of several prestressed concrete box girders were selected from different regions of China to compare the relative error of the calculated and measured value. We indicate that the study of temperature field and thermal stress of prestressed concrete box girders is necessary, and will help engineers to solve the problem in structure design.

  6. 箱桁梁断面斜拉桥涡振性能及抑振措施的研究%Research on vortex-induced vibration and its control for cable-stayed bridge with box-truss composite girder

    Institute of Scientific and Technical Information of China (English)

    冯丛; 华旭刚; 胡腾飞; 陈强; 陈政清

    2016-01-01

    T he cable-stayed Dongting Lake railway bridge under construction was case-studied in this paper. A finite element modeling of the cable-stayed bridge with box-truss composite girder and its vortex-induced vibration were analyzed. T hree finite element schemes for modeling box-truss girder of the bridge,namely the spatial beam model ( SBM) ,spatial plate-beam model( SPBM ) and spatial shell model( SSM ) ,were compared in terms of modal frequency,equivalent mass and mass moment of inertia per unit length. It shows that the results from the SPBM and the SSM are basically the same,while the SBM can't accurately produce the equivalent mass unit length girder for some higher-order lateral modes. T he vortex-induce vibration of the box-truss composite girder was tested in wind tunnel by flexibly mounted rigid sectional model tests. T he results indicate that this cross-section type may experience large-amplitude vertical vortex-induced vibrations at wind attack angle of -3°,which is caused by the vortex shedding at the leading edge of the box-girder part of the cross-section. T he effects of aerodynamic appendix for suppression of vortex-induced vibrations w ere studied and it is found that tw o stabilizers beneath the open orthotropic deck dramatically reduce the vibration amplitude. T he vibration amplitude is within the limit given in design specification when the height of stabilizers is half of the box-girder height; and the vortex-induced vibrations completely diminish when the height of stabilizers is the same as the box-girder height.%以在建的洞庭湖铁路三塔斜拉桥为工程背景,分析了箱桁断面斜拉桥主梁的建模方法以及涡激共振性能。首先比较了主梁建模的空间杆系模型、梁壳组合模型以及三维壳体模型在模态频率、主梁单位长度等效质量和等效质量惯性矩的差异。结果表明,三种模型的模态分析结果基本相近,但空间杆系模型不能准确得到高阶侧弯模

  7. 预防连续箱梁施工裂缝的温度监测与有限元分析%Temperature monitoring and finite element analysis of preventing construction cracks in a continuous box girder

    Institute of Scientific and Technical Information of China (English)

    王海源; 章龙; 张乐文; 张峰

    2011-01-01

    The features of uneven distribution temperature stress in recently poured concrete and the effective measures to prevent temperature cracks were studied. The 0# box girder in the Weihe Specially Long Bridge located in the highway from Xi' an to Tongchuan was taken as a research project, which was computed on MIDAS/FEA( multitier distributed applications services/finite element analysis) finite analysis element software. The temperature field of hydration heat of the concrete in the construction period was numerically calculated by the finite element method. The effects of three different mechanical control measures of crack control were analyzed. Combined with the results of temperature detection, the mechanical control measure was optimized. The results showed that the temperature inside the concrete rose to a peak about 52 hours after the concrete was poured, with or without cooling water pipes in the box temperature difference of the maximum temperature about 10℃. When the temperature difference between inside and outside of the concrete at 20℃ was a good time to remove the template. Temperature stress was concentrated in the junction web plate and diaphragm of the box girder, thus setting the cooling water pipes could improve the uneven distribution of temperature stress. Compared with other results, the whole process temperature monitoring and the finite element dynamic analysis by this method was better at optimizing the engineering measures of crack prevention.%研究混凝土浇筑初期内部温度应力不均匀分布特征和预防温度裂缝的有效措施,以西安至铜川高速公路渭河特大桥某0#箱梁为研究对象,以MIDAS/FEA(multitier distributed applications services/finite element analysis)有限元分析软件为计算平台,采用有限单元法对施工期混凝土水化热温度场进行了数值模拟计算,分析了3种不同防裂工程措施的理论效果,并结合温度监测进行了工程

  8. Prestressed concrete box girder strengthened with comsposition of steel plate and concrete%钢板-混凝土组合加固预应力混凝土箱梁

    Institute of Scientific and Technical Information of China (English)

    石雄伟; 袁卓亚; 马毓泉; 冯威; 陈立

    2012-01-01

    为了研究钢板-混凝土组合加固技术在桥梁加固工程中的应用,提出了钢板-混凝土组合加固预应力混凝土箱梁的抗弯极限承载力计算公式,采用ANSYS软件选用合理单元类型和材料本构关系,对采用钢板-混凝土组合加固的某火灾受损预应力混凝土箱梁桥进行了非线性有限元数值模拟分析对比,并做了加固后效果验证性荷载试验,还对组合加固和粘钢加固效果进行了对比。结果表明:简化公式计算结果与数值分析结果偏差在5%以内;加固后结构关键截面抗弯极限承载力提高30%以上,应变校验系数降低为0.57~0.70,挠度值减小明显,结构基频提高了19%,横向分布系数理论值与实测值比值为0.93~1.05,吻合良好;组合加固梁体校验系数降低为0.66~0.82,较合理且相对均匀,结构受力协同性较好,更有利于提高结构整体受力性能。%In order to study the application of steel plate and concrete composite strengthening(SPCCS) technology in bridge reinforcement,a formulation for calculating ultimate bearing resistance of prestressed concrete box girder was presented.A nonlinear finite element model was established using ANSYS with right material parameters for a prestressed concrete box girder bridge which was damaged in a fire and strengthened with SPCCS.A comparison was made between numerical analysis results and function formula data.A loading test was carried out to verify the effect,the results of SPCCS and steel plate strengthening were compared.The results show that the deviation of numerical analysis results and function formula data is within 5%,the ultimate bending capacity of important section is improved over 30%,the verification coefficient of strain is reduced to the one from 0.57 to 0.70,the bending deflection is decreased significantly,the fundamental frequency of structure is improved by 19%,the ratio of theoretical and observed value of the load distribution

  9. Analysis of Fatigue Stress Property of Steel Box Girder of Jiangyin Changjiang River Bridge%江阴长江大桥钢箱梁疲劳应力特征分析

    Institute of Scientific and Technical Information of China (English)

    吉伯海; 叶枝; 傅中秋; 汪锋; 孙洪滨

    2016-01-01

    为准确评估钢桥结构的疲劳损伤状态和剩余疲劳寿命,以江阴长江大桥为背景,对该桥钢箱梁疲劳裂纹产生位置进行连续疲劳应变监测,获取应变时程数据,结合雨流计数法技术建立日疲劳应力谱;分析应力幅~循环次数分布规律;研究累积损伤度分布特征,建立损伤度分布模型,计算不同车道构造细节疲劳损伤度和剩余寿命。研究结果表明:钢箱梁顶板测点、U肋与横隔板焊接末端处、弧形缺口有效截面最小处均以压应力为主,U 肋以拉应力为主;应力幅累积循环次数分布服从Weibull函数分布;疲劳累积损伤度分布服从Boltzman函数分布,顶板与U肋连接处U肋腹板沿横桥向慢车道疲劳损伤较快车道损伤大,下游车道较上游车道损伤大,其中下游慢车道U肋腹板细节疲劳损伤最大。%To accurately evaluate the fatigue damaging condition and remaining fatigue life of steel bridge structure ,the Jiangyin Changjiang River Bridge was cited as an example .Continuous fatigue strain monitoring was conducted at the locations where fatigue cracks were found on the steel box girder to gain real‐time strain data .The monitoring data ,combined with the rain flow counting method ,were used to set up the daily fatigue stress spectrum to analyze the distribution law of S~ N curve .The distribution law of fatigue accumulating damage was studied .The model of damage distribution was set up ,to calculate the fatigue damages and remaining life of different structural details of the traffic lane .T he results of the study demonstrate that compressive stress was dominant at the testing locations in the steel box girder ,ends of U‐rib and diaphragm welds and least effective cross section of the arc notches ,whereas tensile stress was found primarily on U ribs .The distribution of the accumulated stress cycle follows the way of Weibull function distribu‐tion .The distribution

  10. Mechanics Analysis on Rigid-flexible Composite Pavement Structure of Fabricated Steel Box Girder Bridge Deck%装配式钢箱梁桥面刚柔复合铺装结构力学分析

    Institute of Scientific and Technical Information of China (English)

    吴国雄; 程菓; 伍成忱

    2016-01-01

    选择钢箱梁刚柔复合桥面铺装体系为研究对象,建立正交异形板以及铺装层的三维有限元模型,探索车轮荷载作用下刚柔复合铺装层及其与钢桥面板界面上力学响应的分布规律。分析表明,刚柔复合铺装结构整体刚度较好,铺装层受力的局部效应减弱;纵向拉应力为刚柔复合铺装中拉应力的主要控制指标;正交异性板的刚度突变位置易出现最大应力值。研究结果可对钢桥面铺装设计提供理论依据。%This paper chooses rigid-flexible composite steel box girder bridge deck as the research object, establishes a three-dimensional finite element model of orthotropic plate and pavement to explore the distribution rule of the mechanical response from the rigid-flexible composite pavement and the bridge deck interface under wheel loads. The analysis shows that the overall stiffness of the rigid-flexible composite pavement structure is good, and the local effects of pavement force weakens; longitudinal tensile stress is the main control indicator of the tensile stress in the rigid-flexible pavement com-posite; the stiffness mutation of orthotropic plate is prone to the maximum stress. The results provide a theoretical basis for pavement design.

  11. Analysis for Stress of No.0 Block Space of Variable Cross-section Prestressed Concrete Continuous Box-girder Bridges%变截面预应力混凝土连续箱梁桥0#块空间应力分析

    Institute of Scientific and Technical Information of China (English)

    宁舟; 李传习; 欧见仁

    2013-01-01

    Aiming at the status of insufficient research on influences of stress on shear lag effect of No. 0 blocks of thin-wall box-girder structures, this paper establishes integral modle of the whole bridge based on Midas Civil with some variable cross-section prestressed concrete continuous box-girder bridge as a background project and establishes physical model of No. 0 blocks via ANSYS. The paper analyzes space stress conditions of No. 0 blocks under different working conditions and discloses loaded characteristics and distribution law of stress of No. 0 blocks, and meantime analyzes influences of prestress on shear lag effect of No. 0 blocks of box girders in the state of the max. double cantilevers to obtain conclusions that prestress has inhibitory action for shear lag effect, etc.%针对预应力对薄壁箱梁结构0#块剪滞效应影响研究不足的现状,以某变截面预应力混凝土连续箱梁桥为背景工程,基于Midas Civil建立全桥整体模型,并用ANSYS建立该桥0#块实体模型.分析0#块在不同工况下的空间应力状况,揭示0#块的受力特性和应力分布规律,同时分析最大双悬臂状态下预应力对箱梁0#块剪力滞效应的影响,得出预应力对剪力滞效应有抑制作用等结论.

  12. Research on temperature field and temperature stress of prestressed concrete girders

    OpenAIRE

    Chen Cheng; Kaiyin Zhang

    2011-01-01

    This paper introduces the establishment and simplification of the temperature field and the general calculation method of temperature stress of the prestressed concrete box girders. Three kinds of sunshine temperature gradient models were loaded to a real bridge respectively, and got stress and displacement curves. Research data of several prestressed concrete box girders were selected from different regions of China to compare the relative error of the calculated and measured value. We indic...

  13. Optimisation of plate girders

    NARCIS (Netherlands)

    Abspoel, R.

    2015-01-01

    In many steel structures like buildings, industrial halls and bridges, standardized hot-rolled sections are used. These sections are divided into specific types in Europe and similar profiles in the USA. The range of hot-rolled sections is limited and therefore fabricated plate girders are used when

  14. 双层桥箱内壁车辆碰撞混凝土损伤仿真研究%Simulation Study on Concrete Damage of the Inner Box Collision of the Double Decked Continuous Box Girder Bridge

    Institute of Scientific and Technical Information of China (English)

    沈正峰; 方金苗; 郑净

    2014-01-01

    Double-decked continuous box bridge is a new structure system and how to evaluate the structure damage caused by vehicle collision inner box has a great significance to the wide application of the new structure .This paper researches all conditions of structure damages caused by vehicle collision inner box by means of computerized simulation .The study finds out the concrete injured parts and its degree ,analysis the sensitive factor of concrete damage ,which provides suggestions for the design of double-decked bridge .%双层连续箱梁桥是一种新型结构体系,如何评价车辆撞击箱梁内部造成的结构损伤对于这种新型结构的广泛运用具有重要意义。通过计算机仿真技术研究各种工况下车辆对箱梁桥内壁撞击引起的结构损伤情况,得出混凝土损伤部位以及程度,分析影响混凝土损伤的敏感因子,为双层桥结构设计提供参考。

  15. 流线型闭口箱梁断面风荷载空间相关性试验研究%Spatial correlation of wind loads for cross-section of a streamlined closed box girder

    Institute of Scientific and Technical Information of China (English)

    张冠华; 赵林; 葛耀君

    2012-01-01

    对典型流线型闭口箱梁断面的风荷载效应进行同步测压风洞试验,比较了来流平均风速、湍流度、风攻角、展向间距等不同参数条件下风荷载在空间分布状况,对风速及其荷载效应的空间相关性进行深入研究,从时、频域两个方面来尝试分析现象及原因,探讨影响因素,证实升力、扭矩的展向相关性远大于风速、阻力的相关性,并发现升力与扭矩的相关性规律相似,风速与阻力相关性规律相似;验证了传统随机抖振动气动力理论所存在的不足.%The simultaneous measurement of wind load pressures on a streamline closed box girder's cross-section was conducted with pressure scanning valves in Tongji University wind tunnel, the spatial distribution states of wind load were compared, the reasons for the phenomena were explored, under different wind average speed, turbulence intensity, wind attack angle and span-wise distance. The spatial correlation between wind speed and its load effect was studied in both time domain and frequency one. With correlation coefficient and coherence function, the mechanism and influence factors were analyzed. It was elaborated and confirmed that the span-wise correlations of lift force and torsion moment are much greater than those of wind speed and drag force, and there is a similar law to the correlation of lift force and that of torsion moment, a similar law to the correlation of wind speed and that of drag force. The shortcomings of the traditional random aerodynamic buffeting theory were verified.

  16. Study on Structural Forms of External Prestressing Anchorage for a Novel Continuous UHPC Box-girder Bridge%新型UHPC连续箱梁桥的体外预应力锚固构造形式研究

    Institute of Scientific and Technical Information of China (English)

    邵旭东; 张良; 张松涛; 欧阳泽卉

    2016-01-01

    针对新型UHPC连续箱梁桥的结构特点及预应力体系布置,对其腹板处体外预应力下折索进行齿块锚固研究。对独立矩形齿块进行应力分析,揭示板厚对锚固区壁板外侧“局部弯曲效应”的影响。通过拓扑优化分析构建出一个揭示齿块锚固区传力机理的简化平面杆系模型,提出两种齿块锚固区局部加强的方法。在此基础上,对UHPC箱梁桥的腹板体外预应力锚固齿块进行构造设计,对比6种不同锚固方案,分析横隔板、预应力筋齿块内转向和锚固长度对锚固区受力的影响,最终得出较为合理的体外预应力齿块锚固构造形式。%According to the characteristics of a novel continuous UHPC box-girder bridge and the lay-out of its prestressing system,the anchor block for external tendons on the web was studied.Firstly,the effect of the plate thickness on the“local bending effect”in anchorage zone was evaluated through the anal-ysis of stress in the isolated rectangular anchor block.A simplified plane linkage model was proposed through the topology optimization in order to study the force transfer mechanism in anchorage zone.More-over,two kinds of methods were developed to strengthen the anchorage zone based on the simplified mod-el.On the basis of the above research procedure,six different anchoring schemes of the anchor block for the external tendons were designed.After analyzing and comparing the performance of the different ancho-ring schemes,the effects of diaphragms,steering of prestressing tendons,and anchoring length of the an-chor block on the mechanical behavior of the anchorage zone were evaluated.Finally,a type of reasonable anchor block of the external tendons was obtained.

  17. 箱形梁剪力滞效应分析中的翘曲位移函数及广义内力研究%Study on warping displacement function and generalized internal force in shear lag effect analysis of box girder

    Institute of Scientific and Technical Information of China (English)

    张元海; 康喜东; 林丽霞

    2012-01-01

    Based on the flexural theory of thin-walled box girder, the curve of quadratic parabola is proved to be the reasonable form of the warping displacement function in the shear lag effect analysis of a box girder through investigating the in-plane shear deformation and the bending shear flow distribution in the flanges. The additional deflection induced by shear lag effect is adopted as the generalized displacement. The governing differential equations and the corresponding boundary conditions for shear lag effect of box girder are established by the energy calculus of variations based on the principle of minimum poten- tial energy. The new generalized internal force is defined rigorously,and a simple and convenient formula of stress for shear lag warping is presented which has the same form as the bending stress of elementary beam. A simply supported box girder model is analyzed and the calculated results are in good agreement with the test results, validating the method and formula presented. The generalized moment for shear lag differs from the bending moment in distribution and attenuates quickly. For the simply supported box girder example under concentrated load, shear lag effect increases the mid-span deflection by 12 ~,which should be treated carefully in practice.%以薄壁箱梁的弯曲计算理论为基础,从分析翼缘板的面内剪切变形和弯曲剪力流的分布规律入手,从理论上证明二次抛物线是箱形梁剪力滞效应分析中的合理翘曲位移函数。选取剪力滞效应引起的附加挠度作为广义位移,用基于最小势能原理的能量变分法建立箱形梁剪力滞效应分析的控制微分方程和边界条件。对箱粱横截面上新出现的广义内力给出严密定义,并建立了剪力滞翘曲应力的简便计算公式,它与初等梁弯曲应力公式具有相同的形式。对一个简支箱梁模型的计算表明,计算值与实测值吻合良好,从而证实了本文的分析方

  18. Influence of Traveling Wave Effect Based on Coefficient Reduction on Continuous Curve Box-girder Bridge%基于系数折减的行波效应对连续曲线箱梁桥的影响

    Institute of Scientific and Technical Information of China (English)

    吴多; 李青宁

    2014-01-01

    Traveling wave effect is a main influence factor for the multi-support excitation of large-span structures .It has been unable to meet the needs of engineering earthquake-resistance without considering the traveling wave effect of earth -quake ground-motion ,especially for the curve bridges by complex loading .Large mass model is currently used for the analysis of the traveling wave effect ,then the displacement differential method is used to calculate the relative displace-ment of the structure .However ,the displacement differential method often can lead to displacement “drift” and distortion for more support of large-span structures .Taking a five cross curve box girder bridge as an example ,a traveling wave processing method based on the basal coefficient reduction is proposed ,and the different apparent-wave velocity is used for seismic time-history response analysis .The results show that under the seismic action ,the traveling wave effect is fa-vorable for structural displacement ,and considering the traveling wave of reduction factor can better fix the actual dis -placement under the action of earthquake .Finally when considering the traveling wave effect ,the variable parameters such as the apparent-wave velocity and high pier have a greater influence on the seismic response of curve bridge .There-fore ,in the seismic analysis of curve bridge ,the specific requirements of engineering should be considered for contrast calculation so as to ensure the safety of the design .%行波效应是目前大跨结构中考虑多点激励的一种主要影响因素。特别是针对受力复杂的曲线桥,不考虑地震动的行波效应已经不能满足工程抗震的需求。目前常用大质量模型进行行波效应的分析,然后利用位移差动的方法求出结构的相对位移。对于多支撑的大跨结构来说位移差动的方法经常会导致位移的“漂移”和失真。以一座五跨曲线箱梁桥为例,提出了一种

  19. 铁路箱形混合梁斜拉桥钢-混结合段有限元分析%Finite Element Analysis of Steel and Concrete Joint Section of Railway Hybrid Box Girder Cable-Stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    姚亚东; 杨永清; 刘振标; 蒲黔辉; 施洲

    2015-01-01

    To investigate the force characteristics and force transfer mechanism of the steel and concrete joint section of railway hybrid box girder cable‐stayed bridge ,the Yongjiang River Bridge on the North Ring Link of Ningbo Railway Terminal was taken as an example .The soft‐ware ANSYS was used to establish the three‐dimensional finite element model for the steel and concrete joint section of the bridge ,the force conditions and axial force distribution proportions of the steel shell and concrete in the joint section w ere analyzed .T he results of the analysis demon‐strate that under the action of the calculated load ,the structural longitudinal force‐bearing plates are all in the compression state and the structural stress levels are low .With the exception that the forces in the bearing plate change abruptly ,the changing of the forces in other parts is gentle . The stress levels of the different sections of the concrete are low and certain out‐of‐plane deforma‐tion of the sections occurs .The function of the bearing plate in the force transfer is significant . About 54% axial force of the joint section transfers via the bearing plate while the rest of the axi‐al force transfers via the PBL connectors and shear studs . The proportions of the axial force transfer of the connectors present the saddle‐shape distribution that is large at both ends and small in the middle .%为研究铁路钢箱混合梁斜拉桥钢-混结合段的受力特征及传力机理,以宁波铁路枢纽北环线甬江特大桥为背景,采用ANSYS有限元软件建立该桥钢-混结合段的三维有限元模型,分析钢-混结合段中钢壳体和混凝土的受力及轴力分配比例。结果表明:在计算荷载作用下,结构纵向受力板件均处于受压状态,应力水平较低;除承压板处发生突变外,其他部位变化平缓;混凝土各截面应力水平较低,截面发生一定的面外变形;承压板传

  20. Evaluation on Impact Interaction between Abutment and Steel Girder Subjected to Nonuniform Seismic Excitation

    OpenAIRE

    Yue Zheng; Xiang Xiao; Lunhai Zhi; Guobo Wang

    2015-01-01

    This paper aims to evaluate the impact interaction between the abutment and the girder subjected to nonuniform seismic excitation. An impact model based on tests is presented by taking material properties of the backfill of the abutment into consideration. The conditional simulation is performed to investigate the spatial variation of earthquake ground motions. A two-span continuous steel box girder bridge is taken as the example to analyze and assess the pounding interaction between the abut...

  1. Installation and Control of Large Post-tensioning Pre-stressed High-performance Concrete Box Girders for an Ore Terminal%大型后张预应力高性能混凝土箱梁在矿石码头中的应用控制

    Institute of Scientific and Technical Information of China (English)

    马玉臣

    2011-01-01

    The use of large post-tensioning pre-stressed high-performance concrete box girders used in deepwater berths especially for ore terminals to accommodate ships of more than 250 000 tons is still unprecedented in China. The paper describes that the prestressed girders are suitable for the load and process requirements through various quality control procedures during the construction of Caofeidian Ore Terminal and the successful engineering practice ran provide references for similar projects.%大型后张预应力高性能混凝土箱梁应用在深水泊位特别是25万吨级以上的矿石码头国内尚无先例,文中阐述了该预应力梁在曹妃甸矿石码头工程施工过程中通过多方面质量控制,较好地适应了荷载和工艺要求,其成功应用可为以后类似工程提供借鉴.

  2. Vortex-induced resonance characteristics and anti-vibration measures'mechanism of central-slotted box girders%中央开槽箱梁涡激共振特性及抑振措施机理研究

    Institute of Scientific and Technical Information of China (English)

    杨婷; 周志勇

    2015-01-01

    To study vortex-induced resonance characteristics and anti-vibration measures'mechanism of central-slotted box girders,the large-scale sectional model vibration measurement,pressure measurement and CFD were employed.A long-span cable-stayed bridge over Yangtze River was taken as an example to conduct wind tunnel tests of large-scale sectional model.The test results indicated that it is the maintenance rails located inside aerodynamic susceptible sites that cause the vortex-induced vibration of the bridge.CFD numerical simulation results showed that the upwind flow passing through the curved soffit plate is hindered by the inside maintenance rails to cause an increased width of dead water region in the wake of upwind box section,a continuous and intensive vortex shedding phenomenon occurs due to velocity gradient and the VIV of the bridge main beam section takes place;accordingly,the inside maintenance rails are proposed to offset the center line of the main beam with a certain distance,they are not an obstacle to the high-speed upwind flow;thus the flow separates at the location far away from the knuckle line and the size of dead water region in the upwind box wake is reduced to prevent the vortex shedding.The static pressure test results showed that when shifting the inside maintenance rails,the negative mean pressure at the soffit plate knuckle line,does not change dramatically,the fluctuating pressures on the upwind and downwind inclined panels can be reduced,and the fluctuating energy is dispersed without a consistent predominant frequency.Wind tunnel tests for the modified section were conducted and the results showed that the VIV of the bridge can be suppressed completely.%基于大比例节段模型风洞测振、测压试验及计算流体力学(Computational Fluid Dynamic,CFD)方法进行中央开槽箱梁涡激共振特性及抑振措施机理研究。以芜湖长江公路二桥为例进行大比例节段模型风洞试验。结果显示,位于

  3. Study of Dynamic Performance Finite Element Modeling Methods for Box-Truss Composite Girder Railway Cable-Stayed Bridge%箱桁组合梁铁路斜拉桥动力特性有限元建模方法研究

    Institute of Scientific and Technical Information of China (English)

    张无畏; 胡腾飞; 陈长胜; 荣浩

    2016-01-01

    study show that modal analysis re‐sults gained from the three model calculations are basically consistent , the frequency and main girder equivalent mass gained from the combined plate‐beam element model and spatial shell ele‐ment model are approximate ,nevertheless ,the spatial beam element model could not accurately calculate the main girder uniform equivalent mass of the high‐order lateral bending modes .As an exception ,the dynamic performance of the steel box girder cable‐stayed bridge without truss and with open cross section was analyzed independently .The results of the analysis show that the com‐bined plate‐beam element model and spatial shell element model are in good agreement ,but the in‐ertia moment of the main girder uniform equivalent mass under the first order torsional mode gained from the spatial beam element model reveal an error of 9% .T russ has slight influence on the lateral bending frequency of the main girder ,but can improve the vertical bending frequency and torsional frequency of the main girder ,w hich is favorable for the wind resistant performance of the bridge .

  4. 波形钢腹板连续箱梁剪滞效应引起的附加轴力分析%Additional Axial Force Analysis Caused by Shear lag Effect of Cintinuous Box-girder Bridge with Corrugated Steel Webs

    Institute of Scientific and Technical Information of China (English)

    吴焕庆; 张俊波; 刘世忠; 冀伟; 满自亭

    2013-01-01

    Under the condition of the plane section assumption and without considering the inertia moment of corrugated steel webs,this paper establishes the additional axial force formula for the two spans continuous box-girder bridge with corrugated steel webs based on a cubic parabola shear lag warping function.At the same time,it leads into the additional axial force stress ratio coefficient.Then it analyses the impact of additional axial stress to the influence degree of structural mechanical,which is based on the continuous box-girder bridge with corrugated steel webs under the full cross-uniformly distributed load and mid-span concentrated load.It shows that the value of additional axial stress can be ignored because the additional axial force stress ratio coefficient under the full cross-uniformly distributed load and the mid-span concentrated load is less than 1%.%基于平截面假定并不计波形钢腹板惯性矩,建立了波形钢腹板两跨连续箱梁在三次抛物线剪滞翘曲位移函数下的附加轴力计算式.引入附加轴向应力比系数,分析了波形钢腹板混凝土两跨连续梁在均布荷戢及跨中集中荷载作用下,附加轴向应力对结构受力性能的影响,分析表明:在两种荷栽工况下,附加轴向应力比系数均小于1%,可以忽略其效应.

  5. Optimization Method for Girder of Wind Turbine Blade

    Directory of Open Access Journals (Sweden)

    Yuqiao Zheng

    2014-01-01

    Full Text Available This paper presents a recently developed numerical multidisciplinary optimization method for design of wind turbine blade. The objective was the highest possible blade weight under specified atmospheric conditions, determined by the design giving girder layer and location parameter. Wind turbine blade on box-section beams girder is calculated by ply thickness, main girder and trailing edge. In this study, a realistic 30 m blade from a 1.2 MW wind turbine model of blade girder parameters is established. The optimization evolves a structure which transforms along the length of the blade, changing from a design with spar caps at the maximum thickness and a trailing edge mass to a design with spar caps toward the tip. In addition, the cross-section structural properties and the modal characteristics of a 62 m rotor blade were predicted by the developed beam finite element. In summary, these findings indicate that the conventional structural layout of a wind turbine blade is suboptimal under the static load conditions, suggesting an opportunity to reduce blade weight and cost.

  6. Wind Turbine Blade with Angled Girders

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a reinforced blade for a wind turbine, particularly to a blade having a new arrangement of two or more girders in the blade, wherein each of the girders is connected to the upper part and the lower part of the shell and forms an angle with another girder thereby...

  7. Distortional Buckling Analysis of Steel-Concrete Composite Girders in Negative Moment Area

    Directory of Open Access Journals (Sweden)

    Zhou Wangbao

    2014-01-01

    Full Text Available Distortional buckling is one of the most important buckling modes of the steel-concrete composite girder under negative moment. In this study, the equivalent lateral and torsional restraints of the bottom flange of a steel-concrete composite girder under negative moments due to variable axial forces are thoroughly investigated. The results show that there is a coupling effect between the applied forces and the lateral and torsional restraint of the bottom flange. Based on the calculation formula of lateral and torsional restraints, the critical buckling stress of I-steel-concrete composite girders and steel-concrete composite box girders under variable axial force is obtained. The critical bending moment of the steel-concrete composite girders can be further calculated. Compared to the traditional calculation methods of elastic foundation beam, the paper introduces an improved method, which considers coupling effect of the external loads and the foundation spring constraints of the bottom flange. Fifteen examples of the steel-concrete composite girders in different conditions are calculated. The calculation results show a good match between the hand calculation and the ANSYS finite element method, which validated that the analytic calculation method proposed in this paper is practical.

  8. Evaluation on Impact Interaction between Abutment and Steel Girder Subjected to Nonuniform Seismic Excitation

    Directory of Open Access Journals (Sweden)

    Yue Zheng

    2015-01-01

    Full Text Available This paper aims to evaluate the impact interaction between the abutment and the girder subjected to nonuniform seismic excitation. An impact model based on tests is presented by taking material properties of the backfill of the abutment into consideration. The conditional simulation is performed to investigate the spatial variation of earthquake ground motions. A two-span continuous steel box girder bridge is taken as the example to analyze and assess the pounding interaction between the abutment and the girder. The detailed nonlinear finite element (FE model is established and the steel girder and the reinforced concrete piers are modeled by nonlinear fiber elements. The pounding element of the abutment is simulated by using a trilinear compression gap element. The elastic-perfectly plastic element is used to model the nonlinear rubber bearings. The comparisons of the pounding forces, the shear forces of the nonlinear bearings, the moments of reinforced concrete piers, and the axial pounding stresses of the steel girder are studied. The made observations indicate that the nonuniform excitation for multisupport bridge is imperative in the analysis and evaluation of the pounding effects of the bridges.

  9. Comparison of Stresses of Fatigue-sensitive Regions in Orthotropic Deck of Steel Box Girder for Highway and Railway Bridges%钢箱梁用于公、铁桥梁时正交异性板疲劳敏感部位应力比较

    Institute of Scientific and Technical Information of China (English)

    高立强; 蒲黔辉; 施洲

    2011-01-01

    The scheme of steel box girder used in the design of Yongjiang Railway Cable-stayed Bridge of Ningbo city is the first case in railway bridges in China. For railway bridges, the transverse position of steel rails is stable, and bridge deck pavement is different from that of highway bridges. In order to study the difference of orthotropic deck used in railway bridge and highway bridge, railway bridge and highway bridge deck pavements were installed on the deck separately. With the finite element method, the transverse and longitudinal influence lines of the stresses in the fatigue-sensitive regions with different bridge deck pavements were calculated. The reason why the stress in each fatigue-sensitive region was studied, and the characteristics of steel box girder orthotropic deck for railway bridge and highway bridge were analyzed. With the representative railway and highway vehicles as the loads, the stresses of steel box girder orthotropic deck in some fatigue-sensitive regions were calculated. The results of analysis and calculation show that (1 ) The dispersion of asphalt concrete deck pavement for highway bridge is weak, while that of railway bridge deck pavement is strong. Compared with highway bridge, the values of influence lines of the stresses in the fatigue-sensitive regions are smaller, and the lengths of influence lines are longer for railway bridge. (2) Under theload of normal railway vehicle, the largest stresses of rib-to-diaphragm joint and edge of cutout in diaphragm are similar to that under the load of normal highway vehicle. (3) In comparison with railway bridge, fatigue cracks are likely to emerge at the rib-to-deck joint for highway bridge orthotropic deck.%宁波甬江铁路斜拉桥在设计中采用钢箱梁方案,在铁路桥中为国内首例.铁路桥梁钢轨横向位置固定,桥面铺装也与公路桥梁不同,为研究钢箱粱正交异性板用于铁路桥梁和公路桥梁的区别,在桥面板上分别设置铁路与公路铺

  10. 基于梁格法的预制箱梁横向刚度模拟研究%Study of Transverse Stiffness Simulaton Based on Beam Grillage Method for Prefabricated Box Girder

    Institute of Scientific and Technical Information of China (English)

    杨圣超; 夏兴佳

    2016-01-01

    To correctly simulate the transverse stiffness of the spatial beam grillage model of the prefabricated box beam ,the right deck of the Weijiacun Zhong Bridge on the Zhunxing Heavy Load Expressway was taken as the study background ,to study the influence of the type of the vir‐tual beams in the spatial beam grillage model of a prestressed box beam on the transverse stiffness . The bridge is a 4 × 20 m prestressed concrete continuous box beam bridge ,to which full loads was applied according to the static test results gained when the bridge was completed and transferred , to test the strain and deflection of the main beam .The MIDAS Civil software was used to establish the spatial beam grillage models of the main beam with three types of virtual beams ,to calculate the main beam bending moment under the design loads and testing loads ,and the strain and deflec‐tion of the main beam under the maximum positive bending moment and the related verification co‐efficients ,and the calculated results were compared with the measured ones .The results demon‐strate that the transverse stiffness of the spatial beam grillage model show s sign of increase as the increase of the length of the rigid zone of the virtual beam and the decrease of the efficient length of the virtual beam .And when the part of the virtual beam from the center of the stringers to the in‐ner edge of the stringer webs was set as the rigid zone ,the transverse stiffness simulated by the spatial beam grillage model is the closest to the transverse stiffness of the actual bridge .%为准确模拟预制箱梁空间梁格模型的横向刚度,以准兴重载高速公路魏家村中桥右幅桥为背景,研究预制箱梁空间梁格模型中虚梁形式对横向刚度的影响。该桥为4×20 m预制混凝土连续箱梁桥,按交工静载试验满载加载,测试主梁的应变和挠度;采用M IDAS Civil软件建立3种虚梁形式的主梁空间梁格模型,计算设计荷载和试验

  11. 高速列车运行对铁路简支箱梁空气动力特性的影响%Inf luence of high speed train running on aerodynamic characteristics of railway simple-supported box-girder

    Institute of Scientific and Technical Information of China (English)

    肖军; 李小珍; 刘德军

    2015-01-01

    列车—桥梁系统的空气动力特性不仅受组合断面上的气动绕流影响,而且在顺桥向列车对桥梁的影响还呈现出非均匀性及动态变化。以高速列车通过铁路双线32 m 简支梁桥为例,分析头车前35 m至尾车后35 m范围内的桥梁三分力系数变化规律,得到了高速列车运行对该型桥梁不同位置断面空气动力特性的影响规律。研究发现,在任意时刻列车对铁路桥梁的空气动力特性影响都可划分为覆盖区、过渡区和无影响区3个区段,且随着列车在桥上的运行,列车对桥梁的影响区域在动态变化。提出了一种移动窗口模型方法来动态更新桥梁不同部位的气动力系数。该方法真正实现了列车—桥梁系统的动态气动耦合,能够更为精确地模拟风—车—桥系统耦合分析中的动态风荷载。%T he aerodynamic characteristics of train-bridge system are affected by the aerodynamic flow on a hybrid cross section and the effect of vehicle on bridge presents a non-homogeneous and dynamic variation along the bridge direction. T aking the high speed train passing through railway double line 32 m simple-supported box-girder bridge as an example,the variation law of bridge three-component aerodynamic coefficients from 35 m ahead first vehicle to 35 m behind the last vehicle was analyzed and the influence law of high speed train movement on aerodynamic characteristics of different bridge cross section was obtained. T he results indicated that effect of train on aerodynamic characteristics of railw ay bridge could be divided into 3 sections including the coverage area,the transition zone and the non-influence area at any time and the influence area changes dynamically with the train passing through the bridge. T his paper presented a moving window model to dynamically update the aerodynamic coefficients of different bridge parts and has realized the dynamic aerodynamic coupling of vehicle

  12. Plastic analysis of the lateral effective width of cantilever slabs of reinforced concrete box-girders%基于塑性分析的钢筋混凝土箱梁悬臂板横向受力有效分布宽度

    Institute of Scientific and Technical Information of China (English)

    方志; 郑辉; 刘双阳

    2012-01-01

    目前国内外相关设计规范中关于行车道板横向受力有效分布宽度的取值是基于弹性理论分析结果确定的,不能体现塑性阶段行车道板横向受力特点。通过对2个钢筋混凝土箱梁模型上的4块悬臂板进行荷载试验,得出悬臂板极限荷载和塑性铰线分布形式,并运用塑性分析方法,推导钢筋混凝土箱梁悬臂板在局部荷载作用下塑性有效分布宽度的计算公式。试验结果和理论分析比较表明:悬臂板的塑性有效分布宽度与荷载作用位置及单位板宽正、负极限弯矩值相关;满足构造配筋要求的箱梁悬臂板进行极限状态设计时,建议采用简化的三折线破坏模式进行塑性横向有效分布宽度计算,取正铰线扩散角为45°,负铰线扩散角为60°;荷载作用于悬臂板边缘时基于塑性的横向有效分布宽度是基于弹性分析的1.58倍。%According to the current design code specifications home and abroad, the values of effective width are mostly based on the results of elasticity theory, which cannot represent the characteristics of effective width in the plastic stage. The ultimate load capacity of cantilever slab and the distribution form of plastic yield-lines were acquired through loading experiments of four cantilever slabs of two reinforced concrete box-girders. The formula for calculating the effective width of the slabs under patch load was derived from plastic analysis. By comparing the experimental results with that of theoretical analysis, it is found that the plastic effective width depends on the load-bearing position and both the positive and negative values of ultimate moment, in addition, the simplified tri-linear mode could effectively determine the ultimate strength and plastic effective width of the slabs with at least the minimum reinforcement, and the desirable calculation plastic spread angle is 45~ for the positive yield-line, 60~ for the negative yield

  13. Committee VI.1. Extreme Hull Girder Loading

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2000-01-01

    Committee Mandate. Evaluate and develop direct calculation procedures for extreme wawe loads on ship hull girders. Due consideration shall be given to stochastic and non-linear effects. The procedures shall be assessed by comparison with in-service experiences, model tests and more refined...

  14. Critical Strength of steel Girder Web

    OpenAIRE

    Pratibha M Alandkar; Sandeep M Shiyekar; Mukund R Shiyekar

    2016-01-01

    When a member is subjected to combined action of bending moment, shear and axial force, bending moment & axial force is assumed to resist by whole section and shear is resisted by web only. In such case web shall be designed for combined shear and axial force. The present study determines the strength of web of steel girder under the action of pure shear, pure axial force and combination of it. The classical plate buckling theory is already established to determine the critical buckling st...

  15. Behaviour of parallel girders stabilised with U-frames

    DEFF Research Database (Denmark)

    Virdi, Kuldeep; Azzi, Walid

    2010-01-01

    Lateral torsional buckling is a key factor in the design of steel girders. Stability can be enhanced by cross-bracing, reducing the effective length and thus increasing the ultimate capacity. U-frames are an option often used to brace the girders when designing through type of bridges and where...... overhead bracing is not practical. This paper investigates the effect of the U-frame spacing on the stability of the parallel girders. Eigenvalue buckling analysis was undertaken with four different spacings of the U-frames. Results were extracted from finite element analysis, interpreted and conclusions...

  16. BENDING-SHEAR INTERACTION OF LONGITUDINALLY STIFFENED GIRDERS

    OpenAIRE

    Beg, Darko; Sinur, Franc

    2011-01-01

    To understand behaviour of longitudinally stiffened plated girders subjected to high bending moments and shear forces, four tests on large scale test specimens were performed. The results of these tests were used to verify the numerical model, which was employed for further parametric studies. With a verified simplified numerical model a parametric nonlinear analysis was systematically carried out to determine the resistance of longitudinally stiffened plated girders. Based on 630 numerical s...

  17. Experimentally Validated Nonlinear Analysis of Bridge Plate Girders with Deformations

    Directory of Open Access Journals (Sweden)

    Kużawa Mieszko

    2015-09-01

    Full Text Available Comprehensive methodology of numerical nonlinear analysis of the consecutive phases in the structural behaviour of bridge plate girders with deformations is presented. The analysis concerns all stages of structure loading until failure and especially determination of the ultimate shear load capacity. Verification and validation of the numerical procedures proposed is based on comparison of the calculated results with effects of experimental laboratory shear capacity tests of plate girders carried out at the University of Ljubljana.

  18. Time-domain analysis of wind-induced buffet and wind-resistant measures for cable-stayed bridge with steel box girder at construction stage%大跨度钢箱梁斜拉桥施工过程风致抖振时域分析及抗风措施

    Institute of Scientific and Technical Information of China (English)

    张茜; 周绪红; 狄谨; 王继承

    2013-01-01

    以杭州湾跨海大桥北通航孔斜拉桥为背景,采用ANSYS有限元分析软件对其施工中最大双悬臂及最大单悬臂状态进行了风致抖振响应时域分析.采用谐波合成法进行了随机风场模拟,对塔、梁和索承受的风荷载分别进行了简化,并给出了静风力、抖振力和自激力的时域表达式及自激力在ANSYS中的实现方法;采用“鱼骨式”模型作为斜拉桥主梁的计算模型,分析考虑了结构的几何、气动非线性.分析结果表明:在施工阶段设计风荷载下,主梁悬臂端及塔顶处位移响应较小,风荷载效应与恒载效应组合后,塔根部截面最大拉应力为0.707 MPa;根据抖振响应分析结果和其他因素综合考虑,对杭州湾跨海大桥北通航孔斜拉桥提出了施工过程中有效可行的抗风措施.%Based on the project of north channel cable-stayed bridge of Hangzhou Bay Sea-crossing Bridge, the time-domain analysis of wind-induced buffet was carried out under the double and single jib condition by ANSYS. The random wind field was simulated by WAWS. Buffeting wind loads, which were exerted on tower, girder and cables, were simplified separately. The time-domain expressions of static wind force, buffeting force and full coupled auto-excited force, and how to exert the full coupled auto-excited force in ANSYS were proposed in this paper. Single beam elements were adopted to proceed the time-domain analysis, and the geometric and aerodynamic nonlinear of the structure was considered. Time-domain analysis results show that under the design wind loads at construction stage, the displacement response is smaller at the cantilever end of main girder and the top of pylon. The maximum tensile stress of the section at the root of pylon is 0. 707 MPa after combination of wind loads and dead loads. The wind resistance measures are suggested based on the results of the time-domain analysis and the influence of other factors. 3 tabs, 7 figs, 10

  19. 港珠澳大桥浅水区非通航孔桥组合梁设计%Design of Composite Girders for Non-Navigable Span Bridge of Hong Kong-Zhuhai-Macau Bridge in Shallow Water Area

    Institute of Scientific and Technical Information of China (English)

    罗扣; 王东晖; 张强

    2013-01-01

    The main part of the Hong Kong-Zhuhai-Macau Bridge is a part of the combined bridge and tunnel,of which the non-navigable span bridge in the shallow water area is the 85 m span continuous composite girder bridge that totally has 64 spans of the composite girders and is 5 440 m in length.The span arrangement of the bridge mainly includes two kinds of arrangement of 6)× 85 m and 5)× 85 m.The composite girders are the separated continuous single-cell singlebox girders with constant depth and specifically are composed of the open steel box girders and the concrete deck slabs that are connected each other via shear studs.A steel box girder is the inverted trapezoid structure,a concrete deck slab is the precast full slab in the transverse direction and the grooves are pre-reserved at the locations of the shear studs.To improve the transverse mechanical behavior of the deck slabs,the stringers are set in the sections of the composite girders and to keep the integrity of the slabs,the shear studs are arranged in a way of clustering.The composite girders are erected and installed in each full span by the large transportation and erection floating crane and the girders are closed span by span.%港珠澳大桥主体工程采用桥隧组合方案,其中浅水区非通航孔桥采用85 m连续组合梁桥形式,全长5 440m,共64孔,跨径布置主要采用6×85 m和5×85m2种形式.组合梁采用单箱单室分幅等高连续梁,由开口钢箱梁和混凝土桥面板通过剪力钉联结而成.钢箱梁为倒梯形结构;混凝土桥面板为横向整块预制,在剪力钉处设置预留槽.为改善混凝土桥面板的横向受力性能,该桥组合梁截面设置小纵梁;为保持桥面板的整体性,剪力钉采用集束式布置方式.组合梁采用大型运架一体浮吊整孔安装架设,逐孔合龙.

  20. Suspension Bridge Flutter for Girder with Separate Control Flaps

    DEFF Research Database (Denmark)

    Huynh, T.; Thoft-Christensen, Palle

    Active vibration control of long span suspension bridge flutter using separated control flaps (SFSC) has shown to increase effectively the critical wind speed of bridges. In this paper, an SFSC calculation based on modal equations of the vertical and torsional motions of the bridge girder including...... the flaps is presented. The length of the flaps attached to the girder, the flap configuration and the flap rotational angles are parameters used to increase the critical wind speed of the bridge. To illustrate the theory a numerical example is shown for a suspension bridge of 1000m+2500m+1000m span based...

  1. 高铁槽形梁斜拉桥塔梁固接结构试验研究及数值分析%Experimental Study and Numerical Analysis on Pylon-Girder Rigid Fixity Structure of a Trough Girder Cable-stayed Bridge in High-speed Railway

    Institute of Scientific and Technical Information of China (English)

    戴公连; 粟淼

    2015-01-01

    Based on a single-tower cable-stayed bridge with trough girder in Shanghai-Kunming high speed rail-way,the design method of test model,stress state,ultimate bend-carrying capacity and load transfer path of the pylon-girder rigid fixity structure is investigated through model test and numerical simulation.The results indicate that the stress level of pylon-girder rigid fixity zone is low under the dead and live load in operational stage,where the longitudinal and vertical normal stress is within 6 .5 MPa,providing sufficient safety capacity in the rigid fixity zone.Under the ultimate bending load,the section of the main span girder close to the rigid fixity zone failed first,indicating stronger bending strength of the pylon-girder rigid fixity zone than the girder section.The force transmission features in the side box girder and the deck slab are similar with the main gird-er and pylon-girder rigid fixity zone,which indicates that the side box is the main force bearing component. Compared with the rigid fixity zone,the deck slab of the girder demonstrates a more evident shear lag effect.%以沪昆高铁某独塔斜拉桥为研究对象,模型试验与数值模拟相结合,研究槽形截面斜拉桥的塔梁固接结构模型的试验方法、受力状态、极限承载能力以及传力机理等。研究表明:运营阶段荷载作用下,斜拉桥塔梁固接区的应力水平较低,纵向和竖向正应力在6.5 MP a以内,塔梁结合部具有较强的安全储备;在梁体抗弯强度极限荷载下,靠近固接区主跨侧槽形梁断面最先破坏,固接区截面抗弯强度大于主梁断面;槽形截面边箱梁和桥面板传力特征在主梁和塔梁固接区基本一致,边箱梁为主要受力构件;较之于塔梁固接区,主梁内的桥面板剪力滞效应更为明显。

  2. Experiments and theory on deck and girder crushing

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup; Ocakli, Hasan

    1999-01-01

    This paper is concerned with theoretical and experimental analysis of deep plastic collapse of a deck or deep girder subjected to an in-plane, concentrated load. A theory is derived which is valid until initition of fracture in the structure. The presented experimental results show load-deflectio...

