WorldWideScience

Sample records for plate girders part

  1. Vibration and Buckling of Web Plate of the Plate Girder

    OpenAIRE

    高橋, 和雄; 呉, 明強; 中澤, 聡志; 筑紫, 宏之

    1998-01-01

    The vibration and buckling of the web of the plate girder are studied in this paper. The small deflection theory of the thin plate is used. The finite strip method is employed to solve vibration and buckling of the plate girder. Natural frequenies of buckling properties are shown for various plate girder bridges.

  2. The maximum bending moment resistance of plate girders

    NARCIS (Netherlands)

    Abspoel, R.

    2014-01-01

    In many steel structures like buildings, industrial halls and bridges, standard hot-rolled sections like IPE, HEA, HEB, HEM, HED and UNP in Europe and similar profiles in other regions of the world are used. The range of hot-rolled sections is limited and therefore fabricated plate girders are used

  3. The maximum bending moment resistance of plate girders

    NARCIS (Netherlands)

    Abspoel, R.

    2014-01-01

    In many steel structures like buildings, industrial halls and bridges, standard hot-rolled sections like IPE, HEA, HEB, HEM, HED and UNP in Europe and similar profiles in other regions of the world are used. The range of hot-rolled sections is limited and therefore fabricated plate girders are used

  4. 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.

  5. Fatigue crack detection in a plate girder using Lamb waves

    Science.gov (United States)

    Greve, D. W.; Oppenheim, I. J.; Wu, Wei; Zheng, Peng

    2007-04-01

    We report on the application of wafer-type PZT transducers to the detection of flaws in steel plate girders. In these experiments one transducer is used to emit a pulse and the second receives the pulse and reflections from nearby boundaries, flaws, or discontinuities (pitch-catch mode). In this application there will typically be numerous reflections observed in the undamaged structure. A major challenge is to recognize new reflections caused by fatigue cracks in the presence of these background reflections. A laboratory specimen plate girder was fabricated at approximately half scale, 910 mm deep with an h/t ratio of 280 for the web and a b/t ratio of 16 for the flanges, and with transverse stiffeners fabricated with a web gap at the tension flange. Two wafer-type transducers were mounted on the web approximately 175 mm from the crack location, one on each side of the stiffener. The transducers were operated in pitch-catch mode, excited by a windowed sinusoid to create a narrowband transient excitation. The transducer location relative to the crack corresponded to a total included angle of roughly 30 degrees in the path reflecting from the crack. Cyclic loading was applied to develop a distortion-induced fatigue crack in the web at the web gap location. After appearance of the crack, ultrasonic measurements were performed at a range of center frequencies below the cutoff frequency of the A1 Lamb wave mode. Subsequently the crack was extended mechanically to simulate crack growth under primary longitudinal (bending) stress and the measurements were repeated. Direct differencing of the signals showed arrivals at times corresponding to reflection from the crack location, growing in amplitude as the crack was lengthened mechanically. These results demonstrate the utility of Lamb waves for crack detection even in the presence of numerous background reflections.

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

    OpenAIRE

    A. Lisiecki; J. Szlek; A. Klimpel

    2007-01-01

    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 ...

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

    OpenAIRE

    A. Klimpel; A. Lisiecki; J. Szlek

    2007-01-01

    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 s...

  8. Design Optimization and Structural Performance Evaluation of Plate Girder Bridge Constructed Using a Turn-Over Process

    Directory of Open Access Journals (Sweden)

    Gi-Ha Eom

    2017-03-01

    Full Text Available A recent trend in bridge construction has been the optimization of the cost-to-performance ratio. The most effective way to optimize the cost-to-performance ratio is to maximize the efficiency of the superstructure. Currently, many bridge engineers and designers favor two- or three- girder plate superstructures, due to their cost advantages. However, research on the performance enhancements of the I-type girder in two- or three- girder plate bridges is lacking. One of the most important performance improvement technologies for the I-type girder is the “preflex” method. In the preflex method, the specimen is inverted during the construction process to apply prestressed cambering to the specimen by using self-weight. However, a problem with the preflex construction method is difficulty with inverting the girder/plate system during the concrete curing process. Therefore, a new inverting system called Turn-Over (TO wheel was proposed. Using TO wheels, wider variations to the I-type girder design can be achieved. Using this TO construction method, various cross sectional designs of girder plate systems can be considered due to its easiness in inverting the girder/plate system. In this study, the location of concrete confinement sections between the steel I-beams and concrete plates was varied in an I-girder cross-sectional design. Design parameters included effective height, flange thickness, flange width, confining concrete section width, etc. From this study, the optimum cross-sectional design of the I-girder/concrete plate system was achieved. Then, a single 20 m TO girder/plate system and two 20 m TO girder bridges were constructed and tested to evaluate their performance. From the test, failure behavior, load carrying capacity, crack pattern, etc., are obtained. The results are discussed in detail in this paper.

  9. Locally Corroded Stiffener Effect on Shear Buckling Behaviors of Web Panel in the Plate Girder

    Directory of Open Access Journals (Sweden)

    Jungwon Huh

    2015-01-01

    Full Text Available The shear buckling failure and strength of a web panel stiffened by stiffeners with corrosion damage were examined according to the degree of corrosion of the stiffeners, using the finite element analysis method. For this purpose, a plate girder with a four-panel web girder stiffened by vertical and longitudinal stiffeners was selected, and its deformable behaviors and the principal stress distribution of the web panel at the shear buckling strength of the web were compared after their post-shear buckling behaviors, as well as their out-of-plane displacement, to evaluate the effect of the stiffener in the web panel on the shear buckling failure. Their critical shear buckling load and shear buckling strength were also examined. The FE analyses showed that their typical shear buckling failures were affected by the structural relationship between the web panel and each stiffener in the plate girder, to resist shear buckling of the web panel. Their critical shear buckling loads decreased from 82% to 59%, and their shear buckling strength decreased from 88% to 76%, due to the effect of corrosion of the stiffeners on their shear buckling behavior. Thus, especially in cases with over 40% corrosion damage of the vertical stiffener, they can have lower shear buckling strength than their design level.

  10. Safety Analysis of the Patch Load Resistance of Plate Girders: Influence of Model Error and Variability

    Directory of Open Access Journals (Sweden)

    Farzad Shahabian

    2013-12-01

    Full Text Available This study aims to undertake a statistical study to evaluate the accuracy of nine models that have been previously proposed for estimating the ultimate resistance of plate girders subjected to patch loading. For each model, mean errors and standard errors, as well as the probability of underestimating or overestimating patch load resistance, are estimated and the resultant values are compared one to another. Prior to that, the models are initially calibrated in order to improve interaction formulae using an experimental data set collected from the literature. The models are then analyzed by computing design factors associated with a target risk level (probability of exceedance. These models are compared one to another considering uncertainties existed in material and geometrical properties. The Monte Carlo simulation method is used to generate random variables. The statistical parameters of the calibrated models are calculated for various coefficients of variations regardless of their correlation with the random resistance variables. These probabilistic results are very useful for evaluating the stochastic sensitivity of the calibrated models.

  11. 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...

  12. 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...

  13. 预应力CFRP板加固钢梁抗弯疲劳试验研究%Experimental Study of Flexural Fatigue Performance of Steel Girder Reinforced by Prestressed CFRP Plate

    Institute of Scientific and Technical Information of China (English)

    叶华文; T. Ummenhofer; 强士中

    2009-01-01

    Bonding Prestressed carbon fiber reinforcement polyester (CFRP) plate is a promising technique to strengthen steel member damaged by fatigue. First, a modification of Paris' equation was used to analyze the crack propagation of the steel member strengthened by CFRP plate. Four-point bending fatigue test of pre-cracked steel girder strengthened with prestressed CFRP plates was also conducted to investigate the flexural fatigue performance of reinforced steel girder. In the end a simplified calculation and design method was also presented to estimate the re-quired prestress preliminary to stop the propagation of fatigue cracks. The result shows that (1) this technique pro-duces a significant increment of fatigue life of steel girder which is more than 10 times compared with that of pre-crack stage; (2) the fatigue lives, which extended from the reinforcement with different pre-crack sizes, differ up to 10 times. The post-tensioning method was applied to prestress the CFRP of steel girder plate successfully and an-chorage system can real-time control the prestress in CFRP plates and the prestress loss is slight.%首先,采用修正的Pairs公式分析粘贴预应力CFRP板加固的钢构件的疲劳裂纹扩展行为.然后通过粘贴CFRP板的预制裂纹钢梁4点弯曲进行疲劳试验研究,最后基于阻止裂纹扩展的角度提出一种初步估计加固所需预应力大小的简化计算和设计方法.结果表明,粘贴预应力CFRP板对钢梁疲劳寿命的影响很大,与预制裂纹阶段比寿命提高最高可达10倍以上.不同的预制裂纹,同样的加固措施效果差别可达10倍.采用后张法施加预应力效果很好,锚固装置可以实时控制有效预应力,且预应力损失很小.

  14. Experiment study on fatigue behavior of composite girders with steel plate-concrete composite bridge decks%带钢板-混凝土组合桥面板的组合梁疲劳性能试验研究

    Institute of Scientific and Technical Information of China (English)

    杨勇; 周现伟; 薛建阳; 霍旭东

    2012-01-01

    In order to study the fatigue behaviour of the steel plate-concrete composite-deck composite girders under the fatigue load, constant-amplitude fatigue tests of six specimens of the steel plate-concrete composite-deck composite beam were carried out and static loading experiments of two specimens were conducted. The influence of the main factors including the upper and lower limits of fatigue load and the stress amplitude on the failure modes and the fatigue damage extent of composite girders under fatigue load were focused on. The dynamic deflection, strains of concrete and steel plates, strains of steel beam, residual deflection and residual bearing capacity were measured and analyzed. From the tests results, the fatigue life-spans of the composite girders specimens were directly related with their stress amplitudes, but the upper and lower limits of fatigue load had little effect. With regard to the fatigue failure modes of the composite girders specimens, positive moment composite girders were all failed due to collapse of the steel beam and crush of concrete of compressive zone, but not to the negative moment of composite girders, as a result of steel-beam buckling under static tests after fatigue tests. This paper were very helpful for this type of compsite girders design.%为研究带钢板-混凝土组合桥面板的组合梁在疲劳荷载下的受力性能,对2个试件进行静力试验研究,并对6个试件进行等幅疲劳试验研究。疲劳试验试件按承受正弯矩和承受负弯矩两组类型试件分别考虑,在各组试件中均主要考察疲劳荷载上、下限值及疲劳荷载幅值等因素对带钢板-混凝土组合桥面板组合梁的疲劳破坏模式及疲劳累积损伤的影响。疲劳试验过程中对组合梁试件在各主要循环加载次数下的动挠度、残余挠度、混凝土应变、底部钢板应变、试件钢梁应变及试件受弯刚度进行试验测量和分析。疲劳试验结果表明:正

  15. Experimental Study of Anchor Tensile Plate Cable Anchorage System in Concrete Girder of Actual Bridge%锚拉板式混凝土索梁锚固体系实桥试验研究

    Institute of Scientific and Technical Information of China (English)

    石雪飞; 周军勇; 胡可; 阮欣

    2016-01-01

    为研究索力作用下锚拉板式混凝土索梁锚固体系的受力性能,以五河淮河大桥为工程背景进行实桥试验和有限元分析。选取该桥0号节段混凝土锚拉板进行实桥试验,测试锚拉板在分级索力作用下的应力及变形,采用ANSYS软件建立有限元模型,计算2种连接方式下(考虑混凝土主梁与钢锚拉板的固结与滑移)的应力分布与锚拉板变形。结果表明,钢锚拉板与混凝土主梁在固结或滑移连接方式下,斜拉索锚固区域的应力分布基本相同,但连接区域的应力分布及锚拉板变位差别显著;测试的锚拉板应力和位移与荷载呈现良好线性相关性,最大测点应力296 M Pa ,结构仍处于弹性工作状态;锚拉板应力分布的实测值与有限元计算值吻合,板件应力扩散和传递效果良好;连接区域的实测应力和位移与滑移方式下的有限元分析较吻合,但摩擦系数不主导滑移结果。%To study the mechanical performance of the anchor tensile plate cable anchorage system in concrete girder under the action of the cable tension ,the test and finite element analysis of the steel anchor tensile plate stay cable anchorage system in the concrete main girder of the actu‐al bridge of Wuhe Huaihe River Bridge were carried out .The anchor tensile plate in the segment No .0 of the main girder of the bridge was selected and tested .The stress and displacement of the anchor tensile plate under the different levels of the stay cable tension were measured .The finite element model for the anchor tensile plate was set up ,using the software ANSYS and the stress distribution and the anchor tensile plate displacement under the 2 kinds of the connecting ways (the rigid fixity and sliding connecting of the anchor tensile plate with the concrete main girder ) were calculated .The results show that under the connecting ways of the rigid fixity or sliding connect‐ing of the anchor

  16. 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

  17. 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......, 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...

  18. 夹芯钢板覆盖法(SPS)在钢箱梁桥正交异性桥面板维修加固中的应用与试验%Research on Application of Sandwich Plate System (SPS) on Strengthening Orthotropic Bridge Deck of Steel Box Girder Bridge

    Institute of Scientific and Technical Information of China (English)

    许传博; 胡利平

    2012-01-01

    This paper introduces the application of sandwich plate system SPS ) on strengthening of steel box girder bridge with load test being carried out to verify the effect of SPS, which can provide a reference for the similar engineering practice.%结合工程实例,介绍了夹芯钢板覆盖法(SPS)在钢箱梁桥维修加固中的应用,并通过荷载试验对其加固效果进行了检验,可为类似维修加固工程提供参考。

  19. 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)

  20. RCS Analysis of Plate Geometries, parts 1 and 2

    Science.gov (United States)

    Balanis, Constantine A.; Polka, Lesley A.; Polycarpou, Anastasis C.

    1993-01-01

    High-frequency techniques for Radar Cross Section (RCS) prediction of plate geometries and a physical optics/equivalent currents model for the RCS of trihedral corner reflectors are addressed. In part 1, a Uniform Theory of Diffraction (UTD) model for the principal-plane radar cross section (RCS) of a perfectly conducting, rectangular plate coated on one side with an electrically thin, lossy dielectric is presented. In part 2, the scattering in the interior regions of both square and triangular trihedral corner reflectors are examined.

  1. Analysis of Shrinkage on Thick Plate Part using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Najihah S.N.

    2016-01-01

    Full Text Available Injection moulding is the most widely used processes in manufacturing plastic products. Since the quality of injection improves plastic parts are mostly influenced by process conditions, the method to determine the optimum process conditions becomes the key to improving the part quality. This paper presents a systematic methodology to analyse the shrinkage of the thick plate part during the injection moulding process. Genetic Algorithm (GA method was proposed to optimise the process parameters that would result in optimal solutions of optimisation goals. Using the GA, the shrinkage of the thick plate part was improved by 39.1% in parallel direction and 17.21% in the normal direction of melt flow.

  2. 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.

  3. Neutron detection with imaging plates Part II. Detector characteristics

    CERN Document Server

    Thoms, M

    1999-01-01

    On the basis of the physical processes described in Neutron detection with imaging plates - part I: image storage and readout [Nucl. Instr. and Meth. A 424 (1999) 26-33] detector characteristics, such as quantum efficiency, detective quantum efficiency, sensitivity to neutron- and gamma-radiation, readout time and dynamic range are predicted. It is estimated that quantum efficiencies and detective quantum efficiencies close to 100% can be reached making these kind of detectors interesting for a wide range of applications.

  4. Behavior of horizontally curved steel tubular-flange bridge girders

    Science.gov (United States)

    Fan, Zhuo

    A new type of curved steel bridge girder, called a curved tubular-flange girder, with rectangular tubes as flanges, is proposed and studied in this dissertation. A curved steel tubular-flange girder has much larger torsional stiffness than a curved I-girder and less potential for cross section distortion than a curved box-girder. Therefore, it has potential advantages compared to curved I-girders and box-girders. A theoretical analysis method for systems of curved tubular-flange girders braced by cross frames is presented. A stress analysis method for tubular-flange girders is also provided. The behavior of curved tubular-flange girder systems is studied using the theoretical analysis method and compared to the behavior of the corresponding curved I-girder systems. A parametric study is performed using the theoretical analysis method to investigate the effects of geometric parameters on the behavior of curved tubular-flange girder systems. The studied parameters include tubular-flange width, tubular-flange depth, cross section depth, girder curvature, and the number of cross frames. Finite element analyses are conducted to verify the theoretical analysis method, to study the behavior of a curved tubular-flange girder system under dead load, and to study the behavior of a curved tubular-flange girder system with a composite concrete deck under dead and live load. The study shows that a curved tubular-flange girder system develops much less warping normal stress and cross section rotation than a corresponding curved I-girder system. The difference is especially significant for a single curved girder under its own weight, suggesting that curved tubular-flange girders would be much easier to transport and erect than curved I-girders. As girder curvature increases, the rate of increase in the stresses and displacements for a single I-girder is much greater than for a single curved tubular-flange girder. Smaller cross frame forces develop in a tubular-flange girder

  5. Electromagnetic Confinement and Shaping for Plate-Form Part

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The relationship between melt shape, electromagnetic pressure and magnetic field is studied for electromagnetic confinement and shaping of plate-form part. The results of experimental observation and theoretical inference can be summarized as follows. As the melt thickness a is large enough, causing the ratio of plate thickness to current theoretic skin depth a/δ larger ???B2than 2.2, the electromagnetic pressure acting on melt can be simply expressed as Pn =2μ-, andthe melt shape would be known only by measuring the distribution of magnetic flux density. As a is small and makes the ratio a/δ less than 2.2, the melt shape and electromagnetic pressure for confining and shaping are determined not only by magnetic flux density B but also by melt thickness a, electromagnetic parameterμγ and current frequency f. In this paper, an equation used to calculate electromagnetic pressure acting on “thin plate-form melt” is brought forward.The equation gives a precise relationship between electromagnetic pressure factor p and melt thickness a, electromagnetic parameterμγ and current frequency f.

  6. Maintained ship hull girder ultimate strength reliability considering corrosion and fatigue

    DEFF Research Database (Denmark)

    Hu, Yong; Cui, W.; Pedersen, Preben Terndrup

    2004-01-01

    The prupose of this paper is to propose a methodology to assess the time-variant ultimate strength of ship hull girder under the degradations of corrosion and fatigue. The effects of fatigue cracks on the tensile and compressive residual ultimate strength of stiffened panels and unstiffened plate...

  7. Reliability Assessment for PSC Box-Girder Bridges Based on SHM Strain Measurements

    Directory of Open Access Journals (Sweden)

    Chuang Chen

    2017-01-01

    Full Text Available A reliability assessment method for prestressed concrete (PSC continuous box-girder bridges based on structural health monitoring (SHM strain measurements was proposed. First, due to the fact that measured strain was compositive and the variation periods of its components were different, a series of limit state equations under normal use limit state were given. Then, a linear fitting method was used to determine the relationship between the ambient temperature and the measured strain, which was aimed at extracting the vehicle load effect and the temperature load effect from the measured strain. Finally, according to the equivalent normalization method, the load effects unsatisfying the normal distribution by probability density function fitting were transformed, and the daily failure probabilities of monitored positions were calculated for evaluating the safety state of the girder. The results show that (1 the top plate of the box girder is more sensitive than the bottom plate to the high temperature, (2 the daily and seasonal strain variations induced by uniform temperature reveal an inconsistent tendency to the seasonal variation for mid-span cross sections, and (3 the generalized extreme value distribution is recommended for temperature gradient stress and vehicle induced stress fitting for box-girder bridges.