  3. Preliminary study to facilitate smart structure systems in bridge girders

    Science.gov (United States)

    Kirkpatrick, Thomas C.; Peterson, Danford O.; Rossi, Peter J.; Ray, Laura R.; Livingston, Richard A.

    1999-05-01

    Sensors are currently available and used to monitor structural performance and loads incurred by bridges already in service. However, there has been limited research concerning the stresses that steel bridge girders endure during transport from the manufacturer to the job site and during the installation process. This paper reports the measured stresses on steel bridge girders during transportation from Lancaster, PA to Hanover, NH and during construction of the Ledyard Bridge on the New Hampshire - Vermont border. Two different monitoring system were developed for this data acquisition in a mobile environment. The first, a fiber optic strain monitoring system, utilizing Bragg grating technology. The second utilized an electrical- resistive foil strain gage network, in conjunction with wireless telemetry equipment. Together, these two systems formed a smart structure system for monitoring bridge girders while confirming the accuracy of data gathered through redundancy. Result conclusively demonstrated for the first time, that stresses in beams during transportation are significant and approach the factor of safety margin in girder design.

  4. Bento Boxes

    Science.gov (United States)

    Hasio, Cindy

    2010-01-01

    Bento boxes are common objects in Japanese culture, designed to hold enough lunch for one person. They have individual compartments and sometimes multiple tiers for rice, vegetables, and other side dishes. They are made of materials ranging from wood, cloth, aluminum, or plastic. In general, the greater the number of foods, the better the box is…

  5. Buffeting Response of Suspension Bridge Girder with Separate Control Flaps

    DEFF Research Database (Denmark)

    Huynh, Truc; Thoft-Christensen, Palle

    This paper presents the calculation of the root mean square (RMS) response of a suspension bridge using separate control flaps (SCF) in turbulence conditions. It is assumed that the mean wind velocity is not large enough to cause coupled vibrations and that single mode buffeting response is of in......This paper presents the calculation of the root mean square (RMS) response of a suspension bridge using separate control flaps (SCF) in turbulence conditions. It is assumed that the mean wind velocity is not large enough to cause coupled vibrations and that single mode buffeting response...... on the basis of independent flutter derivatives and independent aeroelastic coefficients from the girder and from the flaps. The theory is demonstrated by a numerical example based on a long-span suspension bridge model with the Great Belt girder....

  6. Performance of Bridge Decks and Girders with Lightweight Aggregate Concrete

    OpenAIRE

    Ramirez, J.A.; Olek, J.; Rolle, Eric Joseph; Manlone, Brian J.

    2000-01-01

    Structural lightweight concrete is a very versatile material and Haydite and Minergy lightweight aggregates can be utilized in the mixture development of concrete for use in girders and decks in bridges. More widespread use of lightweight aggregates (LWA) would result in savings in construction cost due to considerable dead load reduction. The materials phase of this research study evaluated the fresh concrete properties (slump, unit weight, and air content), the mechanical properties of ha...

  7. Precast Prestressed Concrete Truss-Girder for Roof Applications

    Directory of Open Access Journals (Sweden)

    Peter Samir

    2014-01-01

    Full Text Available Steel trusses are the most popular system for supporting long-span roofs in commercial buildings, such as warehouses and aircraft hangars. There are several advantages of steel trusses, such as lightweight, ease of handling and erection, and geometric flexibility. However, they have some drawbacks, such as high material and maintenance cost, and low fire resistance. In this paper, a precast concrete truss is proposed as an alternative to steel trusses for spans up to 48 m (160 ft without intermediate supports. The proposed design is easy to produce and has lower construction and maintenance costs than steel trusses. The truss consists of two segments that are formed using standard bridge girder forms with block-outs in the web which result in having diagonals and vertical members and reduces girder weight. The two segments are then connected using a wet joint and post-tensioned longitudinally to form a crowned truss. The proposed design optimizes the truss-girder member locations, cross-sections, and material use. A 9 m (30 ft long truss specimen is constructed using self-consolidated concrete to investigate the constructability and structural capacity of the proposed design. A finite element analysis of the specimen is conducted to investigate stresses at truss diagonals, verticals, and connections. Testing results indicate the production and structural efficiency of the developed system.

  8. Virtual box

    DEFF Research Database (Denmark)

    Stougaard, Malthe Kirkhoff

    2007-01-01

    Mediated intimacy is the phenomenon where humans use technologies to express, share, or communicate intimate feelings with each other. Typically, technologies supporting mediated intimacy encompass different characteristics than technologies designed to solve specific work-oriented tasks. This pa......Mediated intimacy is the phenomenon where humans use technologies to express, share, or communicate intimate feelings with each other. Typically, technologies supporting mediated intimacy encompass different characteristics than technologies designed to solve specific work-oriented tasks....... This paper reports on the design, implementation and initial evaluation of Virtual Box. Virtual Box attempts to create a physical and engaging context in order to support reciprocal interactions with expressive content. An implemented version of Virtual Box is evaluated in a location-aware environment...

  9. Effects of vertical girder realignment in the Argonne APS storage ring

    International Nuclear Information System (INIS)

    The effects of vertical girder misalignments on the vertical orbit of the Advanced Photon Source (APS) storage ring are studied. Partial sector-realignment is prioritized in terms of the closed-orbit distortions due to misalignments of the corresponding girders in the sectors. A virtual girder-displacement (VGD) method is developed that allows the effects of a girder realignment to be tested prior to physically moving the girder. The method can also be used to anticipate the corrector strengths needed to restore the beam orbit after a realignment. Simulation results are compared to experimental results and found to reproduce the latter quite closely. Predicted corrector strengths are also found to be close to the actual local corrector strengths after a proof-of-principle two-sector realignment was performed

  10. Strengthening of steel–concrete composite girders using carbon fibre reinforced polymer (CFRP) plates

    Indian Academy of Sciences (India)

    S M Mosavi; A Sadeghi Nik

    2015-02-01

    Applying composites in order to strengthen and renew the infrastructures has globally been accepted. Traditional methods to strengthen the out-of-standard structures are costly, time consuming and requires a lot of labour. Today, new techniques are hired using light and strong substances which also resist against corrosion, known as Carbon Fibre Reinforced Polymer (CFRP) plates. Regarding the high tensile strength and proper module of elasticity, CFRP plates are considered as a suitable alternative to strengthen girders. The behaviour of steel–concrete composite girders being statically loaded and strengthened by CFRP plates in this study. The CFRP plates used in this study have been stuck, with epoxy adhesive, under the tensile sections of three steel girders. The results accompanied with analytical study of moment–curvature and numerical analysis done with ANSYS, show that CFRP plates with epoxy adhesive increases the ultimate loading capacity of steel–concrete composite girder. Plastic stiffness of the girders was also increased.

  11. A concrete balanced cantilever box girder bridge in the Netherlands with carbon fibre prestressing cables

    NARCIS (Netherlands)

    Hordijk, D.A.; Bruggeling, A.S.G.; Kaptijn, N.

    1998-01-01

    In the Netherlands a pilot project has started to recognize the possibilities of non-metallic materials for prestressing. This project will also serve to gather more knowledge regarding the properties of non-metallic wires, their anchorages and their application in large tendons. It is intended to a

  12. Wave induced extreme hull girder loads on containerships

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher; Pedersen, Preben Terndrup; Shi, Bill;

    2009-01-01

    This paper provides simple but rational procedures for prediction of extreme wave – induced sectional hull girder forces with reasonable engineering accuracy. The procedures take into account main ship hull characteristics such as: length, breadth, draught, block coefficient, bow flare coefficient...... is used as a base to derive semi-analytical formulas such that approximate wave load calculations can be performed by a simple spreadsheet program. Due to the few input parameters this procedure can be used to estimate the wave-induced bending moments at the conceptual design phase. Since the procedure...

  13. Einstein's Boxes

    OpenAIRE

    Norsen, Travis

    2004-01-01

    At the 1927 Solvay conference, Einstein presented a thought experiment intended to demonstrate the incompleteness of the quantum mechanical description of reality. In the following years, the thought experiment was picked up and modified by Einstein, de Broglie, and several other commentators into a simple scenario involving the splitting in half of the wave function of a single particle in a box. In this paper we collect together several formulations of this thought experiment from the exist...

  14. Design of bridge crane girder strain acquisition system based on virtual instrument

    Directory of Open Access Journals (Sweden)

    Wenxue LIU

    Full Text Available Girder is an important part of the bridge crane, which is also the main force element. In order to prevent accidents, it is necessary to collect the bridge crane girder stress data to analyse the fatigue life. This paper constructs a bridge crane girder strain acquisition system. The hardware system consists of sensors, connectors, data acquisition cards, wireless data transmission groups, POE power and host computer. The software system consists of NI MAX to interface with the computer's NI hardware and software resources,and LabVIEW programming to display and storage the girder strain data. Through this system, positions and working days strain data acquisition for the 50/10 t bridge crane girder gets the key positions strain data. The results show that the girder strain data acquisition system runs stably, channel signals of acquisition task transmit accurately, and the terminal data stores competely, meeting the detection requirements, which provides an important data support for the subsequent fatigue analysis and accurate remaining service life prediction of the crane girder.

  15. Shadow boxing

    OpenAIRE

    Pulford, Donald

    2011-01-01

    Shadow Boxing continues my interest in the production/performance of gender on stage. It tells the story of a closeted, gay boxer and the devastation that ensues when he is outed. The central device is the play’s appeal to the audience’s imagined ‘bad faith’ concerning masculinity and the shock when the attendant expectations are subverted or upturned. I expressed the foundation of our enterprise in the New York programme by quoting from Calvin Thomas’s Masculinity, Psychoanalysis, Straight Q...

  16. Plasticity Theory Analysis about the Bearing Section Limited Strength of Partial Filling Concrete Continuous Composite Girder Bridge%部分充填混凝土连续组合梁桥支座处截面极限强度的塑性理论分析

    Institute of Scientific and Technical Information of China (English)

    姬幸斌; 李文兴; 吴建明

    2012-01-01

      部分充填混凝土窄幅钢箱连续组合梁桥是钢箱-混凝土组合梁与矩形钢管混凝土结构结合的一种新型组合结构梁桥。基于一般钢箱-混凝土连续组合梁桥中支座负弯矩区因混凝土翼板开裂而导致抗弯强度、局部稳定性不足的特点,提出了一种部分充填混凝土窄幅钢箱连续组合梁桥,并对其中支座负弯矩区的正截面强度和支座截面抗剪性能进行了塑性理论分析。%  The narrow range of steel box continuous composite girder bridge that partially filled concrete is a new type of bridge which is composited by steel box-concrete composite girder and rectangular steel tube concrete. As the disadvantage that wing crack in negative moment region causing insufficient of bending strength and local stability of traditional steel box continuous composite girder bridge,a narrow range of steel box continuous composite girder bridge is presented. Then, the plasticity theory analysis is used on normal-section strength of bearing negative moment region and on cross-section support bearing shear performance.

  17. EXPERIMENTAL STUDIES OF WALL GIRDERS IN DIFFERENT TYPES OF BRIDGE DECK

    Directory of Open Access Journals (Sweden)

    O. L. Zakora

    2010-03-01

    Full Text Available The results of experimental studies of wall girders under live load are given in the paper. These studies were conducted in several stages with different types of the bridge floor.

  18. Research on the stiffening girder erection sequence of three-tower suspension bridge

    Institute of Scientific and Technical Information of China (English)

    Zheng Runqing; Luo Xiheng

    2012-01-01

    Compared to the conventional two-tower suspension bridge, the three-tower suspension bridge has obviously different characteristics in structural performance because of the extra middle tower and main span. The construction sequence for the stiffening girder is significantly different between the three-tower suspension bridge and the two-tower suspension bridge. The tangential angle of the main cable is one of the controlling factors of the stiffening girder erection stage for a suspension bridge. According to 5 feasible cases for the stiffening girder erection scheme in Taizhou Bridge, the research about the tangential angle in each case mentioned above was made, and some factors that should be taken into account for the erection scheme of stiffening girder were pointed out.

  19. On the Influence of Hull Girder Flexibility on the Wave

    DEFF Research Database (Denmark)

    Seng, Sopheak; Andersen, Ingrid Marie Vincent; Jensen, Jørgen Juncher

    2012-01-01

    (CFD) solving the Navier-Stokes equations with the free surface captured by a volume-of-fluid (VOF) method. In all procedures the flexibility of the hull girder is modelled as a non-uniform Timoshenko beam. It is observed that the non-linear models agree well with the model tests......Numerical predictions and model test results of the wave induced bending moments in a 9,400 TEU post-Panamax container vessel are presented for two regular wave scenarios. Different numerical procedures have been applied: a linear and non-linear time-domain strip theory and a direct calculation...... and as there is no occurrence of severe slamming in the cases considered, the inexpensive non-linear strip theory is as accurate as the direct CFD calculation method. In a comparison with the results using the rigid body assumption, the increase in the vertical bending moment (VBM) amidships due to the flexibility of the hull...

  20. Onboard monitoring of fatigue damage rates in the hull girder

    DEFF Research Database (Denmark)

    Nielsen, Ulrik Dam; Jensen, Jørgen Juncher; Pedersen, Preben Terndrup;

    2011-01-01

    taking into account whipping stresses. It is conceptually shown how such a method, which integrates onboard estimation of sea states, can be used to deduce decision support with respect to the accumulated fatigue damage in the hull girder.The paper firstly presents a set of measured full-scale wave......-scale onboard acceleration and stress measurements can be used to calculate sea state parameters. These calculated environmental data are verified by a comparison to hindcast data.In the third part of the paper the full-scale fatigue stress ranges are compared to results from an analytical design oriented...... calculation procedure for flexible ship hulls in short-term estimated sea states.Altogether, it is conceptually shown that by a combination of the onboard estimated sea state parameters with the described analytical fatigue damage prediction procedure a method can be established for real-time onboard decision...

  1. Performance evaluation of corrosion-affected reinforced concrete bridge girders using Markov chains with fuzzy states

    Indian Academy of Sciences (India)

    M B ANOOP; K BALAJI RAO

    2016-08-01

    A methodology for performance evaluation of reinforced concrete bridge girders in corrosive environments is proposed. The methodology uses the concept of performability and considers both serviceability- and ultimate-limit states. The serviceability limit states are defined based on the degree of cracking (characterized by crack width) in the girder due to chloride induced corrosion of reinforcement, and the ultimate limit states are defined based on the flexural load carrying capacity of the girder (characterized in terms of rating factor using the load and resistance factor rating method). The condition of the bridge girder is specified by the assignment of a condition state from a set of predefined condition states. Generally, the classification of condition states is linguistic, while the condition states are considered to be mutually exclusive and collectivelyexhaustive. In the present study, the condition states of the bridge girder are also represented by fuzzy sets to consider the ambiguities arising due to the linguistic classification of condition states. A non-homogeneous Markov chain (MC) model is used for modeling the condition state evolution of the bridge girder with time. The usefulness of the proposed methodology is demonstrated through a case study of a severely distressed beam of the Rocky Point Viaduct. The results obtained using the proposed approach are compared with those obtained using conventional MC model. It is noted that the use of MC with fuzzy states leads to conservative decision making for the problem considered in the case study.

  2. Numerical Analysis on Variation of Dynamic Response of Girder Bridges with Torsional Reinforcement Panels

    Directory of Open Access Journals (Sweden)

    Kang Jae-Yoon

    2015-01-01

    Full Text Available The dynamic flexural behaviour of the railway bridge is influenced by its torsional behaviour. Especially, in the case of girder railway bridges, the dynamic response tends to amplify when the natural frequency in flexure (1st vibration mode is close to that in torsion (2nd vibration mode. In order to prevent such situation, it is necessary to adopt a flexural-to-torsional natural frequency ratio larger than 120%. This study proposes a solution shifting the natural frequency in torsion to high frequency range and restraining torsion by installing concrete panels on the bottom flange of the girder so as to prevent the superposition of the responses in the girder bridge. The applicability of this solution is examined by finite element analysis of the shift of the torsional natural frequency and change in the dynamic response according to the installation of the concrete panels. The analytical results for a 30 m-span girder railway bridge indicate that installing the concrete panels increases the natural frequency in torsion by restraining the torsional behaviour and reduces also the overall dynamic response. It is seen that the installation of 100 mm-thick concrete panels along a section of 4 m at both extremities of the girder can reduce the dynamic response by more than 30%.

  3. The Vibration Based Fatigue Damage Assessment of Steel and Steel Fiber Reinforced Concrete (SFRC Composite Girder

    Directory of Open Access Journals (Sweden)

    Xu Chen

    2015-01-01

    Full Text Available The steel-concrete composite girder has been usually applied in the bridge and building structures, mostly consisting of concrete slab, steel girder, and shear connector. The current fatigue damage assessment for the composite girder is largely based on the strain values and concrete crack features, which is time consuming and not stable. Hence the vibration-based fatigue damage assessment has been considered in this study. In detail, a steel-steel fiber reinforced concrete (SFRC composite girder was tested. The steel fiber reinforced concrete is usually considered for dealing with the concrete cracks in engineering practice. The composite girder was 3.3m long and 0.45m high. The fatigue load and impact excitation were applied on the specimen sequentially. According to the test results, the concrete crack development and global stiffness degradation during the fatigue test were relatively slow due to the favourable performance of SFRC in tension. But on the other hand, the vibration features varied significantly during the fatigue damage development. Generally, it confirmed the feasibility of executing fatigue damage assessment of composite bridge based on vibration method.

  4. A EVALUATION OF THE EFFECTIVE PRESTRESS ON TIMBER CONCRETE COMPOSITE GIRDER BRIDGE

    Science.gov (United States)

    Araki, Shogo

    In applying the glulam timber to the large-sized structures, the new types of connections have been developed. In presence, there are a few joint systems using steel plates and bolts. However, those systems are not always adequately satisfied with durability. Therefore, the new joint system by prestressing was developed. In Nagano prefecture, the timber-concrete composite bridge was provided as the standard design of timber bridges, and the joint system is by prestressing. In case of concrete girder, work of prestress decrease by elastic strain, creep, and etc. However, timber-concrete composite girder is not cleared numerically. In this study, we discussed the effective prestress on timber-concrete composite girder based on time-dependent of prestress checked in existing bridge, and we suggest the evaluation method of it.

  5. A Simple Technique to Determine Interface Slip of Stud Connected SCC Girders

    Directory of Open Access Journals (Sweden)

    Rajasankar J.

    2012-01-01

    Full Text Available A simple technique is proposed to compute interface slip of stud connected steel-concrete composite (SCC girders based on the results of a flexure test. The technique makes use of relative longitudinal displacement of the concrete slab and steel beam to calculate the interface slip. In the flexure test of a SCC girder, a cost-effective instrumentation arrangement consisting of mechanical dial gauges is used to measure the relative longitudinal displacement. Responses measured from experiments on SCC girders conducted by the authors are used for numerical implementation and validation of the technique. Alternatively, interface slip is also evaluated by applying an analytical model which is based on first principles of mechanics. The values of interface slip computed by using the proposed technique are found to have close correlation with those of the analytical model. The effect of edge restraint on slip due to friction between steel and concrete is also studied

  6. Approach for analyzing the ultimate strength of concrete filled steel tubular arch bridges with stiffening girder

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-cheng; XIE Xu; ZHANG He; CHEN Heng-zhi

    2007-01-01

    A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch bridge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST arch rib. The geometric nonlinearity, material nonlinearity, influence of the construction process and the contribution of prestressing reinforcement are all taken into consideration. The accuracy of this method is validated by comparing its results with experimental results. Finally, the ultimate strength of an abnormal CFST arch bridge with stiffening girders isinvestigated and the effect of construction method is discussed. It is concluded that the construction process has little effect on the ultimate strength of the bridge.

  7. Welding of girders to insert plates of composite steel-concrete structure of tower in Kuwait

    Directory of Open Access Journals (Sweden)

    A. Lisiecki

    2007-07-01

    Full Text Available Purpose: A study of influence of preheating and MMA welding technique of tee-joints of plate girders to insert plates of a composite steel-concrete structure of the telecommunication tower, on the properties and quality of the concrete in the region of the insert plate has been carried out.Design/methodology/approach: Studies of thermo-mechanical phenomena during manual arc welding MMA of tee-joints between plate girders and insert plates were carried out to identify possible sources of the concrete damage due to high welding temperature and stresses.Findings: It was shown that MMA welding at vertical-up position, by a rutile coated electrode of diameter 3,2 [mm], at welding current 110-120 [A], of the butt welds of tee-joints of girders and the insert plate does not cause any harmful and damaging effect to concrete, which temperature in a region of the contact with the bottom surface of the insert plate does not exceed 240 [°C] during full cycle of welding. Tensile and compression stresses of concrete are transmitted mainly by anchoring bars, fixed in concrete and also by reinforcing fabric of concrete, and do not cause any cracks of concrete.Research limitations/implications: To achieve more consistent results of the numerical analysis of stresses and deformation distribution in the insert plate with experimental results, it is necessary to calculate plastic deformation of materials and also take into consideration nonlinear change of yield point (plasticity as a function of temperature.Practical implications: The technology was applied for welding of the girders to insert plates of the telecommunication tower in Kuwait.Originality/value: Welding procedure specification ensuring high quality of the welded joints of girders and insert plate of composite steel-concrete structure.

  8. Welding of girders to insert plates of composite steel-concrete structure

    Directory of Open Access Journals (Sweden)

    A. Klimpel

    2007-09-01

    Full Text Available Purpose: of this paper: A study of influence of preheating and MMA welding technique of tee-joints of plate girders to insert plates of a composite steel-concrete structure of the telecommunication tower, on the properties and quality of the concrete in the region of the insert plate has been carried out.Design/methodology/approach: Studies of thermo-mechanical phenomena during manual arc welding MMA of tee-joints between plate girders and insert plates were carried out to identify possible sources of the concrete damage due to high welding temperature and stresses.Findings: It was shown that MMA welding at vertical-up position, by a rutile coated electrode of diameter 3,2 [mm], at welding current 110-120 [A], of the butt welds of tee-joints of girders and the insert plate does not cause any harmful and damaging effect to concrete, which temperature in a region of the contact with the bottom surface of the insert plate does not exceed 240 [˚C] during full cycle of welding. Tensile and compression stresses of concrete are transmitted mainly by anchoring bars, fixed in concrete and also by reinforcing fabric of concrete, and do not cause any cracks of concrete.Research limitations/implications: To achieve more consistent results of the numerical analysis of stresses and deformation distribution in the insert plate with experimental results, it is necessary to calculate plastic deformation of materials and also take into consideration nonlinear change of yield point (plasticity as a function of temperature.Practical implications: The technology was applied for welding of the girders to insert plates of the telecommunication tower in Kuwait.Originality/value: Welding procedure specification ensuring high quality of the welded joints of girders and insert plate of composite steel-concrete structure.

  9. Shaping 3-D boxes

    DEFF Research Database (Denmark)

    Stenholt, Rasmus; Madsen, Claus B.

    2011-01-01

    Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data......, making them different from typical, existing box shaping techniques. The basis of the proposed techniques is a new algorithm for constructing a full box from just three of its corners. The evaluation of the new techniques compares their precision and completion times in a 9 degree-of-freedom (Do......F) docking experiment against an existing technique, which requires the user to perform the rotation and scaling of the box explicitly. The precision of the users' box construction is evaluated by a novel error metric measuring the difference between two boxes. The results of the experiment strongly indicate...

  10. NUMERICAL ANALYSIS OF CRACK AND STRAIN BEHAVIOR OF RC SLAB IN STEEL-CONCRETE COMPOSITE GIRDER UNDER NEGATIVE BENDING

    Science.gov (United States)

    Sakaguchi, Junichi; Nakajima, Akinori; Suzuki, Yasuo

    The sophisticated numerical analysis method is required to simulate the strain behavior of the reinforcement and the crack width of the RC slab, although many researches are conducted on the cracking behavior of the RC slab in the composite girder under the negative bending. In this paper, the numerical analysis method is constructed to evaluate the strain behavior of the reinforcement and the crack width of the RC slab in the steel-concrete composite girder subjected to the negative bending. The analysis method using the rigid body spring model takes into account the imperfect composite action between the steel girder and the RC slab, the bond between the reinforcement and the concrete, and the shrinkage of the concrete. As a result, it is confirmed that the analysis method can simulate the crack and the strain behavior of RC slab quantitatively in the steel-concrete composite girder under the negative bending.

  11. Predicting deflections of a simply supported pre-stressed concrete girder subjected to static loads from observed strains

    Science.gov (United States)

    Mufti, Aftab; Jaeger, Leslie; Klowak, Chad; Kyriakopoulos, Nikolas; Bakht, Baidar; Tadros, Gamil

    2007-04-01

    Deflections of structures, such as bridge girders, are often the most difficult to monitor. Strain measurement is relatively simple with the use of electronic strain gauges, fiber optic sensors, or other strain measuring devices. This paper investigates two different methods for predicting or monitoring the deflection of a simply-supported full-scale bridge girder subjected to a partially distributed uniform load using strain measurements. A full-scale pre-stressed concrete bridge girder was instrumented and tested under a static monotonic load in the linear elastic range. This paper highlights the experimentally measured deflections along the length of one half of the girder and compares them to theoretically predicted deflections and deflections predicted using numerical integration along with harmonic analysis of curvatures determined from theoretical and observed experimental strains. Experimental test results indicate that estimating deflections from observed strains is feasible within the linear-elastic range of such girders. The methods outlined for predicting deflections of full-scale pre-stressed concrete bridge girders from observed strains are a valuable tool for structural engineers and for the periodic and continuous monitoring of civil structures such as bridges.

  12. Numerical Simulation for Progressive Collapse of Continuous Girder Bridge Subjected to Ship Impact

    Institute of Scientific and Technical Information of China (English)

    田力; 黄飞

    2014-01-01

    The three-stage simulation method based on LS-DYNA was introduced in this study to simulate the pro-gressive collapse of a continuous girder bridge after a ship-bridge collision. The pile-soil dynamic interaction and the initial stress and deformation of the whole bridge before the collision were considered. By analyzing the damage, de-formation, stress distribution and collapse process of the whole bridge, the results show that the displacement response of the cap beam lags behind the pile cap. The response order of the whole bridge’s components depends on their dis-tances from the collision region. The plastic deformation of soil around piles has a positive effect on delaying the fur-ther increase in the displacement of piles. The impacted pier’s losing stability and its superstructure’s excessive defor-mation are the main reasons leading to the progressive collapse of the continuous girder bridge.

  13. Damage investigation of girder bridges under the Wenchuan earthquake and corresponding seismic design recommendations

    Institute of Scientific and Technical Information of China (English)

    Li Jianzhong; Peng Tianbo; Xu yan

    2008-01-01

    An investigation of girder bridges on National Highway 213 and the Doujiangyan-Wenchuan expressway after the Wenchuan earthquake showed that typical types of damage included:span collapses due to unseating at expansion joints;shear key failure;and damage of the expansion joint due to the slide-induced large relative displacement between the bottom of the girder and the top of the laminated-rubber bearing.This slide,however,can actually act as a form of isolation for the substructure,and as a result,the piers and foundation of most of the bridges on state route 213 suffered minor damage.The exception was the Baihua Bridge,which suffered severe damage.Corresponding seismic design recommendations are presented based on this investigation.

  14. Performance of Bridge Decks and Girders with Lightweight Aggregate Concrete, v. 2 of 2

    OpenAIRE

    Ramirez, J.A.; Olek, J.; Rolle, Eric Joseph; Malone, Brian Joseph

    2000-01-01

    Structural lightweight concrete is a very versatile material and Haydite and Minergy lightweight aggregates can be utilized in the mixture development of concrete for use in girders and decks in bridges. More widespread use of lightweight aggregates (LWA) would result in savings in construction cost due to considerable dead load reduction. The materials phase of this research study evaluated the fresh concrete properties (slump, unit weight, and air content), the mechanical properties of ...

  15. Interactive Shear Buckling Of Plate Girder with Corrugated Web (Analytical Solution)

    OpenAIRE

    Prof.Dr:S.A.Tohamy; Ass.Prof.Dr:A.B.Saddek; Eng: Asmaa.Y.Hamed

    2016-01-01

    This paper presents analytical studies the elastic interactive shear buckling stress of corrugated steel web is calculated by all possible failure criteria (steel yielding, local and global buckling stresses), using Minimum Potential Energy Method to determine critical shear stress of local and global buckling of plate girder with corrugated webs. The results are compared with Finite element method (FEM) using ANSYS/V12. It found that the proposed equations are a good agreement with the resul...

  16. Nonlinear Stability Analysis of a Composite Girder Cable-Stayed Bridge with Three Pylons during Construction

    OpenAIRE

    Xiaoguang Deng; Muyu Liu

    2015-01-01

    Based on the nonlinear stability analysis method, the 3D nonlinear finite element model of a composite girder cable-stayed bridge with three pylons is established to research the effect of factors including geometric nonlinearity, material nonlinearity, static wind load, and unbalanced construction load on the structural stability during construction. Besides, the structural nonlinear stability in different construction schemes and the determination of temporary pier position are also studied...

  17. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  18. The mirror box

    Science.gov (United States)

    Thompson, Gene; Mathieson, Don

    2001-11-01

    The mirror box is an old standby in magic shows and an impressive demonstration of the law of reflection for the physics instructor. The box creates the illusion of an object floating in space by the use of a plane mirror.

  19. Finite Element Analysis of the Effect of Crack Depth and Crack Opening On the Girder

    Directory of Open Access Journals (Sweden)

    Md. Kamrul Hassan

    2011-01-01

    Full Text Available In order to identify the effect of crack depth and opening on the girder, finite element method (FEM has been used in this paper. In FE analysis, six nodded two dimensional plane elements (PLANE-2 are considered. Each node has two degree of freedom such as UX and UY. For the plane elements, a plane stress width/thickness option is chosen. For analytical model of crack of the concrete bridge girder, crack opening was increased from 0.2 mm to 1mm at an interval 0.2 mm and crack depth also increased from 30 mm to 150 mm at an interval 30 mm. The models were discreatized by a triangular mesh and convergence test was executed to obtain satisfactory results from the Plane-2 element. From the numerical result, it is seen that the principal stress become a higher with increased the crack depth and also crack opening with respect to load increasing. But the crack depth at 90 mm and crack opening at 0.6 mm, it has more effect on the girder because the stress concentration is higher than other crack depth and opening.

  20. Construction engineering of steel tub-girder bridge systems for skew effects

    Science.gov (United States)

    Jimenez Chong, Juan Manuel

    Closed structural sections, such as those having circular, rectangular or trapezoidal shape, possess high rotational rigidity when compared to open sections such as I-girders. The high torsional rigidity of closed sections makes them ideal for use in highly curved bridges. In this case, the geometry of the bridge results in large torsional forces. Because of structural efficiency and economy reasons, most of these closed-section bridges consist of a trapezoidal cross-section, with a top concrete slab and bottom and side steel plates. The slab is cast after the steel is erected and thus a system of internal diaphragms and braces is necessary to stabilize the system during erection. During the steel erection and the early stages of the concrete deck placement, the section can be considered as quasi-closed as the top concrete flange has not been cast or is not yet effective. During steel erection, undetermined and/or large torsional forces and/or displacements may result in fit-up problems requiring large stresses to overcome. During concrete deck placement, the undetermined displacements can affect the control of the deck thickness and the final deck geometry, such as the alignment of deck joints and the matching of stages in phased constructions projects. Due to the interactions between their various components, the behavior of curved and skewed tub-girder bridges is significantly more complex than that of straight bridges. When skewed supports are used in tub-girders, the interaction of the girder bending rotations and the displacement constraints induced by the skewed support diaphragms causes twisting of the girders at the supports. These twist rotations introduce additional torques into the system. Both curvature and skew can cause design and construction difficulties, especially at the supports, where the corresponding steel dead load deflections and the large torsional stiffness of the girders may lead to large fit-up forces. Currently, the general

  1. The effects of longitudinal prestressing on the box shear lag by the difference method%纵向预应力对箱梁剪力滞效应的差分解

    Institute of Scientific and Technical Information of China (English)

    刘扬; 王东东

    2013-01-01

    Guided by the energy variational principle and based on the different longitudinal displacements of three parabolas,the basic differential equation of the shear lag of cantilever box girders is obtained,and its feasibility is proved by using the finite difference method.The method is applied to analyze the shear lag effect of cantilever box girder under the longitudinal prestressing of equivalent loaf.Based on the ANSYS,a model which features that the box girder is built and simulated by Solid 95,and the prestressed steel is simulated by Link 10.Later,the model is used to analyze the coefficient distribution rule of the shear lag of the box girder under the longitudinal prestressing,and then this rule is compared with the result from finite difference method.This comparison proves the applicability of the difference method in the study of the shear lag effect of the box girder under longitudinal prestressing of equivalent loaf,and longitudinal prestressing's effects on the shear lag effect of beam is also analyzed.%选取3次抛物线变化的纵向位移,通过能量变分原理得到悬臂箱梁的剪力滞基本微分方程,再利用有限差分法进行求解,将该方法用于分析纵向预应力等效荷载作用下的悬臂箱梁剪力滞效应.运用ANSYS有限元软件建立模型,采用Solid 95单元模拟箱梁,采用Link8单元模拟预应力钢束,分析在纵向预应力作用下箱梁剪滞系数分布规律并与差分法求解的结果进行对比.经过对比,验证了差分法求解纵向预应力等效荷载作用下箱梁剪滞效应的可行性,同时分析了纵向预应力对箱梁剪滞效应的影响.

  2. Cable Tester Box

    Science.gov (United States)

    Lee, Jason H.

    2011-01-01

    Cables are very important electrical devices that carry power and signals across multiple instruments. Any fault in a cable can easily result in a catastrophic outcome. Therefore, verifying that all cables are built to spec is a very important part of Electrical Integration Procedures. Currently, there are two methods used in lab for verifying cable connectivity. (1) Using a Break-Out Box and an ohmmeter this method is time-consuming but effective for custom cables and (2) Commercial Automated Cable Tester Boxes this method is fast, but to test custom cables often requires pre-programmed configuration files, and cables used on spacecraft are often uniquely designed for specific purposes. The idea is to develop a semi-automatic continuity tester that reduces human effort in cable testing, speeds up the electrical integration process, and ensures system safety. The JPL-Cable Tester Box is developed to check every single possible electrical connection in a cable in parallel. This system indicates connectivity through LED (light emitting diode) circuits. Users can choose to test any pin/shell (test node) with a single push of a button, and any other nodes that are shorted to the test node, even if they are in the same connector, will light up with the test node. The JPL-Cable Tester Boxes offers the following advantages: 1. Easy to use: The architecture is simple enough that it only takes 5 minutes for anyone to learn how operate the Cable Tester Box. No pre-programming and calibration are required, since this box only checks continuity. 2. Fast: The cable tester box checks all the possible electrical connections in parallel at a push of a button. If a cable normally takes half an hour to test, using the Cable Tester Box will improve the speed to as little as 60 seconds to complete. 3. Versatile: Multiple cable tester boxes can be used together. As long as all the boxes share the same electrical potential, any number of connectors can be tested together.

  3. The BOXES Methodology Black Box Dynamic Control

    CERN Document Server

    Russell, David W

    2012-01-01

    Robust control mechanisms customarily require knowledge of the system’s describing equations which may be of the high order differential type.  In order to produce these equations, mathematical models can often be derived and correlated with measured dynamic behavior.  There are two flaws in this approach one is the level of inexactness introduced by linearizations and the other when no model is apparent.  Several years ago a new genre of control systems came to light that are much less dependent on differential models such as fuzzy logic and genetic algorithms. Both of these soft computing solutions require quite considerable a priori system knowledge to create a control scheme and sometimes complicated training program before they can be implemented in a real world dynamic system. Michie and Chambers’ BOXES methodology created a black box system that was designed to control a mechanically unstable system with very little a priori system knowledge, linearization or approximation.  All the method need...

  4. Analysis and Study of Force Conditions of Group Shear Studs of Long Span Steel and Concrete Composite Girder Bridge%大跨度钢—混组合梁桥剪力群钉受力分析研究

    Institute of Scientific and Technical Information of China (English)

    赵建; 郑舟军

    2013-01-01

    组合梁仿真分析时将多个剪力钉简化成一个等效剪力群钉进行模拟,不能准确得到每个剪力钉的受力情况.为解决此问题,根据实桥集束式剪力钉布置方式制作剪力群钉推出试件,并进行推出试验,得知群钉中最不利的单个剪力钉承担了32%~37%的总剪力(平均值仅为25%);由大跨度组合箱梁整体模型计算得到剪力群钉受力均值、钢-混凝土相对位移及钢梁与混凝土桥面板的受力状况;根据剪力群钉荷载分配比例对组合梁整体计算得到的剪力钉计算结果进行修正.结果表明,将剪力群钉受力均值换算得到剪力钉受力极值的方法,可实现对大跨度组合梁及其剪力钉的精确仿真分析.%When the simulation analysis of a composite girder is made,the way of simplifying the multiple shear studs of the girder into the equivalent group shear studs can not exactly acquire the force condition of each stud.To solve the problem,the push-out specimen of the group shear studs was fabricated according to the clustering layout of the shear studs of the practical bridge,the push out test for the specimen was carried out and it was consequently known that the single stud in the group shear studs under the worst force condition sustained 32%~37% of the total shear force (while the average value was 25% only).From the calculation of the integral model of the long span composite box girder,the force average values of the group shear studs,the relative displacement of the steel and concrete and the force conditions of the steel girder and concrete deck slabs were acquired and with reference to the load distribution ratios of the group shear studs,the calculation results of the shear studs were modified.The results of the calculation and modification demonstrate that by way of converting from the force average values of the group shear studs to the force ultimate values of the shear studs,the accurate simulation analysis of

  5. Depth in box spaces.

    Science.gov (United States)

    Pont, Sylvia C; Nefs, Harold T; van Doorn, Andrea J; Wijntjes, Maarten W A; Te Pas, Susan F; de Ridder, Huib; Koenderink, Jan J

    2012-01-01

    Human observers adjust the frontal view of a wireframe box on a computer screen so as to look equally deep and wide, so that in the intended setting the box looks like a cube. Perspective cues are limited to the size-distance effect, since all angles are fixed. Both the size on the screen, and the viewing distance from the observer to the screen were varied. All observers prefer a template view of a cube over a veridical rendering, independent of picture size and viewing distance. If the rendering shows greater or lesser foreshortening than the template, the box appears like a long corridor or a shallow slab, that is, like a 'deformed' cube. Thus observers ignore 'veridicality'. This does not fit an 'inverse optics' model. We discuss a model of 'vision as optical user interface'.

  6. Opto-Box

    CERN Document Server

    Bertsche, David; The ATLAS collaboration; Welch, Steven; Smith, Dale Shane; Che, Siinn; Gan, K.K.; Boyd, George Russell Jr

    2015-01-01

    The opto-box is a custom mini-crate for housing optical modules, which process and transfer optoelectronic data. The system tightly integrates electrical, mechanical, and thermal functionality into a small package of size 35x10x8 cm^3. Special attention was given to ensure proper shielding, grounding, cooling, high reliability, and environmental tolerance. The custom modules, which incorporate Application Specific Integrated Circuits (ASICs), were developed through a cycle of rigorous testing and redesign. In total, fourteen opto-boxes have been installed and loaded with modules on the ATLAS detector. They are currently in operation as part of the LHC run 2 data read-out chain.

  7. Nonlinear Stability Analysis of a Composite Girder Cable-Stayed Bridge with Three Pylons during Construction

    Directory of Open Access Journals (Sweden)

    Xiaoguang Deng

    2015-01-01

    Full Text Available Based on the nonlinear stability analysis method, the 3D nonlinear finite element model of a composite girder cable-stayed bridge with three pylons is established to research the effect of factors including geometric nonlinearity, material nonlinearity, static wind load, and unbalanced construction load on the structural stability during construction. Besides, the structural nonlinear stability in different construction schemes and the determination of temporary pier position are also studied. The nonlinear stability safety factors are calculated to demonstrate the rationality and safety of construction schemes. The results show that the nonlinear stability safety factors of this bridge during construction meet the design requirement and the minimum value occurs in the maximum double cantilever stage. Besides, the nonlinear stability of the structure in the side of edge-pylon meets the design requirement in the two construction schemes. Furthermore, the temporary pier can improve the structure stability, effectively, and the actual position is reasonable. In addition, the local buckling of steel girder occurs earlier than overall instability under load in some cable tension stages. Finally, static wind load and the unbalanced construction load should be considered in the stability analysis for the adverse impact.

  8. A Cyber-Physical System for Girder Hoisting Monitoring Based on Smartphones.

    Science.gov (United States)

    Han, Ruicong; Zhao, Xuefeng; Yu, Yan; Guan, Quanhua; Hu, Weitong; Li, Mingchu

    2016-07-07

    Offshore design and construction is much more difficult than land-based design and construction, particularly due to hoisting operations. Real-time monitoring of the orientation and movement of a hoisted structure is thus required for operators' safety. In recent years, rapid development of the smart-phone commercial market has offered the possibility that everyone can carry a mini personal computer that is integrated with sensors, an operating system and communication system that can act as an effective aid for cyber-physical systems (CPS) research. In this paper, a CPS for hoisting monitoring using smartphones was proposed, including a phone collector, a controller and a server. This system uses smartphones equipped with internal sensors to obtain girder movement information, which will be uploaded to a server, then returned to controller users. An alarming system will be provided on the controller phone once the returned data exceeds a threshold. The proposed monitoring system is used to monitor the movement and orientation of a girder during hoisting on a cross-sea bridge in real time. The results show the convenience and feasibility of the proposed system.

  9. Coupled Vibration of Long-Span Railway Curved Girder Bridges and Vehicles

    Institute of Scientific and Technical Information of China (English)

    Shan Deshan; Li Qiao

    2005-01-01

    The structure of a long curved girder bridge is represented with a three-dimensional curved finite element model. Each 4-axle vehicle is modeled by a dynamic system of 35 degrees of freedom. The random irregularities of the track are generated from a power spectral density function under the given track condition. The dynamic interaction between the bridge and train is realized through the contact forces between the wheels and track. Then based on these models, the coupled equations of motion are solved by applying the time-integration and iteration techniques to the coupled system. The proposed formulation and the associated computer program are then applied to a real curved girder bridge. The dynamic responses of the bridge-vehicle system and the derailments and offload factors related to the riding and running safeties of vehicles are computed. The results show that the formulation presented in this paper can well predict dynamic behaviors of both bridge and train with reasonable computation efforts.

  10. A Cyber-Physical System for Girder Hoisting Monitoring Based on Smartphones.

    Science.gov (United States)

    Han, Ruicong; Zhao, Xuefeng; Yu, Yan; Guan, Quanhua; Hu, Weitong; Li, Mingchu

    2016-01-01

    Offshore design and construction is much more difficult than land-based design and construction, particularly due to hoisting operations. Real-time monitoring of the orientation and movement of a hoisted structure is thus required for operators' safety. In recent years, rapid development of the smart-phone commercial market has offered the possibility that everyone can carry a mini personal computer that is integrated with sensors, an operating system and communication system that can act as an effective aid for cyber-physical systems (CPS) research. In this paper, a CPS for hoisting monitoring using smartphones was proposed, including a phone collector, a controller and a server. This system uses smartphones equipped with internal sensors to obtain girder movement information, which will be uploaded to a server, then returned to controller users. An alarming system will be provided on the controller phone once the returned data exceeds a threshold. The proposed monitoring system is used to monitor the movement and orientation of a girder during hoisting on a cross-sea bridge in real time. The results show the convenience and feasibility of the proposed system. PMID:27399710

  11. A Cyber-Physical System for Girder Hoisting Monitoring Based on Smartphones

    Directory of Open Access Journals (Sweden)

    Ruicong Han

    2016-07-01

    Full Text Available Offshore design and construction is much more difficult than land-based design and construction, particularly due to hoisting operations. Real-time monitoring of the orientation and movement of a hoisted structure is thus required for operators’ safety. In recent years, rapid development of the smart-phone commercial market has offered the possibility that everyone can carry a mini personal computer that is integrated with sensors, an operating system and communication system that can act as an effective aid for cyber-physical systems (CPS research. In this paper, a CPS for hoisting monitoring using smartphones was proposed, including a phone collector, a controller and a server. This system uses smartphones equipped with internal sensors to obtain girder movement information, which will be uploaded to a server, then returned to controller users. An alarming system will be provided on the controller phone once the returned data exceeds a threshold. The proposed monitoring system is used to monitor the movement and orientation of a girder during hoisting on a cross-sea bridge in real time. The results show the convenience and feasibility of the proposed system.

  12. A Cyber-Physical System for Girder Hoisting Monitoring Based on Smartphones

    Science.gov (United States)

    Han, Ruicong; Zhao, Xuefeng; Yu, Yan; Guan, Quanhua; Hu, Weitong; Li, Mingchu

    2016-01-01

    Offshore design and construction is much more difficult than land-based design and construction, particularly due to hoisting operations. Real-time monitoring of the orientation and movement of a hoisted structure is thus required for operators’ safety. In recent years, rapid development of the smart-phone commercial market has offered the possibility that everyone can carry a mini personal computer that is integrated with sensors, an operating system and communication system that can act as an effective aid for cyber-physical systems (CPS) research. In this paper, a CPS for hoisting monitoring using smartphones was proposed, including a phone collector, a controller and a server. This system uses smartphones equipped with internal sensors to obtain girder movement information, which will be uploaded to a server, then returned to controller users. An alarming system will be provided on the controller phone once the returned data exceeds a threshold. The proposed monitoring system is used to monitor the movement and orientation of a girder during hoisting on a cross-sea bridge in real time. The results show the convenience and feasibility of the proposed system. PMID:27399710

  13. Hydrophobic, Porous Battery Boxes

    Science.gov (United States)

    Bragg, Bobby J.; Casey, John E., Jr.

    1995-01-01

    Boxes made of porous, hydrophobic polymers developed to contain aqueous potassium hydroxide electrolyte solutions of zinc/air batteries while allowing air to diffuse in as needed for operation. Used on other types of batteries for in-cabin use in which electrolytes aqueous and from which gases generated during operation must be vented without allowing electrolytes to leak out.

  14. Cereal Box Totems.

    Science.gov (United States)

    Jones, AnnMarie

    2002-01-01

    Presents a multicultural project used with fourth-grade students in which they created a three-dimensional totem pole using leftover cereal boxes. Discusses in detail how to create the totem pole. Explains that students learned about Northwest American Indians in class. (CMK)

  15. Effect of nonlinearity of restrainer and supports on the elasto-plastic seismic response of continuous girder bridge

    Directory of Open Access Journals (Sweden)

    Wang Changfeng

    2014-10-01

    Full Text Available During an earthquake, the nonlinearity of the bridge structure mainly occurs at the supports, bridge piers and restrainers. When entering nonlinear stage, members of the bridge structure affect the elasto-plastic seismic response of the whole structure to a certain extent; for multi-span continuous bridges, longitudinal restrainers can be installed on the movable piers to optimise the distribution of seismic force and enable the movable piers to bear a certain amount of seismic effect. In order to evaluate the effect of nonlinearity of restrainer and supports on the elasto-plastic seismic response of continuous girder bridge, analytical models of continuous girder bridge structure considering the nonlinearity of movable supports, restrainers and bridge piers were built and the nonlinear time history analysis was conducted to evaluate the effect of nonlinearity of restraining devices and supports on the elasto-plastic seismic response of continuous girder bridge. Relevant structural measures and recommendation were made to reduce the seismic response of the fixed piers of the continuous girder bridge.

  16. Design Analysis on Steel-Concrete Transition Section of Main Girder of Shangdi Bridge on Beijing-Xinjiang Expressway%京新上地桥主梁钢-混过渡段的设计分析

    Institute of Scientific and Technical Information of China (English)

    徐升桥; 刘永锋

    2013-01-01

    京新上地桥的曲线混凝土主梁采用单点顸推法施工,顶推总重250 000 kN,顶推距离213 m,顶推过程最大悬臂长度63 m.钢导梁预埋于主梁前端,通过剪力连接件和混凝土箱梁连接成整体,以传递顶推过程中的弯矩和剪力.对钢-混凝土过渡段顶、底、腹板的连接件受力性能进行设计分析,并建立实体模型详细分析最不利工况下关键部位的局部应力,结果表明界面连接可靠,钢-混凝土过渡段变形协调、应力分布均匀,设计合理.%Single-point incremental launching method is employed to construct the curved concrete main girder of Shangdi Bridge on Beijing - Xinjiang Expressway. During the incremental launching construction, the total launching weight, distance and maximum cantilever length is respectively 25 000 t, 213 m and 63 m. In order to transfer bending moment and shear force, the steel launching nose is pre-embedded in the front end of the concrete main girder, and is integrally connected with the concrete box girder by shear connectors. For the steel-concrete transition section; mechanical performance of connectors at the top, bottom and web slabs are analyzed firstly; and then, local stress at key positions under the most unfavorable conditions are precisely analyzed by means of solid model. The analysis results show that: connection of the interface is reliable, deformation of the steel-concrete transition section is compatible, and stress distribution is uniform, which indicate that the design is reasonable.

  17. Opto-Box

    CERN Document Server

    Bertsche, David; The ATLAS collaboration

    2015-01-01

    The opto-box is a custom mini-crate for housing optical modules, which process and transfer optoelectronic data. Many novel solutions were developed for the custom design and manufacturing. The system tightly integrates electrical, mechanical, and thermal functionality into a small package of size 35x10x8 cm$^{3}$. Special attention was given to ensure proper shielding, grounding, cooling, high reliability, and environmental tolerance. The custom modules, which incorporate Application Specific Integrated Circuits (ASICs), were developed through a cycle of rigorous testing and redesign. In total, fourteen opto-boxes have been installed and loaded with modules on the ATLAS detector. They are currently in operation as part of the LHC run 2 data read-out chain.

  18. The Box Method

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The velocity level in a room ventilated by jet ventilation is strongly influenced by the supply conditions. The momentum flow in the supply jets controls the air movement in the room and, therefore, it is very important that the inlet conditions and the numerical method can generate a satisfactory...... description of this momentum flow. The Box Method is a practical method for the description of an Air Terminal Device which will save grid points and ensure the right level of the momentum flow....

  19. The Electronic Battle Box

    Science.gov (United States)

    Gouin, Denis; Turcotte, Guy; Lebel, Eric; Gilbert, Annie

    2000-08-01

    The Electronic Battle Box is an integrated suite of planning and decision-aid tools specially designed to facilitate Canadian Armed Force Officers during their training and during their tasks of preparing and conducting military operations. It is the result of a collaborative effort between the Defence Research Establishment Valcartier, the Directorate of Army Doctrine (DAD), the Directorate of Land Requirements (DLR), the G4 staff of 1Cdn Div HQ and CGI Information and Management Consultants Inc. Distributed on CD-ROM, the Electronic Battle Box contains efficient and user-friendly tools that significantly reduce the planning time for military operations and ensure staff officers a better focus on significant tasks. Among the tools are an OrBat Browser and an Equipment Browser allowing to view and edit military organizations, a Task Browser providing facilities to prepare plans using Gantt charts, a Logistic Planner allowing to estimate supply requirements applying complex calculations, and Road, Air and Rail Movement Planners. EBB also provides staff officers with a large set of doctrinal documents in an electronic format. This paper provides an overview of the various tools of the Electronic Battle Box.

  20. Determination of stability of steel girder structures of large surface mining equipment - calculation of the operating strength factor according to the first revision of TGL 13472

    Energy Technology Data Exchange (ETDEWEB)

    Roessiger, R.

    1987-01-01

    The TGL 13472 industrial standard calculation method is explained for steel girder stability and fatigue with the example of a bucket wheel excavator boom. The excavator operates in block mining with the bucket wheel boom slewing 90 degrees. Bucket wheel cutting and girder load forces are determined by a computer program. Their values are listed. Equations for maximum load fatigue and operating strength factor are given along with stability results. Time required for calculations is regarded as reasonable. 4 refs.

  1. Prediction of Fatigue Life of a Continuous Bridge Girder Based on Vehicle Induced Stress History

    Directory of Open Access Journals (Sweden)

    V.G. Rao

    2003-01-01

    Full Text Available The fatigue damage assessment of bridge components by conducting a full scale fatigue testing is often prohibitive. A need, therefore, exists to estimate the fatigue damage in bridge components by a simulation of bridge-vehicle interaction dynamics due to the action of the actual traffic. In the present paper, a systematic method has been outlined to find the fatigue damage in the continuous bridge girder based on stress range frequency histogram and fatigue strength parameters of the bridge materials. Vehicle induced time history of maximum flexural stresses has been obtained by Monte Carlo simulation process and utilized to develop the stress range frequency histogram taking into consideration of the annual traffic volume. The linear damage accumulation theory is then applied to calculate cumulative damage index and fatigue life of the bridge. Effect of the bridge span, pavement condition, increase of vehicle operating speed, weight and suspension characteristics on fatigue life of the bridge have been examined.

  2. Time-Variant Reliability Analysis of FPSO Hull Girder Considering Corrosion Based on Statistics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dao-kun; TANG Wen-yong; ZHANG Sheng-kun

    2007-01-01

    FPSO is a kind of important exploitation platform used in ocean oil and gas industry, which has the unique character of mooring at outsea for a long time. Since it can not be inspected and maintained thoroughly at dock like other kinds of ships, the reliability of FPSO hull girder during the whole service should be focused. Based on latest corrosion database and rational corrosion model, the ultimate strength of one FPSO is calculated under the conditions of slight, moderate and severe corrosion. The results not only provide the reliability under different corrosion conditions, but also do well for further inspection and maintenance research. The results provide necessary foundation for deciding inspection intervals and maintenance measures, which has practical sense to improve the general safety level of ocean engineering.

  3. Analysis of the hull girder vibration by dynamic stiffness matrix method

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ping; ZHAO De-you

    2006-01-01

    Dynamic stiffness matrix method is applied to compute vibration of hull girder in this paper.This method can not only simplify the computational model, but also get much higher frequencies and responses accurately. The analytical expressions of dynamic stiffness matrix of a Timoshenko beam for transverse vibration are presented in this paper. All effects of rotatory inertia and shear deformation are taken into account in the formulation. The resulting dynamic stiffness matrix combined with the Wittrick-Williams algorithm is used to compute natural frequencies and mode shapes of the 299,500 DWT VLCC, and then the vibrational responses are solved by the mode superposition method. The computational results are compared with those obtained from other approximate methods and experiment,and it indicates that the method is accurate and efficient.

  4. Projection optics box

    Science.gov (United States)

    Hale, Layton C.; Malsbury, Terry; Hudyma, Russell M.; Parker, John M.

    2000-01-01

    A projection optics box or assembly for use in an optical assembly, such as in an extreme ultraviolet lithography (EUVL) system using 10-14 nm soft x-ray photons. The projection optics box utilizes a plurality of highly reflective optics or mirrors, each mounted on a precision actuator, and which reflects an optical image, such as from a mask, in the EUVL system onto a point of use, such as a target or silicon wafer, the mask, for example, receiving an optical signal from a source assembly, such as a developed from laser system, via a series of highly reflective mirrors of the EUVL system. The plurality of highly reflective optics or mirrors are mounted in a housing assembly comprised of a series of bulkheads having wall members secured together to form a unit construction of maximum rigidity. Due to the precision actuators, the mirrors must be positioned precisely and remotely in tip, tilt, and piston (three degrees of freedom), while also providing exact constraint.

  5. Optimizationd sign fo erhead raveling rane's box irder%桥式起重机箱形梁的优化设计

    Institute of Scientific and Technical Information of China (English)

    田国富; 孙书慧; 程艳辉

    2000-01-01

    箱形梁桥式起重机是起重机械的一种类型,广泛应用于各厂矿企业。其主要承载结构箱形梁的重量占整机重量的比重最大,为提高整机性能,降低能耗,在对整机受力分析基础上,建立了优化模型,并应用其进行了具体优化设计。%The welded box girder of overhead traveling crane is one kind of cranes used in general plants.The welded box girder is the major loaded part and its weight takes the major part of the machine’s total weight.In order to improve the capacity of the cranes, a kind of optimization model based on the analyzing of loading condition and a optimization design according to it is done.

  6. Linear structural stress analysis of a hull girder penetration and a short longitudinal bulkhead using finite element modeling.

    OpenAIRE

    Baumann, Gregg W.

    1997-01-01

    Approved for public release; distribution unlimited. The objective of this study is to investigate structural shadow zones encountered in shipbuilding design using the I-DEAS (Integrated Design Engineering Analysis Software) software. The term 'shadow zone' refers to areas of low stress concentrations that are caused by lines of stress bending around structural discontinuities. Two ship design situations frequently encountered that result in shadow zones are hull girder penetrations and sh...

  7. The Classroom Animal: Box Turtles.

    Science.gov (United States)

    Kramer, David C.

    1986-01-01

    Provides basic information on the anatomy, physiology, behaviors, and distribution patterns of the box turtle. Offers suggestions for the turtle's care and maintenance in a classroom environment. (ML)

  8. Design of stiffening girder for Taizhou Bridge%泰州大桥加劲梁设计

    Institute of Scientific and Technical Information of China (English)

    单宏伟; 丁磊; 周青

    2012-01-01

    泰州大桥是世界上首座超千米的三塔两跨悬索桥,加劲梁结构体系复杂并有其独特之处.在设计过程中根据三塔悬索桥的结构特点,加劲梁构造细节设计在润扬大桥的基础上做了较大改进和创新,介绍了加劲梁的结构体系、构造设计、结构计算以及梁段的加工制造和架设情况.%Taizhou Bridge is the first three-tower two-span suspension bridge with the main span over 1 000 m in the world. The structural system of the stiffening girder is complicated and unique. Improvement and innovation have been made in detailed structure design of the stiffening girder based on Runyang Bridge according to the structural character of three-pylon two-span suspension bridge. In this paper, the structural system, structure design, structure calculation, manufacturing and erection of the stiffening girder are introduced.

  9. Performances of super-long span prestressed cable-stayed bridge with CFRP cables and RPC girder

    Institute of Scientific and Technical Information of China (English)

    Fang Zhi; Fan Fenghong; Ren Liang

    2013-01-01

    To discuss the applicability of advanced composite carbon fiber reinforced polymer (CFRP) and ultra-high performance concrete reactive powder concrete (RPC) in super-long span cable-stayed bridges , taking a 1 008 m cable-stayed bridge with steel girders and steel cables as an example,a new cable-stayed bridge in the same span with RPC girders and CFRP cables was designed,in which the cable’s cross section was determined by the principle of equivalent cable capacity and the girder’s cross section was determined in virtual of its stiffness, shear capacity and local stability. Based on the methods of finite element analysis,the comparative analysis of these two cable-stayed bridge schemes about static performances,dynamic performances,stability and wind resis-tance behavior were carried out. The results showed that it was feasible to form a highly efficient,durable concrete cable-stayed bridge with RPC girders and CFRP cables and made its applicable span range expand to 1 000 m long around.

  10. ACSYS in a box

    CERN Document Server

    Briegel, C; Hendricks, B; King, C; Lackey, S; Neswold, R; Nicklaus, D; Patrick, J; Petrov, A; Rechenmacher, R; Schumann, C; Smedinghoff, J

    2012-01-01

    The Accelerator Control System at Fermilab has evolved to enable this relatively large control system to be encapsulated into a "box" such as a laptop. The goal was to provide a platform isolated from the "online" control system. This platform can be used internally for making major upgrades and modifications without impacting operations. It also provides a standalone environment for research and development including a turnkey control system for collaborators. Over time, the code base running on Scientific Linux has enabled all the salient features of the Fermilab's control system to be captured in an off-the-shelf laptop. The anticipated additional benefits of packaging the system include improved maintenance, reliability, documentation, and future enhancements.

  11. Glove-box filters

    International Nuclear Information System (INIS)

    Description is given of a device for simply and rapidly assembling and dissassembling the filters used inside sealed enclosures, such as glove-boxes and shielded cells equipped with nippers or manipulators, said filters being of the type comprising a cylindrical casing containing a filtering member, the upper portion of said casing being open so as to allow the gases to be cleaned to flow in, whereas the casing bottom is centrally provided with a hole extended outwardly by a threaded collar on which is screwed a connecting-sleeve to be fixed to the mouth of a gas outlet pipe. To a yoke transverse bar is welded a pin which can be likened to a bent spring-blade, one arm of which welded to said transverse bar, is rectilinear whereas its other arm is provided with a boss cooperating with a cavity made in a protrusion of said pipe, right under the mouth thereof

  12. Polymers in Curved Boxes

    CERN Document Server

    Yaman, K; Solis, F J; Witten, T A

    1996-01-01

    We apply results derived in other contexts for the spectrum of the Laplace operator in curved geometries to the study of an ideal polymer chain confined to a spherical annulus in arbitrary space dimension D and conclude that the free energy compared to its value for an uncurved box of the same thickness and volume, is lower when $D < 3$, stays the same when $D = 3$, and is higher when lowers the effective bending elasticity of the walls, and might induce spontaneous symmetry breaking, i.e. bending. (Actually, the above mentioned results show that {\\em {any}} shell in $D = 3$ induces this effect, except for a spherical shell). We compute the contribution of this effect to the bending rigidities in the Helfrich free energy expression.

  13. COMPARATIVE ANALYSIS OF MODELS OF RAILWAY LOADS C14 AND LM71 FOR GIRDER BRIDGES

    Directory of Open Access Journals (Sweden)

    V. Artomov

    2014-01-01

    Full Text Available Purpose. The article analyzes the railway load LM71 for the purpose of its application in national design projects of the railway girder bridges. Purpose of the article is harmonization of national design codes of enginnering structures with the European standards (Eurocodes. Methodology. Analytical calculation methods (influence lines, the matrix analysis and computer programming are used in the article. Findings. Deflected mode parameters of the railway bridges under the influence of loads C14 and LM71 have certain differences. The extent of these differences depends on length, material of drift structures and also on dynamic coefficients. These dependences should be considered in national design codes and in harmonized with Eurocodes standards. In the further researches relationships between load C14 and models SW, HSLM taking into account various dynamic effects and trains speedis planned to determine. Originality. The presented results, in particular deflected mode parameters (including loads with dynamic coefficients, obtained for the first time. Practical value. Results of research are used in National Annex to the National Standard of Ukraine NSTU-N B EN 1991-2:2010. Eurocode 1. Actions on structures. Part 2. Traffic loads on bridges (EN 1991-2:2003.

  14. A Damage Prognosis Method of Girder Structures Based on Wavelet Neural Networks

    Directory of Open Access Journals (Sweden)

    Rumian Zhong

    2014-01-01

    Full Text Available Based on the basic theory of wavelet neural networks and finite element model updating method, a basic framework of damage prognosis method is proposed in this paper. Firstly, a damaged I-steel beam model testing is used to verify the feasibility and effectiveness of the proposed damage prognosis method. The results show that the predicted results of the damage prognosis method and the measured results are very well consistent, and the maximum error is less than 5%. Furthermore, Xinyihe Bridge in the Beijing-Shanghai Highway is selected as the engineering background, and the damage prognosis is conducted based on the data from the structural health monitoring system. The results show that the traffic volume will increase and seasonal differences will decrease in the next year and a half. The displacement has a slight increase and seasonal characters in the critical section of mid span, but the strain will increase distinctly. The analysis results indicate that the proposed method can be applied to the damage prognosis of girder bridge structures and has the potential for the bridge health monitoring and safety prognosis.

  15. The Black Box QGP

    CERN Document Server

    Tawfik, A

    2006-01-01

    According to the extensive ab initio calculations of lattice QCD, the much large energy density available in the heavy-ion collisions at SPS and now at RHIC should be enough to create the quark-gluon plasma (QGP); a new state of matter in form plasma of free quarks and gluons. The new matter discovered at RHIC is a ''nearly perfect'' fluid rather than a plasma. The shear viscosity is too small. We should then ask about the theoretical and phenomenological consequences and why we simply assumed that the deconfined hadronic matter should be an ideal gas. Finally, I will address five questions; about the properties of the new phases at high temperatures and the orders of phase transitions. Before we clarify such questions, the QGP will remain a kind of black box. One sends a signal via new experiments or simulations and gets another one out if it. Then one try to explain what is going on. I will show that some promising ideas already have been suggested long time ago, but it seems that community didn't care. Is ...

  16. Black Box QGP

    CERN Document Server

    Tawfik, A

    2006-01-01

    According to extensive ab initio calculations of lattice QCD, the very large energy density available in heavy-ion collisions at SPS and now at RHIC must be sufficient to generate quark-gluon plasma (QGP), a new state of matter in the form of plasma of free quarks and gluons. The new state of matter discovered at RHIC seems to be perfect fluid rather than free plasma. Its shear viscosity is assumed to be almost zero. In this work, I first considered the theoretical and phenomenological consequences of this discovery and finally asked questions about the nature of phase transition and properties of matter. It is important to answer these questions, otherwise QGP will remain a kind of black box; one sends a signal via new experiments or simulations or models and gets another one from it. I will show that some promising ideas have already been suggested a long time ago. I will also suggest a new phase diagram with separated deconfinement and freeze-out boundaries and a mixed state of thermal quark matter and bub...

  17. Two-dimensional box plot

    OpenAIRE

    Phattrawan Tongkumchum

    2005-01-01

    In this paper we propose a two-dimensional box plot, a simple bivariate extension of the box plot and the scatter plot. This plot comprises a pair of trapeziums oriented in the direction of a fitted straight line, with symbols denoting extreme values. The choice for the fitted straight resistant line showing the relationship between the two variables is Tukey’s resistance line. The main components of the plot are an inner box containing 50% of the projection points of the observations on the ...

  18. Computing out of the Box

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Baidu unveils "box computing/’ which it hopes will lead to a number of innovations on the InternetBaidu, China’s most popular search engine, held its Technology Innovation Conference 2009 at the China World

  19. Identifying competencies of boxing coaches

    OpenAIRE

    Ioannis Tasiopoulos; Alexandra Tripolitsiot; Apostolos Stergioula

    2014-01-01

    The purpose of this study was to find out the management skills required by boxing coaches to administrate their clubs. For the purposes of this study a scale was constructed which was answered by 98 boxing coaches. Explanatory factor analysis revealed seven factors: Communication-public relations (5 items), event management (4 items), management techniques (4 items), new technologies (4 items), prevention-safety (2 items), sport (5 items) and sports facilities (2 items). The Cronbach of the ...

  20. Plate forming and break down pizza box

    Science.gov (United States)

    Pantisano, Frank; Devine, Scott M.

    1992-01-01

    A standard corrugated paper pizza box is provided with slit cuts cut through the top panel of the pizza box in a shape to form four circular serving plates with a beveled raised edge and cross slit cuts through the bottom panel of the pizza box separating the box into four essentially equal portions for easy disposal.

  1. Stress Analysis of Pier-tower-girder Fixed Region of Cable-stayed Bridge with Trough Girder%槽型断面梁斜拉桥塔梁墩固结区受力特性研究

    Institute of Scientific and Technical Information of China (English)

    戴公连; 粟淼; 刘文硕; 闫斌

    2014-01-01

    In order to increase the structural longitudinal stiffness and facilitate the swing method,the side girders of trough section of the cable-stayed bridge on the Kunming-Shanghai passenger line were in-serted into the pylon so as to form the pier-tower-girder fixed region.For the (32+80+112)m single tower cable-stayed bridge,the structure and force of the fixed region are very complicated.The large gen-eral-purpose finite element software ANSYS was used to establish the pier-tower-girder fixed region model to study the stress distribution of the fixed region.The correctness of this model was verified.Based on this region model,the force transmission and stress distribution of the fixed region were investigated,and the effect of the local structural details on the fixed region stress was studied.The analysis results show that the global stress level of the fixed region is lower than the girder and tower,but there are stress con-centration phenomena in the fixed region,such as the intersection point between the floor of the trough girder and upper tower,and the corner of the human tunnel in the fixed region.The degree of the stress concentration was relieved significantly by improving the structural details.%为增大桥梁纵向刚度、便于转体施工,沪昆客运专线上某(32+80+112)m 槽型截面独塔斜拉桥将槽型梁两边箱插入塔柱中形成塔梁墩固结体系,其构造和受力情况极为复杂。为研究该桥塔梁墩固结区域的应力分布情况,采用大型通用有限元软件 ANSYS建立塔梁墩固结区局部模型并验证模型正确性。在此基础上,分析固结区域结构传力路径和应力分布规律,探讨局部设计细节对固结区应力的影响。研究表明:塔梁墩固结区内整体应力水平低于固结区范围以外截面,但在槽型梁过渡至固结区内部的交接角以及固结区内部过人洞折角等处存在应力集中现象。通过改进结构设计细节可有效缓解各处的应力集中现象。

  2. 福州市螺洲大桥主桥钢箱梁顶推施工技术%Fuzhou Beaufort Bridge Pushing steel box girder construction technology

    Institute of Scientific and Technical Information of China (English)

    黄强

    2011-01-01

    Bridge project with Fuzhou Beaufort introduced Pushing walker pan features and construction techniques of process equipment,and the use of centralized control system.At the same time according to the actual situation of this project,analysis of the top platform and push the design of temporary buttress will not rationality and economy.%结合福州市螺洲大桥工程介绍步履式平移顶推施工技术的特点和工艺设备,以及采用的集中控制系统。同时根据本工程实际情况,分析顶推平台与临时支墩的布置与设计的合理性以及经济性。

  3. 箱梁极限承载力破坏仿真分析%Simulation Analysis of Failure of Box Girder Under Ultimate Bearing Capacity

    Institute of Scientific and Technical Information of China (English)

    尹冠生; 刘晓伟; 张小慧

    2013-01-01

    以J-H-C作为混凝土材料模型,以PLASTIC-KINEMATIC作为钢筋材料模型,用数值模拟箱梁在极限承载力下的破坏.实践证明,这两种材料模型能够较好地模拟箱梁在极限承载力下的破坏.

  4. ABAQUS箱型桥梁的GUI二次开发%Secondary Development for GUI of Box Girder Bridge Based on ABAQUS

    Institute of Scientific and Technical Information of China (English)

    王家林; 李平

    2009-01-01

    介绍了大型通用有限元软件ABAQUS的二次开发功能和利用面向对象语言Python编制参数化建模插件的原理和步骤.以变截面箱型桥梁参数化有限元建模为背景,通过ABAQUS提供的API函数和AFX GUI Toolkit工具包开发了箱梁桥参数化建模菜单和工具条,提高了箱型桥梁的有限元建模速度,为箱型桥梁的精细有限元分析提供了有力的支持.

  5. 佛陈大桥(扩建)连续钢箱梁设计%Design of Continuous Steel-box Girder in Fochen Extension Bridge

    Institute of Scientific and Technical Information of China (English)

    郑楷柱; 何海; 梁立农; 饶瑞

    2015-01-01

    变截面连续钢箱梁在国内应用方兴未艾,对其研究和成熟工程案例相对较少.本文从佛陈大桥(扩建)连续钢箱梁的结构、防腐、铺装、架设等方面进行深入研究并精心设计,使其很好地结合了桥位所处的环境,满足了施工工期的要求.

  6. Optimal Design for UHPC Continuous Box Girder Bridge with 400 m Main Span%主跨400 m的UHPC连续梁桥优化设计

    Institute of Scientific and Technical Information of China (English)

    刘勇; 邵旭东; 詹豪

    2014-01-01

    利用超高性能混凝土(UHPC)的优越性能,提出了与之相适应的新型箱梁结构,目的是利用材料的高强度及新结构的轻型化,解决常规混凝土连续箱梁桥易开裂、下挠和自重过大、跨径难以突破300 m的难题.在原有工作的基础上,对主跨400m的UHPC连续箱梁桥进行了整体性能分析及优化设计,优化内容包括桥梁边跨长度、梁高、板厚等主要参数,以得到其合适的取值范围,根据优化结果建议:边跨与主跨跨径比范围为0.55 ~0.65;中支点梁高与主跨跨径比范围为1/20 ~ 1/25;跨中梁高与支点梁高比范围为1/1.8~1/2.3.整体性能分析结果表明:运用UHPC及新结构,能轻松实现连续梁桥400 m跨径的突破,并具有较大的整体刚度及安全储备.综合考虑长期社会经济效益,在主跨跨径300 ~ 500 m范围内,该新型结构可与斜拉桥、悬索桥等其他桥型形成强有力的竞争选型方案.

  7. First-aid boxes - Reminder

    CERN Multimedia

    GS Department

    2010-01-01

    With a view to ensuring optimum use of the first-aid boxes on the CERN site, we should like to remind you of various changes introduced in March 2009: The TSO of the buildings concerned is responsible for the first-aid boxes, including checking their contents.   First-aid boxes may be restocked ONLY at the CERN stores (SCEM No. 54.99.80). This is no longer possible at the Infirmary. The associated cost is charged to the Departments.   First-aid boxes should be used only for mild injuries. All other cases should be referred to the Medical Service Infirmary (Bldg. 57 – ground-floor, tel. 73802) between 8.00 a.m. and 5.30 p.m. or to the Fire and Rescue Service (tel. 74444). N.B.: This information does not apply to the red emergency first-aid boxes in the underground areas or to the emergency kits for use in the event of being splashed with hydrofluoric acid.

  8. Box graphs and resolutions I

    Directory of Open Access Journals (Sweden)

    Andreas P. Braun

    2016-04-01

    Full Text Available Box graphs succinctly and comprehensively characterize singular fibers of elliptic fibrations in codimension two and three, as well as flop transitions connecting these, in terms of representation theoretic data. We develop a framework that provides a systematic map between a box graph and a crepant algebraic resolution of the singular elliptic fibration, thus allowing an explicit construction of the fibers from a singular Weierstrass or Tate model. The key tool is what we call a fiber face diagram, which shows the relevant information of a (partial toric triangulation and allows the inclusion of more general algebraic blowups. We shown that each such diagram defines a sequence of weighted algebraic blowups, thus providing a realization of the fiber defined by the box graph in terms of an explicit resolution. We show this correspondence explicitly for the case of SU(5 by providing a map between box graphs and fiber faces, and thereby a sequence of algebraic resolutions of the Tate model, which realizes each of the box graphs.

  9. Box graphs and resolutions I

    Science.gov (United States)

    Braun, Andreas P.; Schäfer-Nameki, Sakura

    2016-04-01

    Box graphs succinctly and comprehensively characterize singular fibers of elliptic fibrations in codimension two and three, as well as flop transitions connecting these, in terms of representation theoretic data. We develop a framework that provides a systematic map between a box graph and a crepant algebraic resolution of the singular elliptic fibration, thus allowing an explicit construction of the fibers from a singular Weierstrass or Tate model. The key tool is what we call a fiber face diagram, which shows the relevant information of a (partial) toric triangulation and allows the inclusion of more general algebraic blowups. We shown that each such diagram defines a sequence of weighted algebraic blowups, thus providing a realization of the fiber defined by the box graph in terms of an explicit resolution. We show this correspondence explicitly for the case of SU (5) by providing a map between box graphs and fiber faces, and thereby a sequence of algebraic resolutions of the Tate model, which realizes each of the box graphs.

  10. Numerical analysis of dynamic response of vehicle–bridge coupled system on long-span continuous girder bridge

    Directory of Open Access Journals (Sweden)

    Lipeng An

    2016-07-01

    Full Text Available To systematically study the vehicle–bridge coupled dynamic response and its change rule with different parameters, a vehicle model with seven degrees of freedom was built and the total potential energy of vehicle space vibration system was deduced. Considering the stimulation of road roughness, the dynamic response equation of vehicle–bridge coupled system was established in accordance with the elastic system principle of total potential energy with stationary value and the “set-in-right-position” rule. On the basis of the self-compiled Fortran program and bridge engineering, the dynamic response of long-span continuous girder bridge under vehicle load was studied. This study also included the calculation of vehicle impact coefficient, evaluation of vibration comfort, and analysis of dynamic response parameters. Results show the impact coefficient changes with lane number and is larger than the value calculated by the “general code for design of highway bridges and culverts (China”. The Dieckmann index of bridge vibration is also related to lane number, and the vibration comfort evaluation is good in normal conditions. The relevant conclusions from parametric analyses have practical significance to dynamic design and daily operation of long-span continuous girder bridges in expressways. Safety and comfort are expected to improve significantly with further control of the vibration of vehicle–bridge system.

  11. Identifying competencies of boxing coaches

    Directory of Open Access Journals (Sweden)

    Ioannis Tasiopoulos

    2014-10-01

    Full Text Available The purpose of this study was to find out the management skills required by boxing coaches to administrate their clubs. For the purposes of this study a scale was constructed which was answered by 98 boxing coaches. Explanatory factor analysis revealed seven factors: Communication-public relations (5 items, event management (4 items, management techniques (4 items, new technologies (4 items, prevention-safety (2 items, sport (5 items and sports facilities (2 items. The Cronbach of the scale was 0.85. The five competencies that rated by the coaches were: Supervisors of the area of training, maintaining excellent communication with athletes, using new technologies (e-mail, internet, handling disciplinary matters, accidents, complaints and reports on some sporting games and promoted harmony among athletes. We concluded that boxing coaches understand that the competencies required for meeting their obligations, were related to sports, prevention, safety and communications-public relations.

  12. Study on the Aerodynamic Characteristics of a Single-pylon Cable-stayed Bridge Girder by Numerical Simulation and Wind Tunnel Test

    Directory of Open Access Journals (Sweden)

    Longqi Zhang

    2014-09-01

    Full Text Available The wind induced vibration is one of the key technical problems for long-span bridge design. Therefore, a study on the aerodynamic characteristics of a single-pylon cable-stayed bridge girder is carried out in this paper. The aerostatic coefficient of the bridge girder, including both construction state and service state, is investigated by wind tunnel test with varying wind attack angle. Then based on the computational fluid dynamics (CFD method, the flow field around the bridge girder is visualized numerically. The risk of vortex-induced vibration (VIV is qualitatively evaluated by analyzing the flow features and by considering the Scruton number (Sc. Later a dynamic section model is tested in wind tunnel and the VIV phenomenon is observed subsequently. Results show that the aerodynamic stability is assured by the positive slope of the lift coefficient. The VIV response is influenced by the structural damping and the bridge accessory. The amplitude of VIV response can be lower by increasing the structural damping. The maintenance track rail of the bridge girder also does some good for suppressing the VIV as long as the track rail is located at the appropriate place.

  13. Study on ultimate bearing capacity of hybrid girder%多钢种混用工字钢梁抗弯极限承载力研究

    Institute of Scientific and Technical Information of China (English)

    王鹏飞; 杨晓明; 李海峰

    2012-01-01

    According to the theory of flexural-torsional buckling,25 monosymmetrical I-shaped hybrid girders with 25 top flange strengthened and ordinary girders were modeled by the finite element method.Moreover,the differences between hybrid girders and ordinary girders were critically analysed from the aspects of the ultimate bearing capacity and failure modes.The formula of critical moment was summarised by the regression analysis.The results of this research indicated that the collocation of steel would be significantly optimized and the project cost would be dramatically reduced by rationally applying hybrid girders.%以受弯构件弯扭屈曲理论作为理论基础,对25根上翼缘加强型单轴对称混用工字钢梁及相同跨径与截面尺寸的匀质钢梁进行极限承载力有限元计算,研究多钢种混用钢梁同匀质钢梁在破坏模式、极限承载力等方面的差异性.对有限元计算结果进行回归分析,得出了可用于设计的临界弯矩计算公式.研究结果表明,合理采用混用钢梁的构造理念,可以在满足承载力要求的同时优化钢材搭配,降低工程造价,做到物尽其用.

  14. A Box Full of Kisses

    Institute of Scientific and Technical Information of China (English)

    崔增印

    2008-01-01

    The story goes that some time ago,a man pun- ished his 3-year-old daughter for wasting a roll of gold wrapping paper.Money was tight and he became infuriated when the child tried to decorate a box to put under the Christmas tree.Nevertheless,the little girl brought the gift to

  15. Reference: AT1BOX [PLACE

    Lifescience Database Archive (English)

    Full Text Available AT1BOX Ueda T, Pichersky E, Malik VS, Cashmore AR The level of expression of the to...mato rbcs-3A gene is modulated by a far-upstream promoter element in a developmentary regulated manner. Plant Cell 1:217-227 (1989) PubMed: 2535544; GenBank: S44160; ...

  16. Back office to box office

    DEFF Research Database (Denmark)

    Haigh, Matthew

    sees a mounting unsecured debt where its members see practical value. Between the two, a steward who may not profit from its office delegates it to back-office agents whose fiduciary management is engendered by box office-sized bonuses. Standard theorisation has foundered. The architecture...

  17. On the Dirichlet's Box Principle

    Science.gov (United States)

    Poon, Kin-Keung; Shiu, Wai-Chee

    2008-01-01

    In this note, we will focus on several applications on the Dirichlet's box principle in Discrete Mathematics lesson and number theory lesson. In addition, the main result is an innovative game on a triangular board developed by the authors. The game has been used in teaching and learning mathematics in Discrete Mathematics and some high schools in…

  18. Stress Analysis of Rectangular Boxes Using Fem

    Directory of Open Access Journals (Sweden)

    D.G. Lokhande

    2014-04-01

    Full Text Available Extensive experimental & theoretical contributions have been made to the study of open box structures, but few references dealing with closed boxes have been found. When a rectangular box structure is subjected to certain pressure, stress analysis of rectangular box is necessary to avoid the failure during working condition. In this work, it is proposed to evaluate the stresses in rectangular box by changing L/B ratios 1, 1.5, 2 for different thicknes of 2.5, 5, 7.5 mm & varying fillet radius, using finite element method.To validate finite element stresses, it is necessary to compare these stresses with analytical approach. From the FE analysis of rectangular box, it is seen that cubical box having the lesser stresses & better for stress distribution due to symmetry.The stiffners further reduces the stresses in boxes

  19. On the Effect of Hull Girder Flexibility on the Vertical Wave Bending Moment for Ultra Large Container Vessels

    DEFF Research Database (Denmark)

    Andersen, Ingrid Marie Vincent; Jensen, Jørgen Juncher

    2012-01-01

    of the ship. The theory takes into account non-linear radiation forces (memory effects) through the use of a set of higher order differential equations. The non-linear hydrostatic restoring forces and non-linear Froude-Krylov forces are determined accurately at the instantaneous position of the ship...... in the global hull girder loads as consequence of the increased hull flexibility must be considered. This is especially so as the rules of the classification societies do not explicitly account for the effect of hull flexibility on the global loads. In the present paper an analysis has been carried out...... for the 9,400 TEU container ship used as case-ship in the EU project TULCS (Tools for Ultra Large Container Ships). A non-linear time-domain strip theory is used for the hydrodynamic analysis of the vertical bending moment amidships in sagging and hogging conditions for a flexible and a rigid modelling...

  20. Main: BOX2PVCHS15 [PLACE

    Lifescience Database Archive (English)

    Full Text Available BOX2PVCHS15 S000209 11-May-2006 (last modified) kehi Box 2 of bean (P.v.) chs15 pro...moter; SBF-1 binding site; For a compilation of related GT elements and factors, see Villain et al. (1996); Box 2; chs; chs1

  1. Main: BOX3PVCHS15 [PLACE

    Lifescience Database Archive (English)

    Full Text Available BOX3PVCHS15 S000210 11-May-2006 (last modified) kehi Box 3 of bean (P.v.) chs15 pro...moter; SBF-1 binding site; For a compilation of related GT elements and factors, see Villain et al. (1996); Box 3; chs; chs1

  2. Main: BOX2PSGS2 [PLACE

    Lifescience Database Archive (English)

    Full Text Available BOX2PSGS2 S000204 17-May-1998 (last modified) kehi Box 2 in glutamine synthetase (GS...2) gene in pea (P.s.); Repeated in tandem with a partial palindrome located between the repeats; Located at ca. -300 of pea GS...2; Box 2; glutamine synthetase; GS2; pea (Pisum sativum); TCTAAGCAAAG ...

  3. The Heuristic Interpretation of Box Plots

    Science.gov (United States)

    Lem, Stephanie; Onghena, Patrick; Verschaffel, Lieven; Van Dooren, Wim

    2013-01-01

    Box plots are frequently used, but are often misinterpreted by students. Especially the area of the box in box plots is often misinterpreted as representing number or proportion of observations, while it actually represents their density. In a first study, reaction time evidence was used to test whether heuristic reasoning underlies this…

  4. Illumination box and camera system

    Science.gov (United States)

    Haas, Jeffrey S.; Kelly, Fredrick R.; Bushman, John F.; Wiefel, Michael H.; Jensen, Wayne A.; Klunder, Gregory L.

    2002-01-01

    A hand portable, field-deployable thin-layer chromatography (TLC) unit and a hand portable, battery-operated unit for development, illumination, and data acquisition of the TLC plates contain many miniaturized features that permit a large number of samples to be processed efficiently. The TLC unit includes a solvent tank, a holder for TLC plates, and a variety of tool chambers for storing TLC plates, solvent, and pipettes. After processing in the TLC unit, a TLC plate is positioned in a collapsible illumination box, where the box and a CCD camera are optically aligned for optimal pixel resolution of the CCD images of the TLC plate. The TLC system includes an improved development chamber for chemical development of TLC plates that prevents solvent overflow.

  5. Study on a simple method for bending analysis of composite girders with corrugated steel webs; Hakei koban web wo motsu goseiketa no kan`i mage kaisekiho ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, N.; Yoda, T. [Waseda University, Tokyo (Japan). School of Science and Engineering

    1997-10-15

    An evaluation is being established on composite girders with corrugated steel webs that they are a composite girder having excellent mechanical characteristics. However, structural analysis of these composite girders is not easy even of the one-dimensional analysis. Therefore, a proposal was made on a simple method for bending analysis of a composite girder with corrugated webs having I-section subjected to bending. The result of the analysis using the proposed method was compared with measured values, and the reasonability of the test was investigated including that for the non-linear region. In this analysis, the I-section girder was converted equivalently into a multi-layered beam consisting of cross sections with an equivalent width, and displacement and stress in each layer were approximated linearly by dividing the multi-layered beam into fine layers of `N` number. Formulation was performed by using an ordinary matrix method based on the derived displacement field and stress field. An initial stress method was used for non-linearity analysis of the beams. This analysis was found effective in analyzing a beam subjected to strong effect of shear as in a corrugated steel web composite girder. Among the results of the linearity analyses, the displacement and stress agreed nearly well with the measured values. The non-linearity analysis was performed simply when combined with the initial stress method. 16 refs., 24 figs., 4 tabs.

  6. Das k-Box-Produkt

    OpenAIRE

    Elser, Stefan

    2011-01-01

    Ziel dieser Doktorarbeit ist es, bekannte und oft verwendete Eigenschaften des Tychonow-Produkts in analoger Form für das k-Box-Produkt zu beweisen, was bisher noch nicht geschehen ist, und die Verbindung zwischen der Infinitären Kombinatorik und der Topologie zu vertiefen. In der Infinitären Kombinatorik, ein Zweig der modernen Mengenlehre, bedient man sich gerne topologischer Begriffe, um einerseits Ergebnisse zu verdeutlichen und um andererseits den sehr abstrakten kombinatorischen Be...

  7. Main: BOX1PSGS2 [PLACE

    Lifescience Database Archive (English)

    Full Text Available BOX1PSGS2 S000222 19-August-2004 (last modified) kehi Box 1 element in pea (P.s.) glutamine synthetase (GS...2) gene; An element in a 33-bp AT-rich sequence (box 1) of the 5' end of a GS2 promot...er; Located at -837 to -827 of pea GS2; Multimer of box 1 element was used to isolate a cDNA encoding an AT-...rich DNA binding protein (ATBP-1) (Tjaden & Coruzzi, 1994); Box 1; glutamine synthetase; GS2; ATBp; ATBP-1; pea (Pisum sativum) ATAGAAATCAA ...

  8. Comparison of Simplified Calculation Method of the Box-Slab High-Pile Wharf%箱板式高桩码头简化计算方法比较

    Institute of Scientific and Technical Information of China (English)

    王文仲; 何良德; 杨洋; 张志明; 李新国

    2013-01-01

    This papere elaborates the structure feature of the box-slab high-pile wharf, and introduces the condition of applications and the calculation methods of direct design method, method of equivalent framework and method of virtual intersection girder. The feasibility of the three methods are tested and verify by the instance of project. The three calculation methods are simple, and can be achieved by hand counted or in virtue of some simplified calculation software. Then compare the results of the three methods with the numerical results of the finite element method. On the basis of the comparison, it is obvious that the result of method of virtual intersection girder is the closest to the finite element numerical analysis, the method of equivalent framework is inferior to the method of virtual intersection girder, and the direct design method is relatively more conservative.%阐述了箱板式高桩码头的结构特点,介绍了经验系数法(英国BS8100-85)、等代框架法、虚拟交叉梁法等方法的使用条件,以及计算方法.以具体工程实例验证了3种计算方法应用在码头结构中的可行性.3种方法计算比较简便,可通过手算或借助简单的计算程序实现,并将3种计算方法的计算结果与有限元数值计算结果进行比较.结果表明,虚拟交叉梁法与有限元数值计算结果最为接近,等代框架法次之,经验系数法相比较为保守.

  9. Study of Shear Stud Connector Layout for Composite Girders%结合梁剪力钉布置形式研究

    Institute of Scientific and Technical Information of China (English)

    侯健; 罗扣

    2014-01-01

    为提高结合梁桥桥面板的整体性,并方便施工,对剪力钉集束式(在钢梁腹板的上翼缘每隔一定距离布置1束剪力钉群,各钉群之间留有相应宽度无钉区)布置形式进行研究。通过建立结合梁结构的有限元模型,分别计算恒载、车辆偏载作用下,集束式和均布式(钢梁上翼缘均匀、等间距的剪力钉布置形式)桥面板和剪力钉的滑移量、钢梁的应力、钢梁底板位移等。研究结果表明:剪力钉集束式布置具有桥面板整体性好,施工工序简单等特点;在荷载作用下,剪力钉采用集束式布置能够保证钢梁和混凝土桥面板之间有效传力;汽车偏载作用下,集束式布置也可以保证钢梁与混凝土桥面板之间的有效结合,不会发生桥面板上掀现象。%In order to improve the integrity of the deck of composite girder bridge and for the convenience of construction ,the clustered shear stud connectors arrangement was studied (in the upper flange of the webs of the steel girder ,clusters of shear stud connectors are installed with e-qual intervals and a connector-free zone with certain width among the clusters is reserved ) .The fi-nite element model of the composite girder structure was established to calculate respectively the slip amount of the bridge deck and shear stud connectors ,stress in the steel girder and the dis-placement of the steel girder base plate under the action of dead load and eccentric vehicle load ,for both the clustered arrangement and uniform arrangement (the shear stud connectors are uniformly arranged in the upper flange of the steel girder with equal intervals ) .The results of the study dem-onstrate that the clustered arrangement of shear stud connectors is favorable for the integrity of the bridge deck and simplifies the construction procedures ;under the action of loads ,the clustered ar-rangement of shear stud connectors allows the effective force

  10. 粉房湾长江大桥主桥钢桁梁架设施工技术%Construction Techniques for Erection of Steel Truss Girder of Main Bridge of Fenfangwan Changjiang River Bridge

    Institute of Scientific and Technical Information of China (English)

    王存贵; 王殿永; 高杰; 靳春尚

    2012-01-01

    The main bridge of Fenfangwan Changjiang River Bridge in Chongqing City is a semi-floating system steel truss girder cable-stayed bridge with double pylons, double cable planes and with span arrangement (216. 5 + 464 + 216. 5) m. The main girder of the bridge is designed as the steel truss girder structure erected by the piece-by-piece assembling. In the light of the topographic conditions of the south and north banks, the asymmetric way of erection was chosen for the girder. The steel truss girder on the south bank side was erected from the side span towards the central span. The girder of the side span was assembled on the scaffolding, the girder in the middle was erected first and then the components like the edge stringers and edge deck plates were erected, using the deck truck cranes. The girder for the main span was erected by the cantilever assembling method. The girder of the north bank was erected by the balanced two-cantilever assembling method and the 5 blocks of the girder atop and on both sides of a main pier were assembled on the pier-side brackets.%重庆粉房湾长江大桥主桥为跨度(216.5+464+216.5)m的双塔双索面半飘浮体系钢桁梁斜拉桥,主梁采用钢桁梁结构.钢桁梁采取散拼架设,南、北岸钢桁梁根据地形情况选取了不对称的方式施工.南岸钢桁梁由边跨向中跨架设,边跨钢桁梁采用支架拼装,先架设中间桁架,再利用桥面汽车吊架设边纵梁、边桥面板等构件;主跨钢桁梁采用悬臂拼装.北岸钢桁梁采用双悬臂对称架设,主墩墩顶及两侧共5个节段钢桁梁采用墩旁托架拼装.

  11. Ionization box type radiation detector

    International Nuclear Information System (INIS)

    An ionization box for monitoring radiation rays, a first amplification circuit of a multi-stage amplification circuit employing a MOS type FET as an initial stage amplification device, a second amplification circuit employing a junction type FET as an initial stage amplification device, a first change-over switch for switching ionization current depending on input signals, a second change-over switch for switching output signals, and a signal level discrimination circuit are constituted integrally. When radiation dose rate is low, the ionization current is inputted to the first amplification circuit and outputted as a radiation ray monitor signal and, when the radiation dose rate is increased to higher than a predetermined value, the ionization current is inputted to the second amplification circuit and outputted as a radiation ray monitor signal. That is, monitoring accuracy is high when the ionization current is low since the MOS type FET of high input impedance is used. If the ionization current is higher than a predetermined value, there is no worry that the detection becomes impossible since the junction type FET having less worry of causing characteristic change due to high radiation dose rate is used. Accordingly, ionization box type monitor at a high monitoring reliability can be obtained. (N.H.)

  12. The Lithium Vapor Box Divertor

    Science.gov (United States)

    Goldston, Robert; Hakim, Ammar; Hammett, Gregory; Jaworski, Michael; Myers, Rachel; Schwartz, Jacob

    2015-11-01

    Projections of scrape-off layer width to a demonstration power plant suggest an immense parallel heat flux, of order 12 GW/m2, which will necessitate nearly fully detached operation. Building on earlier work by Nagayama et al. and by Ono et al., we propose to use a series of differentially pumped boxes filled with lithium vapor to isolate the buffering vapor from the main plasma chamber, allowing stable detachment. This powerful differential pumping is only available for condensable vapors, not conventional gases. We demonstrate the properties of such a system through conservation laws for vapor mass and enthalpy, and then include plasma entrainment and ultimately an estimate of radiated power. We find that full detachment should be achievable with little leakage of lithium to the main plasma chamber. We also present progress towards solving the Navier-Stokes equation numerically for the chain of vapor boxes, including self-consistent wall boundary conditions and fully-developed shocks, as well as concepts for an initial experimental demonstration-of-concept. This work supported by DOE Contract No. DE-AC02-09CH11466.