  8. Experiments with Externally Prestressed Continuous Composite Girders

    Directory of Open Access Journals (Sweden)

    M. Safan

    2001-01-01

    Full Text Available Steel-concrete composite girders have attractive potentials when applied in bridge construction. The serviceability performance of continuous composite girders is becoming more and more a deterministic parameter in the design of this type of structures. An effective method for improving this performance is to apply prestressing to control or completely eliminate concrete deck cracking caused by static and time dependent actions. Little literature has been found addressing the experimental analysis of continuous girders prestressed by means of external deviated tendons. The current research aims to investigate the behavior of a double-span steel composite beam externally prestressed by means of continuous tendons in terms of cracking characteristics, load deflection response, and load carrying capacity. The efficiency of prestressing is evaluated by comparing the results to those of a non-prestressed beam with similar cross sections and spans.

  9. Continuous rigid PC frame box girder cantilever pouring construction reasonable maintenance method

    Directory of Open Access Journals (Sweden)

    Wulin

    2015-08-01

    Full Text Available In recent years, prestressed concrete continuous rigid frame box girder plate and web plate produced a large number of non-structural cracks disease caused the attention of large bridge workers, to solve the problem of continuous rigid-frame structure of the cantilever of the disease, this article briefly introduced the cantilever construction method and the performance requirements of modern concrete, through to the modern concrete composition change and keeping in good health on the impact of environment on its early performance analysis summary, points out the present problems of box girder early curing, finally combining with the characteristics of modern concrete performance and the characteristics of the cantilever construction method, puts forward "model attach +manual+automatic water spray mist stick " composite curing method in order to reduce the structural cracks, provides a new train of thought.

  10. 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. 

  11. RESEARCH ON PLATING PARTS USED IN THE OIL INDUSTRY

    Directory of Open Access Journals (Sweden)

    Radu Gabriel ALBULESCU

    2014-05-01

    Full Text Available The paper includes a number of theoretical and experimental results on plating of several pieces from different classes focusing especially on the pieces of the flanges and housings class. For reasons of confidentiality to beneficiaries, the paper presents experimeindustry at the ends of probe drilling and extraction. Have been taken into account these kinds of pieces in the research due to operating conditions and high requests which occur during operation.

  12. Proposal and study of a long-span composite cable-stayed bridge with new hybrid girder; Atarashii gosei kozo shuketa wo mochiita chodai fukugo shachokyo no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, K.; Hishiki, Y.; Furuichi, K. [Kajima Corp., Tokyo (Japan)

    1999-09-30

    A hybrid or mixed structure (composite structures) are a matter of increasing concern which takes in each advantage of steel and concrete. A field of bridges is no exception, with the plan and construction carried out for the new type of composite bridge, such as a composite cable-stayed bridge and a composite extra dose bridge as a long span bridge, and a composite truss bridge and a corrugated steel plate web bridge as a medium-span bridge, with technological development becoming active in this field. In such a technological trend, a hybrid two-girder structure was devised, a structure consisting of a concrete filled steel pipe for a girder and a precast (PC) floor plate for a floor board, as the girder structure of a long-span cable-stayed bridge in the subject research; also, applicability was examined using, as an example, the composite cable-stayed bridge with hybrid girders employed for the span. This paper reports the result of the analysis of the entire system, the analysis made for the purpose of examining the characteristic and the feasibility of this hybrid girder. The analysis revealed the structural feasibility of the long-span composite cable-stayed bridge using two hybrid girders of concrete-filled steel pipes thus devised. (NEDO)

  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. Locking plate osteosynthesis in displaced 4-part fractures of the proximal humerus

    DEFF Research Database (Denmark)

    Brorson, Stig; Frich, Lars H; Winther, Annika;

    2011-01-01

    There is considerable uncertainty about the optimal treatment of displaced 4-part fractures of the proximal humerus. Within the last decade, locking plate technology has been considered a breakthrough in the treatment of these complex injuries....

  15. 不中断交通维修加固板梁桥铰缝病害处治方案%Treatment Scheme of the Hinge Joint Hazard in the Maintenance and Reinforcement of Plate Girder Bridge without Interrupting Traffic

    Institute of Scientific and Technical Information of China (English)

    左智

    2014-01-01

    Along with the improvement of the life quality of people, people require more for the convenience of traffic tra-vel. In this paper, under the uninterrupted traffic situations, the author discussed the construction technology of repairing the hinge joint of hol ow plate of bridge.%随着全民生活品质的提高,人们对于出行交通的便捷要求更高了。本文对在不中断交通的情况下,如何进行桥梁空心板铰缝修复的施工工艺做了重点阐述。

  16. Estimating Design Resistance of Wrought Balcony Girders

    Directory of Open Access Journals (Sweden)

    Jung Karel

    2017-06-01

    Full Text Available The contribution is focused on reliability of balcony girders of a Czech national heritage monument. As preliminary reliability assessment suggests insufficient resistance, a series of nondestructive tests supplemented by a single tensile test are performed and evaluated by the statistical methods. Values of material properties, recommended in standards for historic materials, seem to be overly conservative and it is advised to specify properties of historic metallic materials by tests.

  17. FSW Numerical Simulation of Aluminium Plates by SYSWELD - Part II

    Directory of Open Access Journals (Sweden)

    Jančo Roland

    2016-11-01

    Full Text Available Friction Stir Welding (FSW is one of the most effective solid state joining processes and has numerous potential applications in many industries. The simulation process can provide the evolution of physicals quantities such as temperature, metallurgical phase proportions, stress and strain which can be easily measured during welding. The numerical modelling requires the modelling of the complex interaction between thermal, metallurgical and mechanical phenomena. The aim of this paper is to describe the thermal-fluid simulation of FSW using the finite element method. In the theoretical part of paper heating is provided by the material flow and contact condition between the tool and the welded material. Thermal-mechanical results from the numerical simulation using SYSWELD are also presented for aluminium alloy.

  18. FSW Numerical Simulation of Aluminium Plates by Sysweld - Part I

    Directory of Open Access Journals (Sweden)

    Jančo Roland

    2016-07-01

    Full Text Available Friction Stir Welding (FSW is one of the most effective solid state joining processes and it has numerous potential applications in many industries. The simulation process can provide the evolution of physical quantities such as temperature, metallurgical phase proportions, stress and strain which can be easily measured during welding. The numerical modelling requires the modelling of a complex interaction between thermal, metallurgical and mechanical phenomena. The aim of this paper is to describe the thermal-fluid simulation of FSW using the finite element method. In the theoretical part of the paper heating is provided by the material flow and contact condition between the tool and the welded material. The thermal-fluid results from the numerical simulation for aluminium alloy using SYSWELD are also presented in this paper.

  19. Proximal Humeral Fractures: A Biomechanical Comparison of Locking Plate Constructs in a Cadaveric 3-Part Fracture Model

    OpenAIRE

    2010-01-01

    The purpose of our study was to biomechanically compare, under cyclic loading conditions, fracture site motion, humeral head collapse, and intra-articular hardware penetration in simulated 3-part osteoporotic proximal humeral fractures stabilized with 1 of 2 locking-plate constructs. We performed fixation on simulated 3-part proximal humeral fractures in 10 pairs of cadaveric osteoporotic humeri with a Hand Innovations S3 Proximal Humerus Plate (S3 plate) or an LCP Proximal Humerus Plate (LCP...

  20. 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.

  1. Surgical Management of 3 and 4-Part Proximal Humerus Fractures with Locking Plates in Elderly

    Directory of Open Access Journals (Sweden)

    Emrah Kovalak

    2017-05-01

    Full Text Available Aim: Proximal humeral fractures are approximately 5% of all fractures and, %15-20 is displaced and unstable. By the introduction of locking plates there used to be a substantial rise in the osteosynthesis of the 3 and 4-part proximal humeral fractures. But there is still a lack of consensus for the optimal treatment of these complex fractures. In this retrospective study, we aimed to evaluate the functional outcomes and prognostic factors of 3 and 4-part proximal humerus fractures treated with locking plate osteosynthesis in elderly. Material and Method: 53 patients with displaced 3 and 4-part proximal humeral fractures treated with locking plate osteosynthesis between 2010 and 2015 were included. The fractures were classified according to Neer classification system. Outcomes were assessed by Constant-Murley scoring system (CMS, visual analog pain scale and plain radiographs. In reference to range of motion, forward elevation and abduction of the arm were measured.Results: No statistically significant differences found between the 3- part and 4- part fractures in CMS, forward elevation and, abduction (p>0.05. Pain was significantly higher in 4-part fractures (p=0.035. CMS, forward elevation, and abduction were inversely correlated with age and delay in surgery. There was statistical significance between the patients had complications and those not in terms of CMS, forward elevation and, abduction (p=0.029, p=0.017 and p=0.024. Discussion: Functional outcomes of locking plate fixation of proximal humerus fractures are associated with patient related factors, fracture pattern, surgeon and, the implant. When indications are carefully selected, locking plate osteosynthesis yield good outcomes in surgical treatment of 3 or 4-part proximal humerus fractures.

  2. Optimal Location of Plate Damped Parts by Use of a Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    J.-L. Marcelin

    1994-01-01

    Full Text Available Optimal damping of plates (or beams partially covered by viscoelastic constrained layers is presented. The design variables are the locations and the sizes of the damped parts. The objective function is a linear combination of the first modal damping factors calculated from a specific finite element analysis. The discrete design variable optimization problem is solved using a genetic algorithm.

  3. Stress analysis of box girders with corrugate steel webs under distorsion%波形钢腹板箱梁畸变应力分析

    Institute of Scientific and Technical Information of China (English)

    杨丙文; 黎雅乐; 万水; 张建东

    2011-01-01

    According to mechanical characteristics of box girders with corrugated steel webs and theory of box girders, the warping normal stress of box girders with corrugated steel webs caused by distortion is studied. Considering that corrugated webs have fold effects, the corrugated webs are regarded as an orthotropic plate. Distortion governing differential equations of box girders with corrugated steel webs are derived under the equilibrium relation of plane force system within them. Their distortion angle and distortion bimoment are obtained using the beam elastic foundation (BEF) method , and then the longitudinal distortion stress is obtained. An analytical example is given to compare two types of box girders, concrete box girders and box girders with corrugated steel webs. The results of the example demonstrate that the box girders with corrugated steel webs have less lateral frame stiffness than concrete ones; thus, the distortional warping normal stress of box girders with corrugated steel webs is larger than that of concrete box girders.%在箱梁理论的基础上,根据波形钢腹板箱梁的力学特性,对波形钢腹板箱梁由畸变引起的翘曲正应力进行了研究.考虑到波形钢腹板具有褶皱效应,把波形钢腹板看作正交异性板,利用波形钢腹板箱梁中各板元平面力系的平衡关系,推导出波形钢腹板箱梁的畸变控制微分方程.采用弹性地基梁法解出波形钢腹板箱梁的畸变角和畸变双力矩,最终得到纵向畸变正应力.通过算例对比分析相同截面的波形钢腹板箱梁和混凝土箱梁的畸变翘曲正应力,计算结果表明,波形钢腹板箱梁相对普通混凝土箱梁的横向框架刚度较小,因此由畸变产生的翘曲正应力大于混凝土箱梁的畸变翘曲正应力.