  13. F-box proteins in flowering plants

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In eukaryotes, the ubiquitin-mediated protein degradation pathway has been shown to control several key biological processes such as cell division, development, metabolism and immune response. F-box proteins, as a part of SCF (Skp1-Cullin (or Cdc53)-F-box) complex, functioned by interacting with substrate proteins, leading to their subsequent degradation by the 26S proteasome. To date, several F-box proteins identified in Arabidopsis and Antirrhinum have been shown to play important roles in auxin signal transduction, floral organ formation, flowering and leaf senescence. Arabidopsis genome sequence analysis revealed that it encodes over 1000 predicted F-box proteins accounting for about 5% of total predicted proteins. These results indicate that the ubiquitin-mediated protein degradation involving the F-box proteins is an important mechanism controlling plant gene expression. Here, we review the known F-box proteins and their functionsin flowering plants.

  14. Understanding Recommender Dynamics driving Box Office Revenues

    CERN Document Server

    Yeung, C H; Jin, C -H

    2010-01-01

    We introduce a simple model to investigate the underlying dynamics driving movie box office. Without an explicit reliance on time, the box office of movies evolves naturally by movie-movie competition through reviews listed on a centralized recommender system. A simple mean-field approximation is employed which assumes an average interaction between the competing movies, and describes the interesting box office dynamics. Box office hits are found for movies with quality beyond a critical value, leading to booms in gross box office. Such critical value is dependent on the reviewing behaviors, intention of movie goers for new movies, and the quality of the peer competing movies. Finally we compare our analytical results with simulations and real system and obtain qualitative agreements, suggesting the present model in describing the fundamental dynamics of box office.

  15. Main: BOX1PVCHS15 [PLACE

    Lifescience Database Archive (English)

    Full Text Available BOX1PVCHS15 S000208 11-May-2006 (last modified) kehi Box 1 of bean (P.v.) chs15 pro...moter; one of SBF-1 binding sites in chs15 promoter; Located at -318 to -305; Involved in organ-specific exp...e Villain et al. (1996); Box 1; chs; chs15; CHS; SBF-1; silencer; organ-specific; Gt; GT-1; GT; bean (Phaseolus vulgaris) TAAAAGTTAAAAAC ...

  16. Metod of black box and their us

    OpenAIRE

    Novotný, Martin

    2013-01-01

    This thesis on a topic "black-box method and its use" deals with the description of the method of solving problematic tasks as a black box and its use in teaching. Using the theory of systems and cybernetics disciplines, especially cybernetic-pedagogy attempts to describe this method so that it is as efficient as possible and to maximize the benefits for students. Besides, the implementation of selected black box that will be suitable and used for teaching subjects electrotechnics, automatiza...

  17. Analysis on Wind-Excited Flutter of Cable-Stayed Bridge with Asymmetric Composite Girder and Single Pylon%非对称混合梁独塔斜拉桥风致颤振分析

    Institute of Scientific and Technical Information of China (English)

    杨从娟

    2012-01-01

    With asymmetric composite girder, single pylon and main bridge span arrangement (310+2x 50+2x40) m, the new Haihe River Bridge is a cable-stayed bridge in double cable plane and semi-floating system. The article established space analysis model by using the finite element method, and analyzed the dynamic characteristics under the two stages, respectively the stage of hoisting in maximum single-cantilever status during bridge construction and the stage of completion. Afterwards, the article researched into its vibration model features and periods. Further, the article calculated the critical wind speeds respectively for bending-torsion coupling flutter and for separated-flow coupling flutter based on its dynamic features according to classical theory, also calculated the testing wind speed for bending-torsion coupling flutter and for separated-flow coupling flutter according to the standard specification. Finally, the article assessed the wind-excited flutter of this bridge. The assessment results show that the self-excited flutter of the steel box girder of this bridge can all be restrained under the whole process of assembling of cantilevered method and under the operation process of the completed bridge; the stability index of the completed bridge is bigger than 2. 5 while smaller than 4. 0; so it is suggested that the wind tunnel test for the segment models should be implemented.%新建海河大桥为独塔双索面半漂浮体系的斜拉桥,该桥为非对称混合梁斜拉桥,主桥孔径布置为310m+2x50m+2×40m.利用有限元建立空间分析模型,对该桥施工过程中吊装最大单悬臂状态和成桥状态的2种状态进行动力特性分析,研究其振型特征和周期,根据其动力特性按经典理论计算弯扭耦合颤振和分离流耦合颤振临界风速,并根据规范计算弯扭耦合颤振和分离流耦合颤振检验风速,对该桥风致颤振进行评估;通过评估,该桥钢箱梁悬臂拼装全过程和成桥运营状

  18. Interchangeable breech lock for glove boxes

    Energy Technology Data Exchange (ETDEWEB)

    Lemonds, David Preston

    2015-11-24

    A breech lock for a glove box is provided that may be used to transfer one or more items into the glove box. The breech lock can be interchangeably installed in place of a plug, glove, or other device in a port or opening of a glove box. Features are provided to aid the removal of items from the breech lock by a gloved operator. The breech lock can be reused or, if needed, can be replaced with a plug, glove, or other device at the port or opening of the glove box.

  19. Broken links and black boxes

    DEFF Research Database (Denmark)

    Sindbæk, Søren Michael

    2013-01-01

    Long-distance communication has emerged as a particular focus for archaeological exploration using network theory, analysis, and modelling. Initial attempts to adapt methods from social network analysis to archaeological data have, however, struggled to produce decisive results. This paper argues...... that the archaeological study of communication networks in the past calls for radically different analytical methods from those employed by most other forms of social network analysis. The fragmentary archaeological evidence presents researchers with the task of reconstructing the broken links of a ruined network from...... observable distributions and patterns of association in the archaeological record. In formal terms this is not a problem of network analysis, but network synthesis: the classic problem of cracking codes or reconstructing black-box circuits....

  20. Model Equations: "Black Box" Reconstruction

    Science.gov (United States)

    Bezruchko, Boris P.; Smirnov, Dmitry A.

    Black box reconstruction is both the most difficult and the most tempting modelling problem when any prior information about an appropriate model structure is lacking. An intriguing thing is that a model capable of reproducing an observed behaviour or predicting further evolution should be obtained only from an observed time series, i.e. "from nothing" at first sight. Chances for a success are not large. Even more so, a "good" model would become a valuable tool to characterise an object and understand its dynamics. Lack of prior information causes one to utilise universal model structures, e.g. artificial neural networks, radial basis functions and algebraic polynomials are included in the right-hand sides of dynamical model equations. Such models are often multi-dimensional and involve quite many free parameters.

  1. VORONOI DIAGRAMS WITHOUT BOUNDING BOXES

    Directory of Open Access Journals (Sweden)

    E. T. K. Sang

    2015-10-01

    Full Text Available We present a technique for presenting geographic data in Voronoi diagrams without having to specify a bounding box. The method restricts Voronoi cells to points within a user-defined distance of the data points. The mathematical foundation of the approach is presented as well. The cell clipping method is particularly useful for presenting geographic data that is spread in an irregular way over a map, as for example the Dutch dialect data displayed in Figure 2. The automatic generation of reasonable cell boundaries also makes redundant a frequently used solution to this problem that requires data owners to specify region boundaries, as in Goebl (2010 and Nerbonne et al (2011.

  2. 双塔双索面支座体系混合式结合梁斜拉桥设计%Design of Double Pylons and Cable Plane Supporting System Hybrid Composite Girder Cable-stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    谢波; 程应刚

    2014-01-01

    以洸府河大桥为工程背景,进行了双塔双索面支座体系混合式结合梁斜拉桥的平面、纵断面和横断面设计,介绍了主桥的桥跨布置、桥梁方案,同时进行了中跨结合梁钢主梁、中跨结合梁混凝土桥面板、边跨混凝土主梁、主梁钢-混结合段、斜拉索、主塔和基础的设计,并进行了结构计算。%The plane,longitudinal section and cross section design of double pylons and cable plane supporting system hybrid composite girder cable-stayed bridge was carried out on the background of Guang Fuhe bridge.This paper introduced the bridge span arrangement and scheme,and conducted the design and structure calculation of steel girder in composite girder at midspan,concrete deck in composite girder at midspan,concrete main girder at side span ,steel-concrete mixing section,cable, tower and foundation.

  3. Unification of box shapes in molecular simulations

    NARCIS (Netherlands)

    Bekker, H.

    1997-01-01

    In molecular simulations with periodic boundary conditions the computational box may have five different shapes: triclinic; the hexagonal prism; two types of dodecahedrons; and the truncated octahedron. In this article, we show that every molecular simulation, formulated in one of these boxes, can b

  4. Box Plots in the Australian Curriculum

    Science.gov (United States)

    Watson, Jane M.

    2012-01-01

    This article compares the definition of "box plot" as used in the "Australian Curriculum: Mathematics" with other definitions used in the education community; describes the difficulties students experience when dealing with box plots; and discusses the elaboration that is necessary to enable teachers to develop the knowledge necessary to use them…

  5. Modern biotechnology Panacea or new Pandora's box?

    NARCIS (Netherlands)

    Tramper, J.; Yang Zhu, Yang

    2011-01-01

    According to Greek mythology Pandora was sent down to earth upon the orders of Zeus. She was given a mysterious box which she was not allowed to open. However, Pandora was very curious and when she arrived on earth she couldn?t help taking a peek inside the box. She saw that it was filled with gifts

  6. Cosmetic Foot Surgery: Fashion's Pandora's Box

    Science.gov (United States)

    ... Fashion’s Pandora’s Box? A A A | Print | Share Cosmetic Foot Surgery: Fashion’s Pandora’s Box? Foot and ankle ... extreme and imprudent as it may sound, the cosmetic surgery craze isn't just for faces anymore- ...

  7. 沪通长江大桥大位移梁端伸缩装置动力性能研究%Study of Dynamic Performance of Large Movement Girder End Expansion Devices of Hutong Changjiang River Bridge

    Institute of Scientific and Technical Information of China (English)

    高芒芒; 臧晓秋; 熊建珍

    2015-01-01

    The main ship channel bridge of the Hutong Changjiang River Bridge is a rail-cum-road continuous steel truss girder cable-stayed bridge with a main span of 1 092 m .On both sides of the main ship channel bridge are the 112-m span simply-supported steel truss girder bridges and between the main ship channel bridge and the steel truss girder bridges ,the girder end expansion devices of ± 900 mm movement amount are arranged .To investigate the influences of the expan-sion devices of the bridge on the dynamic responses of the train and bridge ,the train-track-bridge dynamic performance was studied based on the comparative schemes in the preliminary design of the expansion devices .The complete structural model ,including the main ship channel bridge , steel truss girder bridge and girder end expansion device ,was established according to the actual conditions and the train-bridge coupling vibration was analyzed ,using the step-by-step integration method .The results of the study demonstrate that the deformation of the girder end expansion de-vices and the track structures on the main ship channel bridge and the steel truss girder bridges on both sides has differences and the local irregularity in the areas nearby the girder ends causes im-pact to the train and expansion devices ,which will cause excessive responses of the train under some load cases .The acceleration of the supporting girders of the bridge is some high as compared to the relevant design in the girder end expansion device scheme for Tongling Changjiang River Bridge and particularly in the contraction state of the main girder , the said situation is more evident .%沪通长江大桥主航道桥为主跨1 092 m的公铁两用连续钢桁梁斜拉桥,主航道桥两侧为跨度112 m的钢桁简支梁桥 ,主航道桥、钢桁梁桥间设置伸缩量为± 900 m m的梁端伸缩装置.为考察该桥伸缩缝对列车和桥梁动力响应的影响 ,针对其梁端伸缩装置初步设计的比选方案进

  8. Spatial Effect on Railway Trough Girder with Reactive Powder Concrete%铁路活性粉末混凝土槽形梁的空间作用效应

    Institute of Scientific and Technical Information of China (English)

    李志光; 余自若; 王月

    2013-01-01

    The authors carried out three-dimensional finite element analysis on a 32 m railway trough girder which was made of reactive powder concrete.After working out shear lag coefficients under different load conditions,the rule of shear lag was analyzed,and the results indicated that the shear lag effect in this reactive powder concrete trough girder was larger than that of common concrete girder.Further,the spatial effect on transversal and longitudinal bending moments was analyzed,and the study result on the influence lines of transversal bending moments indicated that,due to the spatial effect,any force on any point of the trough girder would cause transversal bending moment which should not be ignored.Finally,the study result on influence lines of longitudinal bending moments showed that,there was spatial effect on equivalent load in reactive powder concrete trough girder; the closer to the girder end the place was,the more obviously the effect became,which also should not be ignored.Therefore,in the design of this kind of railway girder,the spatial effect on the vicinity of girder end should be taken seriously.%对32 m铁路活性粉末混凝土槽形梁进行三维有限元分析,计算出不同工况下的剪力滞系数,并对剪力滞规律进行分析,研究表明该梁的剪力滞效应较普通混凝土梁更加明显;对其横向和纵向弯矩的空间效应进行分析,对横向弯矩影响线的研究表明,受空间作用的影响,梁上任意一点受力均会在某一截面产生不可忽略的横向弯矩;对纵向弯矩影响线的研究表明空间作用对活性粉末混凝土槽形梁换算荷载的影响在越靠近端部影响越明显,且该影响不可忽略,所以在设计该种梁时需要在靠近端部位置充分考虑空间作用的影响.

  9. MADS-box gene evolution - structure and transcription patterns

    DEFF Research Database (Denmark)

    Johansen, Bo; Pedersen, Louise Buchholt; Skipper, Martin;

    2002-01-01

    Mads-box genes, ABC model, Evolution, Phylogeny, Transcription patterns, Gene structure, Conserved motifs......Mads-box genes, ABC model, Evolution, Phylogeny, Transcription patterns, Gene structure, Conserved motifs...

  10. Packing a cake into a box

    KAUST Repository

    Skopenkov, Mikhail

    2011-05-01

    Given a triangular cake and a box in the shape of its mirror image, how can the cake be cut into a minimal number of pieces so that it can be put into the box? The cake has icing, so we are not allowed to put it into the box upside down. V. G. Boltyansky asked this question in 1977 and showed that three pieces always suffice. In this paper we provide examples of cakes that cannot be cut into two pieces to be put into the box. This shows that three is the answer to Boltyansky\\'s question. We also give examples of cakes which can be cut into two pieces. © THE MATHEMATICAL ASSOCIATION OF AMERICA.

  11. Packing a cake into a box

    CERN Document Server

    Skopenkov, Mikhail

    2010-01-01

    Given a cake in form of a triangle and a box that fits the mirror image of the cake, how to cut the cake into a minimal number of pieces so that it can be put into the box? The cake has an icing, so that we are not allowed to put it into the box upside down. V.G. Boltyansky asked this question in 1977 and showed that three pieces always suffice. In this paper we provide examples of cakes that cannot be cut into two pieces to put into the box. This shows that three is the answer to V.G. Boltyansky's question. Also we give examples of cakes which can be cut into two pieces.

  12. Starling nest box monitoring [Rocky Mountain Arsenal

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document described the standard operating procedures for observing and recording data collected from starling nest box monitoring at the Rocky Mountain...

  13. Black-Box Search by Unbiased Variation

    DEFF Research Database (Denmark)

    Lehre, Per Kristian; Witt, Carsten

    2012-01-01

    The complexity theory for black-box algorithms, introduced by Droste, Jansen, and Wegener (Theory Comput. Syst. 39:525–544, 2006), describes common limits on the efficiency of a broad class of randomised search heuristics. There is an obvious trade-off between the generality of the black-box model...... and the strength of the bounds that can be proven in such a model. In particular, the original black-box model provides for well-known benchmark problems relatively small lower bounds, which seem unrealistic in certain cases and are typically not met by popular search heuristics.In this paper, we introduce a more...... restricted black-box model for optimisation of pseudo-Boolean functions which we claim captures the working principles of many randomised search heuristics including simulated annealing, evolutionary algorithms, randomised local search, and others. The key concept worked out is an unbiased variation operator...

  14. Mystery Boxes, X Rays, and Radiology.

    Science.gov (United States)

    Thomson, Norman

    2000-01-01

    Indicates the difficulties of teaching concepts beyond light and color and creating memorable learning experiences. Recommends sequential activities using the mystery box approach to explain how scientists and doctors use photon applications. (YDS)

  15. Spacer for supporting fuel element boxes

    International Nuclear Information System (INIS)

    A spacer plate unit arranged externally on each side and at a predetermined level of a polygonal fuel element box for mutually supporting, with respect to one another, a plurality of the fuel element boxes forming a fuel element bundle, is formed of a first and a second spacer plate part each having the same length and the same width and being constituted of unlike first and second materials, respectively. The first and second spacer plate parts of the several spacer plate units situated at the predetermined level are arranged in an alternating continuous series when viewed in the peripheral direction of the fuel element box, so that any two spacer plate units belonging to face-to-face oriented sides of two adjoining fuel element boxes in the fuel element bundle define interfaces of unlike materials

  16. 黄冈公铁两用长江大桥钢桁梁杆件制造关键技术%Key Techniques for Manufacturing of Members of Steel Truss Girder of Huanggang Changjiang River Rail-cum-Road Bridge

    Institute of Scientific and Technical Information of China (English)

    殷红

    2013-01-01

    The main bridge of Huanggang Changjiang River Rail-cum-Road Bridge is a steel truss girder cable-stayed bridge with double pylons and double cable planes.The chord and web members of the main truss of the bridge were designed as the ones of parallelogram sections.To guarantee the manufacturing quality of the members,the key techniques for the manufacturing were studied.The precision of the geometric dimensions of the members was guaranteed by the techniques of controlling the precision of the inclined angle grooves of the welded edges,fine adjusting the diagonal line dimensions of the diaphragms (controlling the angles of the end openings) and assembling the members on the special jig supports.The precision of the anchor tube positioning was guaranteed by the techniques of converting the spatial positioning dimensions of the anchor tubes into the plane positioning dimensions and controlling the installing,welding procedures of the anchor boxes and the installing precision of the anchor tubes.The assembling quality of the steel truss girder was guaranteed by the techniques of testing the precision of the hole groups at the inclined web member joints by the special testing templates for the web member joints.Practice proves that the key techniques applied to the manufacturing of the members effectively tackle the control problems of the members of parallelogram sections and guarantee the manufacturing precision of the steel truss girder of the bridge.%黄冈公铁两用长江大桥主桥为双塔双索面钢桁梁斜拉桥,其主桁弦杆和腹杆采用平行四边形截面.为保证主桁平行四边形截面杆件的制造质量,对其制造关键技术进行研究.通过控制杆件焊接边斜角坡口精度、微调隔板对角线尺寸(控制端口角度)、应用专用胎架组拼杆件的技术保证杆件形位尺寸的精度.通过将锚管空间定位尺寸转化为平面定位尺寸、控制锚箱安装及焊接工序、控制锚管安装精度的技术

  17. Decommissioning a tritium glove-box facility

    International Nuclear Information System (INIS)

    A large glove-box facility for handling reactive metal tritides was decommissioned. Major sections of the glove box were decontaminated and disassembled for reuse at another tritium facility. To achieve the desired results, decontamnation required repeated washing, first with organic liquids, then with water and detergents. Worker protection was provided by simple ventilation combined with careful monitoring of the work areas and employees. Several innovative techniques are described

  18. BOX-DEATH HOLLOW ROADLESS AREA, UTAH.

    Science.gov (United States)

    Weir, Gordon W.; Lane, Michael

    1984-01-01

    Geologic mapping, geochemical sampling, and a search for prospects and mineralized rock in the Box-Death Hollow Roadless Area, Utah indicate that there is little promise for the occurrence of mineral or energy resources in the area. Additional exploratory drilling by industry seems warranted if wells elsewhere in the region find oil or gas in strata as yet untested in the Box-Death Hollow Roadless Area.

  19. Decommissioning a tritium glove-box facility

    Energy Technology Data Exchange (ETDEWEB)

    Folkers, C.L.; Homann, S.G.; Nicolosi, A.S.; Hanel, S.L.; King, W.C.

    1979-08-08

    A large glove-box facility for handling reactive metal tritides was decommissioned. Major sections of the glove box were decontaminated and disassembled for reuse at another tritium facility. To achieve the desired results, decontamnation required repeated washing, first with organic liquids, then with water and detergents. Worker protection was provided by simple ventilation combined with careful monitoring of the work areas and employees. Several innovative techniques are described.

  20. BOX DIMENSIONS OF α-FRACTAL FUNCTIONS

    Science.gov (United States)

    Akhtar, Md. Nasim; Prasad, M. Guru Prem; Navascués, M. A.

    2016-08-01

    The box dimension of the graph of non-affine, continuous, nowhere differentiable function fα which is a fractal analogue of a continuous function f corresponding to a certain iterated function system (IFS), is investigated in the present paper. The estimates for box dimension of the graph of α-fractal function fα for equally spaced as well as arbitrary data sets are found.

  1. HYDROGEN AND VOC RETENTION IN WASTE BOXES

    Energy Technology Data Exchange (ETDEWEB)

    PACE ME; MARUSICH RM

    2008-11-21

    The Hanford Waste Management Project Master Documented Safety Analysis (MDSA) (HNF-14741, 2003) identifies derived safety controls to prevent or mitigate the risks of a single-container deflagration during operations requiring moving, venting or opening transuranic (TRU)-waste containers. The issue is whether these safety controls are necessary for operations involving TRU-waste boxes that are being retrieved from burial at the Hanford Site. This paper investigates the potential for a deflagration hazard within these boxes and whether safety controls identified for drum deflagration hazards should be applied to operations involving these boxes. The study evaluates the accumulation of hydrogen and VOCs within the waste box and the transport of these gases and vapors out of the waste box. To perform the analysis, there were numerous and major assumptions made regarding the generation rate and the transport pathway dimensions and their number. Since there is little actual data with regards to these assumptions, analyses of three potential configurations were performed to obtain some indication of the bounds of the issue (the concentration of hydrogen or flammable VOCs within a waste box). A brief description of each of the three cases along with the results of the analysis is summarized.

  2. 港珠澳大桥非通航孔85 m连续组合梁桥施工关键技术%Key Construction Techniques for 85 m Non-navigational Channel Con-tinuous Composite Girder Bridge of Hongkong-Zhuhai-Macao Bridge

    Institute of Scientific and Technical Information of China (English)

    潘军

    2016-01-01

    into four modulus ,each being individually bonded ,then as‐sembled to a whole ,afterwards ,the automatic retractable formwork is used to cast concrete .The crack control technique and corrosion protection measures are used .The prefabricated components of the monolithic pile cap and bottom pier lift are transported by the Crane Little Swan ,then hois‐ted and lowered into the interlocked suspension steel box cofferdam ,and precisely positioned and installed by the three‐directional adjusting devices on pier tops .T he steel structure of the compos‐ite girder was firstly fabricated to plate units in the workshop ,then floated to the prefabrication yard in Zhongshan to be assembled span by span .The concrete slabs are longitudinally divided into blocks and transversely prefabricated as a w hole ,w hen the steel structures and concrete slabs are combined to form a composite girder ,the Crane Tianyi ,a ship capable of lifting and erecting gird‐ers ,is used to lift the girders section by section .

  3. Design of the Main Bridge Steel Truss Girder of Xinglong Bridge%兴隆大桥主桥钢桁梁设计

    Institute of Scientific and Technical Information of China (English)

    杨文; 何耀炜

    2016-01-01

    下承式钢桁梁桥因其具有建筑高度低、施工速度快和结构轻巧简洁等优点,成为中等跨度公路桥梁中有竞争力的桥型。文中以兴隆大桥为依托,建立数学分析模型,对下承式钢桁梁桥结构的受力特性进行分析,并指出该类型桥梁施工的方法和技术要点。%The through steel truss girder bridge becomes a bridge type for medium span highway bridg-es with low building height,fast construction speed and the advantages of compact and simple struc-ture.Based on the Xinglong Bridge,a mathematical analysis model is established in this paper to ana-lyze the mechanical characteristics of the steel truss girder bridge,and the method and technical points of the bridge construction are pointed out.

  4. 49 CFR 178.517 - Standards for plastic boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for plastic boxes. 178.517 Section 178... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.517 Standards for plastic boxes. (a) The following are identification codes for plastic boxes: (1) 4H1 for an expanded plastic box; and (2) 4H2 for...

  5. Complementarity in the Einstein-Bohr photon box

    NARCIS (Netherlands)

    Dieks, D.G.B.J.; Lam, S

    2008-01-01

    The Bohr-Einstein photon box thought experiment is a forerunner of the EPR experiment: a packet of radiation escapes from a box, and the box-plus-radiation state remains entangled. Hence, a measurement on the box makes a difference for the state of the far-away radiation long after its escape. This

  6. 49 CFR 230.101 - Steam locomotive driving journal boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not...

  7. Bending analysis of laminated composite box beams

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, A.K.; Patel, H.J.; Pang, S.S. (Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Mechanical Engineering)

    1994-01-01

    Box beams are widely used in weight reduction structures such as aircraft wings. The use of composite box beams further reduces the weight factor for such structures with the same deflection and stress as that of isotropic box beams. The difference in the behavior of composite box beam with different fiber orientation, number of plies, and number of stringers also provides a wide range of designing parameters to achieve the required performance for a given problem. A bending analysis has been carried out for the study of deflections and stresses for box beams of different material (isotropic and laminated composites), size, and number of stringers subjected to different kinds of loading conditions. A finite element model has been developed based on the strain energy principle, and the results are compared with an available commercial code COSMOS/M.'' Experiments using aluminum and scotchply composite laminates were conducted to verify the results. An optimal design for size and number of stiffeners for a given loading condition has been achieved. Investigations have also been carried out to find the effect of transverse shear on the span-wise normal stress.

  8. Advances in the theory of box integrals

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Borwein, J.M.; Crandall, R.E.

    2009-06-25

    Box integrals - expectations <|{rvec r}|{sup s}> or <|{rvec r}-{rvec q}|{sup s}> over the unit n-cube (or n-box) - have over three decades been occasionally given closed forms for isolated n,s. By employing experimental mathematics together with a new, global analytic strategy, we prove that for n {le} 4 dimensions the box integrals are for any integer s hypergeometrically closed in a sense we clarify herein. For n = 5 dimensions, we show that a single unresolved integral we call K{sub 5} stands in the way of such hyperclosure proofs. We supply a compendium of exemplary closed forms that naturally arise algorithmically from this theory.

  9. Nearly Seamless Vacuum-Insulated Boxes

    Science.gov (United States)

    Stepanian, Christopher J.; Ou, Danny; Hu, Xiangjun

    2010-01-01

    A design concept, and a fabrication process that would implement the design concept, have been proposed for nearly seamless vacuum-insulated boxes that could be the main structural components of a variety of controlled-temperature containers, including common household refrigerators and insulating containers for shipping foods. In a typical case, a vacuum-insulated box would be shaped like a rectangular parallelepiped conventional refrigerator box having five fully closed sides and a hinged door on the sixth side. Although it is possible to construct the five-closed-side portion of the box as an assembly of five unitary vacuum-insulated panels, it is not desirable to do so because the relatively high thermal conductances of the seams between the panels would contribute significant amounts of heat leakage, relative to the leakage through the panels themselves. In contrast, the proposal would make it possible to reduce heat leakage by constructing the five-closed-side portion of the box plus the stationary portion (if any) of the sixth side as a single, seamless unit; the only remaining seam would be the edge seal around the door. The basic cross-sectional configuration of each side of a vacuum-insulated box according to the proposal would be that of a conventional vacuum-insulated panel: a low-density, porous core material filling a partially evacuated space between face sheets. However, neither the face sheets nor the core would be conventional. The face sheets would be opposite sides of a vacuum bag. The core material would be a flexible polymer-modified silica aerogel of the type described in Silica/Polymer and Silica/Polymer/Fiber Composite Aero - gels (MSC-23736) in this issue of NASA Tech Briefs. As noted in that article, the stiffness of this core material against compression is greater than that of prior aerogels. This is an important advantage because it translates to greater retention of thickness and, hence, of insulation performance when pressure is

  10. Box truss development and its application

    Science.gov (United States)

    Coyner, J. V.

    1985-04-01

    Since 1977, Martin Marietta Denver Aerospace has aggressively pursued development of deployable structural systems applicable to a wide variety of Shuttle-transportable large space system requirements. This effort has focused on the deployable box truss, mechanisms and materials development, mesh reflector design and fabrication, gate frame truss design and fabrication, and offset-fed antenna design and analysis. The activities discussed are: box truss design; metal matrix composites; precision joints; enhanced passive damping design; mesh reflector development; gate frame truss for solar arrays; 15-meter spinning radio meter; and 60 x 120 meter push broom antenna.

  11. CASAS: A Smart Home in a Box.

    Science.gov (United States)

    Cook, Diane J; Crandall, Aaron S; Thomas, Brian L; Krishnan, Narayanan C

    2013-07-01

    While the potential benefits of smart home technology are widely recognized, a lightweight design is needed for the benefits to be realized at a large scale. We introduce the CASAS "smart home in a box", a lightweight smart home design that is easy to install and provides smart home capabilities out of the box with no customization or training. We discuss types of data analysis that have been performed by the CASAS group and can be pursued in the future by using this approach to designing and implementing smart home technologies.

  12. EnergyBox: Tool improvement and GUI

    OpenAIRE

    Polis, Rihards

    2014-01-01

    EnergyBox is a parametrised estimation tool that uses packet traces as input to simulate the energy consumption of communication in mobile devices. This tool models the transmission behaviour of a smart phone by analysing a recorded packet trace from the device. The purpose of the thesis is to reimplement the original EnergyBox energy consumption modelling tool. The project aims to develop support for a graphical user interface (GUI) and a code base that is easier to modify and maintain. The ...

  13. Investigation on features and tendencies of axle-box heating

    Directory of Open Access Journals (Sweden)

    Olegas LUNYS

    2015-03-01

    Full Text Available Breakdown of rolling stock axle-boxes if not detected in due time may cause a rail accident or disaster. At present, a lot of advanced technologies, modern equipment and devices, which “recognizes” faulty axle-boxes when the train is in motion, have been implemented. However, the timely identification of breakdown of rolling stock axle-boxes still is an acute problem, the initial stage of damage emergence being especially problematic. Presently, rolling stock axle-box breakdown is determined according to the higher than permissible temperature of the axle-box body. The article provides statistical data of dangerously heated axle-boxes, determined train delay durations, the number of delayed trains by danger level, and dependence of damage on the season. After systematization of data on axle-box damage and heating temperatures of broken axle-boxes, heating tendencies of axle-boxes of freight wagons are described. Finally, basic conclusions are given.

  14. M PC复合材料加固空心板梁桥静载试验研究%Study of Static Tests for Using MPC Composite Material to Strengthen Void Plate Girder Bridge

    Institute of Scientific and Technical Information of China (English)

    谷丹丹; 孙全胜

    2015-01-01

    为研究M PC复合材料加固空心板梁桥的有效性,在某跨径13 m的空心板梁桥主梁跨中11 m范围内浇筑M PC复合材料进行加固,桥梁加固前与加固后分别进行静载试验,并采用有限元法建立加固前后主梁的有限元模型,分析加固前后主梁的挠度、裂缝和应变的变化。分析结果表明:工况1(跨中最大弯矩横向对称加载)、工况2(跨中最大弯矩横向偏载加载)下主梁加固后的挠度较加固前分别降低了13.4%、12.6%,加固后主梁的挠度明显减小;在试验过程中,加固后主梁裂缝未见明显变化,裂缝区应变水平降低,较好地抑制了原有裂缝的发展;工况1、工况2下主梁加固后的应变较加固前分别降低了13.75%、14.79%,加固后主梁受拉区应变显著降低;加固后校验系数改善率最大为13.89%,该加固方法能够有效地提高桥梁的承载力和刚度。%To study the efficiency of using MPC composite material to strengthen void plate girder bridge ,within the 11 m area of the midspan of the main girder of a 3 × 13 m void plate girder bridge ,the MPC composite material was cast for the strengthening purpose .Static tests were done before and after the strengthening ,and the finite element method was used to establish the models of the main girder before and after the strengthening ,to analyze the variation of main span deflec‐tion ,cracking and strain .The results of the analysis indicate that under two load cases (load case 1 is the transverse symmetrical loading with maximum midspan bending moment and the load case 2 is the transverse eccentric loading with maximum midspan bending moment .) ,the deflection of main girder reduces by 13 .4% and 12 .6% , respectively , compared with the data before the strengthening ,and the deflection of the main girder after strengthening is distinctively declined . During the process of the tests ,the cracking of the main

  15. Study on injury and fatigue life forecast of gantry crane's girder under rising load%起升载荷下门式起重机主梁损伤与疲劳寿命预测研究

    Institute of Scientific and Technical Information of China (English)

    张强; 王海舰; 胡南

    2015-01-01

    为研究起升载荷下门式起重机主梁的损伤和疲劳寿命,通过有限元软件ANSYS Workbench建立门式起重机主梁力学模型,采用 nsoft 疲劳分析软件对主梁的动静态力学特性和疲劳损伤进行了分析,采用 nCode GlypWorks中的Rainflow 模块对各载荷作用的应力时间历程进行雨流计数、载荷外推和叠加,采用 nCode GlypWorks中的Stress Life模块计算主梁的疲劳寿命以及敏感性分析,得到不同工况下门式起重机箱型主梁应力和应变云图以及叠加后雨流直方图、主梁损伤直方图、裂纹—寿命关系曲线。研究结果表明:主梁的最大等效应力位置在跨中或端部以及主梁与支腿连接部位,易产生疲劳损伤;40 t以上起重量是造成主梁损伤主要载荷;过载、残余应力和表面粗糙度均对主梁的使用寿命具有明显影响。冲击损伤仿真结果与计算结果较为接近,说明冲击损伤计算结果具有较高的可信度。%In order to study the damage and fatigue life of gantry crane's girder under rising load , the mechanical model of gantry crane's girder was established through the finite element software ANSYS Workbench ,the dynamic and static mechanical properties and fatigue damage of girder were analyzed by using fatigue analysis software nsoft ,the rain flow counting ,the extrapolation superstition of the stress time on load w ere carried out by using Rainflow module in nCode Glyp Works .The life stress module in nCode GlypWorks was used to calculate the fatigue life and ana‐lyze the sensitivity of girder ,through w hich the stress and strain image ,superimposed rain flow histogram ,girder damage histogram and crack‐life relationship curve of gantry crane chassis type girder were got .The results showed that ,the maximum equivalent stress positions appeared in the middle or end of the girder ,the joints of girder and legs where were easy to produce fatigue damage;the lifting

  16. Study of Static Tests for Using MPC Composite Material to Strengthen Void Plate Girder Bridge%M PC复合材料加固空心板梁桥静载试验研究

    Institute of Scientific and Technical Information of China (English)

    谷丹丹; 孙全胜

    2015-01-01

    To study the efficiency of using MPC composite material to strengthen void plate girder bridge ,within the 11 m area of the midspan of the main girder of a 3 × 13 m void plate girder bridge ,the MPC composite material was cast for the strengthening purpose .Static tests were done before and after the strengthening ,and the finite element method was used to establish the models of the main girder before and after the strengthening ,to analyze the variation of main span deflec‐tion ,cracking and strain .The results of the analysis indicate that under two load cases (load case 1 is the transverse symmetrical loading with maximum midspan bending moment and the load case 2 is the transverse eccentric loading with maximum midspan bending moment .) ,the deflection of main girder reduces by 13 .4% and 12 .6% , respectively , compared with the data before the strengthening ,and the deflection of the main girder after strengthening is distinctively declined . During the process of the tests ,the cracking of the main girder after the strengthening did not show distinct variation ,the strain level in the cracking area is decreased and the propagation of the original cracking is better curbed .In the contexts of load case 1 and load case 2 ,the strain of the main girder after the strengthening decrease 13 .75% and 14 .79% ,respectively ,compared with data before the strengthening ,and the strain in the tensile area of the main girder is obviously de‐creased .The verification coefficient is improved by a maximum rate of 13 .89% after strengthening and the method is able to effectively improve the load bearing capacity and stiffness of the bridge .%为研究M PC复合材料加固空心板梁桥的有效性,在某跨径13 m的空心板梁桥主梁跨中11 m范围内浇筑M PC复合材料进行加固,桥梁加固前与加固后分别进行静载试验,并采用有限元法建立加固前后主梁的有限元模型,分析加固前后主梁的挠度、裂缝和应变的

  17. Hazard Analysis of Japanese Boxed Lunches (Bento).

    Science.gov (United States)

    Bryan, Frank L.; And Others

    1991-01-01

    For the purposes of identifying contaminants, of assessing risks, and of determining critical food processing control points, hazard analyses were conducted at two "bento" (oriental boxed meals) catering operations. Time and temperature abuses during the holding period, after cooking and prior to consumption, were found to be the primary reason…

  18. A white box perspective on behavioural adaptation

    DEFF Research Database (Denmark)

    Bruni, Roberto; Corradini, Andrea; Gadducci, Fabio;

    2015-01-01

    We present a white-box conceptual framework for adaptation developed in the context of the EU Project ASCENS coordinated by Martin Wirsing. We called it CoDA, for Control Data Adaptation, since it is based on the notion of control data. CoDA promotes a neat separation between application and adap...

  19. RELIABILITY BASED DESIGN OF A GEAR BOX

    Directory of Open Access Journals (Sweden)

    D.MADHUSEKHAR

    2014-08-01

    Full Text Available Reliability is the probability that a system, component or device will perform without failure for a specified period of time under specified operating conditions. The concept of reliability is of great importance in the design of various machine members. Conventional engineering design uses a deterministic approach. It disregards the fact that the material properties, the dimensions of the components and the externally applied loads are statistical in nature. In conventional design this uncertainties are covered with a factor of safety, which is not always successful. The growing trend towards reducing uncertainty and increasing reliability is to use the probabilistic approach. In the present work a three shaft four speed gear box and six speed gear box are designed using reliability principles. For the specified reliability of the system (Gear box, component reliability (Gear pair is calculated by considering the system as a series system. Design is considered to be safe and adequate if the probability of failure of gear box is less than or equal to a specified quantity in each of the two failure modes. . All the parameters affecting the design are considered as random variables and all the random variables are assumed to follow normal distribution. A computer program in C++ is developed to calculate the face widths in bending and surface failure modes. The larger one out of the two values is considered. By changing the variations in the design parameters, variations in the face widths are studied.

  20. PVC posting bags for glove boxes

    International Nuclear Information System (INIS)

    This specification covers the materials, measurements and manufacture of unpigmented PVC posting bags for use on glove boxes, together with methods of testing the materials. These bags are used in the handling of radioactive and toxic materials of a hazardous nature and therefore must be of the highest standard of mechanical strength, leak tightness and general finish. (author)

  1. Cereal Box Design: An Interdisciplinary Graphics Activity

    Science.gov (United States)

    Fitzgerald, Mike; Tsosie, Teri

    2012-01-01

    The cereal box design activity is intriguing both for its simplicity and the resourcefulness that it can generate in young people. Also, it lends itself to a variety of curriculums. It covers both consumerism and Design for the Environment (DfE) concepts broadly and in depth. The activity introduces a wide range of topics. They include graphic…

  2. Using Story Boxes in Language Learning

    Science.gov (United States)

    Collins, Rita

    2009-01-01

    Story boxes and story bags are containers for holding realia that are used to enhance reading and provide a variety of activities for encouraging language acquisition and use. Whatever the packaging, these are good ways to develop students' interest in books. Using realia, or real-life objects, to teach a foreign language is not a novel concept.…

  3. Study of WATCH GRB error boxes

    DEFF Research Database (Denmark)

    Gorosabel, J.; Castro-Tirado, A. J.; Lund, Niels;

    1995-01-01

    We have studied the first WATCH GRB Catalogue ofγ-ray Bursts in order to find correlations between WATCH GRB error boxes and a great variety of celestial objects present in 33 different catalogues. No particular class of objects has been found to be significantly correlated with the WATCH GRBs....

  4. One-Dimensional Oscillator in a Box

    Science.gov (United States)

    Amore, Paolo; Fernandez, Francisco M.

    2010-01-01

    We discuss a quantum-mechanical model of two particles that interact by means of a harmonic potential and are confined to a one-dimensional box with impenetrable walls. We apply perturbation theory to the cases of different and equal masses and analyse the symmetry of the states in the latter case. We compare the approximate perturbation results…

  5. One-dimensional oscillator in a box

    Energy Technology Data Exchange (ETDEWEB)

    Amore, Paolo [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, Colima, Colima (Mexico); Fernandez, Francisco M [INIFTA (UNLP, CCT La Plata-CONICET), Division Quimica Teorica, Blvd 113 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)], E-mail: paolo@ucol.mx, E-mail: fernande@quimica.unlp.edu.ar

    2010-01-15

    We discuss a quantum-mechanical model of two particles that interact by means of a harmonic potential and are confined to a one-dimensional box with impenetrable walls. We apply perturbation theory to the cases of different and equal masses and analyse the symmetry of the states in the latter case. We compare the approximate perturbation results with accurate numerical ones.

  6. 两跨连续斜交梁桥振动台试验研究%Shaking table tests for a two-span continuous skew girder bridge

    Institute of Scientific and Technical Information of China (English)

    许永吉; 卓卫东; 孙颖

    2016-01-01

    The dynamic characteristics and three-dimensional seismic response of a two-span continuous skew girder bridge were analyzed,using parameters,such as,skew angle,shear span ratio,reinforcement ratio and axial compression ratio and so on.Taking a skewed girder bridge of Fujian as an engineering example,a 1 ∶5 scale two-span continuous skewed girder bridge model was designed for shaking table tests.Adopting shaking table tests and FE numerical analysis, the seismic responses and damage characteristics of the skewed girder bridge were studied.Results of shaking table tests showed that the structure's acceleration response and displacement response are guite different under different types of ground motion and at the same site or different types of ground motion and at different sites;under the same skew angle. the smaller the axial compression ratio,the larger the acceleration and displacement responses;when the axial compression ratio is the same,the smaller the skew angle,the larger the acceleration and displacement responses;a reasonable choice of skew angle has a great influence on the dynamic performance of skew bridges in the design of skew bridges.%选取了斜交角、配箍率和轴压比等设计参数,对两跨连续斜交梁桥进行结构动力特性分析和单向地震动输入下结构的地震反应分析。以福建省高速公路某座斜交梁桥为工程背景,设计制作了一座1/5缩尺两跨连续混凝土斜交梁桥试验模型,结合振动台模型试验和数值模拟分析,研究斜交梁桥地震响应及震害特点。振动台模型试验结果表明:不同场地类别的地震动及同一场地类别但不同的地震动作用下,结构的加速度响应、位移响应差别较大;在相同斜交角时,轴压比越小,加速度和位移响应越大;当轴压比相同时,斜交角越小,加速度和位移响应越大。从试验可知,在斜交桥设计中,合理选择斜交角对桥梁动力性能有很大的影响。

  7. 大板梁翼板对接焊缝的超声波检测%Ultrasonic Testing on Butt Weld of Wing Plate of Main Girder

    Institute of Scientific and Technical Information of China (English)

    唐垚; 喻星星

    2015-01-01

    The ultrasonic testing method of the butt weld of the wing plate with a thickness of 140 mm of the main girder in the utility boiler is introduced. The selection of the probe, the determination of the scanning method in the detection process and the method for depicting the DAC curve using the CSK-Ⅳ test block are mainly discussed.%介绍了电站锅炉大板梁140 mm厚翼板对接焊缝的超声波检测方法. 主要论述了检测过程中探头的选取、 扫查方式的确定以及利用CSK-Ⅳ试块制作DAC曲线的方法.

  8. Application of Defense Technology Commonly Used in Boxing Match

    Institute of Scientific and Technical Information of China (English)

    Zhixiao Li[1; Jianjun Liu[2

    2015-01-01

    Boxing defense technology is a kind of techniques to prevent the opponent from attacking successfully. Boxing is a kind of sports that needs close cooperation between attack and defense. Attack is used for defense, where there is no attack, there will be no defense, and vice versa. Defense technology is the foundation of attack technology, therefore, defense is of vital importance in boxing match.

  9. 76 FR 41411 - Group E Post Office Box Service

    Science.gov (United States)

    2011-07-14

    ... PO Box customers are assigned the smallest available box that reasonably accommodates their daily mail volume. b. Eligibility for Group E PO Boxes does not extend to: 1. Individual tenants, contractors... Federal Register proposed rule (75 FR 71642-71643) to clarify eligibility, simplify the standards,...

  10. 47 CFR 90.241 - Radio call box operations.

    Science.gov (United States)

    2010-10-01

    ... remains on for a period in excess of three minutes. The automatic cutoff system must be designed so the... Safety Pool for highway call box systems subject to the following requirements: (1) Call box transmitters... effective radiated power (ERP). (3) The height of a call box antenna may not exceed 6.1 meters (20...

  11. 49 CFR 230.103 - Tender roller bearing journal boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Tender roller bearing journal boxes. 230.103... Locomotives and Tenders Running Gear § 230.103 Tender roller bearing journal boxes. Tender roller bearing journal boxes shall be maintained in a safe and suitable condition....

  12. 49 CFR 230.102 - Tender plain bearing journal boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Tender plain bearing journal boxes. 230.102... Locomotives and Tenders Running Gear § 230.102 Tender plain bearing journal boxes. Plain bearing journal boxes... expected to damage the bearing; or have a detrimental effect on the lubrication of the journal and...

  13. Fatal exit the automotive black box debate

    CERN Document Server

    Kowalick, Tom

    2005-01-01

    "Fatal Exit: The Automotive Black Box Debate cuts through thirty years of political wrangling and institutional biases to provide an argument for the Motor Vehicle Event Data Recorder (MVEDR). This automotive equivalent of an airplane's flight recorder or black box is intended to solve the mysteries of car crashes and improve the safety of our roads. The reader is taken inside the automotive industry and the government highway safety establishment to foster an understanding of the politics and the positions on all sides of this safety debate. The author takes an unbiased approach, chronologically presenting each argument and uncovering the agendas and mandates of each of the stakeholders." "This publication is essential reading for all consumers who need to have their voices heard on this critical issue, as well as for attorneys, public safety advocates, public policy administrators, engineers, automotive professionals, journalists, and insurance executives."--Jacket.

  14. The Central Nervous System of Box Jellyfish

    DEFF Research Database (Denmark)

    Garm, Anders Lydik; Ekström, Peter

    2008-01-01

    of behaviors in the box jellyfish such as obstacle avoidance and navigation. The need to process the visual information and turn it into the appropriate behavior puts strong demands on the nervous system of box jellyfish, which appears more elaborate than in other cnidarians. Here, the central part...... of this nervous system is described. Each rhopalium holds a separate part of the CNS with 1,000 nerve cells and a large amount of neuropil. The rhopalial nervous system has several subsystems defined by the anatomy, location, and immunocytochemistry of the cells. Most of the subsystems connect to one or more...... of the eye types, and it is likely that the rhopalial nervous system accounts for most of the visual processing. The major part of the CNS is made up of a ring nerve encircling the bell shaped body. The ring nerve holds around 10,000 cells and is directly connected to all four rhopalial nervous systems...

  15. The gradient flow in a twisted box

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Alberto [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2013-08-15

    We study the perturbative behavior of the gradient flow in a twisted box. We apply this information to define a running coupling using the energy density of the flow field. We study the step-scaling function and the size of cutoff effects in SU(2) pure gauge theory. We conclude that the twisted gradient flow running coupling scheme is a valid strategy for step-scaling purposes due to the relatively mild cutoff effects and high precision.

  16. Adaptive Techniques to find Optimal Planar Boxes

    CERN Document Server

    Barbay, J; Pérez-Lantero, P

    2012-01-01

    Given a set $P$ of $n$ planar points, two axes and a real-valued score function $f()$ on subsets of $P$, the Optimal Planar Box problem consists in finding a box (i.e. axis-aligned rectangle) $H$ maximizing $f(H\\cap P)$. We consider the case where $f()$ is monotone decomposable, i.e. there exists a composition function $g()$ monotone in its two arguments such that $f(A)=g(f(A_1),f(A_2))$ for every subset $A\\subseteq P$ and every partition $\\{A_1,A_2\\}$ of $A$. In this context we propose a solution for the Optimal Planar Box problem which performs in the worst case $O(n^2\\lg n)$ score compositions and coordinate comparisons, and much less on other classes of instances defined by various measures of difficulty. A side result of its own interest is a fully dynamic \\textit{MCS Splay tree} data structure supporting insertions and deletions with the \\emph{dynamic finger} property, improving upon previous results [Cort\\'es et al., J.Alg. 2009].

  17. T-box factors determine cardiac design.

    Science.gov (United States)

    Hoogaars, W M H; Barnett, P; Moorman, A F M; Christoffels, V M

    2007-03-01

    The heart of higher vertebrates is a structurally complicated multi-chambered pump that contracts synchronously. For its proper function a number of distinct integrated components have to be generated, including force-generating compartments, unidirectional valves, septa and a system in charge of the initiation and coordinated propagation of the depolarizing impulse over the heart. Not surprisingly, a large number of regulating factors are involved in these processes that act in complex and intertwined pathways to regulate the activity of target genes responsible for morphogenesis and function. The finding that mutations in T-box transcription factor-encoding genes in humans lead to congenital heart defects has focused attention on the importance of this family of regulators in heart development. Functional and genetic analyses in a variety of divergent species has demonstrated the critical roles of multiple T-box factor gene family members, including Tbx11, -2, -3, -5, -18 and -20, in the patterning, recruitment, specification, differentiation and growth processes underlying formation and integration of the heart components. Insight into the roles of T-box factors in these processes will enhance our understanding of heart formation and the underlying molecular regulatory pathways. PMID:17380306

  18. Changes in position and quality of preferred nest box: effects on nest box use by laying hens

    DEFF Research Database (Denmark)

    Riber, Anja Brinch; Nielsen, Birte L.

    2013-01-01

    Using laying hens, we investigated whether position of a nest box, both within the pen and relative to other nest boxes, influenced the preference for a nest box, and how a sudden and marked change to the preferred box influenced the use of nest boxes by the hens. Groups (n=12) of 15 Isa Warren...... hens were housed in pens, each with five identical nest boxes in different positions: Two single (in a corner or not) and a triplet of nest boxes (one of which in a corner). The use of nest boxes was determined by the number of eggs laid daily in each box. Three experiments, each lasting 10 days, were...... carried out. First, the undisturbed use of each of the nest box types was investigated, and a strong preference (P<0.001) was found for single nest boxes in a corner, with 62% of the nest box eggs laid there. Second, each of the hen groups was moved to another pen allocated at random, and where the...

  19. Effectiveness of box trainers in laparoscopic training

    Directory of Open Access Journals (Sweden)

    Dhariwal Anender

    2007-01-01

    Full Text Available Rationale and Objectives: Various devices are used to aid in the education of laparoscopic skills ranging from simple box trainers to sophisticated virtual reality trainers. Virtual reality system is an advanced and effective training method, however it is yet to be adopted in India due to its cost and the advanced technology required for it. Therefore, box trainers are being used to train laparoscopic skills. Hence this study was undertaken to assess the overall effectiveness of the box-training course. Study Procedure: The study was conducted during six-day laparoscopic skills training workshops held during 2006. Twenty five surgeons; age range of 26 to 45 years, of either sex, who had not performed laparoscopic surgery before; attending the workshop were evaluated. Each participant was given a list of tasks to perform before beginning the box-training course on day one and was evaluated quantitatively by rating the successful completion of each test. Evaluation began when the subject placed the first tool into the cannula and ended with task completion. Two evaluation methods used to score the subject, including a global rating scale and a task-specific checklist. After the subject completed all sessions of the workshop, they were asked to perform the same tasks and were evaluated in the same manner. For each task completed by the subjects, the difference in the scores between the second and first runs were calculated and interpreted as an improvement as a percentage of the initial score. Statistical Analysis: Wilcoxon matched-paired signed-ranks test was applied to find out the statistical significance of the results obtained. Results: The mean percentage improvement in scores for both the tasks, using global rating scale, was 44.5% + 6.930 (Mean + SD. For task 1, using the global rating scale mean percentage improvement was 49.4% + 7.948 (Mean + SD. For task 2, mean percentage improvement using global rating scale was 39.6% + 10.4 (Mean

  20. 折线形腹板钢梁的局部承压性能有限元分析%The finite element analysis on folded web steel girder under patch loading

    Institute of Scientific and Technical Information of China (English)

    庄晖; 黄炳生

    2012-01-01

    The steel beams with folded webs are produced by substituting the folded webs for flat webs, this is a kind of the steel girders with corrugation webs. And such products have superior load-carrying capacity and favorable economic advantages. At present,studies on the behavior of the steel girders under patch loading are scarce at home and abroad. So this paper presents the finite element analysis on folded wed steel girders under patch loading. Observe the failure of the models and the factors that influence the ultimate capacity. Prepare for the text success.%折线形腹板钢梁是将传统钢梁中的平腹板用折线形钢板来代替,是波纹腹板钢梁的一种.该钢梁具有较高的承载力及良好的经济优势.目前,在国内外仅对梯形腹板钢梁的局部承压性能有少量研究.本文作者采用有限元方法对折线形腹板钢梁局部承压性能进行研究,了解其在实际试验中可能发生的破坏模式和各因素对其局部承压力性能的影响,并为今后试验作准备.

  1. Effect of Plate Girder Bridge with Different Coupling Stiffness on Stress of Concrete Slab%不同连接程度板桁桥对混凝土板应力的影响

    Institute of Scientific and Technical Information of China (English)

    任钢; 肖杰; 丁颖

    2012-01-01

    In terms of 64m through semi-combined plate girder bridge which is used more widely at present,the effect of coupling stiffness between concrete steel truss girder and distribution distance of shear key on concrete slab is analyzed and compared by changing the coupling stiffness and distribution distance.The calculation shows that with the increase of coupling stiffness axial stress of concrete slab increases while beading stress is slightly affected.By decreasing the distribution distance of shear key,stress of concrete slab at the upside of longitudinal girder is largely affected and the stress at the edge while along the center line is slightly affected.%针对目前高速铁路应用较多的64m下承式板桁半结合桥,通过改变混凝土与钢桁梁之间连接刚度以及剪力键分布距离来分析比较其对混凝土应力的影响,计算表明,连接刚度的增加,混凝土板的轴向应力随之增加,但弯曲应力影响较小。通过剪力键布置间距减小,纵梁上方处混凝土板应力影响较大,而混凝土边缘以及中心线处应力影响较小。

  2. 附加轴向位移对薄壁箱梁翼板应力的影响%Influence of Additional Axial Displacement on Flange Stress of Thin-walled Box Girder

    Institute of Scientific and Technical Information of China (English)

    冀伟; 吴焕庆; 刘世忠

    2013-01-01

    带有任意悬臂的梯形单箱单室箱梁,在定义其位移翘曲函数时,需要在全截面上附加一均匀的轴向位移,以使纵向位移在全截面上构成轴力自平衡.为确定附加轴向位移对箱梁上、下翼板应力的影响程度,首先定义剪滞翘曲函数分别取为2次、3次和4次抛物线,并考虑翼板宽度及其至截面形心轴距离的影响,利用截面轴力自平衡条件,建立了附加轴向位移的表达式,进而分析了其主要特点.然后用最小势能原理推导出控制微分方程和箱梁上、下翼板应力的求解方程.最后将文中计算方法所得结果、实测值和SAP板壳单元的计算结果进行对比,发现3者吻合良好.因此,在计算翼板应力时,考虑附加轴向位移与否对箱梁上、下翼板应力的影响程度均较小,可以忽略不计.

  3. 活性粉末混凝土与普通混凝土组合箱梁的受力性能%The Static and Dynamic Properties of Combination Box Girders Composed of Reactive Powder Concrete and Conventioal Concrete

    Institute of Scientific and Technical Information of China (English)

    肖国梁; 高日; 李承根

    2004-01-01

    提出将活性粉末混凝土(Reactive Powder Concrete,以下简称RPC)与普通混凝土组合箱梁应用于实际工程的设计构想,并用有限元的方法分析了该箱梁的静力性能、破坏特征、自振周期以及在列车荷载作用下的动力响应.将分析与试验进行比较,得出该箱梁的性能良好和经济性好的结论.

  4. 浅谈客运专线支架现浇箱梁临近营业线施工的现场管理%Of Passenger Dedicated stent situ box girder near the construction site management of business lines

    Institute of Scientific and Technical Information of China (English)

    王立军

    2012-01-01

    文章通过对京石客运专线JS-1标永定河特大桥支架现浇箱梁临近营运线施工现场管理过程的介绍,阐述了在临近既有线位置施工,支架现浇箱梁的现场管理方法及控制措施.

  5. Calculation and Analysis of Lateral Frame of Streamlined Flat Concrete Box Girder%扁平流线型混凝土箱梁横向计算与分析

    Institute of Scientific and Technical Information of China (English)

    张忠良

    2009-01-01

    结合厦门仙岳路高架桥工程,采用平面杆系程序和空间有限元分析程序,对扁平流线型箱梁的横向受力模式、跨中横隔板对箱梁的整体性的影响和腹板剪力分配规律进行研究.

  6. 砼连续箱梁人行天桥振动特性测试与分析%Vibration characteristics test and analysis on concrete box girder continuous pedestrian bridge

    Institute of Scientific and Technical Information of China (English)

    张冠华; 葛耀君

    2009-01-01

    以某座普通钢筋砼连续箱梁人行天桥为工程背景,通过对其振动特性进行大量实测试验,利用有限元理论对结构整体进行计算,深入分析其大幅度竖向、侧向振动的成因,结合实测数据探讨现行人行桥振动舒适度评价方法所存在的不足之处,评价天桥的舒适程度,为该桥的质量检测与评价提供依据,并提出了人行天桥振动舒适性评价建议.这为今后对该类桥梁的设计、维修加固具有实际参考价值.

  7. 箱梁水化热和日照辐射温度效应研究%Research on Temperature Effect of Hydration Heat of Box Girder and Solar Radiation

    Institute of Scientific and Technical Information of China (English)

    段辉林

    2013-01-01

    结合某连续刚构桥的施工监控,对箱梁在施工阶段的水化热影响以及运营阶段的日照辐射影响进行了研究.利用ANSYS计算出:受水化热影响,箱梁最大内外温差值达到了63℃;受日照辐射影响,箱梁项板与腹板处产生应力集中,设计时应当引起重视.

  8. Research of the Virtual Beam Spacing during Modeling Virtual Beams of Small Box-Girder Bridge%小箱梁桥虚拟横梁建模法中虚横梁间距选取研究

    Institute of Scientific and Technical Information of China (English)

    葛素娟; 李静斌

    2009-01-01

    利用大型有限元通用软件MIDAS对40 m跨小箱梁桥建立实体单元模型和虚拟横梁单元模型,针对不同虚横梁间距模型分别计算了6种荷载工况下的跨中竖向位移,并与实体单元模型跨中竖向位移相比较,得出虚横梁问距为1/10~1/8跨长时,与实体单元的误差最小,建模时依据该结论取虚横梁间距.此结论也可以供其他跨径小箱梁桥建模计算时参考.

  9. 梁格法分析小箱梁桥虚拟横梁刚度模拟%Virtual beam stiffness simulation of grillage method analysis of small box girder bridge

    Institute of Scientific and Technical Information of China (English)

    冯文焕; 苏巨峰

    2013-01-01

    采用梁格法分析小箱梁桥时,为了简便准确的模拟虚拟横梁刚度,根据小箱梁桥的横向构造提出一种分段式模拟虚拟横梁的方法,并以一跨30 m简支小箱梁桥为例,通过与板单元模型计算结果对比,验证了这种方法的有效性和准确性.

  10. DFBX boxes - electrical and cryogenic distribution boxes for the superconducting magnets in the LHC straight sections

    CERN Document Server

    Zbasnik, J P; Gourlay, S A; Green, M A; Hafalia, A Q; Kajiyama, Y; Knolls, M J; La Mantia, R F; Rasson, J E; Reavill, D; Turner, W C

    2003-01-01

    DFBX distribution boxes provide cryogenic and electrical services to superconducting quadrupoles and to a superconducting dipole at either end of four of the long straight sections in the LHC. The DFBX boxes also provide instrumentation and quench protection to the magnets. Current for the quadrupole and the dipole magnet is delivered through leads that combine HTS and gas cooled leads. Current for the 600 A and 120 A correction magnets is provided by pure gas-cooled leads. The bus bars from the leads to the magnets pass through low leak-rate lambda plugs between 1.8 K and 4.4 K. The heat leak into the 1.9 K region from the liquid helium tank is determined by the design of the lambda plugs. This paper describes the DFBX boxes and their function of delivering current and instrumentation signals to the magnets. (2 refs).

  11. 49 CFR 178.512 - Standards for steel or aluminum boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for steel or aluminum boxes. 178.512... aluminum boxes. (a) The following are identification codes for steel or aluminum boxes: (1) 4A for a steel box; and (2) 4B for an aluminum box. (b) Construction requirements for steel or aluminum boxes are...

  12. Research on High Speed Maglev Transrapid Girder-on-Bridge System%高速磁浮桥上梁轨道系统方案研究

    Institute of Scientific and Technical Information of China (English)

    成广伟

    2012-01-01

    针对高速磁浮交通新项目前期选线中主要采用的高架线路方案开展了相关工程化应用研究,并介绍了针对高速磁浮高架线路轨道系统方案的优化研究进展.研究立足于优化磁浮系统布置、提高安全疏散效率、节约用地、提高环境保护水平等原则,明确了桥上梁轨道系统方案及相关系统设备布置,提出了结合桥上梁形式的安全疏散逃生方案.通过动模型试验与有限元仿真分析方法,研究了磁浮列车通过桥上梁结构时的空气动力学性能,表明磁浮列车的高速通过空气动力学性能符合要求;结合上海磁浮示范线进行了桥上梁方案的在线模拟展示和降噪性能测试,结果表明,结合声屏障,可将磁浮列车高速气动噪声降低最高13 dB(A).研究结论在相关工程方案中得到了应用,可为类似高速交通系统工程提供参考.%The construction application study on the elevated structure proposed in the new high speed rnaglev transportation line and the advances on the high speed maglev transrapid girder-on-bridge system are introduced in this paper. New practical elevated guideway system is designed based on the principles of optimization of the maglev system arrangement, high escape efficiency, economic use of land and better environment protection, etc. One new guideway system type is provided together with the system arrangement, and one new escape system is provided which can be used in the girder on bridge maglev system. With model test and simulation analysis, the aerodynamic effect of this structure when maglev trains passing was examined, and the test results show that the aerodynamic effect when maglev vehicle passing by is acceptable. This girder on bridge system was presented on the Shanghai maglev demonstration line, and the noise reduction effect was tested. Test results show that noise can be reduced to 13 dB( A) with the barrier screen fixed. Conclusions introduced in this paper

  13. Adaptation of Black-Box Software Components

    Directory of Open Access Journals (Sweden)

    Rolf Andreas Rasenack

    2008-01-01

    Full Text Available The globalization of the software market leads to crucial problems for software companies. More competition between software companies arises and leads to the force on companies to develop ever newer software products in ever shortened time interval. Therefore the time to market for software systems is shortened and obviously the product life cycle is shortened too. Thus software companies shortened the time interval for research and development. Due to the fact of competition between software companies software products have to develop low-priced and this leads to a smaller return on investment. A big challenge for software companies is the use of an effective research and development process to have these problems under control. A way to control these problems can be the reuse of existing software components and adapt those software components to new functionality or accommodate mismatched interfaces. Complete redevelopment of software products is more expensive and time consuming than to develop software components. The approach introduced here presents novel technique together with a supportive environment that enables developers to cope with the adaptability of black-box software components. A supportive environment will be designed that checks the compatibility of black-box software components with the assistance of their specifications. Generated adapter software components can take over the part of adaptation and advance the functionality. Besides, a pool of software components can be used to compose an application to satisfy customer needs. Certainly this pool of software components consists of black-box software components and adapter software components which can be connected on demand.

  14. Experimental Study on Stability of Breakwaters with Penetrating Box Foundations

    Institute of Scientific and Technical Information of China (English)

    别社安; 李伟; 李增志; 任增金; 及春宁

    2003-01-01

    The breakwater with top-sealed, shallow and wide penetrating box foundations is a new type of structure, applicable to deep water and soft seabed. The relations of horizontal and vertical bearing capacities of the box foundation structure as well as the instability-induced failure modes to its dimensions and external loads are discussed through static model tests and wave tests. The mechanical properties of the stability of the box foundation are similar to those of embedded rigid foundations, i.e. the vertical stresses at the bottom of the box are distributed in a linear pattern under the action of vertical loads, and passive and active soil pressures are developed at the front and back sides of the box under the action of horizontal loads; there are two instability-induced failure modes of the foundation structure-horizontal slide along the box base and tilting due to insufficient local vertical bearing capacity of the soil beneath the box base. The stability of box foundations can be analyzed by use of the methods applied to analysis of the embedded rigid foundations. To increase the width of the box is the most effective way to improve the stability of box foundations.

  15. Test procedure for boxed waste assay system

    International Nuclear Information System (INIS)

    This document, prepared by Los Alamos National Laboratory's NMT-4 group, details the test methodology and requirements for Acceptance/Qualification testing of a Boxed Waste Assay System (BWAS) designed and constructed by Pajarito Scientific Corporation. Testing of the BWAS at the Plutonium Facility (TA55) at Los Alamos National Laboratory will be performed to ascertain system adherence to procurement specification requirements. The test program shall include demonstration of conveyor handling capabilities, gamma ray energy analysis, and imaging passive/active neutron accuracy and sensitivity. Integral to these functions is the system's embedded operating and data reduction software

  16. MULTIFRACTAL FORMALISMS:BOXED VERSUS CENTERED INTERVALS

    Institute of Scientific and Technical Information of China (English)

    Jacques Peyriére

    2003-01-01

    There are mainly two approaches to the multifractal analysis of measures.The first one,which is used in applications and in studying problems arising from dynamical systems,uses a hierarchy of boxes.The second one,which is more satisfactory from the viewpoint of geometric measure theory, uses more intrinsic concepts.This article is an account of a work by J.Barral,F.Ben Nasr,and J.Peyriére[3] which provides a bridge between these two theories.

  17. The Transformation of the "Black Box"

    OpenAIRE

    JIMENEZ DOMENECH, LUCIA

    2012-01-01

    The idea of this project is to convert an old office building downtown into an energy-neutral high-rise village. The assignment contained the office building located in the city centre of Groningen at Eendrachtskade 2, commonly called the "Black Box". It was built in 1976, and the actual technical condition is poor with inadequate insulation. When the building remains empty in 2014, the most obvious next thing to happen is the demolition. But, due to climate impact, the objective is to reuse ...

  18. LHC Crab Cavity Coupler Test Boxes

    CERN Document Server

    Mitchell, James; Burt, Graeme; Calaga, Rama; Macpherson, Alick; Montesinos, Eric; Silva, Subashini; Tutte, Adam; Xiao, Binping

    2016-01-01

    The LHC double quarter wave (DQW) crab cavities have two different types of Higher Order Mode (HOM) couplers in addition to a fundamental power coupler (FPC). The FPC requires conditioning, so to achieve this we have designed a radio-frequency (RF) quarter wave resonator to provide high transmission between two opposing FPCs. For the HOM couplers we must ensure that the stop-band filter is positioned at the cavity frequency and that peak transmission occurs at the same frequencies as the strongest HOMs. We have designed two test boxes which preserve the cavity spectral response in order to test the couplers.

  19. Smart Distribution Boxes, Complete Energy Management

    Energy Technology Data Exchange (ETDEWEB)

    Platise, Uros

    2010-09-15

    Present households demand side management implementations are turning conventional appliances into smart ones to support auto demand (AutoDR) response function. Present concept features a direct link between the power meters and appliances. In this paper new concept and example of implementation of a so-called Smart Distribution Box (SmartDB) is represented for complete energy and power management. SmartDBs, as an intermediate layer, are extending smart grid power meter functionality to support AutoDR with fast and guaranteed response times, distributed power sources, and besides provide full control over energy management and extra safety functions to the consumers.

  20. Determinants of Box Products of Paths

    CERN Document Server

    Pragel, Daniel

    2011-01-01

    Suppose that G is the graph obtained by taking the box product of a path of length n and a path of length m. Let M be the adjacency matrix of G. If n=m, H.M. Rara showed in 1996 that det(M)=0. We extend this result to allow n and m to be any positive integers, and show that, if gcd(n+1,m+1)>1, then det(M)=0; otherwise, if gcd(n+1,m+1)=1, then det(M)=(-1)^(nm/2).

  1. Choreographies with Secure Boxes and Compromised Principals

    DEFF Research Database (Denmark)

    Carbone, Marco; Guttman, Joshua

    2009-01-01

      We equip choreography-level session descriptions with a simple abstraction of a security infrastruc- ture. Message components may be enclosed within (possibly nested) ”boxes” annotated with the intended source and destination of those components. The boxes are to be implemented with cryp...... regular strands so that it could actually occur, in combination with any possible activity of compromised principals. It is delivery guaranteed (DG) realized if, in addition, every message transmitted to a regular participant is also delivered. We define a novel transition system on skeletons, in which...

  2. Box model for channels of human migration

    CERN Document Server

    Vitanov, Nikolay K

    2016-01-01

    We discuss a mathematical model of migration channel based on the truncated Waring distribution. The truncated Waring distribution is obtained for a more general model of motion of substance through a channel containing finite number of boxes. The model is applied then for case of migrants moving through a channel consisting of finite number of countries or cities. The number of migrants in the channel strongly depends on the number of migrants that enter the channel through the country of entrance. It is shown that if the final destination country is very popular then large percentage of migrants may concentrate there.

  3. An Architectural Alternative to the Big Box

    OpenAIRE

    Fowler, Kristen Faye

    2008-01-01

    Wal-Mart has plans to open a store in the town of Blacksburg, Virginia. The fact that there is already a Wal-Mart store, in the town of Christiansburg, just four miles away from the proposed location makes this idea ridiculous for some. A large group of Blacksburg residents are opposed to the idea of a Wal-Mart in their town. The usual complaints are about how it will affect small businesses and traffic. The core concept of the â big boxâ store is not the problem. The idea of being abl...

  4. Teaching Outside the Box: ARL Librarians' Integration of the "One- Box" into Student Instruction

    Science.gov (United States)

    Kulp, Christina; McCain, Cheryl; Scrivener, Laurie

    2014-01-01

    This article reports the results of a survey that targeted reference and instruction librarians who work at libraries that are members of the Asso- ciation of Research Libraries (ARL). Respondents were asked to indicate whether or not they teach students to use the one-box tool, and why or why not. Based on the responses of the 352 librarians who…

  5. Hairy Black Holes in a Box

    CERN Document Server

    Basu, Pallab; Subramanian, P N Bala

    2016-01-01

    We do a systematic study of the phases of gravity coupled to an electromagnetic field and charged scalar in flat space, with box boundary conditions. The scalar-less box has previously been investigated by Braden, Brown, Whiting and York (and others) before AdS/CFT and we elaborate and extend their results in a language more familiar from holography. The phase diagram of the system is analogous to that of AdS black holes, but we emphasize the differences and explain their origin. Once the scalar is added, we show that the system admits both boson stars as well as hairy black holes as solutions, providing yet another way to evade flat space no-hair theorems. Furthermore both these solutions can exist as stable phases in regions of the phase diagram. The final picture of the phases that emerges is strikingly similar to that found recently for holographic superconductors in global AdS, arXiv: 1602.07211. Our construction lays bare certain previously unnoticed subtleties associated to the definition quasi-local c...

  6. Roles of F-box Proteins in Plant Hormone Responses

    Institute of Scientific and Technical Information of China (English)

    Haichuan YU; Jiao WU; Nanfei XU; Ming PENG

    2007-01-01

    The F-box protein is an important component of the E3 ubiquitin ligase Skpl-Cullin-F-box protein complex. It binds specific substrates for ubiquitin-mediated proteolysis. The F-box proteins contain a signature F-box motif at their amino-terminus and some protein-protein interaction motifs at their carboxyterminus, such as Trp-Asp repeats or leucine rich repeats. Many F-box proteins have been identified to be involved in plant hormone response as receptors or important medial components. These breakthrough findings shed light on our current understanding of the structure and function of the various F-box proteins,their related plant hormone signaling pathways, and their roles in regulating plant development.

  7. Visual pigments of the box jellyfish species Chiropsella bronzie

    DEFF Research Database (Denmark)

    O*Connor, Megan; Garm, Anders Lydik; Marshall, Justin;

    2010-01-01

    Box jellyfish (Cubomedusae) possess a unique visual system comprising 24 eyes of four morphological types. Moreover, box jellyfish display several visually guided behaviours, including obstacle avoidance and light-shaft attractance. It is largely unknown what kind of visual information box...... jellyfish use for carrying out these behaviours. Brightness contrast is almost certainly involved, but it is also possible that box jellyfish extract colour information from their surroundings. The possible presence of colour vision in box jellyfish has previously been investigated using behavioural......, electrophysiological and immunohistochemical methods. However, the results from these studies are to some degree conflicting and inconclusive. Here, we present results from an investigation into the visual system of the box jellyfish Chiropsella bronzie, using microspectrophotometry and immunohistochemistry. Our...

  8. 斜拉桥主梁应变监测分析%Girder Strain Analysis of a Cable-stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    邵平

    2012-01-01

    The health monitoring system of the bridge maintenance management is an important means to ensure the safety operation. To grasp the working condition, strain analysis is necessary. With practical engineering of a bridge in Xinmi, appling finite-element analysis software of MIDAS/Civil to establish the space model, we analysis the stress of the girder in the construction stage and compare the academic value and the practical value. The conclusion will provide a reference to the same bridges.%基于健康监测系统的桥梁养护管理是保证其安全运营的重要手段.而对监测数据进行分析以把握结构的工作状态是一个必须环节.结合新密某桥梁的工程实践,运用有限元软件建立主梁有限元空间模型,模拟分析施工阶段主梁应力,并对应力理论值和实测值进行对比与分析.结论将为同类桥梁应力监测提供参考.

  9. Live-Load Testing Application Using a Wireless Sensor System and Finite-Element Model Analysis of an Integral Abutment Concrete Girder Bridge

    Directory of Open Access Journals (Sweden)

    Robert W. Fausett

    2014-01-01

    Full Text Available As part of an investigation on the performance of integral abutment bridges, a single-span, integral abutment, prestressed concrete girder bridge near Perry, Utah was instrumented for live-load testing. The live-load test included driving trucks at 2.24 m/s (5 mph along predetermined load paths and measuring the corresponding strain and deflection. The measured data was used to validate a finite-element model (FEM of the bridge. The model showed that the integral abutments were behaving as 94% of a fixed-fixed support. Live-load distribution factors were obtained using this validated model and compared to those calculated in accordance to recommended procedures provided in the AASHTO LRFD Bridge Design Specifications (2010. The results indicated that if the bridge was considered simply supported, the AASHTO LRFD Specification distribution factors were conservative (in comparison to the FEM results. These conservative distribution factors, along with the initial simply supported design assumption resulted in a very conservative bridge design. In addition, a parametric study was conducted by modifying various bridge properties of the validated bridge model, one at a time, in order to investigate the influence that individual changes in span length, deck thickness, edge distance, skew, and fixity had on live-load distribution. The results showed that the bridge properties with the largest influence on bridge live-load distribution were fixity, skew, and changes in edge distance.

  10. 某单梁桥式起重机主梁有限元分析%Finite Element Analysis of Overhead Crane Girder

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      以某起重量为3 t ,跨度为16.5 m的单梁电动葫芦桥式起重机主梁为例,运用有限元软件ANSYS采用自顶向下和自底向上相结合的方法建模,然后进行计算、分析,最后运用有限元计算结果校核主梁的强度、刚度,并提出了合理建议,为今后相近类型起重机主梁设计提供参考。%Taking an overhead crane with 16 .5 m span and 3 t lifting capacity as example ,combining the top-down method and down-top method ,the paper set up the the model of the crane girder by use of finite element software ANSYS .Then the intensity and toughness of the main beam was calculated and checked .Some reasonable suggestion was put forward for the design of overhead cranes in future .

  11. 某矮塔斜拉桥主梁受力分析研究%Analysis of Main Girder Stress of a Low Tower Cable -stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    郑报文; 张安林; 夏伟

    2014-01-01

    矮塔斜拉桥是介于连续梁桥和普通斜拉桥之间的新型桥梁,其受力以主梁为主,拉索为辅。本文通过有限元软件M IDAS建立全桥模型,对主梁最大双悬臂状态及成桥状态进行受力分析,并获得相关结论,可为同类桥型设计提供参考依据。%Low tower cable-stayed bridge is a new type of hybrid structure between continuous bridge and cable-stayed bridge based in the main girder and cable supplement of the force .Finite element software called Midas/Civil was used to build up calculation model of the bridge ,then focused on ana‐lyzing the structural behavior at the stages as follows :the maximum twin cantilever ,end of construc‐tion state .On the basis of it ,proposes the maximum internal force of construction process shall be the control basis ,and need further analysis of NO .0 block of similar bridge ,in the hope of providing ref‐erence to the similar bridge .

  12. Cash Flow Prediction Using a Grey-Box Model

    OpenAIRE

    Pang, Yang; Opong, Kwaku; Moutinho, Luia; Li, Yun

    2015-01-01

    This paper tackles the problem of financial forecasting by extending methods developed in automation, engineering and computing science. Current methods existing in the literature for firm-level cash flows are first analysed. Then a grey-box modelling method is developed to elevate the performance of cash-flow prediction. Linear panel data modelling is used as a benchmark model. Experiments with out-of-sample tests are used to validate the grey-box approach. Encouragingly, nonlinear grey-box ...

  13. Average of Distribution and Remarks on Box-Splines

    Institute of Scientific and Technical Information of China (English)

    LI Yue-sheng

    2001-01-01

    A class of generalized moving average operators is introduced, and the integral representations of an average function are provided. It has been shown that the average of Dirac δ-distribution is just the well known box-spline. Some remarks on box-splines, such as their smoothness and the corresponding partition of unity, are made. The factorization of average operators is derived. Then, the subdivision algorithm for efficient computing of box-splines and their linear combinations follows.

  14. Ion-wake field inside a glass box

    Science.gov (United States)

    Chen, Mudi; Dropmann, Michael; Zhang, Bo; Matthews, Lorin S.; Hyde, Truell W.

    2016-09-01

    The confinement provided by a glass box is proving ideal for the formation of vertically aligned structures and a convenient method for controlling the number of dust particles comprising these dust structures as well as their sizes and shapes. In this paper, the electronic confinement of the glass box is mapped, and the particle interactions between the particle pairs inside the glass box are measured. The ion-wake field is shown to exist within the glass box, and its vertical and horizontal extents are measured.

  15. Ion-wake Field inside a Glass Box

    CERN Document Server

    Chen, Mudi; Zhang, Bo; Matthews, Lorin S; Hyde, Truell W

    2016-01-01

    The confinement provided by a glass box is proving ideal for the formation of vertically aligned structures and a convenient method for controlling the number of dust particles comprising these dust structures, as well as their size and shape. In this paper, the electronic confinement of the glass box is mapped and the particle interactions between the particle pairs inside the glass box are measured. The ion-wake field is shown to exist within the glass box and its vertical and horizontal extent is measured.

  16. Counting Closed String States in a Box

    CERN Document Server

    Meana, M L; Peñalba, J P; Meana, Marco Laucelli; Peñalba, Jesús Puente

    1997-01-01

    The computation of the microcanonical density of states for a string gas in a finite volume needs a one by one count because of the discrete nature of the spectrum. We present a way to do it using geometrical arguments in phase space. We take advantage of this result in order to obtain the thermodynamical magnitudes of the system. We show that the results for an open universe exactly coincide with the infinite volume limit of the expression obtained for the gas in a box. For any finite volume the Hagedorn temperature is a maximum one, and the specific heat is always positive. We also present a definition of pressure compatible with R-duality seen as an exact symmetry, which allows us to make a study on the physical phase space of the system. Besides a maximum temperature the gas presents an asymptotic pressure.

  17. Design Research: Six Views in a Box

    DEFF Research Database (Denmark)

    2011-01-01

    This book is a report from a class on design research at the Danish Design School. Ten students had ten weeks to conduct design research based on approaches, methods and techniques from co-design focusing on the Alzheimer’s disease as experienced by people with Alzheimer’s, their relatives...... and close relations, and professional caretakers. Alzheimer's destroys brain cells, causing memory loss and problems with thinking and behavior severe enough to affect work, lifelong hobbies and social life. As Alzheimer’s is a fatal disease that affects many people, there is a strong interest in finding...... professional organizations in a user-driven approach to explore and learn what it means to identify and admit that a person has Alzheimer’s. Apart from making contributions to the common box, the students have written reports in which they reflect on their work both in relation to the design research process...

  18. 三维地震动作用下曲线连续梁桥减震控制研究%Seismic mitigation control for a curved continuous girder bridge with 3-D ground motion action

    Institute of Scientific and Technical Information of China (English)

    亓兴军; 申永刚

    2012-01-01

    In order to reduce seismic damage effect of a curved girder bridge with double supports, the seismic response mitigation control technique with liquid viscous dampers was presented. The spatial finite element model and dynamic simulation model of a curved continuous girder bridge were established, and viscous dampers were set at the kinetic bearings of piers in tangent and radial orientations. Seismic mitigation effectiveness of active control, semi-active control and passive control for the bridge was calculated and analyzed with three-dimensional (3-D) ground motion input. The results indicated that the curved girder bridge has distinct characteristic of seismic coupling between longitudinal and transversal orientations; three orientations of the ground motion must be input simultaneously and longitudinal and transversal dampers are set simultaneously when seismic mitigation responses are calculated; the viscous dampers can control internal forces of inside pier and outside pier to be close to each other; the three mitigation approaches can effectively reduce displacement of girder and internal force of fixed piers of the curved girder bridge; the differences of seismic mitigation effectiveness and seismic response time histories are smaller for the three mitigation approaches; active control and semi-active control have no obvious advantage, and the passive control with viscous dampers can be widely applied in actual seismic design of a curved girder bridge.%为了减少双支承曲线梁桥的地震破坏效应,提出了利用液体粘滞阻尼器进行曲线梁桥减震控制的方法,建立曲线连续梁桥的空间有限元模型和动力仿真模型,在桥梁墩台活动支座部位设置切向和径向液体粘滞减震装置,输入三维地震动计算分析了桥梁主动控制、半主动控制和被动控制三种减震方法的减震效果.结果表明,曲线梁桥的地震反应表现出显著的纵桥向与横桥向的耦合特性,在减震控制

  19. A Comparison of Energy Expenditure During "Wii Boxing" Versus Heavy Bag Boxing in Young Adults.

    Science.gov (United States)

    Perusek, Kristen; Sparks, Kenneth; Little, Kathleen; Motley, Mary; Patterson, Sheila; Wieand, Jennifer

    2014-02-01

    Traditional computer videogames are sedentary, whereas new computer videogames, such as the Nintendo(®) (Redmond, WA) "Wii™ Sports" games, allow users to physically interact while playing the sport. Energy expenditure (EE), heart rate (HR), and rating of perceived exertion (RPE) during heavy bag boxing versus the Nintendo "Wii Boxing" game were compared. Fifteen males and 14 females (mean age, 25.6 years; height, 171.3 cm; weight, 71.8 kg) randomly selected (by a coin toss) heavy bag boxing or "Wii Boxing" for their first test session and completed the other protocol at their second session at least 2 days later. Each session lasted for a total duration of 30 minutes and consisted of 10 3-minute exercise bouts with measurements of HR, RPE, and EE obtained from indirect calorimetry. A paired-samples t test was used to analyze the results. Significant differences were found for HR (bag, 156 beats per minute; Wii, 138 beats per minute; P=0.001) and RPE (bag, 13.8; Wii, 11.4; P=0.0001) but not for EE (bag, 8.0 kcal/minute; Wii, 7.1 kcal/minute; bag, 241 total kcal; Wii, 213 total kcal; P=0.078). The results suggest that computer active videogames, such as the Nintendo Wii, have the potential to provide similar EE as their traditional forms of exercise and may be a sufficient replacement for traditional target HR zone activities, especially in less fit individuals. Further research is needed to compare EE for different "Wii Sports" games with those for their traditional forms of exercise.

  20. Validating SimpleBox-Computed Steady-State Concentration Ratios

    NARCIS (Netherlands)

    Bakker J; Brandes LJ; Hollander HA den; Meent D van de; Struijs J; SEC; IMP; LER

    2004-01-01

    The validity of the multi-media model SimpleBox version 2.0 with respect to its specific use in the procedure of testing the coherence of independently derived environmental quality objectives is evaluated. The SimpleBox procedure for testing the coherence of environmental quality objectives has bee

  1. Olympic Sports(ⅩⅣ):Boxing

    Institute of Scientific and Technical Information of China (English)

    姜全红

    2004-01-01

    Boxing has a long sporting history.The earliest evidence of boxing is found in Egypt around 3000 B.C.The sport was introduced to the Olympic Games by the Greeks in the late 7th century B.C.. Greek boxers used thongs of soft leather to bind their hands

  2. Faster Black-Box Algorithms Through Higher Arity Operators

    DEFF Research Database (Denmark)

    Doerr, Benjamin; Johannsen, Daniel; Kötzing, Timo;

    2011-01-01

    We extend the work of Lehre and Witt (GECCO 2010) on the unbiased black-box model by considering higher arity variation operators. In particular, we show that already for binary operators the black-box complexity of LeadingOnes drops from (n2) for unary operators to O(n log n). For OneMax, the (n...

  3. Effect of auricular acupuncture on oxygen consumption of boxing athletes

    Institute of Scientific and Technical Information of China (English)

    LIN Zen-Pin; WANG Chung-Yuan; JANO Tsong-Rong; MA Tso-chiang; CHIA Fan; LIN Jaung-Geng; HSU Jen-Jeng; HO Tsung-Jung

    2009-01-01

    @@ Boxing is an official sport at the 2008 Beijing Olympic Games and the fast development of world-class high strength training and sport science has made a significant impact on scientific training. Boxing needs high cardio-respiratory function, speed, muscle strength, and anaerobic and intensive physical demands including weight control covering the grading of athlete's.

  4. 49 CFR 215.107 - Defective plain bearing box: General.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.107 Defective plain bearing box: General. A railroad may not place or continue in service a car, if the car has— (a) A plain bearing box that does not contain visible free oil; (b) A...

  5. Empty Tissue Boxes: Considering Poverty in Diversity Discourse

    Science.gov (United States)

    Cuthrell, Kristen; Ledford, Carolyn; Stapleton, Joy

    2007-01-01

    A preservice teacher doing her internship overhears some of her students asking a classmate why he regularly takes home empty tissue boxes. The boy replies that he builds cities and bridges with his empty boxes. His classmates then ask why he does not just build a city with Legos or building blocks. The preservice teacher listens intently as the…

  6. Natural Interaction Based Online Military Boxing Learning System

    Science.gov (United States)

    Yang, Chenglei; Wang, Lu; Sun, Bing; Yin, Xu; Wang, Xiaoting; Liu, Li; Lu, Lin

    2013-01-01

    Military boxing, a kind of Chinese martial arts, is widespread and health beneficial. In this paper, the authors introduce a military boxing learning system realized by 3D motion capture, Web3D and 3D interactive technologies. The interactions with the system are natural and intuitive. Users can observe and learn the details of each action of the…

  7. A System for Cooling inside a Glove Box

    Science.gov (United States)

    Sanz, Martial

    2010-01-01

    An easy, efficient, reliable, and low-cost method of constructing a cooling system using a simple circulating pump is described. The system is employed in conjunction with an inert atmosphere glove box to achieve the synthesis of air- and moisture-sensitive compounds inside the glove box at controlled, low temperatures without contaminating the…

  8. Dream Box Learning. What Works Clearinghouse Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2013

    2013-01-01

    "DreamBox Learning" is a supplemental online mathematics program that provides adaptive instruction for students in grades K-5 and focuses on number and operations, place value, and number sense. The What Works Clearinghouse (WWC) identified one study of "DreamBox Learning" that both falls within the scope of the Elementary…

  9. Decontamination and dismantling of large plutonium-contamined glove boxes

    International Nuclear Information System (INIS)

    This report describes the work performed in the frame of two C.E.C. - Contracts FI1D-002400-B Decommissioning of very large glove boxes and FI1D-0058 Decommissioning of a complex glove box structure to be dismounted partially on place. Detailed information is given about each glove box. The selection of the solution Transportation of the glove boxes to a specialized dismantling plant is justified. The necessary contacts inside the BELGONUCLEAIRE MOX plant and between the latter and other organizations are explained. The problems of manipulating large gloves are listed and the retained solution of building a so called Stiffening frame around each glove box is described. Furthermore information is given concerning required operators time for cleaning, manipulating, packing and dismantling together with received doses and quantities of waste produced. Concerning the glove box unit partially to be dismounted on place, detailed information is given about the way the glove boxes have been treated prior to this partial dismantling on place and about the way this partial dismantling has been performed. From these results one can conclude that such a delicate task can be performed without major difficulties. Finally information is given of the decontamination test of a highly Pu contaminated glove box with freon with rather poor results and of the preliminary CO2 blasting tests on non active samples

  10. Getting started with Oracle VM VirtualBox

    CERN Document Server

    Dash, Pradyumna

    2013-01-01

    A step-by-step guide that will show you how to install, configure, and manage VirtualBox.This book is for system administrators, technical architects, and virtualization enthusiasts who want to learn how to set up a virtual machine. Knowledge of the Linux environment is expected. Prior experience with VirtualBox or knowledge of virtualization is not required.

  11. Effect of inlet box on performance of axial flow fans

    Institute of Scientific and Technical Information of China (English)

    Jingyin LI; Hua TIAN; Xiaofang YUAN

    2008-01-01

    Numerical investigations on 3D flow fields in an axial flow fan with and without an inlet box have been extensively conducted, focusing on the variation of fan performance caused by the internal flow fields and the velocity evenness at the exit of the inlet box. It is interest-ing to find that although the inlet box is well designed in accordance with basic design principles, there is a flow separation region in it. Furthermore, this flow separation and the resulting uneven velocity distribution at the exit lead to some decrease in the efficiency and an increase in the total pressure rise of the fan. This research shows that the inlet box needs further improvement and such a check on the flow fields is of value for the design of inlet boxes.

  12. Aspect ratio dependence in magnetorotational instability shearing box simulations

    CERN Document Server

    Bodo, G; Cattaneo, F; Rossi, P; Ferrari, A

    2008-01-01

    Aims: We study the changes in the properties of turbulence driven by the magnetorotational instability in a shearing box, as the computational domain size in the radial direction is varied relative to the height Methods: We perform 3D simulations in the shearing box approximation, with a net magnetic flux, and we consider computational domains with different aspect ratios Results: We find that in boxes of aspect ratio unity the transport of angular momentum is strongly intermittent and dominated by channel solutions in agreement with previous work. In contrast, in boxes with larger aspect ratio, the channel solutions and the associated intermittent behavior disappear. Conclusions: There is strong evidence that, as the aspect ratio becomes larger, the characteristics of the solution become aspect ratio independent. We conclude that shearing box calculations with aspect ratio unity or near unity may introduce spurious effects.

  13. Getting started with Citrix VDI-in-a-Box

    CERN Document Server

    Brown, Stuart Arthur

    2013-01-01

    A practical and fast-paced guide that gives you all the information you need to simplify and streamline virtual desktops so you get a production-quality solution while instantly lowering your costs and improving security.Getting Started with Citrix VDI-in-a-Box is great for IT professionals who are new to VDI-in-a-Box and who are looking for a good grounding in the product. You may be planning to research VDI-in-a-Box in more detail, or you may be tasked with researching how VDI-in-a-Box could improve the productivity of your organization. No prior knowledge of VDI-in-a-Box is required, just a

  14. Grey-box modelling of pharmacokinetic/pharmacodynamic systems

    DEFF Research Database (Denmark)

    Tornøe, Christoffer Wenzel; Jacobsen, Judith L; Pedersen, Oluf;

    2004-01-01

    Grey-box pharmacokinetic/pharmacodynamic (PK/PD) modelling is presented as a promising way of modelling PK/PD systems. The concept behind grey-box modelling is based on combining physiological knowledge along with information from data in the estimation of model parameters. Grey-box modelling...... consists of using stochastic differential equations (SDEs) where the stochastic term in the differential equations represents unknown or incorrectly modelled dynamics of the system. The methodology behind the grey-box PK/PD modelling framework for systematic model improvement is illustrated using simulated...... data and furthermore applied to Bergman's minimal model of glucose kinetics using clinical data from an intravenous glucose tolerance test (IVGTT). The grey-box estimates of the stochastic system noise parameters indicate that the glucose minimal model is too simple and should preferably be revised...

  15. Local contact analysis and improvement measures of continuous steel girder incremental launching%连续钢梁顶推过程局部接触分析及改善措施

    Institute of Scientific and Technical Information of China (English)

    田仲初; 陈耀章; 赵利平; 程永舟

    2012-01-01

    In order to study local force characters of the large span continuous steel tank girder incremental launching, taking a 6× 90 m vertical curve of variable curvature continuous steel girder as the research object, the whole simulation model was set up by the software MIDAS 2006 with "beam remain still and only lower supports reverse move" method. Then based on the analysis re- suits of the whole girder, a "beam-shell-solid-contact" hybrid finite element model was set up with ANSYS APDL and by means of Excel and CAD assistance under the unfavorable condition. The theoretical and measured values show that the steel girder local force meets the requirements at the sliding part, but the angular displacement is too large. According to the actual engineering situation, two effective improvements are suggested to solve a series of problems which are caused by the exaggerated angular displacement, the one is that the steps nose beam is adopted in the first measure, the second measure adopt a combination of steps nose beam, weights and in- creasing the stiffness of part of the steel beam. 6 tabs, 9 figs, 13 refs.%为了研究大跨度连续钢梁顶推的局部受力特性,以6×90m变曲率竖曲线连续钢梁顶推为研究对象,根据梁不动、下部支撑移动的"倒退"方法,采用商用程序MIDAS 2006建立顶推整体有限元模型,并对其进行仿真分析。在此基础上,根据顶推整体仿真计算结果,选取滑道处钢梁最不利工况,借助EXCEL和CAD等辅助工具,运用ANSYS的APDL语言快速建立"梁-壳-实-接触"混合有限元模型。理论和实测值均表明:最不利工况下滑道处钢梁局部受力满足要求,但转角位移过大。结合工程实际情况,提出了2种有效改善措施:第一种采用台阶导梁;第二种采用台阶导梁、压重和增大部分钢梁截面刚度的组合方式。

  16. IEA Common Exercise 4: ARX, ARMAX and grey-box models for thermal performance characterization of the test box

    DEFF Research Database (Denmark)

    Bacher, Peder; Andersen, Philip Hvidthøft Delff

    In this report results of applying time series models for assessing the thermal performance of the IEA Annex 58 test box based on data given in the Common Exercise 4 (CE4), which was measured in Almeria, Spain. Both ARX, ARMAX and grey-box models are applied. Finally, the same models are fitted...