  4. 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.

  5. 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...... 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...

  6. 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...

  7. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    ’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  8. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  9. Neutron detection with imaging plates Part I. Image storage and readout

    CERN Document Server

    Thoms, M; Wilkinson, C

    1999-01-01

    The detection of neutrons with imaging plates is based on a sequence of physical processes, which are happening during the neutron exposure and the readout of the image information. These processes are investigated in detail starting with the neutron absorption and conversion to secondary radiation by various neutron converter materials and ending with the detection of the photostimulated luminescence, which is emitted during the readout. It is shown that these processes can be quantified by several key parameters, such as i.e. the neutron absorption cross section, the emitted secondary energy and the conversion efficiency of released secondary energy to storage centers in the storage phosphor. The resulting detector characteristics are described in the second part, namely, Neutron detection with imaging plates - part II: detector characteristics [Nucl. Instr. and Meth. A 424 (1999) 34-39].

  10. Neutron detection with imaging plates Part I. Image storage and readout

    Science.gov (United States)

    Thoms, M.; Myles, D.; Wilkinson, C.

    1999-11-01

    The detection of neutrons with imaging plates is based on a sequence of physical processes, which are happening during the neutron exposure and the readout of the image information. These processes are investigated in detail starting with the neutron absorption and conversion to secondary radiation by various neutron converter materials and ending with the detection of the photostimulated luminescence, which is emitted during the readout. It is shown that these processes can be quantified by several key parameters, such as i.e. the neutron absorption cross section, the emitted secondary energy and the conversion efficiency of released secondary energy to storage centers in the storage phosphor. The resulting detector characteristics are described in the second part, namely, Neutron detection with imaging plates - part II: detector characteristics [Nucl. Instr. and Meth. A 424 (1999) 34-39].

  11. [The Extended Deltoid-Split Approach for Plating Four-Part Proximal Humeral Fractures].

    Science.gov (United States)

    Schiffer, G; Sayar, A; Thelen, U

    2016-08-01

    The deltoideopectoral approach is established as the gold standard in the surgical treatment of proximal humeral fractures. As an alternative, we demonstrate the extended deltoid approach with an intraoperative video. A direct lateral incision is performed and the anterior parts of the axillary nerve are identified and preserved. In our experience, this approach allows improved visualisation of the greater tuberosity and easier positioning of locking plates. Clinically relevant neurological injuries cannot be seen in our patients or in the literature.

  12. Seismo-electromagnetic phenomena in the western part of the Eurasia-Nubia plate boundary

    OpenAIRE

    Silva, H. G; Bezzeghoud, M.; J. P. Rocha; P. F. Biagi; Tlemçani, M.; Rosa, R.N.; M. A. Salgueiro da Silva; Borges, J. F.; Caldeira, B.; Reis, A. H.; MANSO M.

    2011-01-01

    This paper presents a future research plan that aims to monitor Seismo-electromagnetic (SEM) phenomena in the western part of the Eurasia-Nubia plate boundary (WENP). This region has a significant tectonic activity [1] combined with relatively low electromagnetic noise levels and for that reason presents the possibility to perform high quality SEM measurements. Further, it is known that low-frequency [ultra (ULF), very (VLF), and low-frequencies (LF)] electromag- netic (EM) waves produce m...

  13. Girder Support Scheme for the LCLS Undulator System

    Energy Technology Data Exchange (ETDEWEB)

    Welch, J.

    2005-01-31

    Differential settlement of the foundation of the LCLS Undulator Hall will cause quadrupoles to move and the electron beam trajectory to distort. The resulting phase errors will decrease the FEL power and require time consuming beam-based alignment sessions to correct. By supporting quadrupoles on girders, with three quadrupoles to a girder, the foundation motion induced phase error between the beam and the X Ray radiation can be reduced by a factor of 5 compared with supporting each quadrupole with a separate column. This comes about because the motions of three quadrupoles on a girder are linearly correlated so their effect on the beam is largely canceled out. Thus a girder support scheme can significantly help to extend the time between required beam based alignments and contribute to a more stable operation of the LCLS FEL beam.

  14. The vibration research of the AC dipole-girder system for CSNS/RCS

    CERN Document Server

    Renhong, Liu; Huamin, Qu; Ling, Kang; Motuo, Wang; Guangyuan, Wang; Haijing, Wang

    2013-01-01

    China spallation neutron source(CSNS) is a high intensity proton accelerator based facility, and its accelerator complex includes two main parts: an H- linac and a rapid cycling synchrotron(RCS). The rcs accumulates the 80MeV proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25 Hz. The AC dipole of the RCS is operated at a 25Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the magnet. The dipole magnet of RCS is active vibration equipment which is different with ground vibration accelerator. It is very important to design and research the dynamic characteristic of the dipole-girder system. This paper takes the dipole and girder as a specific model system, a method for researching the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. The ansys simulation method plays a very important role in the girder structure design stage. With the m...

  15. Study the vibration and dynamic response of the dipole girder system for CSNS/RCS

    CERN Document Server

    Renhong, Liu; JunSong, Zhang; GuangYuan, Wang

    2015-01-01

    China Spallation Neutron Source is a high intensity proton accelerator based facility, and its accelerator complex includes two main parts an H- linac and a rapid cycling synchrotron. The RCS accumulates the 80MeV proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25Hz. The dipole of the CSNS RCS is operated at a 25 Hz sinusoidal alternating current which causes severe vibrate. The vibration will influence the long term safety and reliable operation of the magnet. The dipole of the CSNS RCS is an active vibration equipment which is different from the ground vibration accelerator. It is very important to design and study the dynamic characteristics of the dipole girder system. This paper takes the dipole and girder as a specific model system, a method for studying the dynamic characteristics of the system is put forward by combining theoretical calculation with experimental testing. The modal parameters with and without vibration isolator of the dipole girder system are obtain through ANSYS s...

  16. 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)

  17. Active Vibration Control of Plate Partly Treated with ACLD Using Hybrid Control

    Directory of Open Access Journals (Sweden)

    Dongdong Zhang

    2014-01-01

    Full Text Available A finite element model of plate partly treated with ACLD treatments is developed based on the constitutive equations of elastic, piezoelectric, viscoelastic materials and Hamilton’s principle. The Golla-Hughes-Mctavish (GHM method is employed to describe the frequency-dependent characteristics of viscoelastic material (VEM. A model reduction is completed by using iterative dynamic condensation and balance model reduction method to design an effective control system. The emphasis is concerned on hybrid (combined feedback/feedforward control system to attenuate the vibration of plates with ACLD treatments. The optimal linear quadratic Gaussian (LQG controller is considered as a feedback channel and the adaptive filtered-reference LMS (FxLMS controller is used as a feedforward channel. They can be utilized individually or in a hybrid way to suppress the vibration of plate/ACLD system. The results show that the hybrid controller which combines feedback/feedforward together can reduce the displacement amplitude of plate/ACLD system subjected to a complicated disturbance substantially without requiring more control effort. Furthermore, the hybrid controller has more rapid and stable convergence rate than the adaptive feedforward FxLMS controller. Meanwhile, perfect robustness to phase error of the cancellation path in feedforward controller and the weight matrices in feedback LQG controller is demonstrated in proposed hybrid controller. Therefore, its application in structural engineering can be highly appreciated.

  18. A pinned or free-floating plate on a thin viscous film. Part 1: A rigid plate

    CERN Document Server

    Trinh, Philippe H; Stone, Howard A

    2013-01-01

    We investigate a pinned or free-floating rigid plate lying on the free surface of a thin film of viscous fluid, which itself lies on top of a horizontal substrate that is moving to the right at a constant speed. Examples of situations in which this can occur include blade coating and the motion of a contact lens on the tear film of the eye after a blink. In contrast to the extensive previous work on fixed and clamped plates, in the present work we allow the plate to change both its position and orientation in response to the flow. Asymptotic and numerical analyses are described, and, in particular, we explain, in appropriate dimensionless terms, the role of the speed of the substrate, surface tension, viscosity and, in the case of a pinned plate, the prescribed pressure in the reservoir of fluid upstream of the plate, in determining the possible equilibrium configurations.

  19. Error compensation of thin plate-shape part with prebending method in face milling

    Science.gov (United States)

    Yi, Wei; Jiang, Zhaoliang; Shao, Weixian; Han, Xiangcheng; Liu, Wenping

    2015-01-01

    Low weight and good toughness thin plate parts are widely used in modern industry, but its flexibility seriously impacts the machinability. Plenty of studies focus on the influence of machine tool and cutting tool on the machining errors. However, few researches focus on compensating machining errors through the fixture. In order to improve the machining accuracy of thin plate-shape part in face milling, this paper presents a novel method for compensating the surface errors by prebending the workpiece during the milling process. First, a machining error prediction model using finite element method is formulated, which simplifies the contacts between the workpiece and fixture with spring constraints. Milling forces calculated by the micro-unit cutting force model are loaded on the error prediction model to predict the machining error. The error prediction results are substituted into the given formulas to obtain the prebending clamping forces and clamping positions. Consequently, the workpiece is prebent in terms of the calculated clamping forces and positions during the face milling operation to reduce the machining error. Finally, simulation and experimental tests are carried out to validate the correctness and efficiency of the proposed error compensation method. The experimental measured flatness results show that the flatness improves by approximately 30 percent through this error compensation method. The proposed method not only predicts the machining errors in face milling thin plate-shape parts but also reduces the machining errors by taking full advantage of the workpiece prebending caused by fixture, meanwhile, it provides a novel idea and theoretical basis for reducing milling errors and improving the milling accuracy.