  17. Stationary seismic analysis of multi-span simply supported girder bridge%多跨简支梁桥平稳地震响应分析

    Institute of Scientific and Technical Information of China (English)

    马青青; 张鸿儒

    2013-01-01

    应用单位脉冲函数,建立了简支梁桥的纵向振动频响函数方程,基于传递函数,提出了用于求解多跨简支梁桥纵向位移和轴力的动态频响函数的计算方法.以六跨简支梁桥为算例,求解了跨中最大位移和轴力,并给出了脉冲荷载作用下相应的傅里叶振幅谱.结果表明,中间各跨跨中位移较大,两侧跨中轴力较大,响应谱的变化规律与位移和轴力的变化一致.%Based on the unit impulse function principle, the frequency response function equation of longitudinal vibration for simply supported beam bridge is established. According to the transfer matrix principle, the calculation method of the dynamic frequency response function for the vertical displacement and axial force of multi-span simply supported beam bridge is proposed. Taking six cross-simply supported girder bridge as an example, the maximum displacement and axial force are solved, and the corresponding Fourier amplitude spectrum under pulse loads is provided. The calculation results show that the mid-pan displacement in the middle of the bridge is bigger than that in the side of the bridge, but the axial force shows an inverse tendency. The changes of the amplitude spectrums are consistent with the displacement and axial force respectively.

  18. U-girder coupling vibration and comfort evaluation of new vehicle-bridge%新型U型梁车桥耦合及舒适性评定

    Institute of Scientific and Technical Information of China (English)

    王彬力; 白光亮

    2011-01-01

    This study aim at exploring the impact on the passenger comfort of dynamic response of U - girder in vehicle - bridge system for urban rail transit. In order to study the impact, a rail vehicle dynamics model with 31 DOFs (degrees of freedom) was established by employing linear rail model. A standard span of 30 m single line U - shaped structure, which is in the elevated section of Chongqing City Metro line Project in the west of Liang hill, was taken as the study object. The analysis of coupling vibration in vehicle - bridge system was calculated by using a self - compiled program and compared with the field test results to show the correctness of the established dynamic model and the self - compiled program. According to ISO2631. UIC513 and GB5595 -85 evaluation standard, the train ride comfort was evaluated. The results show the train ride comfort is good.%为探讨城市轨道交通U型梁车桥系统车桥耦合振动对旅客舒适性的影响,采用线性化轮轨模型建立了31个自由度的车辆动力学模型.以重庆市轨道交通一号线工程中梁山以西高架区间所采用标准跨径为30m的单线小U结构为对象,采用自编程序和通用对机车车辆过桥时的车桥耦合振动进行了分析,参照IS02631.UIC513和GB5595-85评价标准,对列车乘坐舒适性进行了评定,结果表明,列车具有良好的乘坐舒适性.

  19. Damage Identification of Box Beam Based on Curvature Theory Method%基于曲率模态的箱梁损伤识别方法研究

    Institute of Scientific and Technical Information of China (English)

    张旭; 葛继平; 李胡生; 严平

    2012-01-01

    With the rapid development of the high-speed railway, the damage identification study of high-speed railway bridges has become a hot research topic. In this paper, the feasibility study is made on damage identification of the finite element model of the reinforced concrete box girder using solid elements by curvature model theory. An analysis is made of the variation of damage factors with the changes in damage locations, damage degrees and the positions of measuring points. The results show that structure damage can be identified more accurately and comprehensively with the application of curvature model theory with solid elements. It provides a reference for the detection of high-speed railway bridges in the future.%随着我国高速铁路的快速发展,针对高速铁路中桥梁的损伤识别研究已成为热门领域。通过曲率模态理论对实体单元建立的混凝土箱梁有限元模型进行损伤识别可行性研究,分析不同损伤位置、损伤程度和测点位置条件下损伤指标的变化。结果表明,结合曲率模态理论方法和实体单元建模方法可以更加全面准确地对损伤结构进行识别,为今后高速铁路桥梁检测提供参考。

  20. Technology integration box beam failure study

    Science.gov (United States)

    Shuart, M. J.; Ambur, Damodar R.; Davis, D. D., Jr.; Davis, R. C.; Farley, G. L.; Lotts, C. G.; Wang, J. T.

    1993-01-01

    Composite structures have the potential to be cost-effective, structurally efficient primary aircraft structures. The Advanced Composites Technology (ACT) Program has the goal to develop the technology to exploit this potential for heavily loaded aircraft structures. As part of the ACT Program, Lockheed Aeronautical Systems Company completed the design and fabrication of the Technology Integration Box Beam (TIBB). The TIBB is an advanced composite prototype structure for the center wing section of the C-130 aircraft. Lockheed subjected the TIBB to downbending, upbending, torsion and combined upbending and torsion load conditions to verify the design. The TIBB failed at 83 percent of design ultimate load for the combined upbending and torsion load condition. The objective of this paper is to describe the mechanisms that led to the failure of the TIBB. The results of a comprehensive analytical and experimental study are presented. Analytical results include strain and deflection results from both a global analysis of the TIBB and a local analysis of the failure region. These analytical results are validated by experimental results from the TIBB tests. The analytical and experimental results from the TIBB tests are used to determine a sequence of events that resulted in failure of the TIBB. A potential cause of failure is high stresses in a stiffener runout region. Analytical and experimental results are also presented for a stiffener runout specimen that was used to simulate the TIBB failure mechanisms.

  1. On (2,3)-agreeable Box Societies

    CERN Document Server

    Abrahams, Michael; Zell, Thierry

    2009-01-01

    The notion of $(k,m)$-agreeable society was introduced by Deborah Berg et al.: a family of convex subsets of $\\R^d$ is called $(k,m)$-agreeable if any subfamily of size $m$ contains at least one non-empty $k$-fold intersection. In that paper, the $(k,m)$-agreeability of a convex family was shown to imply the existence of a subfamily of size $\\beta n$ with non-empty intersection, where $n$ is the size of the original family and $\\beta\\in[0,1]$ is an explicit constant depending only on $k,m$ and $d$. The quantity $\\beta(k,m,d)$ is called the minimal \\emph{agreement proportion} for a $(k,m)$-agreeable family in $\\R^d$. If we only assume that the sets are convex, simple examples show that $\\beta=0$ for $(k,m)$-agreeable families in $\\R^d$ where $kboxes, i.e. cuboids with sides parallel to the coordinates hyperplanes. We derive explicit formulas for the first non-trivial case: the case...

  2. Opening up a Colourful Cosmic Jewel Box

    Science.gov (United States)

    2009-10-01

    The combination of images taken by three exceptional telescopes, the ESO Very Large Telescope on Cerro Paranal , the MPG/ESO 2.2-metre telescope at ESO's La Silla observatory and the NASA/ESA Hubble Space Telescope, has allowed the stunning Jewel Box star cluster to be seen in a whole new light. Star clusters are among the most visually alluring and astrophysically fascinating objects in the sky. One of the most spectacular nestles deep in the southern skies near the Southern Cross in the constellation of Crux. The Kappa Crucis Cluster, also known as NGC 4755 or simply the "Jewel Box" is just bright enough to be seen with the unaided eye. It was given its nickname by the English astronomer John Herschel in the 1830s because the striking colour contrasts of its pale blue and orange stars seen through a telescope reminded Herschel of a piece of exotic jewellery. Open clusters [1] such as NGC 4755 typically contain anything from a few to thousands of stars that are loosely bound together by gravity. Because the stars all formed together from the same cloud of gas and dust their ages and chemical makeup are similar, which makes them ideal laboratories for studying how stars evolve. The position of the cluster amongst the rich star fields and dust clouds of the southern Milky Way is shown in the very wide field view generated from the Digitized Sky Survey 2 data. This image also includes one of the stars of the Southern Cross as well as part of the huge dark cloud of the Coal Sack [2]. A new image taken with the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile shows the cluster and its rich surroundings in all their multicoloured glory. The large field of view of the WFI shows a vast number of stars. Many are located behind the dusty clouds of the Milky Way and therefore appear red [3]. The FORS1 instrument on the ESO Very Large Telescope (VLT) allows a much closer look at the cluster itself. The telescope's huge mirror

  3. SUPERSTITIOUS BEHAVIOR AMONG JUDO, TAEKWONDO AND BOXING PLAYERS

    Directory of Open Access Journals (Sweden)

    Gaurav Dureja

    2016-04-01

    Full Text Available Purpose: The present study was designed to measure superstitious behavior among Judo, Taekwondo and Boxing players. Material: Thirty (N=30 male inter-college level players with the age group of 19-25 years were selected through purposive sampling technique to act as subjects from affiliated colleges of Panjab University, Chandigarh. They were further divided into three groups: Group-A [Judo (n=10], Group-B [Taekwondo (n=10] and Group-C [Boxing (n=10]. One Way Analysis of Variance (ANOVA was applied to find out the differences among judo, taekwondo and boxing players. Where ‘F’ values found significant, Least Significant Differences (LSD Post-hoc test was applied to find out the direction and degree of difference. Results: The level of significance was set at 0.05. The result revealed significant differences among judo, taekwondo and boxing players on the sub parameters: clothing and appearance, preparation, team ritual and coach. However, no significant differences have been observed on the sub-parameters fetish, game/competition, prayer and parameter superstitious (Total. Conclusions: The obtained results showed significant differences on the sub-parameter Coach among Judo, Taekwondo and Boxing players. While calculating the mean values of entire groups, it has been observed that Boxing players demonstrate significantly better on the sub-parameter Coach. Therefore, it can be ascertained that Boxing players are more confident that coach bring a lucky charm to our game.

  4. Probability boxes on totally preordered spaces for multivariate modelling

    CERN Document Server

    Troffaes, Matthias C M; 10.1016/j.ijar.2011.02.001

    2011-01-01

    A pair of lower and upper cumulative distribution functions, also called probability box or p-box, is among the most popular models used in imprecise probability theory. They arise naturally in expert elicitation, for instance in cases where bounds are specified on the quantiles of a random variable, or when quantiles are specified only at a finite number of points. Many practical and formal results concerning p-boxes already exist in the literature. In this paper, we provide new efficient tools to construct multivariate p-boxes and develop algorithms to draw inferences from them. For this purpose, we formalise and extend the theory of p-boxes using Walley's behavioural theory of imprecise probabilities, and heavily rely on its notion of natural extension and existing results about independence modeling. In particular, we allow p-boxes to be defined on arbitrary totally preordered spaces, hence thereby also admitting multivariate p-boxes via probability bounds over any collection of nested sets. We focus on t...

  5. Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

    Energy Technology Data Exchange (ETDEWEB)

    Beach, R.; Burdick, A.

    2014-03-01

    This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Box Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

  6. Reliability Based Optimum Design of a Gear Box

    OpenAIRE

    D.MADHUSEKHAR; DR.K. MADHAVA REDDY

    2014-01-01

    The gear box represents an important mechanical sub system. In machine tools, the propose of a gear box is to provide a series of useful output speeds so that the machining operation can be carried out at its most optimum operating conditions high spindle speeds with low feed rate for roughing operations. An important aspect in the design of machine tool transmission is to keep the cost and volume of the gear box to a minimum. The probabilistic approach to design has been considered to be mor...

  7. Security of the AES with a Secret S-Box

    DEFF Research Database (Denmark)

    Tiessen, Tyge; Knudsen, Lars Ramkilde; Kölbl, Stefan;

    2015-01-01

    How does the security of the AES change when the S-box is replaced by a secret S-box, about which the adversary has no knowledge? Would it be safe to reduce the number of encryption rounds? In this paper, we demonstrate attacks based on integral cryptanalysis which allow to recover both the secret...... key and the secret S-box for respectively four, five, and six rounds of the AES. Despite the significantly larger amount of secret information which an adversary needs to recover, the attacks are very efficient with time/data complexities of 217/216, 238/240 and 290/264, respectively. Another...

  8. Design of (70+125+70) m Continuous Girder Bridge by Swing Method Crossing above Existing Railways%(70+125+70)m跨铁路转体连续梁桥设计

    Institute of Scientific and Technical Information of China (English)

    刘润舟

    2013-01-01

    Crossing above both the Nanchang-Jiujiang Intercity Railway and Beijing-Kowloon Railway, the main bridge of Gong’an Bridge is a continuous prestressed concrete girder bridge with the span arrangement of (70+125+70)meters. This thesis introduced how to select the bridge site and bridge type, how to design the bridge structure, how to select the calculation parameters, and how to erect the girder by swing method. Meanwhile, by using finite element software named Dr. Bridge, the bridge structure was calculated and analyzed longitudinally and transversely, and the results show that all the structural strengths, stresses, displacements, etc. can accord with the relevant provisions of the design codes.%共安大桥主桥上跨昌九城际、京九铁路,采用(70+125+70) m预应力混凝土连续梁,对桥位和桥型确定、桥梁结构设计和计算参数选取,以及转体施工方案进行介绍。采用有限元软件桥梁博士对桥梁结构进行纵向计算分析,结果表明结构强度、应力、位移等均满足设计规范的有关规定。

  9. 基于 ANSYS 软件对钢板梁桥的结构优化分析%Analysis on structure optimization of steel plate girder bridge based on ANSYS software

    Institute of Scientific and Technical Information of China (English)

    刘健

    2016-01-01

    以坦桑尼亚铁路桥为例,采用ANSYS有限元软件,从自重载荷、横向风载、交变载荷方面,对钢板梁桥的主梁进行了仿真分析,结合桥梁在三种载荷作用下的应变、应力情况,制定了针对性的加固措施,有利于桥梁结构的优化处理。%Taking the Tanzania railway bridge as an example,this paper used ANSYS finite element software,from the gravity load,transverse wind load,alternating load aspects,made simulation analysis on the main girder of steel plate girder bridge,combining with the strain,stress sit-uation of bridge under three kinds loads,formulated targeted reinforcement measures,beneficial to the optimization treatment of bridge structure.

  10. The AirQuality SenseBox

    Science.gov (United States)

    Demuth, Dustin; Nuest, Daniel; Bröring, Arne; Pebesma, Edzer

    2013-04-01

    In the past year, a group of open hardware enthusiasts and citizen scientists had large success in the crowd-funding of an open hardware-based sensor platform for air quality monitoring, called the Air Quality Egg. Via the kickstarter platform, the group was able to collect triple the amount of money than needed to fulfill their goals. Data generated by the Air Quality Egg is pushed to the data logging platform cosm.com, which makes the devices a part of the Internet of Things. The project aims at increasing the participation of citizens in the collection of data, the development of sensors, the operation of sensor stations, and, as data on cosm is publicly available, the sharing, visualization and analysis of data. Air Quality Eggs can measure NO2 and CO concentrations, as well as relative humidity and temperature. The chosen sensors are low-cost and have limited precision and accurracy. The Air Quality Egg consists of a stationary outdoor and a stationary indoor unit. Each outdoor unit will wirelessly transmit air quality measurements to the indoor unit, which forwards the data to cosm. Most recent versions of the Air Quality Egg allow a rough calibration of the gas sensors and on-the-fly conversion from raw sensor readings (impedance) to meaningful air quality data expressed in units of parts per billion. Data generated by these low-cost platforms are not intended to replace well-calibrated official monitoring stations, but rather augment the density of the total monitoring network with citizen sensors. To improve the usability of the Air Quality Egg, we present a new and more advanced concept, called the AirQuality SenseBox. We made the outdoor platform more autonomous and location-aware by adding solarpanels and rechargeable batteries as a power source. The AirQuality SenseBox knows its own position from a GPS device attached to the platform. As a mobile sensor platform, it can for instance be attached to vehicles. A low-cost and low-power wireless chipset

  11. GREEN SUPERCOMPUTING IN A DESKTOP BOX

    Energy Technology Data Exchange (ETDEWEB)

    HSU, CHUNG-HSING [Los Alamos National Laboratory; FENG, WU-CHUN [NON LANL; CHING, AVERY [NON LANL

    2007-01-17

    The computer workstation, introduced by Sun Microsystems in 1982, was the tool of choice for scientists and engineers as an interactive computing environment for the development of scientific codes. However, by the mid-1990s, the performance of workstations began to lag behind high-end commodity PCs. This, coupled with the disappearance of BSD-based operating systems in workstations and the emergence of Linux as an open-source operating system for PCs, arguably led to the demise of the workstation as we knew it. Around the same time, computational scientists started to leverage PCs running Linux to create a commodity-based (Beowulf) cluster that provided dedicated computer cycles, i.e., supercomputing for the rest of us, as a cost-effective alternative to large supercomputers, i.e., supercomputing for the few. However, as the cluster movement has matured, with respect to cluster hardware and open-source software, these clusters have become much more like their large-scale supercomputing brethren - a shared (and power-hungry) datacenter resource that must reside in a machine-cooled room in order to operate properly. Consequently, the above observations, when coupled with the ever-increasing performance gap between the PC and cluster supercomputer, provide the motivation for a 'green' desktop supercomputer - a turnkey solution that provides an interactive and parallel computing environment with the approximate form factor of a Sun SPARCstation 1 'pizza box' workstation. In this paper, they present the hardware and software architecture of such a solution as well as its prowess as a developmental platform for parallel codes. In short, imagine a 12-node personal desktop supercomputer that achieves 14 Gflops on Linpack but sips only 185 watts of power at load, resulting in a performance-power ratio that is over 300% better than their reference SMP platform.

  12. 侵蚀性环境下桥梁CFRP/BFRP加固后的长期性能试验%Experiment for Long-term Performance of Bridge Girders Strengthened with CFRP/BFRP Sheets and Subjected to Erosion Environment

    Institute of Scientific and Technical Information of China (English)

    孙晓燕; 董伟伟; 王海龙; 何世钦

    2013-01-01

    为了研究侵蚀性环境下服役桥梁构件采用纤维材料加固后的长期性能,对11根具有初始锈蚀损伤的钢筋混凝土梁式构件采用碳纤维布(CFRP)和玄武岩纤维布(BFRP)加固后继续退化的承载力及服役性能进行试验.通过对加固后构件进行电化学加速锈蚀和盐液浸润干湿循环模拟不同程度的后续服役性能退化,研究侵蚀性环境对CFRP和BFRP加固构件在不同后续服役期的承载力、刚度等性能影响规律,同时对比了2种加固材料的耐久性能和成本效益.结果表明:侵蚀性环境下加固后的桥梁构件承载能力评估需综合考虑钢筋锈蚀引起的承载力降低和侵蚀性环境对纤维利用效率的降低;CFRP对刚度提高显著,而BFRP加固具有更好的延性;考虑加固后长期服役性能,CFRP加固后具有较好的耐久性,而BFRP具有较高的成本效益.%To investigate the long-term performance of existing bridge girders strengthened with fiber reinforced plastics (FRP) sheets and subjected to erosion environment, the bearing capacity and service performance experiments of 11 reinforced concrete (RC) girders, which were strengthened with carbon fiber reinforced plastics (CFRP) and basalt fiber reinforced polymer (BFRP) sheets after initial corrosion damage, were conducted. Different subsequent performance degradations for strengthened girders were simulated through electrochemical accelerated corrosion together with wet/dry cycles of salt solution. The effect of environmental erosion on capacity, stiffness and other parameters of CFRP/BFRP strengthened girders in different follow-up service time was tested. The durabilities and costs of the two strengthening materials were also investigated. The results show that the capacity evaluation of bridge girders strengthened with FRP sheets should consider the effect of rebar corrosion together with the environmental reduction of FRP strengthening; the CFRP strengthening improves

  13. Necropsy Report - Eaastern Pipistrelle Box Culvert I-55 Grenada, MS

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Necropsy report of a eastern pipisttrelle tricolored bat found dead in a box culvert along I55, near Grenada, MS provides no indication of whitenose syndrome.

  14. Experts’ Misinterpretation of Box Plots – a Dual Processing Approach

    Directory of Open Access Journals (Sweden)

    Stephanie Lem

    2014-11-01

    Full Text Available Recent studies have shown that students often misinterpret the area of the box in box plots as representing the frequency or proportion of observations in that interval, while it actually represents density. This misinterpretation has been shown to be based on the saliency of this area and can be explained by heuristic reasoning as defined by dual process theories. In this study we tested whether expert users of box plots also display this misinterpretation and show signs of the same heuristic reasoning as found in students. Using a reaction time test, we found signs of heuristic reasoning in experts, both with respect to accuracy and reaction times. If even experts have difficulty interpreting box plots, one can question whether these are an appropriate form of representation to use when reporting data and deserve the prominent place they currently have in the statistics curriculum.

  15. Matter-wave dark solitons in box-like traps

    CERN Document Server

    Sciacca, M; Parker, N G

    2016-01-01

    Motivated by the experimental development of quasi-homogeneous Bose-Einstein condensates confined in box-like traps, we study numerically the dynamics of dark solitons in such traps at zero temperature. We consider the cases where the side walls of the box potential rise either as a power-law or a Gaussian. While the soliton propagates through the homogeneous interior of the box without dissipation, it typically dissipates energy during a reflection from a wall through the emission of sound waves, causing a slight increase in the soliton's speed. We characterise this energy loss as a function of the wall parameters. Moreover, over multiple oscillations and reflections in the box-like trap, the energy loss and speed increase of the soliton can be significant, although the decay eventually becomes stabilized when the soliton equilibrates with the ambient sound field.

  16. BoxLib with Tiling: An AMR Software Framework

    CERN Document Server

    Zhang, Weiqun; Day, Marcus; Nguyen, Tan; Shalf, John; Unat, Didem

    2016-01-01

    In this paper we introduce a block-structured adaptive mesh refinement (AMR) software framework that incorporates tiling, a well-known loop transformation. Because the multiscale, multiphysics codes built in BoxLib are designed to solve complex systems at high resolution, performance on current and next generation architectures is essential. With the expectation of many more cores per node on next generation architectures, the ability to effectively utilize threads within a node is essential, and the current model for parallelization will not be sufficient. We describe a new version of BoxLib in which the tiling constructs are embedded so that BoxLib-based applications can easily realize expected performance gains without extra effort on the part of the application developer. We also discuss a path forward to enable future versions of BoxLib to take advantage of NUMA-aware optimizations using the TiDA portable library.

  17. Fusion welded fabrication of unshielded steel glove boxes

    International Nuclear Information System (INIS)

    This part of the Specification together with Part 1 covers the manufacture, testing, inspection and delivery of stainless steel glove boxes including such fittings internally and externally as shown on relevant drawings. (author)

  18. Fusion welded fabrication of unshielded steel glove boxes

    International Nuclear Information System (INIS)

    This Specification deals with the manufacture, testing, inspection and delivery of fabricated glove boxes, including such internal and/or external fittings as are shown on the relevant drawings. (author)

  19. Immunohistochemical evidence for multiple photosystems in box jellyfish

    DEFF Research Database (Denmark)

    Ekström, Peter; Garm, Anders Lydik; Pålsson, Jonas;

    2008-01-01

    Cubomedusae (box jellyfish) possess a remarkable visual system with 24 eyes distributed in four sensory structures termed rhopalia. Each rhopalium is equipped with six eyes: two pairs of pigment cup eyes and two unpaired lens eyes. Each eye type probably captures specific features of the visual......, and electroretinograms (ERG) to determine their spectral sensitivity. All photoreceptor cells of the two lens eyes of the box jellyfish Tripedalia cystophora and Carybdea marsupialis displayed immunoreactivity for an antibody directed against the zebrafish ultraviolet (UV) opsin, but not against any of eight other...... data demonstrate that the lens eyes of box jellyfish utilize a single opsin and are thus color-blind, and that there is probably a different photopigment in the pigment cup eyes. The results support our hypothesis that the lens eyes and the pigment cup eyes of box jellyfish are involved in different...

  20. Sizing Procedures for a Fibre Reinforced Plastic Box

    Directory of Open Access Journals (Sweden)

    K. Kamal

    1992-10-01

    Full Text Available A fibre-reinforced plastic (FRP box is an important class of structural component employed as the bending, torsion, or bending-torsion load bearing member in the modern light- weight structures. This paper presents various steps involved in the design of such a box beginning with preliminary analysis and optimization to the final sizing. The box made up of carbon fibre composite is a typical numerical example of such FRP construction. Numerical results obtained from the static stress analysis, the panel buckling analysis and the structural optimization as used for this sizing exercise, are presented. It is believed that the complete procedure of analysis using finite element method and then sizing of any FRP box in a comprehensive way, is reported for the first time.

  1. Trial manufacture of portable type `WISH BOX`; Kahangata WISH BOX no shisaku kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Ushiyama, I.; Sakuma, H.; Qin, W. [Ashikaga Institute of Technology, Tochigi (Japan); Onai, Y.

    1996-10-27

    This paper proposes the small portable type power source `WISH BOX` (wind and solar hybrid) composed of a small wind power generator and solar cell panels. Since solar radiation and wind power are complementary to each other in seasons, day and night, and fine and cloudy weather, WISH BOX is useful for standalone power source in non-power areas of developing countries, life spot in disasters, and outdoor leisure. The most small light-weight high-performance AIR303 produced by Southwest Windpower Co., USA is used as wind power generator, and two 50W solar cell panels HSC-5010-S produced by Daido Hokusan Co. is used. Sealed lead storage batteries (12V, 20Ah each) are also connected to cope with load fluctuation. In comparison with conventional portable gasoline engine generators, this environment-friendly generator is featured by fuel-free, no emission of gases, no noises and no fire occurrence, and can also supply stable power with small batteries even in the nighttime and cloudy weather by combining wind power. The generator of 400,000 yen is now in field experiment. 2 refs., 5 figs.

  2. Maximal unitarity for the four-mass double box

    OpenAIRE

    Johansson, Henrik; Kosower, David A.; Larsen, Kasper J.

    2014-01-01

    We extend the maximal-unitarity formalism at two loops to double-box integrals with four massive external legs. These are relevant for higher-point processes, as well as for heavy vector rescattering, VV -> VV. In this formalism, the two-loop amplitude is expanded over a basis of integrals. We obtain formulas for the coefficients of the double-box integrals, expressing them as products of tree-level amplitudes integrated over specific complex multidimensional contours. The contours are subjec...

  3. Gray-box modelling approach for description of storage tunnel

    DEFF Research Database (Denmark)

    Harremoës, Poul; Carstensen, Jacob

    1999-01-01

    The dynamics of a storage tunnel is examined using a model based on on-line measured data and a combination of simple deterministic and black-box stochastic elements. This approach, called gray-box modeling, is a new promising methodology for giving an on-line state description of sewer systems. ...... in a SCADA system because the most important information on the specific system is provided on-line...

  4. SOME RECURRENCE FORMULAS FOR BOX SPLINES AND CONE SPLINES

    Institute of Scientific and Technical Information of China (English)

    Patrick J. Van Fleet

    2004-01-01

    A degree elevation formula for multivariate simplex splines was given by Micchelli[6] and extended to hold for multivariate Dirichlet splines in [8]. We report similar formulae for multivariate cone splines and box splines. To this end, we utilize a relation due to Dahmen and Micchelli[4] that connects box splines and cone splines and a degree reduction formula given by Cohen, Lyche, and Riesenfeld in [2].

  5. SOME RECURRENCE FORMULAS FOR BOX SPLINES AND CONE SPLINES

    Institute of Scientific and Technical Information of China (English)

    Patrick J. Van Fleet

    2002-01-01

    A degree elevation formula for multivariate simplex splines was given by Micchelli [6] and extended to hold for multivariate Dirichlet splines in [8]. We report similar formulae for multivariate cone splines and box_splines. To this end, we utilize a relation due to Dahmen and Micchelli [4] that connects box splines and cone splines and a degree reduction formula given by Cohen, Lyche, and Riesenfeld in [2].

  6. Reliability Based Optimum Design of a Gear Box

    Directory of Open Access Journals (Sweden)

    D.Madhusekhar

    2014-10-01

    Full Text Available The gear box represents an important mechanical sub system. In machine tools, the propose of a gear box is to provide a series of useful output speeds so that the machining operation can be carried out at its most optimum operating conditions high spindle speeds with low feed rate for roughing operations. An important aspect in the design of machine tool transmission is to keep the cost and volume of the gear box to a minimum. The probabilistic approach to design has been considered to be more rational compared to the conventional design approach based on the factor of safety. The existence of uncertainties in either engineering simulations or manufacturing processes calls for a reliability-based design optimization (RBDO model for robust and cost-effective designs. In the present work a three shaft four speed gear box is designed using reliability principles. For the specified reliability of the system (Gear box, component reliability (Gear pair is calculated by considering the system as a series system. Design is considered to be safe and adequate if the probability of failure of gear box is less than or equal to a specified quantity in each of the two failure modes. A FORTRAN program has been developed to calculate the mean values of face widths of gears for the minimum mass of gear box. By changing the probability of failure of system variations in the face widths are studied. The reliability based optimum design results are compared with those obtained by deterministic optimum design. The minimum mass of the gear box is increase as the specified values of the reliability is increased.

  7. Jewelry boxes contaminated by Aspergillus oryzae: an occupational health risk?

    Science.gov (United States)

    Bellanger, Anne-Pauline; Roussel, Anaïs; Millon, Laurence; Delaforge, Marcel; Reboux, Gabriel

    2012-01-01

    In 2009, 100,000 jewelry boxes, manufactured in China, were delivered to a jewelry manufacturer in Besançon, France. All the boxes were contaminated by mold. Because the workers refused to handle these jewelry boxes, the company contacted our laboratory to determine how to deal with the problem. Three choices were available: (1) decontaminate the boxes, (2) return the boxes to the Chinese manufacturer, or (3) destroy the entire shipment. Based on microscopic identification, the culture analysis was positive for A. oryzae. This could not be confirmed by molecular techniques because of the genetic proximity of A. oryzae and A. flavus. Because A. flavus can produce aflatoxins, we tested for them using mass spectrometry. Aflatoxins B1, B2, G1, G2, and M1 were not detected; however, given the specifics of this situation, we could not discard the possibility of the presence of other aflatoxins, such as P1, B3, GM2, and ethoxyaflatoxin B2. We concluded that the contamination by A. oryzae was probably due to food products. However, because of the possible presence of aflatoxins, occupational health risks could not be entirely ruled out. The decision was therefore taken to destroy all the jewelry boxes by incineration. To avoid a similar situation we propose: (1) to maintain conditions limiting mold contamination during production (not eating on the work site, efficient ventilation systems); (2) to desiccate the products before sending them; and (3) to closely control the levels of dampness during storage and transport.

  8. Ultra-low power S-Boxes architecture for AES

    Institute of Scientific and Technical Information of China (English)

    XING Ji-peng; ZOU Xue-cheng; GUO Xu

    2008-01-01

    It is crucial to design energy-efficient advancedcncryption standard (AES) cryptography for low power embeddedsystems powered by limited battery. Since the S-Boxes consumemuch of the total AES circuit power, an efficient approach toreducing the AES power consumption consists in reducing theS-Boxes power consumption. Among various implementationsof S-Boxes, the most energy-efficient one is the decoder-switch-encoder (DSE) architecture. In this paper, we refine the DSEarchitecture and propose one faster, more compact S-Boxesarchitecture of lower power: an improved and full-balanced DSEarchitecture. This architecture achieves low power consumptionof 68 μW at 10 MHz using 0.25 μm 1.8V UMC CMOStechnology. Compared with the original DSE S-Boxes, it furtherreduces the delay, gate count and power consumption by 8%,14% and 10% respectively. At the sane time, simulation resultsshow that the improved DSE S-Boxes has the best performanceamong various S-Boxes architectures in terms of power-areaproduct and power-delay product, and it is optimal forimplementing low power AES cryptography.

  9. Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

    Energy Technology Data Exchange (ETDEWEB)

    Beach, R. [IBACOS, Inc., Pittsburgh, PA (United States); Burdick, A. [IBACOS, Inc., Pittsburgh, PA (United States)

    2014-03-01

    This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance. IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations. These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

  10. Closure of an analytical chemistry glove box in alpha laboratory

    International Nuclear Information System (INIS)

    The works with plutonium are performed in gloves box, operated below atmospheric pressure, to protect the experimenters from this alpha-active material. After 12 years of continual processes, it was necessary the decommissioning of the chemistry glove box in our alpha-laboratory. A great deal of our attention was devoted to the working techniques because of extreme care needed to avoid activity release. The decommissioning includes the following main operations: a) Planning and documentation for the regulatory authority. b) Internal decontamination with surface cleaning and chelating agents. c) Measurement of the remainder internal radioactivity. d) Sealing of the glove ports and nozzles. e) Disconnection of the glove box from the exhaust duct. f) Design and construction of a container for the glove box. g) Transportation of the glove box from alpha-laboratory, to a transitory storage until its final disposal. The above mentioned operations are described in this paper including too: data of personal doses during the operations, characteristics and volumes of radioactive wastes and a description of the instrument used for the measurement of inside glove box activity. (Author)

  11. Performance and testing of a hot box storage solar cooker

    Energy Technology Data Exchange (ETDEWEB)

    Nahar, N.M. [Central Arid Zone Research Inst., Rajasthan (India)

    2003-05-01

    A hot box solar cooker with used engine oil as a storage material has been designed, fabricated and tested so that cooking can be performed even in the late evening. The performance and testing of a storage solar cooker have been investigated by measuring stagnation temperatures and conducting cooking trials. The maximum stagnation temperature inside the cooking chambers of the hot box solar cooker with storage material was the same as that of the hot box solar cooker without storage during the day time, but it was 23 deg C more in the storage solar cooker from 1700 to 2400 h. The efficiency of the hot box storage solar cooker has been found to be 27.5%. Cooking trials were also conducted. The rice and green gram washed split were kept at 1730 h, and these were cooked perfectly by 2000 h in the hot box storage solar cooker, while these were not cooked in the hot box solar cooker without storage. (Author)

  12. Principal Investigator-in-a-Box

    Science.gov (United States)

    Young, Laurence R.

    1999-01-01

    Human performance in orbit is currently limited by several factors beyond the intrinsic awkwardness of motor control in weightlessness. Cognitive functioning can be affected by such factors as cumulative sleep loss, stress and the psychological effects of long-duration small-group isolation. When an astronaut operates a scientific experiment, the performance decrement associated with such factors can lead to lost or poor quality data and even the total loss of a scientific objective, at great cost to the sponsors and to the dismay of the Principal Investigator. In long-duration flights, as anticipated on the International Space Station and on any planetary exploration, the experimental model is further complicated by long delays between training and experiment, and the large number of experiments each crew member must perform. Although no documented studies have been published on the subject, astronauts report that an unusually large number of simple errors are made in space. Whether a result of the effects of microgravity, accumulated fatigue, stress or other factors, this pattern of increased error supports the need for a computerized decision-making aid for astronauts performing experiments. Artificial intelligence and expert systems might serve as powerful tools for assisting experiments in space. Those conducting space experiments typically need assistance exactly when the planned checklist does not apply. Expert systems, which use bits of human knowledge and human methods to respond appropriately to unusual situations, have a flexibility that is highly desirable in circumstances where an invariably predictable course of action/response does not exist. Frequently the human expert on the ground is unavailable, lacking the latest information, or not consulted by the astronaut conducting the experiment. In response to these issues, we have developed "Principal Investigator-in-a-Box," or [PI], to capture the reasoning process of the real expert, the Principal

  13. Experimental Study of Mechanical Behavior of Spatial Circular Steel Tube Truss and Concrete Composite Girder%空间圆管桁架混凝土组合梁受力性能试验研究

    Institute of Scientific and Technical Information of China (English)

    陈建兵; 陈荣; 李强

    2014-01-01

    空间圆管桁架混凝土组合结构是一种新型组合结构,为了解其受力特点、破坏机理、变形能力、管桁架杆件的内力分布规律及界面相对滑移等,设计制作了2根弦杆未填充混凝土的不同混凝土翼板厚度的空间圆管桁架混凝土组合梁模型试件,采用三分点对称加载,对其进行受力性能试验研究。研究表明,在对称荷载作用下,组合梁的破坏形式为弯曲破坏,同时伴随有受拉腹杆节点焊缝的强度破坏;空间圆管桁架组合梁具有良好的承载能力和变形能力,相同荷载下,混凝土板厚的组合梁的承载能力高于板薄的组合梁;组合梁破坏时,其跨中挠度约为跨径的1/200;不考虑界面相对滑移的情况下,截面应变满足平截面假定;加载前期,支点截面界面相对滑移量大于 L/8截面,而加载后期,L/8截面界面相对滑移量大于支点截面;腹杆为非轴心受拉或受压杆件,且跨中位置腹杆的轴力较小,梁端位置腹杆的轴力较大。%The spatial steel truss of circular steel tubes and concrete composite structure is a new type of composite structure .In order to examine its load bearing behavior ,failure mechanism , deformability ,internal force distribution law of tubular truss members and interface relative slip -page ,a spatial steel truss of circular tubes and concrete composite girder model was designed and fabricated .The model was characterized by its two chords that are not filled with concrete as well as the concrete flange plates with variable thickness .Loads were symmetrically applied at the 1/3 and 2/3 locations of the calculated span length of the girder proposed .The mechanical behavior of the model was experimentally studied .The results of the study indicate that under the action of symmetric loads ,the composite girder succumbs to bending failure ,concurrently with strength damage at the welding joints of the tensile web

  14. 空间圆管桁架混凝土组合梁受力性能试验研究%Experimental Study of Mechanical Behavior of Spatial Circular Steel Tube Truss and Concrete Composite Girder

    Institute of Scientific and Technical Information of China (English)

    陈建兵; 陈荣; 李强

    2014-01-01

    空间圆管桁架混凝土组合结构是一种新型组合结构,为了解其受力特点、破坏机理、变形能力、管桁架杆件的内力分布规律及界面相对滑移等,设计制作了2根弦杆未填充混凝土的不同混凝土翼板厚度的空间圆管桁架混凝土组合梁模型试件,采用三分点对称加载,对其进行受力性能试验研究。研究表明,在对称荷载作用下,组合梁的破坏形式为弯曲破坏,同时伴随有受拉腹杆节点焊缝的强度破坏;空间圆管桁架组合梁具有良好的承载能力和变形能力,相同荷载下,混凝土板厚的组合梁的承载能力高于板薄的组合梁;组合梁破坏时,其跨中挠度约为跨径的1/200;不考虑界面相对滑移的情况下,截面应变满足平截面假定;加载前期,支点截面界面相对滑移量大于 L/8截面,而加载后期,L/8截面界面相对滑移量大于支点截面;腹杆为非轴心受拉或受压杆件,且跨中位置腹杆的轴力较小,梁端位置腹杆的轴力较大。%The spatial steel truss of circular steel tubes and concrete composite structure is a new type of composite structure .In order to examine its load bearing behavior ,failure mechanism , deformability ,internal force distribution law of tubular truss members and interface relative slip -page ,a spatial steel truss of circular tubes and concrete composite girder model was designed and fabricated .The model was characterized by its two chords that are not filled with concrete as well as the concrete flange plates with variable thickness .Loads were symmetrically applied at the 1/3 and 2/3 locations of the calculated span length of the girder proposed .The mechanical behavior of the model was experimentally studied .The results of the study indicate that under the action of symmetric loads ,the composite girder succumbs to bending failure ,concurrently with strength damage at the welding joints of the tensile web

  15. A novel method to design S-box based on chaotic map and genetic algorithm

    Science.gov (United States)

    Wang, Yong; Wong, Kwok-Wo; Li, Changbing; Li, Yang

    2012-01-01

    The substitution box (S-box) is an important component in block encryption algorithms. In this Letter, the problem of constructing S-box is transformed to a Traveling Salesman Problem and a method for designing S-box based on chaos and genetic algorithm is proposed. Since the proposed method makes full use of the traits of chaotic map and evolution process, stronger S-box is obtained. The results of performance test show that the presented S-box has good cryptographic properties, which justify that the proposed algorithm is effective in generating strong S-boxes.

  16. A novel method to design S-box based on chaotic map and genetic algorithm

    International Nuclear Information System (INIS)

    The substitution box (S-box) is an important component in block encryption algorithms. In this Letter, the problem of constructing S-box is transformed to a Traveling Salesman Problem and a method for designing S-box based on chaos and genetic algorithm is proposed. Since the proposed method makes full use of the traits of chaotic map and evolution process, stronger S-box is obtained. The results of performance test show that the presented S-box has good cryptographic properties, which justify that the proposed algorithm is effective in generating strong S-boxes. -- Highlights: ► The problem of constructing S-box is transformed to a Traveling Salesman Problem. ► We present a new method for designing S-box based on chaos and genetic algorithm. ► The proposed algorithm is effective in generating strong S-boxes.

  17. A novel method to design S-box based on chaotic map and genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yong, E-mail: wangyong_cqupt@163.com [State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing 400044 (China); Key Laboratory of Electronic Commerce and Logistics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); Wong, Kwok-Wo [Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong (Hong Kong); Li, Changbing [Key Laboratory of Electronic Commerce and Logistics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); Li, Yang [Department of Automatic Control and Systems Engineering, The University of Sheffield, Mapping Street, S1 3DJ (United Kingdom)

    2012-01-30

    The substitution box (S-box) is an important component in block encryption algorithms. In this Letter, the problem of constructing S-box is transformed to a Traveling Salesman Problem and a method for designing S-box based on chaos and genetic algorithm is proposed. Since the proposed method makes full use of the traits of chaotic map and evolution process, stronger S-box is obtained. The results of performance test show that the presented S-box has good cryptographic properties, which justify that the proposed algorithm is effective in generating strong S-boxes. -- Highlights: ► The problem of constructing S-box is transformed to a Traveling Salesman Problem. ► We present a new method for designing S-box based on chaos and genetic algorithm. ► The proposed algorithm is effective in generating strong S-boxes.

  18. Behaviors of super-long span prestressed cable-stayed bridge with CFRP cables and UHPC girder%CFRP拉索预应力超高性能混凝土斜拉桥力学性能分析

    Institute of Scientific and Technical Information of China (English)

    方志; 任亮; 凡凤红

    2012-01-01

    To discuss the applicability of carbon fiber reinforced polymer (CFRP) cables and reactive powder concrete ( RPC) in super-long span cable-stayed bridges, taking a 1 008 m cable-stayed bridge using steel girder and steel cables as example, a cable-stayed bridge with the same span using RPC (reactive powder concrete) as the girder and advanced composite material CFRP (carbon fiber reinforced polymer) as the cable was designed, in which the cable cross section was determined by the principles of equivalent cable strength and the beam cross section was determined considering the stiffness, shear capacity and local stability. Based on the method of finite element analysis, the comparative study of these two structures on their static properties, dynamic properties, stability and wind resistance were carried out. The results show that it is feasible for using RPC as the girder and CFRP as the cable so as to form a highly efficient, durable cable-stayed bridge of concrete structure and make its applicable span reach about 1 000 m long.%为了探讨碳纤维复合材料(carbon fiber reinforced polymer,CFRP)和超高性能活性粉末混凝土(reactive powder concrete,RPC)在超大跨度斜拉桥中应用的可行性,以主跨1008m的大跨度钢主梁斜拉桥设计方案为例,采用拉索的等强度原则将原桥钢索替换成CFRP索,考虑截面刚度、截面应力和局部稳定等要求,将原桥钢主梁替换成RPC主梁,拟订了一座等跨度的CFRP拉索、RPC主梁斜拉桥方案.采用有限元法分别对两种方案结构的静力特性、动力特性、稳定性能以及抗风性能等进行了分析与比较.结果表明:从结构受力性能角度而言,采用超高性能混凝土主梁和CFRP拉索构成千米级跨度混凝土斜拉桥的结构体系是可行的.

  19. 钢主梁拱桥组合桥面系力学性能分析%MECHANICAL BEHAVIOR ANALYSIS OF COMPOSITE DECK FLOOR OF ARCH BRIDGE WITH STEEL GIRDER

    Institute of Scientific and Technical Information of China (English)

    苏庆田; 李杰; 董冰

    2012-01-01

    钢-混凝土组合结构桥面系近几年开始在拱桥结构中使用,拱桥中组合桥面系受力复杂,其力学性能受钢与混凝土是否连接、是否张拉系杆以及混凝土的浇注顺序等影响.该文采用空间有限元模型,开展了钢主梁拱桥组合桥面系的力学性能研究.研究表明:在钢主梁拱桥结构中混凝土桥面板与钢主梁是否结合对桥面系的整体受力影响甚微,只对桥面系局部位置的混凝土桥面板应力分布有所影响;拱桥中是否安装系杆对桥面系的受力影响较大,而且桥面系的受力与系杆张拉力有密切关系;对于组合桥面系的拱桥采用一次浇筑混凝土桥面板施工方法的桥面系受力要明显优于采用分段浇筑混凝土桥面板的方法.%A steel-concrete composite deck has been used in acrh bridges recently. The mechanism of a composite deck is complex, and was affected by the factors of setting connections between concrete decks and steel girder or not, setting tied bars or not, different deck concrete casting sequences etc. In this paper, mechanical behaviors of a composite deck floor of an arch bridge with steel girders are analyzed by a spatial finite element model. The research results show that whether setting connections between concrete decks and a steel girder or not slightly affects the total mechanical behavior of a deck floor but influents the local stress of the deck; whether setting tied bar affects the deck floor mechanical property greatly and the deck floor stress depends on the tension force of tied bars heavily; as to arch bridge with a composite deck floor, the mechanical behavior of deck floors with casting deck concrete by one time is superior to that of deck floors with casting deck concrete by several times.

  20. Implications of Big Box Retail Location on Regional Profits, Consumer Utility, and Land Rents

    OpenAIRE

    Stater, Mark; Visser, Michael S.

    2008-01-01

    This paper uses a monocentric city model to examine the effects of big box retailing on local retail prices, land values and utility. Relative to small local retailers, the big box offers a price discount that increases in its marginal cost advantage. Big box entry reduces local retail prices and profits, but provides an increase in household utility that depends positively on the distance between the big box location and the CBD. However, big box locations are unstable with imperfectly compe...

  1. Study on the Dietary Plan of Boxing Athletes during the Period of Weight Loss

    OpenAIRE

    Bo Ma

    2015-01-01

    The study combined with the principle of reasonable weight loss for the boxing athletes by stating the overview of the boxing athlete's weight loss, as well as its influence on the function index of boxing athletes as the weight loss of boxing athletes can directly affect sports performance. It discusses the nutritional supplement measures of boxing athletes during the period of the slow and rapid weight loss stage.

  2. Study on the Dietary Plan of Boxing Athletes during the Period of Weight Loss

    Directory of Open Access Journals (Sweden)

    Bo Ma

    2015-05-01

    Full Text Available The study combined with the principle of reasonable weight loss for the boxing athletes by stating the overview of the boxing athlete's weight loss, as well as its influence on the function index of boxing athletes as the weight loss of boxing athletes can directly affect sports performance. It discusses the nutritional supplement measures of boxing athletes during the period of the slow and rapid weight loss stage.

  3. Integrated Box Interrogation System (IBIS) Preliminary Design Study

    Energy Technology Data Exchange (ETDEWEB)

    DR. Stephen Croft; Mr. David Martancik; Dr. Brian Young; Dr. Patrick MJ Chard; Dr. Robert J Estop; Sheila Melton; Gaetano J. Arnone

    2003-01-13

    Canberra Industries has won the tendered solicitation, INEEL/EST-99-00121 for boxed waste Nondestructive Assay Development and Demonstration. Canberra will provide the Integrated Box Interrogation System (IBIS) which is a suite of assay instrumentation and a data reduction system that addresses the measurement needs for Boxed Wastes identified in the solicitation and facilitates the associated experimental program and demonstration of system capability. The IBIS system will consist of the next generation CWAM system, i.e. CWAM II, which is a Scanning Passive/Active Neutron interrogation system which we will call a Box Segmented Neutron Scanner (BSNS), combined with a physically separate Box Segmented Gamma-ray Scanning (BSGS) system. These systems are based on existing hardware designs but will be tailored to the large sample size and enhanced to allow the program to evaluate the following measurement criteria:Characterization and correction for matrix heterogeneity Characterization of non-uniform radio-nuclide and isotopic compositions Assay of high density matrices (both high-Z and high moderator contents)Correction for radioactive material physical form - such as self shielding or multiplication effects due to large accumulations of radioactive materials.Calibration with a minimal set of reference standards and representative matrices.THis document summarizes the conceptual design parameters of the IBIS and indicates areas key to the success of the project where development is to be centered. The work presented here is a collaborative effort between scientific staff within Canberra and within the NIS-6 group at LANL.

  4. Integrated Box Interrogation System (IBIS) Preliminary Design Study

    International Nuclear Information System (INIS)

    Canberra Industries has won the tendered solicitation, INEEL/EST-99-00121 for boxed waste Nondestructive Assay Development and Demonstration. Canberra will provide the Integrated Box Interrogation System (IBIS) which is a suite of assay instrumentation and a data reduction system that addresses the measurement needs for Boxed Wastes identified in the solicitation and facilitates the associated experimental program and demonstration of system capability. The IBIS system will consist of the next generation CWAM system, i.e. CWAM II, which is a Scanning Passive/Active Neutron interrogation system which we will call a Box Segmented Neutron Scanner (BSNS), combined with a physically separate Box Segmented Gamma-ray Scanning (BSGS) system. These systems are based on existing hardware designs but will be tailored to the large sample size and enhanced to allow the program to evaluate the following measurement criteria:Characterization and correction for matrix heterogeneity Characterization of non-uniform radio-nuclide and isotopic compositions Assay of high density matrices (both high-Z and high moderator contents)Correction for radioactive material physical form - such as self shielding or multiplication effects due to large accumulations of radioactive materials.Calibration with a minimal set of reference standards and representative matrices.THis document summarizes the conceptual design parameters of the IBIS and indicates areas key to the success of the project where development is to be centered. The work presented here is a collaborative effort between scientific staff within Canberra and within the NIS-6 group at LANL

  5. Software sensors based on the grey-box modelling approach

    DEFF Research Database (Denmark)

    Carstensen, J.; Harremoës, P.; Strube, Rune

    1996-01-01

    -box model for the specific dynamics is identified. Similarly, an on-line software sensor for detecting the occurrence of backwater phenomena can be developed by comparing the dynamics of a flow measurement with a nearby level measurement. For treatment plants it is found that grey-box models applied to on......-line measurements. With respect to the development of software sensors, the grey-box models possess two important features. Firstly, the on-line measurements can be filtered according to the grey-box model in order to remove noise deriving from the measuring equipment and controlling devices. Secondly, the grey......-box models may contain terms which can be estimated on-line by use of the models and measurements. In this paper, it is demonstrated that many storage basins in sewer systems can be used as an on-line flow measurement provided that the basin is monitored on-line with a level transmitter and that a grey...

  6. Boxes and Sound Quality in AN Italian Opera House

    Science.gov (United States)

    COCCHI, A.; GARAI, M.; TAVERNELLI, C.

    2000-04-01

    The “Teatro Comunale” (City Theatre) in Bologna is an Italian opera house of the 18th century, designed by the famous architect Antonio Galli Bibiena. Largely built in masonry, it has been only partially restored and altered several times, but never destroyed and rebuilt. The study of its acoustics, while interesting for itself, offers the opportunity to investigate the role of the boxes, which constitute the most evident characteristic of Italian opera houses. The study was carried on at first by measurements, acquiring binaural impulse responses in the stalls and in the boxes, and then by computer simulation, modelling also some changes which cannot be done in the real hall. The measurements revealed clear differences between the listening quality in the boxes and in the stalls, especially regarding ITDG, clarity and IACC. Computer simulations show how the sound field in the historical theatre could be if the sound absorption of the boxes were changed, adding some velvet curtains, as was done in ancient times, and clarify the effects of the cavities which constitutes the boxes.

  7. Internal Behavioral Modeling of Embedded Systems through State Box Structures

    Directory of Open Access Journals (Sweden)

    V. Chandra Prakash

    2011-05-01

    Full Text Available Clean Room Software Engineering (CRSE methodology is intended for the development of high quality systems. The methodology is centered on three structures which include Black Box (BB, State Box (SB and Clear Box (CB and it assures high quality through implementation of Verification and Validation models at every stage of development. The models, suggested earlier, are built using the Mathematics for implementing the formalism which is needed to assure high quality. The mathematical way of implementing the formalism has been proved to be complex, unwieldy and impracticable. The Verification and Validation methods suggested are classical and do not support formalism which is the key element of CRSE. In this paper, three UML models and the associated algorithms have been proposed that help developing state box structures in more formal way and also to automate the process of generating State Box Structures. The refined CRSE model incorporating the suggested models is also presented. The models are used to develop the internal behavior of a Pilot Project called “Temperature Monitoring and Controlling of Nuclear Reactor System” (TMCNRS which is an embedded system designed in more formal and automated way.

  8. Computational Fluid Dynamics Analysis of Flexible Duct Junction Box Design

    Energy Technology Data Exchange (ETDEWEB)

    Beach, Robert [IBACOS, Inc., Pittsburgh, PA (United States); Prahl, Duncan [IBACOS, Inc., Pittsburgh, PA (United States); Lange, Rich [Applied Science Consultants, LLC, Pittsburgh, PA (United States)

    2013-12-01

    IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics (CFD) simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance. Current Air Conditioning Contractors of America (ACCA) guidance (Group 11, Appendix 3, ACCA Manual D, Rutkowski 2009) allows for unconstrained variation in the number of takeoffs, box sizes, and takeoff locations. The only variables currently used in selecting an equivalent length (EL) are velocity of air in the duct and friction rate, given the first takeoff is located at least twice its diameter away from the inlet. This condition does not account for other factors impacting pressure loss across these types of fittings. For each simulation, the IBACOS team converted pressure loss within a box to an EL to compare variation in ACCA Manual D guidance to the simulated variation. IBACOS chose cases to represent flows reasonably correlating to flows typically encountered in the field and analyzed differences in total pressure due to increases in number and location of takeoffs, box dimensions, and velocity of air, and whether an entrance fitting is included. The team also calculated additional balancing losses for all cases due to discrepancies between intended outlet flows and natural flow splits created by the fitting. In certain asymmetrical cases, the balancing losses were significantly higher than symmetrical cases where the natural splits were close to the targets. Thus, IBACOS has shown additional design constraints that can ensure better system performance.

  9. Inferring 3D Articulated Models for Box Packaging Robot

    CERN Document Server

    Yang, Heran; Cong, Matthew; Saxena, Ashutosh

    2011-01-01

    Given a point cloud, we consider inferring kinematic models of 3D articulated objects such as boxes for the purpose of manipulating them. While previous work has shown how to extract a planar kinematic model (often represented as a linear chain), such planar models do not apply to 3D objects that are composed of segments often linked to the other segments in cyclic configurations. We present an approach for building a model that captures the relation between the input point cloud features and the object segment as well as the relation between the neighboring object segments. We use a conditional random field that allows us to model the dependencies between different segments of the object. We test our approach on inferring the kinematic structure from partial and noisy point cloud data for a wide variety of boxes including cake boxes, pizza boxes, and cardboard cartons of several sizes. The inferred structure enables our robot to successfully close these boxes by manipulating the flaps.

  10. Thinking outside the box: fluctuations and finite size effects

    Science.gov (United States)

    Villamaina, Dario; Trizac, Emmanuel

    2014-05-01

    The isothermal compressibility of an interacting or non-interacting system may be extracted from the fluctuations of the number of particles in a well-chosen control volume. Finite size effects are prevalent and should be accounted for to obtain a meaningful, thermodynamic compressibility. In the traditional computational setup, where a given simulation box is replicated with periodic boundary conditions, we study particle number fluctuations outside the box (i.e. when the control volume exceeds the box itself), which bear relevant thermodynamic information. We also investigate the related problem of extracting the compressibility from the structure factor in the small wave-vector limit (k → 0). The calculation should be restricted to the discrete set of wave-vectors k that are compatible with the periodicity of the system, and we assess the consequences of considering other k values, a widespread error among beginners.

  11. 悬索桥板桁结合型加劲梁剪力滞计算的简化方法%Simplified Calculation Method for Shear Lag of Plate and Truss Composite Stiffening Girder of Suspension Bridge

    Institute of Scientific and Technical Information of China (English)

    沈锐利; 颜智法; 唐茂林; 朱军颖

    2015-01-01

    T he simplified calculation method for the shear lag of floor system of the plate and truss composite stiffening girder of suspension bridge was researched in the light of the shear lag characteristics of such type of the structure because the work load of modeling for calculating the shear lag ,using the plate and shell finite element method was enormous and the working efficiency was low .In the simplified method ,the truss in the floor system was converted into a continuous thin‐wall girder by the equivalent beam method and the finite element model of the single main girder suspension bridge that could consider the shear deformation influences w as set up .Based on the variational calculus ,the loading influential intervals that considered the structural geometric nonlinearity influences were taken as the span length of an equivalent simply‐supported girder ,the live load ,suspender forces and bearing reaction forces acting on the intervals were taken as the loads and the shear lag under the action of the combination load was solved on the principle of su‐perposition .By way of example of a railway suspension bridge to be built ,the ANSYS was used to set up the plate and shell finite element model for the w hole bridge of the bridge and the calculation of the shear lag of the model w as analyzed and compared to that implemented by the simplified method .The results of the analysis and comparison proved that the simplified method has high cal‐culation accuracy .%针对采用板壳有限元方法计算悬索桥板桁结合型加劲梁桥面系剪力滞的建模工作量巨大、效率低下的情况,根据该类结构剪力滞的特性,研究其简化计算方法。该方法采用换算梁法将板桁结合桥面系桁梁换算为连续薄壁梁;建立能够考虑剪切变形影响的单主梁悬索桥有限元模型;以变分法为基础,将考虑了结构几何非线性影响的加载影响区间作为等效简支梁的跨

  12. 混凝土曲线梁桥双向规则性判别参数影响分析探讨%Bidirectional Regularity Discriminant Parameter Impact Analysis for Concrete Curve Girder Bridge

    Institute of Scientific and Technical Information of China (English)

    王忠欲; 程鹏; 罗德专

    2013-01-01

    为给我国桥梁抗震设计规范的修订提供参考资料,从抗震设计反应谱理论角度,通过改变地震动的输入方向,引入抗侧力桥墩的“相对墩底剪力比”参数来判别混凝土曲线梁桥的双向规则性,探讨了圆心角、曲线半径、跨径、跨宽比和跨高比等结构参数变化对混凝土曲线梁桥横桥向和纵桥向规则性地震行为的影响规律.研究表明:圆心角是影响混凝土曲线梁桥双向规则性的主要因素,而跨径、跨宽比和跨高比等参数的影响可以忽略,曲线半径不应作为定义规则曲线梁桥的参数;曲线梁桥当满足单跨圆心角φ小于35°,且多跨一联累计圆心角φ小于55°时具有双向规则性,规则曲线梁桥的地震力可比拟为等参的直线桥进行简化抗震计算,计算结果偏于保守.%Aimed at providing references for Chinese seismic design code revision, from seismic design response spectrum theory of view, by changing input direction of ground motion, "relative pier shear ratio" parameter of resist lateral force piers is introducied to judge concrete curve girder bridge's bidirectional directions regularity.This study conducts structure parameters change affecting the lateral and longitudinal regularity seismic behavior of concrete curve girger bridge, such as central angle, curve radius, span, the span-width ratio and span-height ratio parameter, etc.Research shows: Central angle parameter is the major factor affecting the bidirectional regularity of concrete curve girder bridge, while the influences by span, span-width ratio and span-height ratio parameters can be ignored ; Curve radius should not be used to define regular curve girder bridge as one parameter; As a curve girder bridge meets the central angle φ less than 35 degrees, meanwhile the accumulative total of central angle of multispans Ψ less than 55 degrees, It satisfies bidirectional regularity,so it can be analyzed by simplified antiseismic

  13. Research on New Type of Connection between Launching Nose and Main Girder%顶推钢导梁与主梁新型连接方式研究

    Institute of Scientific and Technical Information of China (English)

    张威振; 杨素娟

    2016-01-01

    The screw-thread steel bar is often used for the connection between launching nose and main girder in typical incremental launching process. Because the thickness of the web plate is thin and the launching nose is not matched with the height of the girder, it is difficult to meet the needs of incremental launching construction by using conventional screw-thread steel bar connection method. To solve this problem, this paper presents a new method of connection by combining shear force distribution beam with horizontal screw-thread steel bars. The practice proves that the connection is simple and applicable. The successful application provides good and meaningful references for the launching nose connection of other similar flyovers ( crossing over railway and highway) .%常规顶推施工中钢导梁与主梁多采用精轧螺纹钢连接方式。由于某铁路桥主梁腹板厚度较薄、导梁与主梁高度不相匹配,采用常规的连接方式难以满足受力的需要。为解决这一难题,对常规顶推方案进行改进与创新,提出一种剪力分配梁与水平向精轧螺纹钢相结合的新型连接方式,方便地解决了工程实际需求。实践证明,该连接方式操作简单、适用性强。该方案的成功运用可以作为类似跨线桥(跨铁路、公路等)顶推施工导梁连接方案的借鉴。

  14. Analysis of Influence Factors of Structure Stability for SingleColumn Pier Continuous Girder Bridge%独柱墩连续梁桥的稳定影响因素分析

    Institute of Scientific and Technical Information of China (English)

    吴玉华; 蔡若红; 杨育人

    2011-01-01

    Taking the case of Jinhua-Taizhou section of zhuyong highway, 23 simulation models of single-column pier continuous girder bridge were established by MIDAS finite element program. The major factors which would affect the stability of curved girder bridge, such as the radius of curvature, the length of bridge, the space between two bearings and the offset distance of bearing placed on the single-column pier etc. The results show that the radius of curvature has great effect on the negative counter-force of bearing. The bearing separation is likely to occur when the radius of curvature is less than 200 m and the length of bridge is greater than 100 m. That the appropriate layout offset distance of bearing and enlargement of the space between bearings can assure lower possibility of bearing separation and enhance the ability of bridge performance against overturning.%以诸永高速金华台州段工程为例,采用MIDAS有限元分析程序,构建了23座独柱墩连续箱梁桥的仿真模型,系统分析和总结了影响弯梁桥稳定性的主要影响因素,如曲率半径、桥梁长度、联端支座间距、独柱墩支座预设偏心等.结果表明:桥梁曲率半径对支座负反力影响很大,当曲率半径小于200 m,桥梁长度大于100 m时较易发生支座脱空现象;增大联端支座间距,合理设置支座偏心距,可减小支座出现脱空的可能性,提高桥梁的抗倾覆能力.

  15. MECHANICAL BEHAVIOR OF STUD SHEAR CONNECTORS IN COMPOSITE GIRDER OF APPROACH BRIDGE OF JIUBAO BRIDGE%九堡大桥引桥组合梁焊钉受力性能研究

    Institute of Scientific and Technical Information of China (English)

    高璞

    2012-01-01

    九堡大桥引桥为多跨连续组合箱梁桥,截面为开口梯形钢梁与混凝土桥面板组合形式,钢梁与混凝土板间设置了大量的圆柱体焊钉连接件,连接件受力形式与传统钢板梁组合桥不同.文中结合该工程,采用ANSYS有限元程序建立其空间实体模型,采用弹簧单元详细模拟了焊钉,计算了焊钉连接件的受力,分析了焊钉连接件的受力特点.结果表明:焊钉连接件不仅承受沿纵桥向的剪力,还承受沿横桥向的剪力及沿竖向的拉拔力,连接件所受的剪力和拉拔力在全桥范围分布规律复杂.%The approch bridge of Jiubao bridge was a multi - span continous composite bridge,whose cross section composed of open trapezoid section steel girder and concrete slabs. Magnitude of headed studs were layout at die interface of steel girder and concrete slab. Mechanical behavior of studs in this type of composite beam is different from that in the steel plate composite beam. Combined with this project, finite element program ANSYS was used to set the solide spatial model in which spring elements were adopted to simulate the studs. Thus mechanical behavior of studs were achieved and analyzed. The analysis results show that; studs carry not only longitudinal shear force along the bridge;but also transverse shear force and vertical tension force, the distribution patterns of diese forces along the whole bridge were complex.

  16. Seismic vulnerability analysis of regular continuous girder bridges%规则连续梁桥地震易损性研究

    Institute of Scientific and Technical Information of China (English)

    张菊辉; 管仲国

    2014-01-01

    Structural performance indices for regular continuous girder bridges under different damage states were discussed based on the displacement ductility ratio.On the OpenSees platform,a structural dynamic analysis model was established by using nonlinear fiber beam elements.100 earthquake ground motion records were selected,and the nonlinear time-history analysis was performed,thus the fragility curves under different damage states were constructed. Through parametric analysis,the effects of pier height,bearing types and transverse reinforcement ratios on the fragility curves were studied.The results show that the development degree of ductility of the continuous bridge has a great effect on the structural seismic vulnerability.The fragility curves obtained under minor damage and moderate damage seem to be very close;while under extensive damage,the bridge shows a good performance against earthquake forces.With the increase of pier height,the lower level of damage probability of the structure is observed;meanwhile,the improvement in the fragility by using the plate rubber bearings is excellent for a short-pier bridge,but very limited for a high-pier one. The effect of increasing the transverse reinforcement ratio on fragility curves can be neglected for structural damage in early stage,but it can significantly increase the structural capacity from collapse.%基于位移延性比探讨规则连续梁桥在不同损伤状态下的结构性能控制指标;基于OpenSees平台采用纤维模型建立结构动力分析模型,选取100条强震记录通过非线性时程反应分析计算结构地震易损性曲线。研究不同墩高、支座形式及配箍率对结构地震易损性影响,结果表明,连续梁桥的地震易损性受延性发育程度影响较大,发生中等与轻微破坏概率较相近,对严重破坏有较好的耐损性;结构耐损性随墩高的增大而增加;采用板式橡胶支座可显著提高矮墩桥梁的耐损性,对

  17. Fermi hypernetted chain calculations in a periodic box

    International Nuclear Information System (INIS)

    The Fermi hypernetted chain theory is reformulated to perform calculations with a finite number of fermions in a periodic box. The proposed method is expected to be useful to estimate the finite size effects in Quantum Monte Carlo simulations. Moreover, it can deal with anisotropic correlations as well as with different shaped boxes. Results are given for the neutron matter Bethe homework Hamiltonian and for nuclear matter with spin-isospin dependent central interactions. It is found that finite size effects come from both the kinetic and the potential energy expectation values

  18. AN ALGORITHM FOR AUTOMATICALLY GENERATING BLACK-BOX TEST CASES

    Institute of Scientific and Technical Information of China (English)

    XuBaowen; NieChanghai; 等

    2003-01-01

    Selection of test cases plays a key role in improving testing efficiency.Black-box testing is an important way of testing,and is validity lies on the secection of test cases in some sense.A reasonable and effective method about the selection and generation of test cascs is urgently needed.This letter first introduces some usual methods on black-box test case generation,then proposes a new glgorithm based on interface parameters and discusses its properties,finally shows the effectiveness of the algorithm.

  19. AN ALGORITHM FOR AUTOMATICALLY GENERATING BLACK-BOX TEST CASES

    Institute of Scientific and Technical Information of China (English)

    Xu Baowen; Nie Changhai; Shi Qunfeng; Lu Hong

    2003-01-01

    Selection of test cases plays a key role in improving testing efficiency. Black-box testing is an important way of testing, and its validity lies on the selection of test cases in some sense. A reasonable and effective method about the selection and generation of test cases is urgently needed. This letter first introduces some usualmethods on black-box test case generation,then proposes a new algorithm based on interface parameters and discusses its properties, finally shows the effectiveness of the algorithm.

  20. Host-Guest Interactions in ExBox4+

    CERN Document Server

    Das, Ranjita

    2014-01-01

    The host-guest interaction between benzene or azine with the newly synthesized ExBox4+ complex is studied with the help of DFT. The solvent phase interaction energy is found to decrease with gradual substitution of methine group of guest benzene ring with N atom in the resultant azine@ExBox4+ complex. The nature of bonding interaction is studied with the help of newly developed NCI plot program package along with energy decomposition analysis (EDA) and charge decomposition analysis (CDA). The interaction is mostly pi-type van der Waals interaction.

  1. Principal investigator in a box: Version 1.2 documentation

    Science.gov (United States)

    Adolph, Jurine; Bhatnagar, Rajiv; Colombano, Silvano P.; Compton, Michael; Frainer, Richard; Groleau, Nicolas; Holden, Kritina; Lai, Sen-Hao; Lam, Chih-Chao; Manahan, Meera

    1990-01-01

    Principal Investigator (PI) in a box is a computer system designed to help optimize the scientific results of experiments that are performed in space. The system will assist the astronaut experimenters in the collection and analysis of experimental data, recognition and pursuit of 'interesting' results, optimal use of the time allocated to the experiment, and troubleshooting of the experiment apparatus. This document discusses the problems that motivate development of 'PI-in-a-box', and presents a high- level system overview and a detailed description of each of the modules that comprise the current version of the system.

  2. Tests of CMS Hadron Forward Calorimeter Upgrade Readout Box Prototype

    CERN Document Server

    Chatrchyan, Sergey; Sirunyan, Albert; Tumasyan, Armen; Mossolov, Vladimir; Shumeiko, Nikolai; Cornelis, Tom; Ochesanu, Silvia; Roland, Benoit Florent; Staykova, Zlatka; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Spilbeeck, Alex; Alves, Gilvan Augusto; Martins, Thiago Dos Reis; Pol, Maria Elena; Vaz Da Silva Filho, Mario; Alda Junior, Walter Luiz; Carvalho, Wagner De Paula; Chinellato, Jose Augusto; De Oliveira Martins, Carley Pedro; Figueiredo, Diego Matos; Tonelli Manganote, Edmilson Jose; Molina Insfran, Jorge Andres; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Rosa Lopes Zachi, Alessandro; Finger, Miroslav; Finger, Michael; Tsamalaidze, Zviad; Borras, Kerstin; Gunnellini, Paolo; Jung, Hannes; Knutsson, Albert Hans; Lutz, Benjamin; Ribeiro Cipriano, Pedro Miguel; Sen, Niladri; Baus, Colin; Katkov, Igor; Ulrich, Ralf Matthias; Wohrmann, H; Panagiotou, Apostolos; Bencze, Gyorgy; Horvath, D; Bala, Suman; Gupta, Ruchi; Jindal, M; Lal, Manjit Kaur; Nishu, Nishu; Saini, Lovedeep Kaur; Banerjee, Sunanda; Bhattacharya, S; Gomber, Bhawna; Jain, Shilpi; Khurana, Raman; Sharan, Manoj Kumar; Aziz, Tariq; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Katta, Sudhakar; Banerjee, Sudeshna; Dugad, Shashikant Raichand; Etesami, Seyed Mohsen; Fahim, Ali; Jafari, Abideh; Paktinat Mehdiabadi, Saeid; Zeinali, Maryam; Penzo, Aldo; Afanasyev, A; Bunin, Pavel; Ershov, Yuri; Fedoseev, Oleg; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Konoplynikov, V; Malakhov, Alexander; Moisenz, Petr; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoly; Andreev, Yuri; Dermenev, Alexander; Krasnikov, Nikolay; Pashenkov, Anatoli; Tlisov, Danila; Toropin, A; Epshteyn, Vladimir; Erofeeva, Maria; Gavrilov, Vladimir; Kosov, Mikhail Vladimirovich; Kudinov, Ilya; Lychkovskaya, Natalia; Popov, V; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Vlassov, Evgueni; Zhokin, Alexander; Belyaev, A; Boos, Eduard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Korotkikh, Vladimir; Lokhtin, Igor; Markina, Anastasia; Obraztsov, Stepan; Perfilov, Maxim; Petrushanko, Sergey; Popov, Andrey; Savrin, Victor; Snigirev, Alexander; Vardanyan, Irina; Andreev, V; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Vinogradov, Alexey; Bayshev, Igor; Bityukov, Sergey; Grishin, Viatcheslav; Kryshkin, Victor; Petrov, V; Ryutin, Roman; Sobol, Andrey; Turchanovich, Leonid; Troshin, Sergey; Uzunyan, Andrey; Volkov, Alexey; Santanastasio, Francesco; Adiguzel, Aytul; Bakirci, Numan Mustafa; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; G�kbulut, Gul; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Karapinar, Guler; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Latife Nukhet; Vergili, Mehmet; Aliyev, Takhmasib; Deniz, Muhammed; Guler, Ali Murat; Ozpineci, Altug; Serin, Meltem; Sever, Ramazan; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Gulmez, Erhan; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Ozkorucuklu, Suat; Sonmez, Nasuf; Cankocak, Kerem; Levchuk, Leonid; Hatakeyama, Kenichi; Liu, H; Scarborough, Tara Ann; Rumerio, Paolo; Heister, Arno; Hill, C; Lawson, Philip Daniel; Lazic, Dragoslav; Rohlf, James; St. John, Jason; Sulak, Lawrence; Gennadiy, G; Laird, Edward; Landsberg, Greg; Narain, Meenakshi; Sinthuprasith, Tutanon; Tsang, Ka Vang; Long, Owen Rosser; Nguyen, Harold; Paramesvaran, Sudarshan; Sturdy, Jared; Stuart, David; To, Wing; West, Christopher Alan; Apresyan, Artur; Chen, Y; Mott, Alexander Robert; Spiropulu, Maria; Winn, David; Abdoulline, Salavat; Anderson, J; Chlebana, Frank; Freeman, James; Green, Daniel; Hanlon, J; Hirschauer, James Francis; Joshi, Umeshwar; Kunori, Shuichi; Musienko, Yuri; Sharma, Seema; Spalding, William Jeffrey; Tkaczyk, Slawomir; Vidal, Richard; Whitmore, Juliana; Wu, W; Gaultney, Vanessa; Linn, Stephan; Markowitz, Pete Edward; Martinez, German Ruben; Gleyzer, Sergei; Hagopian, Sharon Lee; Hagopian, Vasken; Jenkins, Charles Merrill; Baarmand, Marc M; Dorney, Brian L; Vodopiyanov, Igor; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren James; Duru, Firdevs; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony Richard; Nachtman, Jane; Newsom, Charles Ray; Norbeck, John Edwin; Olson, Jonathan Edward; Onel, Yasar; Ozok, Ferhat; Sen, Sercan; Schmidt, Ianos; Tiras, Emrah; Yetkin, Taylan; Yi, Kai; Kenny, Raymond Patrick; Murray, Michael Joseph; Wood, Jeffrey Scott; Baden, Andrew; Calvert, Brian Michael; Eno, Sarah Catherine; Gomez, Jaime Arturo; Grassi, Tullio; Hadley, Nicholas John; Kellogg, Richard; Kolberg, Ted; Lu, Y; Marionneau, Matthieu; Mignerey, Alice Louise Cox; Peterman, Alison Marie; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite Belt; Kao, Shih-Chuan; Klapoetke, Kevin Humphrey; Mans, Jeremiah Michael; Pastika, Nathaniel Joseph; Kroeger, Robert; Rahmat, Rahmat; Sanders, David; Cremaldi, Lucien Marcus; Jain, S; Anastassov, Anton; Velasco, Mayda Marie; Won, Steven; Heering, Adriaan; Karmgard, Daniel; Pearson, Tessa Jae; Ruchti, Randal; Berry, Edmund A; Halyo, Valerie; Hebda, Philip; Hunt, Adam Paul; Lujan, Paul Joseph; Marlow, Daniel; Medvedeva, Tatiana; Saka, Halil; Tully, Christopher; Zuranski, Andrzej Maciej; Barnes, Virgil Everett; Laasanen, Alvin; Bodek, Arie; Chung, Yeon Sei; de Barbaro, Pawel Jan; Eshaq, Yossof; Garcia-bellido, Aran Angel; Goldenzweig, Pablo David; Han, Ji Yeon; Harel, Amnon; Miner, Daniel Carl; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert Adam; Flanagan, Will Hogan; Kamon, Teruki; Montalvo, Roy Joaquin; Sakuma, Tai; Akchurin, Nural; Damgov, Jordan; Dudero, Phillip Russell; Kovitanggoon, Kittikul; Lee, Sung Won; Libeiro, Terence; Volobouev, Igor; Gurrola, Alfredo; Milstene, Caroline

    2012-01-01

    A readout box prototype for CMS Hadron Forward calorimeter upgrade is built and tested in CERN H2 beamline. The prototype is designed to enable simultaneous tests of different readout options for the four anode upgrade PMTs, new front-end electronics design and new cabling. The response of the PMTs with different readout options is uniform and the background response is minimal. Multi-channel readout options further enhance the background elimination. Passing all the electronics, mechanical and physics tests, the readout box proves to be capable of providing the forward hadron calorimeter operations requirements in the upgrade era.

  3. Ancestry and diversity of the HMG box superfamily

    OpenAIRE

    Laudet, V; Stehelin, D.; Clevers, J.C.

    1993-01-01

    The HMG box is a novel type of DNA-binding domain found in a diverse group of proteins. The HMG box superfamily comprises a.o. the High Mobility Group proteins HMG1 and HMG2, the nucleolar transcription factor UBF, the lymphoid transcription factors TCF-1 and LEF-1, the fungal mating-type genes mat-Mc and MATA1, and the mammalian sex-determining gene SRY. The superfamily dates back to at least 1,000 million years ago, as its members appear in animals, plants and yeast. Alignment of all known ...

  4. 碳纤维板在重载铁路低高度钢筋混凝土板梁体外预应力加固中的应用研究%Study on application of carbon f iber plate in external prestress reinforcing for low-height reinforcement concrete slab girder on heavy haul railway

    Institute of Scientific and Technical Information of China (English)

    刘吉元; 马林

    2015-01-01

    迄今,预应力碳纤维板应用于重载铁路钢筋混凝土梁加固改造的实例较少,其加固效果尚需深入研究。本文先阐述了体外预应力加固钢筋混凝土构件的设计思路,又根据现行铁路规范对加固前后梁体的应力、挠度及裂缝宽度进行了检算,并通过试验场内的静载试验验证了预应力碳纤维板加固钢筋混凝土板梁的加固效果。研究结果表明,采用预应力碳纤维板加固钢筋混凝土梁能够显著提高梁体受力性能,在1.2倍ZH荷载作用下能够满足运营要求,该技术可以在重载铁路加固改造中推广应用。%T here were few applications of prestressed carbon fiber plate in reinforcement of reinforced concrete girders used in heavy haul railway. In the paper,the design idea of external prestressing used in concrete girders reinforcement was introduced,and the stress,deflection and crack width of the girders before and after reinforcement were calculated according to the current railway code. T he effect of reinforcement was verified though the static load tests. T he results indicated that the prestressed carbon fiber plate used for reinforce concrete slab girders can significantly improve the stress performance of girder,and satisfy the operational requirements under the 1. 2 times ZH load. T his technology was suggested to apply in the reinforcement of reinforced concrete slab girders used in heavy haul railway.

  5. Dynamic inhomogeneous S-Boxes in AES: a novel countermeasure against power analysis attacks

    Institute of Scientific and Technical Information of China (English)

    Chen Yicheng; Zou Xuecheng; Liu Zhenglin; Han Yu; Zheng Zhaoxia

    2008-01-01

    Substitution boxes (S-Boxes) in advanced encryption standard (AES) are vulnerable to attacks by power analysis. The general S-Boxes masking schemes in circuit level need to adjust the design flow and library databases. The masking strategies in algorithm level view each S-Box as an independent module and mask them respectively, which are costly in size and power for non-linear characteristic of S-Boxes. The new method uses dynamic inhomogeneous S-Boxes instead of traditional homogeneous S-Boxes, and arranges the S-Boxes randomly. So the power and data path delay of substitution unit become unpredictable. The experimental results demonstrate that this scheme takes advantages of the circuit characteristics of various S-Box implementations to eliminate the correlation between crypto operation and power. It needs less extra circuits and suits resource constrained applications.

  6. F-box protein FBXL2 inhibits gastric cancer proliferation by ubiquitin-mediated degradation of forkhead box M1.

    Science.gov (United States)

    Li, Liang-qing; Pan, Dun; Chen, Hui; Zhang, Lin; Xie, Wen-jun

    2016-02-01

    F-box/LRR-repeat protein 2 (FBXL2), a component of Skp-Cullin-F box (SCF) ubiquitin E3 ligase, has been shown to inhibit tumorigenesis by targeting and ubiquitinating several oncoproteins. However, its role in gastric cancer remains poorly understood. Here, by tandem mass spectrometry, we show that FBXL2 interacts with forkhead box M1 (FoxM1) transcription factor. As a result, FBXL2 promotes ubiquitination and degradation of FoxM1 in gastric cancer cells. Furthermore, overexpression of FBXL2 inhibits, while its deficiency promotes cell proliferation and invasion. Expression levels of cell-cycle regulators (Cdc25B and p27), which are down-stream target effectors of FoxM1, are also regulated by FBXL2. Therefore, our results uncover a previous unknown network involving FBXL2 and FoxM1 in the regulation of gastric cancer growth.

  7. Energy Savings Assessment for Digital-to-Analog Converter Boxes

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Hoi Ying Iris; Meier, Alan; Brown, Richard

    2011-01-18

    The Digital Television (DTV) Converter Box Coupon Program was administered by the U.S. government to subsidize purchases of digital-to-analog converter boxes, with up to two $40 coupons for each eligible household. In order to qualify as Coupon Eligible Converter Boxes (CECBs), these devices had to meet a number of minimum performance specifications, including energy efficiency standards. The Energy Star Program also established voluntary energy efficiency specifications that are more stringent than the CECB requirements. In this study, we measured the power and energy consumptions for a sample of 12 CECBs (including 6 Energy Star labeled models) in-use in homes and estimated aggregate energy savings produced by the energy efficiency policies. Based on the 35 million coupons redeemed through the end of the program, our analysis indicates that between 2500 and 3700 GWh per year are saved as a result of the energy efficiency policies implemented on digital-to-analog converter boxes. The energy savings generated are equivalent to the annual electricity use of 280,000 average US homes.

  8. How Users Search the Library from a Single Search Box

    Science.gov (United States)

    Lown, Cory; Sierra, Tito; Boyer, Josh

    2013-01-01

    Academic libraries are turning increasingly to unified search solutions to simplify search and discovery of library resources. Unfortunately, very little research has been published on library user search behavior in single search box environments. This study examines how users search a large public university library using a prominent, single…

  9. The Electronic Box Office: Humanities and Arts On the Cable.

    Science.gov (United States)

    Adler, Richard; Baer, Walter S.

    A series of essays examines the potential of cable television (CATV) for increasing the diversity and quality of television programing. Specifically, they explore what an electronic box office could do to encourage new production sources and develop new mechanisms for distributing programing in the humanities and performaing arts. The introduction…

  10. Features for Exploiting Black-Box Optimization Problem Structure

    DEFF Research Database (Denmark)

    Tierney, Kevin; Malitsky, Yuri; Abell, Tinus

    2013-01-01

    Black-box optimization (BBO) problems arise in numerous scientic and engineering applications and are characterized by compu- tationally intensive objective functions, which severely limit the number of evaluations that can be performed. We present a robust set of features that analyze the tness...

  11. 77 FR 74513 - Folding Gift Boxes From China

    Science.gov (United States)

    2012-12-14

    ...)). Background The Commission instituted this review on April 2, 2012 (77 FR 19714) and determined on July 6, 2012 that it would conduct an expedited review (77 FR 42762, July 20, 2012). The Commission transmitted... COMMISSION Folding Gift Boxes From China Determination On the basis of the record \\1\\ developed in...

  12. A Grey-Box Model for Spray Drying Plants

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik;

    2013-01-01

    are compared to datasets gathered at GEA Process Engineering’s test facility. The identified grey-box model parameters are identified from data and the resulting model fits the data well. The complexity of the model has been selected such that it is suitable for development of real-time optimization algorithms...

  13. Multidisciplinary Design and Optimization Framework for Aircraft Box Structures

    NARCIS (Netherlands)

    Van Dijk, R.E.C.; Zhao, X.; Wang, H.; Van Dalen, F.

    2012-01-01

    Competitive aircraft box structures are a perfect compromise between weight and price. The conceptual design process of these structures is a typical Multidisciplinary Design and Optimization effort, normally conducted by human engineers. The iterative nature of MDO turns development into a long and

  14. The Box Model and the Acoustic Sounder, a Case Study

    DEFF Research Database (Denmark)

    Jensen, Niels Otto; Lundtang Petersen, Erik

    1979-01-01

    Concentrations of SO2 in a large city during a subsidence situation are predicted as a function of time by means of a simple box model and the predictions are compared to actual SO2 concentration measurements. The agreement between model results and measurements is found to be excellent. The model...

  15. Downhole stuffing box aids pumping of heavy crude

    Energy Technology Data Exchange (ETDEWEB)

    Franco, A.

    1970-09-21

    Petroleos Mexicanos (Pemex) has found a new way to produce heavy oil from pumping wells. The key component is a bottomhole stuffing box which reduces the friction of the pumping string during the downstroke. The relatively simple system, already proven successful in the Ebano-Panuco area of Mexico, could be easily applied wherever operators are faced with the task of producing highly viscous oil and coping with the problem of constant sucker-rod string breakage. Basically, Pemex' method consists of a special downhole stuffing box and polished rod anchored at the end of the pumping string. The isolated tubing is filled with water to minimize friction, and the heavy oil is produced through the annular space between the tubing and casing strings. With Pemex' new downhole stuffing box, friction is minimized. Even though the system is applicable to practically any type of completion (any size of tubing and casing), Pemex has found it to be ideally suited for wells having 8-5/8-8in. casing or larger. The accompanying line diagram of a hookup for a well with 8-5/8-in. casing and 3-in. tubing shows the necessary installations. The stuffing box features a groove bolt at the top to allow tightening of a packing element without having to remove the assembly from the hole.

  16. [Interprofessional pill box management in an ambulatory care setting].

    Science.gov (United States)

    Abrecht, Loïc; Anchisi, Annick; Widmer, Daniel; Bugnon, Olivier; Du Pasquier, Sophie; Jotterand, Sébastien; Karlen, Martine; Herzig, Lilli

    2014-11-26

    Complex multimorbid patients are now more common in ambulatory care and the management of their medication more frequently needs interprofessional collaboration. This qualitative study explored health professional's main challenges when introducing, preparing and sharing the use of a pill box for a patient. Another objective of this study was to explore options for improving care in these situations.

  17. Ancient origin of animal U-box ubiquitin ligases

    Directory of Open Access Journals (Sweden)

    Marín Ignacio

    2010-10-01

    Full Text Available Abstract Background The patterns of emergence and diversification of the families of ubiquitin ligases provide insights about the evolution of the eukaryotic ubiquitination system. U-box ubiquitin ligases (UULs are proteins characterized by containing a peculiar protein domain known as U box. In this study, the origin of the animal UUL genes is described. Results Phylogenetic and structural data indicate that six of the seven main UUL-encoding genes found in humans (UBE4A, UBE4B, UIP5, PRP19, CHIP and CYC4 were already present in the ancestor of all current metazoans and the seventh (WDSUB1 is found in placozoans, cnidarians and bilaterians. The fact that only 4 - 5 genes orthologous to the human ones are present in the choanoflagellate Monosiga brevicollis suggests that several animal-specific cooptions of the U box to generate new genes occurred. Significantly, Monosiga contains five additional UUL genes that are not present in animals. One of them is also present in distantly-related protozoans. Along animal evolution, losses of UUL-encoding genes are rare, except in nematodes, which lack three of them. These general patterns are highly congruent with those found for other two families (RBR, HECT of ubiquitin ligases. Conclusions Finding that the patterns of emergence, diversification and loss of three unrelated families of ubiquitin ligases (RBR, HECT and U-box are parallel indicates that there are underlying, linage-specific evolutionary forces shaping the complexity of the animal ubiquitin system.

  18. The Popcorn Box Activity and Reasoning about Optimization

    Science.gov (United States)

    Whiteley, Walter J.; Mamolo, Ami

    2012-01-01

    A well-known optimization problem is the Popcorn Box investigation, which involves a movie theater snack container. The problem has been tailored for classroom investigations by the Ontario Association for Mathematics Education. The exploration was designed for students in grades 9 through 12. A common strategy proposed for algebra students is to…

  19. Developing Box Plots While Navigating the Maze of Data Representations

    Science.gov (United States)

    Duncan, Bruce; Fitzallen, Noleine

    2013-01-01

    The learning sequence described in this article was developed to provide students with a demonstration of the development of box plots from authentic data as an illustration of the advantages gained from using multiple forms of data representation. The sequence follows an authentic process that starts with a problem to which data representations…

  20. Immunohistochemical evidence for multiple photosystems in box jellyfish.

    Science.gov (United States)

    Ekström, Peter; Garm, Anders; Pålsson, Jonas; Vihtelic, Thomas S; Nilsson, Dan-Eric

    2008-07-01

    Cubomedusae (box jellyfish) possess a remarkable visual system with 24 eyes distributed in four sensory structures termed rhopalia. Each rhopalium is equipped with six eyes: two pairs of pigment cup eyes and two unpaired lens eyes. Each eye type probably captures specific features of the visual environment. To investigate whether multiple types of photoreceptor cells are present in the rhopalium, and whether the different eye types possess different types of photoreceptors, we have used immunohistochemistry with a range of vertebrate opsin antibodies to label the photoreceptors, and electroretinograms (ERG) to determine their spectral sensitivity. All photoreceptor cells of the two lens eyes of the box jellyfish Tripedalia cystophora and Carybdea marsupialis displayed immunoreactivity for an antibody directed against the zebrafish ultraviolet (UV) opsin, but not against any of eight other rhodopsin or cone opsin antibodies tested. In neither of the two species were the pigment cup eyes immunoreactive for any of the opsin antibodies. ERG analysis of the Carybdea lower lens eyes demonstrated a single spectral sensitivity maximum at 485 nm suggesting the presence of a single opsin type. Our data demonstrate that the lens eyes of box jellyfish utilize a single opsin and are thus color-blind, and that there is probably a different photopigment in the pigment cup eyes. The results support our hypothesis that the lens eyes and the pigment cup eyes of box jellyfish are involved in different and specific visual tasks. PMID:18504619

  1. Visual control of steering in the box jellyfish Tripedalia cystophora

    DEFF Research Database (Denmark)

    Petie, Ronald; Garm, Anders; Nilsson, Dan-Eric

    2011-01-01

    Box jellyfish carry an elaborate visual system consisting of 24 eyes, which they use for driving a number of behaviours. However, it is not known how visual input controls the swimming behaviour. In this study we exposed the Caribbean box jellyfish Tripedalia cystophora to simple visual stimuli a...... their bell in such a way that, if not tethered, they would turn and swim away from the dark area. We conclude that the visual system of T. cystophora has a predictable effect on swimming behaviour.......Box jellyfish carry an elaborate visual system consisting of 24 eyes, which they use for driving a number of behaviours. However, it is not known how visual input controls the swimming behaviour. In this study we exposed the Caribbean box jellyfish Tripedalia cystophora to simple visual stimuli...... to the darkening of one quadrant of the equatorial visual world by (1) increasing pulse frequency, (2) creating an asymmetry in the structure that constricts the outflow opening of the bell, the velarium, and (3) delaying contraction at one of the four sides of the bell. This causes the animals to orient...

  2. Testing the Box-Cox Parameter for an Integrated Process

    NARCIS (Netherlands)

    J. Huang (Jian); M. Kobayashi (Masahito); M.J. McAleer (Michael)

    2011-01-01

    textabstractThis paper analyses the constant elasticity of volatility (CEV) model suggested by Chan et al. (1992). The CEV model without mean reversion is shown to be the inverse Box-Cox transformation of integrated processes asymptotically. It is demonstrated that the maximum likelihood estimator o

  3. Fitting boxes to Manhattan scenes using linear integer programming

    KAUST Repository

    Li, Minglei

    2016-02-19

    We propose an approach for automatic generation of building models by assembling a set of boxes using a Manhattan-world assumption. The method first aligns the point cloud with a per-building local coordinate system, and then fits axis-aligned planes to the point cloud through an iterative regularization process. The refined planes partition the space of the data into a series of compact cubic cells (candidate boxes) spanning the entire 3D space of the input data. We then choose to approximate the target building by the assembly of a subset of these candidate boxes using a binary linear programming formulation. The objective function is designed to maximize the point cloud coverage and the compactness of the final model. Finally, all selected boxes are merged into a lightweight polygonal mesh model, which is suitable for interactive visualization of large scale urban scenes. Experimental results and a comparison with state-of-the-art methods demonstrate the effectiveness of the proposed framework.

  4. Optimizing PHB and Protease Production by Box Behnken Design

    Directory of Open Access Journals (Sweden)

    Amro Abd al fattah Amara

    2013-04-01

    Full Text Available Mixed culture is more suitable to adapt more flexible fermentation process and produce different product simultaneously. In this study a mixed Bacillus culture was investigated for their ability to produce the bioplastic "Polyhydroxybutyrate" and both of the mesophilic and the thermophilic proteases in one flask. Box-Behnken experimental design was used. The produced amount of PHB has been increased significantly. Meanwhile there is a competition between PHB and proteases. The maximum produced amount of PHB using Box-Behnken design was 2.82 g/l/48 h with protease activity equal to 41.9 Units/ml/48 h for thermophilic proteases and 99.65 Units/ml/48 h for mesophilic proteases. Excel solver was used for extra-optimization for the optimum conditions obtained from Box-Behnken experiments and its model. The maximum PHB obtained after using Excel solver was 2.88 g/l/48 h. The maximum mesophilic and thermophilic activities obtained at the same PHB production conditions were 175.68 and 243.38 Units/ml respectively. The model accuracy as obtained from Excel solver was 118.8%, which prove the power of the experimental design in optimizing such complicated process. The strategies used in this study are recommended for the production of PHB and different proteases simultaneously using Bacillus mixed culture. ABSTRAK: Kultur campuran adalah lebih sesuai bagi proses penapaian yang fleksibel dan ia boleh menghasilkan produk yang berbeza secara serentak. Dalam kajian ini keupayaan  menghasilkan "Polyhydroxybutyrate" bioplastik serta mesofilik dan termofilik protease dalam satu flask oleh  kultur Bacillus campuran telah disiasat. Eksperimen rekabentuk Box-Behnken telah digunakan. Jumlah PHB yang dikeluarkan meningkat dengan ketara dan terdapat persaingan antara PHB dan protease. Jumlah keluaran PHB maksima menggunakan rekabentuk Box-Behnken adalah 2.82 g/l/48 jam dengan aktiviti protease sama dengan 41.9 Unit/ml/48 jam untuk protease termofilik dan 99.65 Unit

  5. Experimental Study on Vehicle-Bridge Dynamic Characteristics of Thin-Walled Trough Girder Bridge for Urban Rail Transit%城市轨道交通薄壁槽形梁车桥动力特性试验研究

    Institute of Scientific and Technical Information of China (English)

    吴亮秦; 吴定俊; 李奇

    2011-01-01

    Field tests were conducted on a standard span thin-walled trough girder bridge for the elevated urban rail transit. The free vibration characteristics of the bridge, such as the frequency, mode and damping ratio were got. The test data for both the bridge and train during the train passing through the bridge, including the displacement, amplitude, stress and the acceleration responses of the bridge and the acceleration of the carbody were obtained and analyzed. The analysis results show that the deflection-span ratio of the girder body is less than the code limit. No resonance phenomenon occurs as the train passing through the bridge. The vertical stiffness of the girder body meets the requirements. The transverse fundamental frequency of the girder span is greater than the code value while the transverse fundamental frequency of the bridge is smaller. The lateral amplitude at the pier top is larger. The transverse stiffness of the girder body meets the requirements, whereas the stiffness of the pier is somewhat insufficient. Local vibration is found in the roadbed slab and the web. Therefore, more attention should be paid to the local stability of running lines and the web when the design speed is increased. The total longitudinal bending dynamic coefficient of the girder body is smaller than specification regulated value. However, the local transverse bending dynamic coefficient of the roadbed slab is much larger than the total longitudinal bending dynamic coefficient of the girder body. The acceleration of the bridge deck is within the limit. Judging by Sperling index and ISO2631 evaluation index, the ride comfort of the test train running on the bridge is found to be excellent. According to the test and analysis, thin-walled trough girder is proved to be suitable for elevated urban rail transit.%对城轨高架标准跨薄壁槽形梁桥进行现场测试,获得桥梁的频率、振型、阻尼比等自振特性,以及列车通过时桥梁的位移、振幅

  6. Enhancing Advanced Encryption Standard S-Box Generation Based on Round Key

    Directory of Open Access Journals (Sweden)

    Julia Juremi

    2015-05-01

    Full Text Available This paper presents a new AES-like design for key- dependent AES using S-box rotation. The algorithm involves key expansion algorithm together with S-box rotation and this property can be used to make the S-box key-dependent, hence providing a better security to the block cipher. Fixed S-box allows attackers to study S- box and find weak points while by using key-dependent S-Box approach, it makes it harder for attacker to do any offline analysis of an attack of one particular set of S- boxes. The cipher structure resembles the original AES, only the S-box is made key-dependent without changing the value. This new design is tested using the NIST Statistical Test and will be further cryptanalyzed with algebraic attack in order to permit its subversion or evasion.