  20. Error Compensation of Thin Plate-shape Part with Prebending Method in Face Milling

    Institute of Scientific and Technical Information of China (English)

    YI Wei; JIANG Zhaoliang; SHAO Weixian; HAN Xiangcheng; LIU Wenping

    2015-01-01

    Low weight and good toughness thin plate parts are widely used in modern industry, but its flexibility seriously impacts the machinability. Plenty of studies focus on the influence of machine tool and cutting tool on the machining errors. However, few researches focus on compensating machining errors through the fixture. In order to improve the machining accuracy of thin plate-shape part in face milling, this paper presents a novel method for compensating the surface errors by prebending the workpiece during the milling process. First, a machining error prediction model using finite element method is formulated, which simplifies the contacts between the workpiece and fixture with spring constraints. Milling forces calculated by the micro-unit cutting force model are loaded on the error prediction model to predict the machining error. The error prediction results are substituted into the given formulas to obtain the prebending clamping forces and clamping positions. Consequently, the workpiece is prebent in terms of the calculated clamping forces and positions during the face milling operation to reduce the machining error. Finally, simulation and experimental tests are carried out to validate the correctness and efficiency of the proposed error compensation method. The experimental measured flatness results show that the flatness improves by approximately 30 percent through this error compensation method. The proposed method not only predicts the machining errors in face milling thin plate-shape parts but also reduces the machining errors by taking full advantage of the workpiece prebending caused by fixture, meanwhile, it provides a novel idea and theoretical basis for reducing milling errors and improving the milling accuracy.

  1. Acoustic Emission Monitoring of Multicell Reinforced Concrete Box Girders Subjected to Torsion

    OpenAIRE

    Marya Bagherifaez; Arash Behnia; Abeer Aqeel Majeed; Chai Hwa Kian

    2014-01-01

    Reinforced concrete (RC) box girders are a common structural member for road bridges in modern construction. The hollow cross-section of a box girder is ideal in carrying eccentric loads or torques introduced by skew supports. This study employed acoustic emission (AE) monitoring on multicell RC box girder specimens subjected to laboratory-based torsion loading. Three multicell box girder specimens with different cross-sections were tested. The aim is to acquire AE analysis data indicative fo...

  2. Shrinkage Analysis on Thick Plate Part using Response Surface Methodology (RSM

    Directory of Open Access Journals (Sweden)

    Isafiq M.

    2016-01-01

    Full Text Available The work reported herein is about an analysis on the quality (shrinkage on a thick plate part using Response Surface Methodology (RSM. Previous researches showed that the most influential factor affecting the shrinkage on moulded parts are mould and melt temperature. Autodesk Moldflow Insight software was used for the analysis, while specifications of Nessei NEX 1000 injection moulding machine and P20 mould material were incorporated in this study on top of Acrylonitrile Butadiene Styrene (ABS as a moulded thermoplastic material. Mould temperature, melt temperature, packing pressure and packing time were selected as variable parameters. The results show that the shrinkage have improved 42.48% and 14.41% in parallel and normal directions respectively after the optimisation process.

  3. Wave induced extreme hull girder loads on containerships

    DEFF Research Database (Denmark)

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

    2009-01-01

    , forward speed and hull flexibility. The vertical hull girder loads are evaluated for specific operational profiles. Firstly a quadratic strip theory is presented which can give separate predictions for the hogging and sagging bending moments and shear forces and for hull girder loads. Then this procedure...... 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...

  4. 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

  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. 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...

  7. 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.

  8. Seismicity and Seismic Hazard along the Western part of the Eurasia-Nubia plate boundary

    Science.gov (United States)

    Bezzeghoud, Mourad; Fontiela, João; Ferrão, Celia; Borges, José Fernando; Caldeira, Bento; Dib, Assia; Ousadou, Farida

    2016-04-01

    The seismic phenomenon is the most damaging natural hazard known in the Mediterranean area. The western part of the Eurasia-Nubia plate boundary extends from the Azores to the Mediterranean region. The oceanic part of the plate boundary is well delimited from the Azores Islands, along the Azores-Gibraltar fault to approximately 12°W (west of the Strait of Gibraltar). From 12°W to 3.5°E, including the Iberia-Nubia region and extending to the western part of Algeria, the boundary is more diffuse and forms a wider area of deformation. The boundary between the Iberia and Nubia plates is the most complex part of the margin. This region corresponds to the transition from an oceanic boundary to a continental boundary, where Iberia and Nubia collide. Although most earthquakes along this plate boundary are shallow and generally have magnitudes less than 5.5, there have been several high-magnitude events. Many devastating earthquakes, some of them tsunami-triggering, inflicted heavy loss and considerable economic damage to the region. From 1920 to present, three earthquakes with magnitudes of about 8.0 (Mw 8.2, 25 November 1941; Ms 8.0, 25 February 1969; and Mw 7.9, 26 May 1975) occurred in the oceanic region, and four earthquakes with magnitudes of about 7.0 (Mw 7.1, 8 May 1939, Santa Maria Island and Mw 7.1, January 1980, Terceira and Graciosa Islands, both in the Azores; Ms 7.1, 20 May 1931, Azores-Gibraltar fracture zone; and Mw 7.3, 10 October 1980, El Asnam, Algeria) occurred along the western part of the Eurasia-Nubia plate boundary. In general, large earthquakes (M ≥7) occur within the oceanic region, with the exception of the El Asnam (Algeria) earthquakes. Some of these events caused extensive damage. The 1755 Lisbon earthquake (˜Mw 9) on the Portugal Atlantic margin, about 200 km W-SW of Cape St. Vincent, was followed by a tsunami and fires that caused the near-total destruction of Lisbon and adjacent areas. Estimates of the death toll in Lisbon alone (~70

  9. Assessment and Strengthening of a Fire Damaged Prestressed Concrete Continuous Girder Bridge%某预应力混凝土连续梁桥火损评估与加固

    Institute of Scientific and Technical Information of China (English)

    刘华; 高宗余; 刘其伟; 张军雷

    2015-01-01

    某大桥靠岛岸侧的5×35 m连续梁引桥于2012年某日凌晨3时左右遭受火灾。为恢复该桥的使用功能,针对火损后的桥跨进行现场检测,并结合火场温度和结构温度场的模拟分析,对结构的受损程度进行综合评定。结果表明箱梁表面有较大面积的混凝土崩落,且造成钢筋外露,受火灾影响最为严重的是内侧翼板处,因火损导致8根横向预应力钢绞线外露。在此基础上针对箱梁混凝土火损后剥落采取砂浆修补或灌注并结合粘贴锚固钢板的措施;针对翼板横向预应力火损采取增设钢结构隔板的措施;针对结构整体采用张拉粘贴预应力碳纤维板的措施进行维修加固。经试验评定,验证了加固方案实施后的桥梁承载能力得以恢复。%T he 5 × 35‐m span continuous girder approach bridge of a bridge on the island bank side caught fire at about 03 :00 in the early morning in a day in 2012 .To restore the operational function of the bridge ,the fire damaged spans of the bridge were inspected in the field ,the fire temperatures and temperature fields of the structure were simulated and analyzed and the damage degrees of the structure were comprehensively assessed .The results of the assessment show that rather great area of concrete spalling occurs on the surface of the box girder of the bridge and the concrete spalling causes the exposure of the reinforcement .The part of the box girder affected most severely by the fire damage is the inner side cantilever slab w here 8 transverse prestressing steel wire strands are exposed owing to the fire .According to the assessment ,the concrete spal‐ling of the box girder is repaired by the measure of plastering or grouting the cement mortar and binding the anchor steel plates .The damaged prestressing steel wire strands of the cantilever slab are repaired by the measure of adding the steel partition plates and the w hole structure is repaired and

  10. Proximal humeral fractures: a biomechanical comparison of locking plate constructs in a cadaveric 3-part fracture model.

    Science.gov (United States)

    Rose, David M; Sutter, Edward G; Mears, Simon C; Gupta, Rohit R; Belkoff, Stephen M

    2010-11-01

    The purpose of our study was to biomechanically compare, under cyclic loading conditions, fracture site motion, humeral head collapse, and intra-articular hardware penetration in simulated 3-part osteoporotic proximal humeral fractures stabilized with 1 of 2 locking-plate constructs. We performed fixation on simulated 3-part proximal humeral fractures in 10 pairs of cadaveric osteoporotic humeri with a Hand Innovations S3 Proximal Humerus Plate (S3 plate) or an LCP Proximal Humerus Plate (LCP plate; 1 each for each pair). The specimens were potted, mounted on a materials testing machine, and subjected to 5000 cycles of abduction in the scapular plane, loading through the supraspinatus tendon. Interfragmentary displacement at 2 virtual points (the most medial aspect of the calcar and the most superior aspect of the osteotomy line between the greater tuberosity and humeral head) was measured using an optical tracking system. Humeral head rotation was also measured. We used a generalized linear latent and mixed model to check for an effect of cyclic loading and treatment on the parameters of interest (significance, P fracture site motion, it is unknown whether the magnitude of the motion is clinically significant.

  11. Seismo-electromagnetic phenomena in the western part of the Eurasia-Nubia plate boundary

    Science.gov (United States)

    Gonçalves da Silva, Hugo; Bezzeghoud, Mourad; Biagi, Pier; Namorado Rosa, Rui; Salgueiro da Silva, Manuel; Caldeira, Bento; Heitor Reis, Artur; Borges, José Fernando; Tlemçani, Mouhaydine; Manso, Marco

    2010-05-01

    This paper presents a future research plan that aims to monitor Seismo-electromagnetic (SEM) phenomena in the western part of the Eurasia-Nubia plate boundary (WENP). This region has a significant tectonic activity [1] combined with relatively low electromagnetic noise levels and for that reason presents the possibility to perform high quality SEM measurements. Further, it is known that low-frequency [ultra (ULF), very (VLF), and low-frequencies (LF)] electromagnetic (EM) waves produce more convincing earthquake precursors (compared to higher frequencies) because of less contamination, large skin depth, and low attenuation [2]. Thus, two SEM effects will be considered: ULF electromagnetic field emissions [3], and VLF/LF radio broadcastings [4]. With respect to the ULF measurements, as a start, three ULF sensors are planned to be installed in the South of Iberian Peninsula supported by the existing networks of seismic research stations. Subsequent development of this initial plan could result in the implementation of a lager ULF monitoring network not only in the Iberian Peninsula, but also in the rest of Europe. Possible integration in the SEGMA array is now under consideration. Another perspective is to use a portable station to track seismic events. Regarding the VLF/LF radio broadcastings, a receiver is planned to be mounted in University of Évora. Radio signals from up to 10 transmitters (in these bands) of interest to study the seismic activity in the WENP region will be monitored. Actually, the radio path from the transmitter to the receiver should cross the epicentral area, therefore two possible transmitters are the ones installed in Monaco (France) and Sicily (Italy). Furthermore, the system will integrate the INFREP network and in this context it will not be restricted to WENP region. With the development of these research plans we aim to collect novel SEM data emerging from the seismic activity in the WENP region. We expect to address the time

  12. Influence of location and parameters of stiffeners on the stability of a square plate under shear

    Directory of Open Access Journals (Sweden)

    Pritykin Aleksey Igorevich

    Full Text Available Application of flexible-walled beams is rather effective because the reducing of wall thickness compared to ordinary welded beams leads to substantial reduction of metal expenditure for the walls and its more rational use. The operation experience of such beams shows that the loss of local stability of a wall takes place near bearing cross section with characteristic diagonal type of half waves, indicating, that the reason for the stability loss is in shear deformation. In plate girder with slender web big transverse forces appear, which leads to its buckling as a result of shear. One of the ways to increase stability of the parts of web near supports is to install stiffeners. In the given work the task of finding critical stresses of fixed square plate with installed inclined stiffener is considered. Investigations were performed with the help of finite element method and were experimentally checked. Recommendations were given on the choice of optimal size of the stiffener.

  13. Spatial Finite Element Analysis for Dynamic Response of Curved Thin-Walled Box Girder Bridges

    Directory of Open Access Journals (Sweden)

    Yinhui Wang

    2016-01-01

    Full Text Available According to the flexural and torsional characteristics of curved thin-walled box girder with the effect of initial curvature, 7 basic displacements of curved box girder are determined. And then the strain-displacement calculation correlations were established. Under the curvilinear coordinate system, a three-noded curved girder finite element which has 7 degrees of freedom per node for the vibration characteristic and dynamic response analysis of curved box girder is constructed. The shape functions are used as the interpolation functions of variable curvature and variable height to accommodate to the variation of curvature and section height. A MATLAB numerical analysis program has been implemented.

  14. Vibration analysis of a rectangular thin isotropic plate with a part-through surface crack of arbitrary orientation and position

    Science.gov (United States)

    Bose, Tanmoy; Mohanty, A. R.

    2013-12-01

    In this paper, vibration analysis of a rectangular thin isotropic plate with a part-through surface crack of arbitrary orientation and position is performed by using the Kirchhoff plate theory. Simply supported (SSSS), clamped (CCCC) and simply supported-clamped (SCSC) boundary conditions are considered for the analysis. First, the governing differential equation of a cracked plate is formulated. A modified line spring model is then used to formulate the crack terms in the governing equation. Next, by the application of Burger's formulation, the differential equation is transformed into the well-known Duffing equation with cubic and quadratic nonlinearities. The Duffing equation is then solved by the method of multiple scales (MMS) to extract the frequency response curve. Natural frequencies are evaluated for different values of length, angle and position of a part-through surface crack. Some results are compared with the published literature. Amplitude variation with different values of length, angle and position of a part-through surface crack are presented, for all three types of the plate boundary conditions.

  15. 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.

  16. Life-Cycle Management Strategy on Steel Girders in Bridges

    Directory of Open Access Journals (Sweden)

    Kevin K. L. So

    2012-01-01

    Full Text Available The major problems affecting the service life of bridges are related to various factors such as fatigue-sensitive details, increased service loads, corrosion deterioration, and the lack of proper maintenance. Among them, corrosion deterioration and fatigue damages of structures particularly to steel girder bridges are the most common ones. Bridges of different structural forms, at different locations or under different climates, may suffer from various degrees of deterioration. Steel girders at different positions of a bridge may also suffer from different degrees of damage. How to effectively maintain the bridge asset at a minimal cost and how to predict the time for future works are crucial, particularly when government funding sources become stretched. A comprehensive bridge management framework assisting stakeholders to appropriately and reasonably prioritize their future maintenance-related works in their bridge stocks, such that stakeholders can better allocate the limited resources, is utmost concerned. This paper proposes an integrated life-cycle management (LCM strategy on steel girders in bridges in which corrosion deterioration and fatigue damage prediction models are mapped with girders’ performance conditions. A practical example to demonstrate the applicability of the proposed LCM strategy is also illustrated.

  17. 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.

  18. Fixation of 3- and 4-part proximal humerus fractures using the PHILOS plate: mid-term results.

    Science.gov (United States)

    Gaheer, Rajinder Singh; Hawkins, Amanda

    2010-09-07

    Treatment of unstable, displaced, and comminuted fractures of the proximal humerus remains challenging, and optimal treatment continues to be controversial. Fifty-six patients with displaced 3- and 4-part fractures of the proximal humerus had open reduction and internal fixation using the proximal humeral internal locking system (PHILOS) plate (Synthes, Stratec Medical Ltd, Mezzovico, Switzerland). Data were collected retrospectively, and clinical and radiological outcomes were assessed. Mean follow-up was 40 months (range, 18-62 months). The study shows that the PHILOS plate gives good results in the treatment of displaced 3- and 4-part fractures of the proximal humerus. Good fracture stability can be achieved early, allowing early mobilization without compromising fracture union. Most importantly, it requires minimal soft tissue dissection, does not need contouring, and gives good stability. No differences were observed in the functional outcomes of patients younger and older than 65 years. Few complications were associated with the plate, and the number of ≥2 surgeries was minimal. The complications noted were 1 case each of superficial wound infection, failure of the plate, and persistent stiffness. One patient had screw perforation of the humeral head articular surface, and 1 had subacromial impingement. Of the 32 patients who had been in active employment before the injury, 28 returned to their previous occupation.

  19. 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.

  20. Numerical Simulation of Projectile Impact on Mild Steel ArmourPlates using LS-DYNA: Part I: Validation

    Directory of Open Access Journals (Sweden)

    A. Deb

    2008-05-01

    Full Text Available The paper describes  the simulation of impact of jacketed projectiles on steel armour plates usingexplicit finite element analysis as implemented in LS-DYNA. Validation of numerical modelling includesa comprehensive mesh convergence study leading to insights not previously reported in literature,using shell, solid, and axisymmetric elements for representing target plates. It is shown for a numberof cases that with a proper choice of contact algorithm, element size, and strain rate-dependent materialproperties, computed projectile residual velocities can match closely with corresponding test-basedvalues. The modelling requirements are arrived at by correlating against published test residual velocities1for variants of mild steel plates (designated as MS1, MS2 and MS3 of different thicknesses at impactvelocities in the range of ~820-870 m/s. Using the validated numerical procedure, a number of parametricstudies such as the effect of projectile shape and geometric aspect ratios as well as plate thickness onresidual velocity have been carried out and presented in Part II of the current paper.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lessner, E.

    1999-04-14

    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.

  2. Performance of streamlined bridge decks in relation to the aerodynamics of a flat plate

    DEFF Research Database (Denmark)

    Larose, Guy; Livesey, Flora M.

    1997-01-01

    The aerodynamics of three modern bridge decks are compared to the aerodynamics of a 16:1 flat plate. The comparisons are made on the basis of the analytical evaluation of the performance of each cross-section to the buffeting action of the wind. In general, the closed-box girders studied in this ...... in this paper showed buffeting responses similar to a flat plate with the exception of the multi-box girder which performed much better aerodynamically.......The aerodynamics of three modern bridge decks are compared to the aerodynamics of a 16:1 flat plate. The comparisons are made on the basis of the analytical evaluation of the performance of each cross-section to the buffeting action of the wind. In general, the closed-box girders studied...

  3. Study of Treating Schemes For Long-Term Downwarping Deterioration of Main Girder of A Bridge%某桥主梁长期下挠病害处治方案研究

    Institute of Scientific and Technical Information of China (English)

    蔡巍; 江湧; 陈波

    2015-01-01

    某桥主桥为主跨400 m的斜拉桥,1995年建成通车。在交通量激增、荷载超载、预应力损失等因素作用下,部分桥跨主梁呈现下挠加剧,主梁混凝土出现剥落、露筋及开裂等病害。为抑制主梁下挠不断发展的趋势,采用结构自重减载方式(将混凝土人行道板置换为轻型钢人行道板)来部分减缓主梁下挠,并对箱梁顶板底面粘贴碳纤维布进行加固。采用有限元软件建立主桥模型,计算结构自重减载及粘贴碳纤维布对改善主梁下挠的作用效应。结果表明,将混凝土人行道板置换成轻型钢人行道板后,主梁下挠程度相对减小;碳纤维布与主梁共同参与受力,在一定程度上抑制了混凝土病害进一步发展,也避免了因混凝土开裂而造成的主梁下挠,验证了该加固方案的可行性。%A Bridge was opened to traffic in 1995 .Its main bridge is a cable‐stayed bridge with a main span of 400 m .According to the inspection report ,the downwarping of main girder in some spans had been exarcebated ,the main girder concrete began to spalling ,deteriations including con‐crete spalling ,reinforcement exposure and concrete cracking were also found ,the causes of which can be attributed to the surge of traffic ,over load and prestress loss .To curb the exarcerbation of main girder downwarping ,the way of relieving the self weight of the structure was used to partial‐ly slow down the main girder downwarping ,specifically by replacing the concrete slabs in the side‐walks by the ligh weight steel plates ,and the main girder was strengthened by gluing carbon fiber sheet on the base of the top plate of the box girder .The finite element software was used to estab‐lish the model of the main bridge ,to calculate the effect of structural self weight reduction and car‐bon fiber sheets strengthening on the enhancement of main girder downwarping .The results of the calculation indicate

  4. 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 interest. The RMS response is determined on the basis of the equation of motion, which is formulated stochastically according to the wind random turbulence components. It is further assumed that the sum of the motion-induced forces and the buffeting-induced forces from the girder and the flaps is computed...