  7. Conversion of Chemical Reaction Energy into Useful Work in the Van't Hoff Equilibrium Box

    Science.gov (United States)

    Bazhin, N. M.; Parmon, V. N.

    2007-01-01

    The ideal van't Hoff equilibrium box is described in detail. It shows that van't Hoff equilibrium box divided in two parts can simultaneously produce heat and useful work without violation of the first law of thermodynamics.

  8. 77 FR 38705 - Draft Specification for Airport Light Bases, Transformer Housings, Junction Boxes, and...

    Science.gov (United States)

    2012-06-28

    ... Federal Aviation Administration Draft Specification for Airport Light Bases, Transformer Housings... comment on the Draft ``Specification for Airport Light Bases, Transformer Housings, Junction Boxes, and... recommendations for airport light bases, transformer housings, junction boxes and accessories. The FAA has...

  9. Experimental Research and Numerical Simulation of Wing Boxes under Pure Bending Load

    OpenAIRE

    Peiyan Wang; Shile Yao; Xinmei Wang; Zhufeng Yue

    2014-01-01

    Two full-scale wing boxes with different types of butt joints were investigated under pure bending load, and numerical methods, including global analysis and detailed analysis, were proposed to determine the reasons for failure of the wing boxes. Wing boxes were tested under bending loads applied by a multichannel force control system. The experimental results showed that the region of the butt joint was the weakest location of the wing boxes, and the damage loads were far less than the desig...

  10. Specific Genomic Fingerprints of Phosphate Solubilizing Pseudomonas Strains Generated by Box Elements

    OpenAIRE

    Mohammad Bagher Javadi Nobandegani; Halimi Mohd Saud; Wong Mui Yun

    2014-01-01

    Primers corresponding to conserved bacterial repetitive of BOX elements were used to show that BOX-DNA sequences are widely distributed in phosphate solubilizing Pseudomonas strains. Phosphate solubilizing Pseudomonas was isolated from oil palm fields (tropical soil) in Malaysia. BOX elements were used to generate genomic fingerprints of a variety of Pseudomonas isolates to identify strains that were not distinguishable by other classification methods. BOX-PCR, that derived genomic fingerprin...

  11. The Role of Protein Electrostatics in Facilitating the Catalysis of DEAD-box Proteins

    OpenAIRE

    Frenz, Christopher M.

    2008-01-01

    Protein electrostatic states have been demonstrated to play crucial roles in catalysis, ligand binding, protein stability, and in the modulation of allosteric effects. Electrostatic states are demonstrated to appear conserved among DEAD-box motifs and evidence is presented that the structural changes that occur to DEAD box proteins upon ligand binding alter the DEAD-box motif electrostatics in a way the facilitates the catalytic role of the DEAD-box glutatmate.

  12. Photoluminescence and electro-optic properties of small (25-35 nm diameter) quantum boxes

    Science.gov (United States)

    Davis, L.; Ko, K. K.; Li, W.-Q.; Sun, H. C.; Lam, Y.; Brock, T.; Pang, S. W.; Bhattacharya, P. K.; Rooks, M. J.

    1993-05-01

    The luminescence and electro-optic properties of buried 25-35 nm quantum boxes have been measured. The quantum boxes were defined by a combination of molecular beam epitaxial growth and regrowth, electron beam lithography, and dry etching. The photoluminescence from 35 nm boxes shows a blue shift of about 15 meV compared to the bulk luminescence and an enhancement, taking into account the fill factor. An enhanced effective linear electrooptic coefficient is observed for the quantum boxes.

  13. Comparison of Laparoscopy Training Using the Box Trainer Versus the Virtual Trainer

    OpenAIRE

    Mohammadi, Yousef; Lerner, Michelle A.; Sethi, Amanjot S.; Sundaram, Chandru P.

    2010-01-01

    Background and Objectives: To evaluate whether training on a virtual reality laparoscopic simulator improves the performance on a laparoscopic box trainer. Methods: Twenty-six subjects were trained using a box trainer, and 17 participants were trained using a virtual simulator. Participants in the experimental group completed 1 session of 5 exercises on the box trainer, 4 sessions on the virtual simulator, and a final session on the box trainer. Participants in the control group completed 6 s...

  14. Visual pigment in the lens eyes of the box jellyfish Chiropsella bronzie

    OpenAIRE

    O'Connor, Megan; Garm, Anders; Marshall, Justin N.; Hart, Nathan S.; Ekström, Peter; Skogh, Charlotta; Nilsson, Dan-Eric

    2010-01-01

    Box jellyfish (Cubomedusae) possess a unique visual system comprising 24 eyes of four morphological types. Moreover, box jellyfish display several visually guided behaviours, including obstacle avoidance and light-shaft attractance. It is largely unknown what kind of visual information box jellyfish use for carrying out these behaviours. Brightness contrast is almost certainly involved, but it is also possible that box jellyfish extract colour information from their surroundings. The possible...

  15. Combining Multiple External Representations and Refutational Text: An Intervention on Learning to Interpret Box Plots

    Science.gov (United States)

    Lem, Stephanie; Kempen, Goya; Ceulemans, Eva; Onghena, Patrick; Verschaffel, Lieven; Van Dooren, Wim

    2015-01-01

    Box plots are frequently misinterpreted and educational attempts to correct these misinterpretations have not been successful. In this study, we used two instructional techniques that seemed powerful to change the misinterpretation of the area of the box in box plots, both separately and in combination, leading to three experimental conditions,…

  16. Entanglement and decoherence of a micromechanical resonator via coupling to a Cooper box

    OpenAIRE

    Armour, A. D.; Blencowe, M. P.; Schwab, K. C.

    2001-01-01

    We analyse the quantum dynamics of a micromechanical resonator capacitively coupled to a Cooper box. With appropriate quantum state control of the Cooper box, the resonator can be driven into a superposition of spatially separated states. The Cooper box can also be used to probe the environmentally-induced decoherence of the resonator superposition state.

  17. Justification procedure of hydrogen safety of RU BN compartments as exemplified by steam generator box

    International Nuclear Information System (INIS)

    Basic proposals on completing calculational procedures of sodium cooled reactors hydrogen safety justification, particularly steam generator (SG) box, are presented. It is pointed out that hydrogen appearance in SG box is possible only in accidents with multiple failures. The data presented shows that hydrogen safety and explosion-proofness of fast reactor facility SG box are provided without any special complex and expensive means

  18. 76 FR 16350 - Medical Devices; Ovarian Adnexal Mass Assessment Score Test System; Labeling; Black Box Restrictions

    Science.gov (United States)

    2011-03-23

    ... addition of this black box warning to product labeling, advertising, and marketing materials, the Agency... Assessment Score Test System; Labeling; Black Box Restrictions AGENCY: Food and Drug Administration, HHS... be in a black box and must appear in all labeling, advertising, and promotional material. The...

  19. Is Think Outside the Box 21st Century Code for Imagination, Innovation, Creativity, Critical Thinking, Intuition?

    Science.gov (United States)

    Notar, Charles E.; Padgett, Sharon

    2010-01-01

    It is the authors' contention that there is no such thing as "thinking outside the box." However, the term has become an iconic phrase for a generation. The discussion presents the authors' thoughts on why there is no box in which to think outside. If there is a box, then accidental learning would never exist for students.

  20. THE USE OF EVENT DATA RECORDER (EDR – BLACK BOX

    Directory of Open Access Journals (Sweden)

    Gabriel Nowacki

    2014-03-01

    Full Text Available The paper refers to the registration of road events by a modern device called EDR – black box for all types of the motor vehicles. The device records data concerning vehicle’s technical condition, the way it was driven and RTS. The recorder may be used in private and commercial cars, taxies, buses and trucks. The recorder may serve the purpose of a neutral witness for the police, courts and insurance firms, for which it will facilitate making the reconstruction of the road accidents events and will provide a proof for those who caused them. The device will bring efficient driving, which will significantly contribute to decreasing the number of road accidents and limiting the environmental pollution. In the end in the last year German parliament backed a proposal to the European Commission to put black boxes, which gather information from vehicles involved in accidents, in all the new cars from 2015 on.

  1. Application of glove box robotics to hazardous waste management

    International Nuclear Information System (INIS)

    Lawrence Livermore Laboratory (LLNL) is developing a semi-automated system for handling, characterizing, processing, sorting, and repackaging hazardous wastes containing tritium. The system combines an IBM developed gantry robot with a special glove box enclosure designed to protect the operators and minimize the potential release of tritium to the atmosphere. All hazardous waste handling and processing will be performed remotely using the robot in a telerobotic mode for one-of-a-kind functions and in an autonomous mode for repetitive type operations. The system will initially be used in conjunction with a portable gas system designed to capture any gaseous phase tritium released into the glove box. This paper presents the objectives of this program, provides background related to LLNL's robotics and waste handling program, describes the major system components, outlines system operation, and discusses current status and plans

  2. Safeguards Approaches for Black Box Processes or Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Marcano, Helly; Gitau, Ernest TN; Hockert, John; Miller, Erin; Wylie, Joann

    2013-09-25

    The objective of this study is to determine whether a safeguards approach can be developed for “black box” processes or facilities. These are facilities where a State or operator may limit IAEA access to specific processes or portions of a facility; in other cases, the IAEA may be prohibited access to the entire facility. The determination of whether a black box process or facility is safeguardable is dependent upon the details of the process type, design, and layout; the specific limitations on inspector access; and the restrictions placed upon the design information that can be provided to the IAEA. This analysis identified the necessary conditions for safeguardability of black box processes and facilities.

  3. Application Analysis of Ad Lamp-box Controller

    Institute of Scientific and Technical Information of China (English)

    FANG Yuan; LU Bin

    2014-01-01

    The ad lamp-box controller is designed in consideration that ordinary urban ad lights usually remain lit through the night and a specially assigned staff needs to be on duty to control their switches. It can be automatically controlled with a photo resistance testing the day and night as well as a CD4060 chip controlling the length of time interval between switching the ad lamp-boxes on and off. In this way, both energy and labor can be saved with the controller. It is matching with the target of“constructing a conservation-minded society”in our country and deserves to be promoted in market with its practical signifi-cance.

  4. Smart Remote for the Setup Box Using Gesture Control

    Directory of Open Access Journals (Sweden)

    Surepally Uday Kumar

    2016-04-01

    Full Text Available The basic purpose of this project is to provide a means to control a set top box (capable of infrared communication, in this case Hathway using hand gestures. Thus, this system will act like a remote control for operating set top box, but this will be achieved through hand gestures instead of pushing buttons. To send and receive remote control signals, this project uses an infrared LED as Transmitter. Using an infrared receiver, an Arduino can detect the bits being sent by a remote control. And to playback a remote control signal, the Arduino can flash an infrared LED at 38 kHz. With this project we can design a gesture controlled remote by using a glove, it can be fixed to the hand, we can send any signal of any length, at any related frequency, and thus we can design a universal remote.

  5. Gas box control system for Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    The Tandem Mirror Experiment-Upgrade (TMX-U) uses several methods to feed gas (usually deuterium) at different energies into the plasma region of the machine. One is an arrangement of eight high-speed piezo-electric valves mounted on special manifolds (gas box) that feed cold gas directly to the plasma. This paper describes the electronic valve control and data acquisition portions of the gas box, which are controlled by a desk-top computer. Various flow profiles have been developed and stored in the control computer for ready access by the operator. The system uses two modes of operation, one that exercises and characterizes the valves and one that operates the valves with the rest of the experiment. Both the valve control signals and the pressure transducers data are recorded on the diagnostics computer so that they are available for experiment analysis

  6. Competitive markets, collective action, and the Big Box Retailer problem

    Directory of Open Access Journals (Sweden)

    Brent D. Beal

    2012-11-01

    Full Text Available I use a stylized scenario—the Big Box retailer Problem—to demonstrate that the presence of behavioural interdependence in economic markets may result in deficient outcomes that are both stable and supported by ongoing participant behaviour. I present a theoretical discussion of social dilemmas and use the Big Box retailer Problem to illustrate that these characteristics—stability and ongoing support—cannot be reliably employed as indicators of outcome efficiency. Equally important is the conclusion that upfront costs and the ongoing necessity of monitoring and encouraging contributory behaviour are not reliable indicators of the relative inefficiency of outcomes associated with collective action. Questions are raised regarding the ethical responsibilities of business educators and the implications of social dilemmas for corporate social responsibility research.

  7. Observational semantics of the Prolog Resolution Box Model

    CERN Document Server

    Deransart, Pierre; Ferrand, Gérard

    2007-01-01

    This paper specifies an observational semantics and gives an original presentation of the Byrd box model. The approach accounts for the semantics of Prolog tracers independently of a particular Prolog implementation. Prolog traces are, in general, considered as rather obscure and difficult to use. The proposed formal presentation of its trace constitutes a simple and pedagogical approach for teaching Prolog or for implementing Prolog tracers. It is a form of declarative specification for the tracers. The trace model introduced here is only one example to illustrate general problems relating to tracers and observing processes. Observing processes know, from observed processes, only their traces. The issue is then to be able to reconstitute, by the sole analysis of the trace, part of the behaviour of the observed process, and if possible, without any loss of information. As a matter of fact, our approach highlights qualities of the Prolog resolution box model which made its success, but also its insufficiencies...

  8. Free box^k Scalar Conformal Field Theory

    CERN Document Server

    Brust, Christopher

    2016-01-01

    We consider the generalizations of the free U(N) and O(N) scalar conformal field theories to actions with higher powers of the Laplacian, box^k, in general dimension d. We study the spectra, Verma modules, anomalies and OPE of these theories. We argue that in certain d and k, the spectrum contains zero norm operators which are both primary and descendant, as well as extension operators which are neither primary nor descendant. In addition, we argue that in even dimensions d <= 2k, there are well-defined operator algebras which are related to the box^k theories and are novel in that they have a finite number of single-trace states.

  9. Box jellyfish use terrestrial visual cues for navigation.

    Science.gov (United States)

    Garm, Anders; Oskarsson, Magnus; Nilsson, Dan-Eric

    2011-05-10

    Box jellyfish have an impressive set of 24 eyes of four different types, including eyes structurally similar to those of vertebrates and cephalopods [1, 2]. However, the known visual responses are restricted to simple phototaxis, shadow responses, and object avoidance responses [3-8], and it has been a puzzle why they need such a complex set of eyes. Here we report that medusae of the box jellyfish Tripedalia cystophora are capable of visually guided navigation in mangrove swamps using terrestrial structures seen through the water surface. They detect the mangrove canopy by an eye type that is specialized to peer up through the water surface and that is suspended such that it is constantly looking straight up, irrespective of the orientation of the jellyfish. The visual information is used to navigate to the preferred habitat at the edge of mangrove lagoons. PMID:21530262

  10. Box jellyfish use terrestrial visual cues for navigation

    DEFF Research Database (Denmark)

    Garm, Anders; Oskarsson, Magnus; Nilsson, Dan-Eric

    2011-01-01

    Box jellyfish have an impressive set of 24 eyes of four different types, including eyes structurally similar to those of vertebrates and cephalopods [1, 2]. However, the known visual responses are restricted to simple phototaxis, shadow responses, and object avoidance responses [3-8], and it has...... been a puzzle why they need such a complex set of eyes. Here we report that medusae of the box jellyfish Tripedalia cystophora are capable of visually guided navigation in mangrove swamps using terrestrial structures seen through the water surface. They detect the mangrove canopy by an eye type...... that is specialized to peer up through the water surface and that is suspended such that it is constantly looking straight up, irrespective of the orientation of the jellyfish. The visual information is used to navigate to the preferred habitat at the edge of mangrove lagoons....

  11. Study of Aerodynamic Parameters of Truss Girder Bridge with Inverted Trapezoid Section Under Skew Wind%斜向风作用下倒梯形桁梁桥气动力参数研究

    Institute of Scientific and Technical Information of China (English)

    郑史雄; 张龙奇; 张向旭; 张俊明

    2015-01-01

    To study the influences of the aerodynamic parameters on the aerodynamic charac‐teristics of the rail‐cum‐road truss girder bridge with inverted trapezoid section under skew wind , two kinds of the truss girder models with inverted trapezoid sections of different dimensions were selected and the wind tunnel tests for the models under various combined cases of the completed bridge and construction state ,wide range of wind yawed angles (0°~180°) and different wind at‐tack angle flow were carried out .The five‐component force coefficients of the models were meas‐ured and the test values were compared to the results of the traditional skew wind decomposition theory .The results of the tests show that the maximum values of the force coefficients of the transverse bridge direction all appear at the wind yawed angle of about 15° while the maximum val‐ues of the force coefficients of the longitudinal bridge direction appear at the yawed angle of about 60° .For the truss girder bridge with such type of the trapezoid section ,the wind from the trans‐verse bridge direction is not necessarily the worst flow in the calculation of the transverse bridge wind‐induced response and the wind force of the longitudinal bridge direction can not be ignored . The comparison of the wind tunnel test results to the skew wind decomposition theory tells that the ratios of the force coefficients of the transverse and longitudinal bridge directions obtained by the tests and the decomposition theory have certain deviations .%为研究气动力参数对倒梯形断面公铁两用桁梁桥在斜向风作用下气动特性的影响,采用2种不同断面尺寸的倒梯形断面桁梁模型,针对成桥状态与施工状态,在大范围风偏角(0°~180°)与不同风攻角来流条件多种组合工况下进行风洞试验,测量其五分力系数,并将试验值与传统斜向风分解理论结果进行对比。试验结果表明:横桥向力系数最大

  12. The Boxing Day Tsunami: Could the Disaster have been Anticipated?

    Science.gov (United States)

    Cummins, P. R.; Burbdige, D.

    2005-05-01

    The occurrence of the 26 December, 2004 Sumatra-Andaman earthquake and the accompanying "Boxing Day" Tsunami, which killed over 280,00, has been described as one of the most lethal natural disasters in human history. Many lives could have been saved had a tsunami warning system, similar to that which exists for the Pacific Ocean, been in operation for the Indian Ocean. The former exists because great subduction zone earthquakes have generated destructive, Pacific-wide tsunami in the Pacific Ocean with some frequency. Prior to 26 December, 2004, all of the world's earthquakes with magnitude > 9 were widely thought to have occurred in the Pacific Ocean, where they caused destructive tsunami. Could the occurrence of similar earthquakes and tsunami in the Indian Ocean been predicted prior to the 2004 Box Day Tragedy? This presentation will argue that the answer is "Yes". Almost without exception (the exception being the 1952 Kamchatka earthquake) the massive subduction zone earthquakes and tsunami of the Pacific Ocean have been associated with the subduction of relatively young ocean lithosphere (literature and were the subject of recent research. In particular, research by Zachariasen et al. (1999 and 2000) had inferred that the magnitude of the 1833 event may have been as high as 9.2. Calculations for the tsunami that might have been associated with this event had shown, prior to 26 Dec, that it would affect the entire Indian Ocean basin, although due to the earthquake's location 1000 km southeast of the Boxing day event, the effects in the Bay of Bengal would not have been as severe. Thus, it seems to this author that the Boxing Day event could and should have been anticipated. This presentation will further consider why it was not, and what steps can be taken to anticipate and mitigate the effects of future events that may occur in the Indian Ocean and elsewhere.

  13. Mutated hybrid inflation in $f(R,{\\Box}R)$-gravity

    CERN Document Server

    Iihoshi, Masao

    2010-01-01

    A new hybrid inflationary scenario in the context of $f(R,{\\Box}R)$-gravity is proposed. Demanding the waterfall field to 'support the potential from below' [unlike the original proposal by Stewart in Phys. Lett. B345, 414 (1995)], we demonstrate that the scalar potential is similar to that of the large-field chaotic inflation model proposed by Linde in Phys. Lett. B129, 177 (1983).

  14. Evaluation of multi-box diagrams in six dimensions

    International Nuclear Information System (INIS)

    We present a simple method which simplifies the evaluation of the on-shell multiple box diagrams reducing them to triangle type ones. For the L-loop diagram one gets the expression in terms of Feynman parameters with 2L-fold integration. As examples we consider the 2 and 3 loops cases, the numerical integration up to six loops is also presented. The method is valid in six dimensions where neither UV not IR divergences appear

  15. Black-Box Algorithms for Sampling from Continuous Distributions

    OpenAIRE

    Hörmann, Wolfgang; Leydold, Josef

    2006-01-01

    For generating non-uniform random variates, black-box algorithms are powerful tools that allow drawing samples from large classes of distributions. We give an overview of the design principles of such methods and show that they have advantages compared to specialized algorithms even for standard distributions, e.g., the marginal generation times are fast and depend mainly on the chosen method and not on the distribution. Moreover these methods are suitable for specialized tasks like sampling ...

  16. Chinese boxes: "Typhoon" and Conrad's history of the Chinese

    OpenAIRE

    Kerr, D.

    2009-01-01

    This essay examines the novel "Typhoon," by Joseph Conrad, as a story about Chinamen coolies and seamen onboard a steamer transporting Chinese laborers. It argues that the Chinese boxes of the coolies represent several versions of the history of the Chinese and that the coolies are also representatives of a civilization with ideas and institutions, a law and order of nature. It also describes the images of Chinese life and their association to sociality, cooperation, nourishment, simplicity, ...

  17. Venom Proteome of the Box Jellyfish Chironex fleckeri

    OpenAIRE

    Brinkman, Diane L; Ammar Aziz; Alex Loukas; Jeremy Potriquet; Jamie Seymour; Jason Mulvenna

    2012-01-01

    The nematocyst is a complex intracellular structure unique to Cnidaria. When triggered to discharge, the nematocyst explosively releases a long spiny, tubule that delivers an often highly venomous mixture of components. The box jellyfish, Chironex fleckeri, produces exceptionally potent and rapid-acting venom and its stings to humans cause severe localized and systemic effects that are potentially life-threatening. In an effort to identify toxins that could be responsible for the serious heal...

  18. A NEW PRINCIPAL PIVOTING SCHEME FOR BOX LINEAR COMPLEMENTARITY PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    WANGZHEMIN

    1997-01-01

    Judice and Pires developed in recent years principal pivoting methods for the solving ofthe so-called box linear complementarity problems (BLCPs) where the constraint matrices are restrictedly supposed to be of P-matrices. This paper aims at presenting a new principal pivoting scheme for BLCPs where the constraint matrices are loosely supposed to be row sufficient. This scheme can be applied to the solving of convex quadratic programs subject to linear constraints and arbitrary upper and lower bound constraints on variables.

  19. ArduiPod Box: a low-cost and open-source Skinner box using an iPod Touch and an Arduino microcontroller.

    Science.gov (United States)

    Pineño, Oskar

    2014-03-01

    This article introduces the ArduiPod Box, an open-source device built using two main components (i.e., an iPod Touch and an Arduino microcontroller), developed as a low-cost alternative to the standard operant conditioning chamber, or "Skinner box." Because of its affordability, the ArduiPod Box provides an opportunity for educational institutions with small budgets seeking to set up animal laboratories for research and instructional purposes. A pilot experiment is also presented, which shows that the ArduiPod Box, in spite of its extraordinary simplicity, can be effectively used to study animal learning and behavior.

  20. An Introduction to Plum Blossom Boxing: History, Culture and Practice

    Directory of Open Access Journals (Sweden)

    Guodong Zhang

    2012-07-01

    Full Text Available Meihuaquan (“Plum Blossom Fist [Boxing]” has traditionally been practiced as vernacular (folk art practiced among the Han ethnic group residing in the Shandong, Henan and Hebei Provinces of China. Historical documentation dates Plum Blossom Boxing to the seventeenth century. The classic Chinese novel, Shuǐhǔ Zhuàn (Marsh Chronicles recounts the martial exploits of Shandong’s twelfth century outlaw heroes who may have been Mei Boxers, also. Thus, for perhaps a millennium, the region has been noted for vernacular martial arts and social banditry. The region’s rampant lawlessness promoted highly-developed martial prowess among both lawbreakers and those who were required to protect themselves against the brigands. Cultural, economic, and environmental factors in the region gave rise to heterodox political and religious beliefs that frequently served as a catalyst for martial sects, most notably the “Boxers” who at the turn of the twentieth century, came into conflict with the imperial government. These factors laid the groundwork for the “character traits” of the art while Taoism, the Five Elements theory, and a concept of predictable change shaped Plum Boxing’s strategic and mechanical principles. In the past decade, there have been efforts to globalize this vernacular martial art. Rather than driving Plum Boxing to extinction it is likely that the folk and the “larger than local” will co-exist.

  1. Packaging design criteria modified fuel spacer burial box. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, P.F.

    1994-09-13

    Various Hanford facilities must transfer large radioactively contaminated items to burial/storage. Presently, there are eighteen Fuel Spacer Burial Boxes (FSBBs) available on the Hanford Site for transport of such items. Previously, the FSBBS were transported from a rail car to the burial trench via a drag-off operation. To allow for the lifting of the boxes into the burial trench, it will be necessary to improve the packagings lifting attachments and provide structural reinforcement. Additional safety improvements to the packaging system will be provided by the addition of a positive closure system and package ventilation. FSBBs that are modified in such a manner are referred to as Modified Fuel Spacer Burial Boxes (MFSBs). The criteria provided by this PDC will be used to demonstrate that the transfer of the MFSB will provide an equivalent degree of safety as would be provided by a package meeting offsite transportation requirements. This fulfills the onsite transportation safety requirements implemented in WHC-CM-2-14, Hazardous Material Packaging and Shipping. A Safety Analysis Report for Packaging (SARP) will be prepared to evaluate the safety of the transfer operation. Approval of the SARP is required to authorize transfer. Criteria are also established to ensure burial requirements are met.

  2. Comparative Analysis of Synchronous and Asynchronous Construction of Tower and girder of Yongjiang Railway Cable Stayed Bridge%甬江铁路斜拉桥索塔塔梁同异步施工方法对比分析

    Institute of Scientific and Technical Information of China (English)

    胡晓东; 陈平

    2016-01-01

    The extra-long bridge of Yongjiang River is a domestic first large-span railway cable-stayed bridge with hybrid girder and 177.91 m diamond-type tower. In order to analyze the impact of synchronous and asynchronous constructions of tower and girder on the stress state and linearity of the tower, a finite element model is established to simulate the entire construction process. The comparative analysis reveals that the stress and line of the tower resulted from the two construction methods are of some difference, and both methods meet design requirement, but the asynchronous construction method can save much time. According to the comparative analysis and the actual lagging of the south cable-tower, the south tower and the north tower employ synchronous and asynchronous construction methods respectively, and as a consequence, the synchronization of progress and good economic and social benefits are obtained.%甬江特大桥为国内首座铁路大跨度钢箱混合梁斜拉桥,钻石形索塔高177.91 m。通过建立索塔与下横梁同、异步施工有限元模型,模拟分析同、异步施工对索塔受力状态及线形的影响。对比分析表明,同、异步施工的索塔受力及线形略有差异,均能满足设计要求,而异步施工较同步在工期上有较大优势。根据对比分析及南岸索塔工期滞后的实际情况,甬江特大桥南北岸索塔分别采用了塔梁异步与塔梁同步的施工方法,最后实现工期的同步,收到了良好的经济与社会效益。

  3. Box-Cox变换及其在STATA软件中的实现

    Institute of Scientific and Technical Information of China (English)

    陶庄

    2007-01-01

    目的:向医疗卫生领域的一线工作者介绍Box-Cox变换.方法:利用STATA软件包拟合Box-Cox回归模型.结果:通过使用示例数据库进行拟合,成功的进行了Box-Cox变换,并进行了回归分析.结论:使用Box-Cox变换是解决应变量不符合正态分布的重要方法,而STATA软件提供了进行Box-Cox变换的可行之道.

  4. Analysis of effective flange width of small radius curved bridge with single box and double chamber%小半径单箱双室曲线桥梁翼缘有效宽度的研究

    Institute of Scientific and Technical Information of China (English)

    方飞; 张杰; 张鲲; 张振; 方诗圣

    2013-01-01

    针对小半径单箱双室曲线梁桥的剪力滞效应以及选取其翼缘有效宽度的问题,文章依托实际工程,采用有限元软件ABAQUS建立某曲线梁桥的空间有限元模型,分析了荷载为重力、汽车荷载等共同作用下结构的变形和内力,研究不同曲率半径下,剪力滞效应及其对小半径曲线梁桥翼缘有效宽度取值的影响。结果表明:对于单箱双室箱形截面,不同半径作用下,中腹板对应的有效宽度都小于两侧宽度;相比直线桥而言,对于不同的曲率半径,内腹板对应的有效宽度大于外侧腹板;随着曲率半径的减小,各个腹板对应的有效宽度的差值也越来越大。故在确定小半径单箱双室曲线梁桥翼缘有效宽度时,可以在现行桥梁设计规范的计算宽度基础上乘以修正系数。%The shear lag effect of small radius curved bridge with single box and double chamber and the selection of the effective width of flange were studied .Based on the practical engineering ,the de-formation and the inner force of the structure under the interaction of load gravity and vehicle load were analyzed by the spatial finite element model of a curved girder bridge using the finite element software ABAQUS .The shear lag effect of small radius curved bridge with single box and double chamber under different radius of curvature and the influence on the flange’s value were studied .The results show that under the influence of different radius ,the corresponding effective width of medium web is less than bilateral web width for the section of single box and double chamber single box ;com-pared with the straight bridge ,the corresponding effective width of medial web is larger than lateral web’s under different radius of curvature ;the differences of the corresponding effective width of each web become larger and larger with the decrease of radius of curvature .In a conclusion ,the calculative width of current

  5. 太阳日总辐射量的Box-Jenkins模型%BOX-JENKINS MODEL FOR DAILY SOLAR RADIATION

    Institute of Scientific and Technical Information of China (English)

    王敏; 丁明

    2012-01-01

    基于天文辐射和日照率数据,采用系统辨识的方法建立了模拟太阳日总辐射量的BJ( Box-Jenkins)模型.该模型与传统的(A)ngstr(m)的日总辐射量的计算公式相比,模拟和预测效果更好.%Based on astronomical radiation and percentage of possible sunshine data, the BJ (Box-Jenkins) model for daily solar irradiation is established using system identification method. The simulation and the one-step forecast results of the BJ model are better than Angstrm formula of the calculation.

  6. Monte Carlo simulation experiments on box-type radon dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, Khalid, E-mail: kjamil@comsats.edu.pk; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

    2014-11-11

    Epidemiological studies show that inhalation of radon gas ({sup 222}Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the {sup 222}Rn concentrations (Bq/m{sup 3}) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter’s dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (η{sub int}) and alpha hit efficiency (η{sub hit}). The η{sub int} depends upon only on the dimensions of the dosimeter and η{sub hit} depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper

  7. Monte Carlo simulation experiments on box-type radon dosimeter

    Science.gov (United States)

    Jamil, Khalid; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

    2014-11-01

    Epidemiological studies show that inhalation of radon gas (222Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the 222Rn concentrations (Bq/m3) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter's dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (ηint) and alpha hit efficiency (ηhit). The ηint depends upon only on the dimensions of the dosimeter and ηhit depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper explains that how radon concentration from the

  8. Saturation of the magnetorotational instability in the unstratified shearing box with zero net flux: convergence in taller boxes

    Science.gov (United States)

    Shi, Ji-Ming; Stone, James M.; Huang, Chelsea X.

    2016-03-01

    Previous studies of the non-linear regime of the magnetorotational instability in one particular type of shearing box model - unstratified with no net magnetic flux - find that without explicit dissipation (viscosity and resistivity) the saturation amplitude decreases with increasing numerical resolution. We show that this result is strongly dependent on the vertical aspect ratio of the computational domain Lz/Lx. When Lz/Lx ≲ 1, we recover previous results. However, when the vertical domain is extended Lz/Lx ≳ 2.5, we find the saturation level of the stress is greatly increased (giving a ratio of stress to pressure α ≳ 0.1), and moreover the results are independent of numerical resolution. Consistent with previous results, we find that saturation of the magnetorotational (MRI) in this regime is controlled by a cyclic dynamo which generates patches of strong toroidal field that switches sign on scales of Lx in the vertical direction. We speculate that when Lz/Lx ≲ 1, the dynamo is inhibited by the small size of the vertical domain, leading to the puzzling dependence of saturation amplitude on resolution. We show that previous toy models developed to explain the MRI dynamo are consistent with our results, and that the cyclic pattern of toroidal fields observed in stratified shearing box simulations (leading to the so-called butterfly diagram) may also be related. In tall boxes the saturation amplitude is insensitive to whether or not explicit dissipation is included in the calculations, at least for large magnetic Reynolds and Prandtl number. Finally, we show MRI turbulence in tall domains has a smaller critical Pmc, and an extended lifetime compared to Lz/Lx ≲ 1 boxes.

  9. Insights into the quality of DnaA boxes and their cooperativity

    DEFF Research Database (Denmark)

    Hansen, Flemming G.; Christensen, Bjarke Bak; Nielsen, Christina Bang;

    2006-01-01

    Plasmids carrying the mioC promoter region with its two DnaA boxes are as efficient in titration of DnaA protein as plasmids carrying a replicationinactivated oriC region with its five DnaA boxes. The two DnaA boxes upstream of the mioC promoter were mutated in various ways to study the cooperati......Plasmids carrying the mioC promoter region with its two DnaA boxes are as efficient in titration of DnaA protein as plasmids carrying a replicationinactivated oriC region with its five DnaA boxes. The two DnaA boxes upstream of the mioC promoter were mutated in various ways to study...... the cooperativity between the DnaA boxes, and to study in vivo the in vitrodefined 9mer DnaA box consensus sequence TTA/TTNCACA). The quality and cooperativity of the DnaA oxes were determined in two complementary ways: as titration of DnaA protein leading to derepression of the dnaA promoter, and as repression...... of the mioC promoter caused by the DnaA protein binding to the DnaA boxes. Titration of DnaA protein correlated with repression of the mioC promoter. The level of titration and repression with the normal promoter-proximal box (TTTTCCACA) depends strongly on the presence and the quality of a DnaA box...

  10. A neurologist's reflections on boxing. V. Conclude remarks.

    Science.gov (United States)

    Unterharnscheidt, F

    1995-01-01

    Clinical and morphological publications have shown convincingly, that participation in boxing leads to a severe permanent brain damage. The extent of the brain damage is correlated to the number of bouts fought, which correspondents in a certain way how many blows against his head a boxer received and to his weight class. The intensity of a boxing blow of a heavyweight is much more severe than those achieved by boxers of lighter weight classes. The permanent brain damage in a boxer, the amateur and the professional boxer, manifests itself in several clinical syndromes in which the pyramidal, the extrapyramidal and the cerebellar systems are involved. A traumatic Parkinsonism, in its complete or abortive form, develops as the result of the numerous boxing blows a boxer sustains in his boxing career. Especially lateral parts of the substantia nigra are affected and reveal at macroscopical and microscopical examination a severe loss of pigmented neurons. Melanin pigment is visible free in the tissue and/or is phagozytosed in macrophages and glial cells. The traumatic Parkinson syndrome, often only in an abortive form, is combined in a boxer with additional clinical and morphological findings due to traumatic lesions in other areas of the brain. It is not as pure as in a patient with a Parkinson syndrome sui generis. The permanent brain damage in a boxer is diffuse, involving all areas of the brain. Especially involved are the large neurons of different layers of the cerebral cortex, the neurons of the Ammons horn formation, the Purkinje cells of the cerebellum. In place of destroyed and lost neurons, proliferation of glial elements, especially astroglial cells, has occurred. The defects are first replaced by protoplasmatic astroglial elements, and later by fibrillary astroglia. The destroyed neurons are replaced by glial scar tissue, which cannot perform the functions of the lost neurons. It is a process which is called partial necrosis of brain tissue. There is no

  11. Fano-Kondo and the Kondo box regimes crossover in a quantum dot coupled to a quantum box.

    Science.gov (United States)

    Apel, Victor M; Orellana, Pedro A; Pacheco, Monica; Anda, Enrique V

    2013-12-18

    In this work, we study the Kondo effect of a quantum dot (QD) connected to leads and to a discrete set of one-particle states provided by a quantum box represented by a quantum ring (QR) pierced by a magnetic flux side attached to the QD. The interplay between the bulk Kondo effect and the so-called Kondo box regime is studied. In this system the QR energies can be continuously modified by the application of the magnetic field. The crossover between these two regimes is analyzed by changing the connection of the QD to the QR from the weak to the strong coupling regime. In the weak coupling regime, the differential conductance develops a sequence of Fano-Kondo anti-resonances due to destructive interference between the discrete quantum ring levels and the conducting Kondo channel provided by the leads. In the strong coupling regime the differential conductance has very sharp resonances when one of the Kondo discrete sub-levels characterizing the Kondo box is tuned by the applied potential. The conductance, the current fluctuations and the Fano coefficient result as being the relevant physical magnitudes to be analyzed to reveal the physical properties of these two Kondo regimes and the crossover region between them. The results were obtained by using the slave boson mean field theory (SBMFT). PMID:24275637

  12. 基于两水平设防的连续梁桥抗震性能分析%Seismic Performance Analysis of Continuous Girder Bridge Based on Two-level Design Approach

    Institute of Scientific and Technical Information of China (English)

    邓小伟

    2012-01-01

    According to the new ideas and new methods by guidelines for seismic design of highway bridges (JTG / T B02-01-2008) , with the background of a continuous girder bridge in the area of 7 degree earthquake intensity, an elastic-plastic finite element model is established for dynamic characteristics analysis, seismic response spectrum analysis and nonlinear time history analysis, to reveal the force and deformation under earthquake action of two levels. Furthermore, the seismic performance is evaluated to provide a reference for seismic design of bridges.%根据《公路桥梁抗震设计细则》(JTG/T B02—01—2008)中的抗震设防新理念和新方法,以Ⅶ度区某连续梁桥为工程背景,建立了弹塑性有限元模型,依次进行了动力特性分析、地震反应谱分析和非线性时程分析,揭示了两级地震作用下桥梁的受力及变形情况,并对桥梁的抗震性能进行了评价,可供桥梁抗震设计参考.

  13. 基于 Flash 平台下的钢筋工程量计算--以框架梁为例%Reinforced Concrete Construction Volume Calculation Based on Flash Platform:Taking Frame Girder as an Example

    Institute of Scientific and Technical Information of China (English)

    李云春; 李敬民; 马文杰; 王瑞; 陈双红

    2013-01-01

      在工程造价工作中,有关钢筋工程量的枯燥的平法表示法和繁琐的计算往往令初学者望而生畏,甚至失去了学习的兴趣。本文主要通过 Flash 强大的动画演示功能和内置的 AcionScript 脚本语言,以一根框架梁为例,将平淡无奇的钢筋平法图形像动画一样生动、形象地展示出来,并配以文字说明与计算方法,让钢筋工程量计算的学习变得简单易学,并较大程度地增强学习者的学习兴趣。%In the administration of engineering cost, students often have difficulties in P -method expression and cumbersome calculations of reinforced concrete construction volume, even lost interest in learning. Taking a frame girder as an example, the paper shows the P-method figure through Flashi and built-in AcionScript scripting language, with a text description and calculation methods; it makes calculation of reinforced concrete construction volume simply and easy, and enhances students ' interest in learning.

  14. 大跨径斜拉桥塔墩梁固结处空间受力分析%Analysis of Spatial Mechanical Behavior of Pylon, Girder and Pier Rigid Fixity Structures of Long-span Cable-stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    黄力; 刘志权; 石雪飞

    2012-01-01

    The Huaihe and Five Rivers Bridge of Anhui is hybrid girder cable-stayed bridge, with span arrangement (246 +125) m and single tower double cable planes tower pier beam consolidation system. Midas/ Civil is used to establish a space truss model for the overall analysis to determine the most unfavorable parts of the tower-pier-beam loading conditions. With the large general-purpose finite element software ANSYS, three-dimensional solid model tower-pier-beam consolidation is established, which provides scientific and theoretical basis for the design and construction.%安徽五河淮河桥大桥为混合梁斜拉桥,跨径布置为(246+125)m,为独塔双索面塔墩梁固结体系.利用Midas/Civil建立空间杆系模型进行整体静力分析,确定塔墩梁部位四种最不利荷载工况,得到其活载影响线加载位置和荷载大小.再利用大型通用有限元软件ANSYS建立塔墩梁固结处三维实体模型进行受力分析,为设计与施工提供科学理论依据.

  15. 基于梁格法的某简支板梁桥荷载研究%Probe: Load of a Simple-supported Plate Girder Bridge Based on Grillage Method

    Institute of Scientific and Technical Information of China (English)

    宋书军; 李辉

    2012-01-01

    Using the finite element software "MIDAS" and taking a simplified plate girder bridge as an example,the whole space grillage is modeled in this paper.The static characteristics and dynamic characteristics are analyzed,and the corresponding theorey is reviewd.The comparison test shows that the overall stiffness and carrying capacity of the bridge are improved particulary in terms of safty tolerance.%以某简支板梁桥为例,利用桥梁专用有限元软件MIDAS/CIVIL建立全桥空间梁格模型,分析了该桥的静力特性、动力特性,得到相应的理论值,并与实测值进行比较,对新建桥梁结构做出性能评估.结果表明:该桥整体刚度较大,承载能力较好,结构具有一定的安全储备.

  16. Replacement of roller-track girder on overburden conveying bridge F60 at the Walzow opencast mine of LAUBAG; Rollbahntraegerwechsel an der Abraumfoerderbruecke F60 im Tagebau Welzow der Lausitzer Braunkohle AG

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, E. [LAUBAG, Senftenberg (Germany); Nies, G. [MAN TAKRAF Foerdertechnik GmbH, Lauchhammer (Germany)

    1996-11-01

    After an operating time of about 20 years damage, mainly in the form of cracks in welds, occurs on the roller-track girders of the overburden conveying bridges. The causes of this damage are the quality of the H 45/60 steel that is used and the structural design of this assembly. In order to ensure safe operation of the conveying bridge until such time as the Welzow-South opencast mine is worked-out, the main over-run sections were replaced. Including all secondary and auxiliary structures, about 700 t of steel structure had to be fabricated anew. This entire replacement campaign was accompanied by a number of quality assurance measures in order to preclude any subsequent reworking, which would entail great expense. (orig.) [Deutsch] Nach ca. 20jaehriger Betriebszeit kommt es an den Rollbahntraegern der Abraumfoerderbruecken zu Schaeden, hauptsaechlich zu Schweissnahtrissen. Ursachen dafuer sind die Qualitaet des eingesetzten Stahles H 45/60 und die konstruktive Gestaltung dieser Baugruppe. Um die Foerderbruecke bis zum Auslaufen des Tagebaues Welzow-Sued sicher betreiben zu koennen, wurden die Hauptueberrollbereiche ausgetauscht. Einschliesslich aller Neben- und Hilfskonstruktionen mussten ca. 700 t Stahlbau neu gefertigt werden. Die gesamte Massnahme wurde begleitet von einer Reihe Qualitaetssicherungsmassnahmen, um jegliche Nacharbeit, die sehr aufwendig waere, auszuschliessen. (orig.)

  17. 49 CFR 231.1 - Box and other house cars built or placed in service before October 1, 1966.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Box and other house cars built or placed in... APPLIANCE STANDARDS § 231.1 Box and other house cars built or placed in service before October 1, 1966. Except for box and other house cars that comply with either § 231.27 or § 231.28, each box and...

  18. Impact attenuation of protective boxing and taekwondo headgear.

    Science.gov (United States)

    O'Sullivan, David M; Fife, Gabriel P

    2016-11-01

    This study aimed to compare the impact attenuation performance of boxing and taekwondo headgear in terms of peak linear and rotational acceleration. To measure the impact attenuation of headgear, a standardized (American Society for Testing and Materials (ASTM) F-2397) martial arts headgear striker was used to impart impacts to a 50th Percentile Male Hybrid III Crash Test Dummy head and neck complex. Two boxing (Adidas and Greenhill) and two taekwondo (Adidas and Nike) headgear, approved by the Association Internationale de Boxe Amateur and the World Taekwondo Federation (WTF), were selected. Each of the selected headgear was fitted to the Hybrid III head and subsequently subjected to five impacts at the front and side with a maximum impact interim time of 60 seconds by the rotating striker at 8 ± 0.3 m/s. Linear and rotational acceleration were recorded at 10,000 Hz. There were significant interactions of the impact location and brand on the rotational acceleration, F(3,40) = 6.7, p < .05. There were significant main effects of both impact location F(1,40) = 9.07, p < .05 and headgear brand F(3,40) = 9.9, p < .05 on the linear acceleration. Pairwise comparisons show significant differences between the front and side for both linear and rotational acceleration. The headgear tested failed the ASTM high impact test requirement to reduce the linear acceleration to below a threshold of 150 g. Further development of headgear to reduce impact linear and rotational acceleration magnitudes should be called for by the relevant sport governing bodies and initiated by headgear manufactures.

  19. Introduction to game physics with Box2D

    CERN Document Server

    Parberry, Ian

    2013-01-01

    Written by a pioneer of game development in academia, Introduction to Game Physics with Box2D covers the theory and practice of 2D game physics in a relaxed and entertaining yet instructional style. It offers a cohesive treatment of the topics and code involved in programming the physics for 2D video games. Focusing on writing elementary game physics code, the first half of the book helps you grasp the challenges of programming game physics from scratch, without libraries or outside help. It examines the mathematical foundation of game physics and illustrates how it is applied in practice thro

  20. Numerical Computation of Two-loop Box Diagrams with Masses

    CERN Document Server

    Yuasa, F; Hamaguchi, N; Ishikawa, T; Kato, K; Kurihara, Y; Fujimoto, J; Shimizu, Y

    2011-01-01

    A new approach is presented to evaluate multi-loop integrals, which appear in the calculation of cross-sections in high-energy physics. It relies on a fully numerical method and is applicable to a wide class of integrals with various mass configurations. As an example, the computation of two-loop planar and non-planar box diagrams is shown. The results are confirmed by comparisons with other techniques, including the reduction method, and by a consistency check using the dispersion relation.