  5. 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

    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 (...... (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...

  6. CONTRIBUTIONS OF THE POSSIBILITY OF USING ULTRASOUND IN PLATING PROCESS PARTS

    Directory of Open Access Journals (Sweden)

    Gheorghe AMZA

    2014-05-01

    Full Text Available The efficiency of the plating process in the ultrasonic field is primarily dependent on the mode of introducing the ultrasonic energy into the welding bath. The research undertaken has revealed that the propagation of ultrasound in the liquid metal bath has a significant influence on the transfer process filler material through the electric arc and on the process of crystallization. All these influences are attributed to the two basic phenomena due to the propagation of ultrasound in liquid enviroments and ultrasonic cavitation and the acceleration of diffusion process

  7. 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.

  8. Design plan and checking calculation for the reinforcement of prestressed continuous box girder bridges%预应力连续箱梁桥加固设计及验算

    Institute of Scientific and Technical Information of China (English)

    张胜

    2016-01-01

    某预应力连续箱梁桥运营15年后,箱梁内外出现了较多的裂缝、钢筋锈蚀和台后填土沉降等病害,已影响桥梁结构的正常使用和安全。根据该桥的质量检测报告,提出了箱梁顶板采用增厚钢筋混凝土、箱室顶板内表面采用粘贴钢板和碳纤维相结合以及箱梁腹板粘贴钢板的加固方法。通过理论计算和荷载试验对加固后的桥梁承载力进行了验算和检测,结果表明,结构承载力和刚度都有明显地提高,能保证桥梁的正常使用。%A prestressed continuous box girder bridge appeared various diseases in fifteen years, for instance, cracks of the inside and outside surface of the box girder, steel corrosion and the obvious settlement of filling at back abutment. The disease has affected the normal use and safety of the bridge structure. Based on the testing reports of the bridge, a feasible strengthening method is put forward: The roof of box girder is strengthened by the thick reinforced concrete;The top plate of the box is strengthened by steel plate and carbon fiber, and box girder webs is strengthened by steel plate. The carrying capacity of the reinforced bridge is checked by the theoretical calculation and the load test. The results show that the bearing capacity and stiffness of the structure are obviously improved and can meet the requirements of normal use.

  9. Analysis of Strength on Thick Plate Part using Genetic Algorithm Optimisation Method

    Directory of Open Access Journals (Sweden)

    Azlan S.M.

    2016-01-01

    Full Text Available This study focuses on the optimisation of the injection moulding parameters to maximise the strength ofmoulded parts using a simulation software. The moulded parts were injected with Acrylonitrile- Butadiene-Styrene (ABS whereas mould temperature, melt temperature, packing pressure and packing time were selected as variable process parameters. The polynomial model obtained using Design of Experiment (DOE was integrated with the Response Surface Methodology (RSM and Centre Composite Design (CCD. The RSM was supported with Genetic Algorithm (GA to anticipate the optimum value of processing parameters with the highest strength. It was found that strength of the parts can be improved 2.2% using the methodology reported herein.

  10. Module-Scale Simulation of Forward Osmosis Module-Part A: Plate-and-Frame

    Directory of Open Access Journals (Sweden)

    Muhammad Roil Bilad

    2016-09-01

    Full Text Available In forward osmosis (FO, a semi-permeable membrane separates a concentrated draw and a diluted feed solution. FO has emerges as a promising alternative for various applications. To support further development of FO process, a larger scale optimization is required to accurately envisage the most critical factors to be explored. In this study, we applied a mass-transfer model coupled with the mass conservation and area discretization to simulate the performance of plate-and-frame FO modules (10 sheets of 1x1m. Effects of numerous parameters were simulated: modes, flow orientations (co-, counter- and cross-currents, spacers and spacer properties, membrane parameters and operational parameters. Results show that counter-current flow orientation offers the highest flux with minimum spatial distribution. Module performance can be improved by developing FO membrane through reducing membrane structural (S parameter and increasing water permeability (A: increasing A-value only significant at low S-value, and vice versa (i.e., for A-value of 1 LMH/atm, S-value must be below 50 µm. Furthermore, inclusion of spacer in the flow channel slightly increases the flux (merely up to 2%. Module performance can also be enhanced by increasing feed flow rate, lowering solute in the feed and increasing solute in the draw solution.

  11. 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.

  12. Analysis of Biaxially Stressed Bridge Deck Plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Bondum, Tommi Højer

    2012-01-01

    The ultimate state analysis of bridge deck plates at the intersection zone between main girders and transverse beams is complicated by biaxial membrane stresses, which may be in compression or tension in either direction depending on the bridge configuration and the specific location. This paper...... presents a detailed investigation of the ultimate capacity of simply supported plates subjected to biaxial loads. The full interaction domain of combinations of compressive and tensile loads has been investigated including a large number of imperfections. It was found that non-standard imperfection modes...

  13. Wire position system to consistently measure and record the location change of girders following ground changes

    Science.gov (United States)

    Choi, H. J.; Lee, S. B.; Lee, H. G.; Y Back, S.; Kim, S. H.; Kang, H. S.

    2017-07-01

    Several parts that comprise the large scientific device should be installed and operated at the accurate three-dimensional location coordinates (X, Y, and Z) where they should be subjected to survey and alignment. The location of the aligned parts should not be changed in order to ensure that the electron beam parameters (Energy 10 GeV, Charge 200 pC, and Bunch Length 60 fs, Emittance X/Y 0.481 μm/0.256 μm) of PAL-XFEL (X-ray Free Electron Laser of the Pohang Accelerator Laboratory) remain stable and can be operated without any problems. As time goes by, however, the ground goes through uplift and subsidence, which consequently deforms building floors. The deformation of the ground and buildings changes the location of several devices including magnets and RF accelerator tubes, which eventually leads to alignment errors (∆X, ∆Y, and ∆Z). Once alignment errors occur with regard to these parts, the electron beam deviates from its course and beam parameters change accordingly. PAL-XFEL has installed the Hydrostatic Leveling System (HLS) to measure and record the vertical change of buildings and ground consistently and systematically and the Wire Position System (WPS) to measure the two dimensional changes of girders. This paper is designed to introduce the operating principle and design concept of WPS and discuss the current situation regarding installation and operation.

  14. 运架一体式架梁机隧道架梁技术%Tunnel Girder Skill of Transported Frame Integrated Girder Machine

    Institute of Scientific and Technical Information of China (English)

    乐锋

    2013-01-01

      本文介绍了运架一体式架梁机的组成结构,施工前的各项准备工作。本文详细阐述了运架一体式架梁机进出隧道架设第一孔或最后一孔双线整孔预制箱梁的施工技术。%This article describes the structure composition of the transported frame integrated girder machine and the preparatory work before construction. This paper describes the double track prefabricated box girder construction technology of entering and going out the first or last hole of tunnel for the transported frame integrated girder machine.

  15. 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.

  16. 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.

  17. Rubidium-strontium geochronology and plate-tectonic evolution of the southern part of the Arabian Shield

    Science.gov (United States)

    Fleck, Robert J.; Greenwood, W.R.; Hadley, D.G.; Anderson, R.E.; Schmidt, D.L.

    1980-01-01

    Rubidium-strontium studies of Precambrian volcanic and plutonic rocks of the Arabian Shield document an early development of the Arabian craton between 900 and 680 m.y. (million years) ago. Geologic studies indicate an island-arc environment characterized by andesitic (dioritic) magmas, volcaniclastic sedimentation, rapid deposition, and contemporaneous deformation along north or northwest-trending axes. Magmatic trends show consistent variation in both composition and geographic location as a function of age. The oldest units belong to an assemblage of basaltic strata exposed in western Saudi Arabia that yield an age of 1165:!:110 m.y. The oldest andesitic strata studied yield an age of 912:!:76 m.y. The earliest plutonic units are diorite to trondhjemite batholiths that range from 800 to 9,00 m.y. in age and ,occur along the western and southern parts of Saudi Arabia. Younger plutonic units, 680 to 750 m.y. in age, range from quartz diorite to granodiodte and become more abundant in the central and northeastern parts of the Arabian Shield. Initial 'Sr/ 86 Sr ratios for both dioritic groups range from 0.7023 to 0.7030 and average 0.7027. The absence of sialic detritus in sedimentary units and the evidence for an island-arc environment suggest the early development of the Arabian craton at a convergent plate margin between plates of oceanic lithosphere. Active subduction apparently extended from at least 900 m.y. to about 680 m.y. Subsequent to this subduction-related magmatism and tectonism, called the Hijaz tectonic cycle, the Arabian craton was sutured to the late Precambrian African plate in a collisional event. This period of orogeny, represented in Arabia and eastern Africa by the Mozambiquian or Pan-African event, extended from some time before 650 m.y. to at least 540 m.y. and perhaps 520 m.y. B.P. Although the tectonic processes of subduction and continental collision during the 900+ to 500-m.y. period require similar directions of plate convergence, the

  18. Early results for treatment of three- and four-part fractures of the proximal humerus using the PHILOS plate system.

    Science.gov (United States)

    Moonot, P; Ashwood, N; Hamlet, M

    2007-09-01

    Secure fixation of displaced proximal fractures of the humerus is a challenging problem. A total of 32 patients with acutely displaced three- or four-part proximal fractures of the humerus were treated by open reduction and internal fixation using the proximal humeral internal locking system (PHILOS) plate. There were 23 women and nine men with a mean age of 59.9 years (18 to 87). Data were collected prospectively and the outcomes were assessed using the Constant score. The mean follow-up was for 11 months (3 to 24). In 31 patients (97%) the fracture united clinically and radiologically at a mean of 10 weeks (8 to 24). The mean Constant score at final review was 66.5 (30 to 92). There was no significant difference in outcome when comparing patients aged more than 60 years (18 patients) with those aged less than 60 years (14 patients) (t-test, p = 0.8443). There was one case each of nonunion, malunion and a broken screw in the elderly population. This plate provides an alternative method of fixation for fractures of the proximal humerus. It provides a stable fixation in young patients with good-quality bone sufficient to permit early mobilisation. Failure of the screws to maintain fixation in the elderly remains a problem.

  19. TLC of alkaloids on cyanopropyl bonded stationary phases. Part II. Connection with RP18 and silica plates.

    Science.gov (United States)

    Petruczynik, Anna; Waksmundzka-Hajnos, Monika; Plech, Tomasz; Tuzimski, Tomasz; Hajnos, Michał Ł; Jóźwiak, Grzegorz; Gadzikowska, Maria; Rompała, Anna

    2008-04-01

    Some standards of the alkaloids and synthetic or natural mixtures are separated by two-dimensional thin-layer chromatography (TLC) on different adsorbent layers. Normal- and reversed-phase systems are used to obtain significant differences in the separation selectivity. Optimization of the one-dimensional TLC separation of the alkaloids' standards is performed on cyanopropyl-silica, RP18W, and silica layers in various eluents containing (besides diluent and modifier) silanol blockers, such as diethyl amine or ammonia. The most selective systems are used for the separation of the alkaloids' mixtures by two-dimensional TLC with an adsorbent gradient method. The mixtures of alkaloids or plant extracts (Chelidonium majus, Fumaria officinalis, or Glaucium flavum) are chromatographed in system I; the plates are connected with the plate pre-coated with various adsorbent, and partly separated fractions are transferred to the second layer and developed in system II. CN-silica-RP18W and CN-silica-silica are used as the connected layers. The alkaloids are identified by R(F) values of standards, and the components of plant extracts are identified in both systems, and by the comparison of UV spectra obtained in diode array detector densitometry.

  20. 2-D Finite Difference Modeling of the D'' Structure Beneath the Eastern Cocos Plate: Part I

    Science.gov (United States)

    Helmberger, D. V.; Song, T. A.; Sun, D.

    2005-12-01

    The discovery of phase transition from Perovskite (Pv) to Post-Perovskite (PPv) at depth nears the lowermost mantle has revealed a new view of the earth's D'' layer (Oganov et al. 2004; Murakami et al. 2004). Hernlund et al. (2004) recently pusposed that, depending on the geotherm at the core-mantle boundary (CMB), a double-crossing of the phase boundary by the geotherm at two different depths may also occur. To explore these new findings, we adopt 2-D finite difference scheme (Helmberger and Vidale, 1988) to model wave propagation in rapidly varying structure. We collect broadband waveform data recorded by several Passcal experiments, such as La Ristra transect and CDROM transect in the southwest US to constrain the lateral variations in D'' structure. These data provide fairly dense sampling (~ 20 km) in the lowermost mantle beneath the eastern Cocos plate. Since the source-receiver paths are mostly in the same azimuth, we make 2-D cross-sections from global tomography model (Grand, 2002) and compute finite difference synthetics. We modify the lowermost mantle below 2500 km with constraints from transverse-component waveform data at epicentral distances of 70-82 degrees in the time window between S and ScS, essentially foward modeling waveforms. Assuming a velocity jump of 3 % at D'', our preferred model shows that the D'' topography deepens from the north to the south by about 120 km over a lateral distance of 300 km. Such large topography jumps have been proposed by Thomas et al. (2004) using data recorded by TriNet. In addition, there is a negative velocity jump (-3 %) 100 km above the CMB in the south. This simple model compare favorably with results from a study by Sun, Song and Helmberger (2005), who follow Sidorin et al. (1999) approach and produce a thermodynamically consistent velocity model with Pv-PPv phase boundary. It appears that much of this complexity exists in Grand's tomographic maps with rapid variation in velocities just above the D''. We also

  1. Shaping frequency response of a vibrating plate for passive and active control applications by simultaneous optimization of arrangement of additional masses and ribs. Part I: Modeling

    Science.gov (United States)

    Wrona, Stanislaw; Pawelczyk, Marek

    2016-03-01

    An ability to shape frequency response of a vibrating plate according to precisely defined demands has a very high practical potential. It can be applied to improve acoustic radiation of the plate for required frequencies or enhance acoustic isolation of noise barriers and device casings by using both passive and active control. The proposed method is based on mounting severaladditional ribs and masses (passive and/or active) to the plate surface at locations followed from an optimization process. This paper, Part I, concerns derivation of a mathematical model of the plate with attached elements in the function of their shape and placement. The model is validated by means of simulations and laboratory experiments, and compared with models known from the literature. This paper is followed by a companion paper, Part II, where the optimization process is described. It includes arrangement of passive elements as well as actuators and sensors to improve controllability and observability measures, if active control is concerned.

  2. Geo-energy Test Beds: part of the European Plate Observing System

    Science.gov (United States)

    Stephenson, Michael; Schofield, David; Luton, Christopher; Haslinger, Florian; Henninges, Jan; Giardini, Domenico

    2016-04-01

    For 2020, the EU has committed to cutting its greenhouse gas emissions to 20% below 1990 levels and further cuts are being decided for 2050. This commitment is one of the headline targets of the Europe 2020 growth strategy and is being implemented through binding legislation. This decarbonisation of the EU economy is one dimension of an overall EU energy and climate framework that is mutually interlinked with the need to ensure energy security, promote a fully integrated energy market, promote energy efficiency and promote research innovation and competitiveness. Power generation will have to take a particularly large part in emissions reductions (-54 to -68% by 2030 and -93 to -99% by 2050), mainly by focussing on increasing surface renewables (wind, tidal and solar) but also on carbon capture and storage on fossil fuel and biofuel power plants, shale gas, nuclear and geothermal power. All the above generation technologies share common geological challenges around containment, safety and environmental sustainability. In a densely populated continent, this means that high levels of subsurface management are needed to fully realise the energy potential. In response to this need, across Europe, public and private sector funded, experimental test and monitoring facilities and infrastructures (Geo-energy Test Beds, GETB) are being developed. These GETB investigate the processes, technology and practices that facilitate the sustainable exploitation of Geo-energy resources and are of intense interest to the public and regulators alike. The vision of EPOS IP Work Package 17 (wp17) is to promote research and innovation in Geo-energy that reflects core European energy priorities through provision of virtual access to data and protocols and trans-national access to GETB experiments. This will be achieved through provision of access to continuous strategic observations, promotion of the integrated use of data and models from European GETB, development of underpinning research

  3. Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 2: Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available The separator plays a key role on the performance of passive air-breathing flat-plate MFCs (FPMFC as it isolates the anaerobic anode from the air-breathing cathode. The goal of the present work was to study the separator characteristics and its effect on the performance of passive air-breathing FPMFCs. This was performed partially through characterization of structure, properties, and performance correlations of eight separators presented in Part 1. Current work (Part 2 presents a numerical model developed based on the mixed potential theory to investigate the sensitivity of the electrode potentials and the power output to the separator characteristics. According to this numerical model, the decreased peak power results from an increase in the mass transfer coefficients of oxygen and ethanol, but mainly increasing mixed potentials at the anode by oxygen crossover. The model also indicates that the peak power is affected by the proton transport number of the separator, which affects the cathode pH. Anode pH, on the other hand, remains constant due to application of phosphate buffer solution as the electrolyte. Also according to this model, the peak power is not sensitive to the resistivity of the separator because of the overshadowing effect of the oxygen crossover.

  4. 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.

  5. 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.

  6. 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%.

  7. 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.

  8. 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.

  9. Acoustic emission monitoring of multicell reinforced concrete box girders subjected to torsion.

    Science.gov (United States)

    Bagherifaez, Marya; Behnia, Arash; Majeed, Abeer Aqeel; Hwa Kian, Chai

    2014-01-01

    Reinforced concrete (RC) box girders are a common structural member for road bridges in modern construction. The hollow cross-section of a box girder is ideal in carrying eccentric loads or torques introduced by skew supports. This study employed acoustic emission (AE) monitoring on multicell RC box girder specimens subjected to laboratory-based torsion loading. Three multicell box girder specimens with different cross-sections were tested. The aim is to acquire AE analysis data indicative for characterizing torsion fracture in the box girders. It was demonstrated through appropriate parametric analysis that the AE technique could be utilized to effectively classify fracture developed in the specimens for describing their mechanical behavior under torsion. AE events localization was presented to illustrate the trend of crack and damage propagation in different stages of fracture. It could be observed that spiral-like patterns of crack were captured through AE damage localization system and damage was quantified successfully in different stages of fracture by using smoothed b-value analysis.

  10. Acoustic Emission Monitoring of Multicell Reinforced Concrete Box Girders Subjected to Torsion

    Directory of Open Access Journals (Sweden)

    Marya Bagherifaez

    2014-01-01

    Full Text Available Reinforced concrete (RC box girders are a common structural member for road bridges in modern construction. The hollow cross-section of a box girder is ideal in carrying eccentric loads or torques introduced by skew supports. This study employed acoustic emission (AE monitoring on multicell RC box girder specimens subjected to laboratory-based torsion loading. Three multicell box girder specimens with different cross-sections were tested. The aim is to acquire AE analysis data indicative for characterizing torsion fracture in the box girders. It was demonstrated through appropriate parametric analysis that the AE technique could be utilized to effectively classify fracture developed in the specimens for describing their mechanical behavior under torsion. AE events localization was presented to illustrate the trend of crack and damage propagation in different stages of fracture. It could be observed that spiral-like patterns of crack were captured through AE damage localization system and damage was quantified successfully in different stages of fracture by using smoothed b-value analysis.

  11. 预应力活性粉末混凝土箱梁抗弯性能试验%Experiment on Flexural Behaviors of Prestressed Reactive Powder Concrete Box Girders

    Institute of Scientific and Technical Information of China (English)

    方志; 刘明; 郑辉

    2015-01-01

    In order to study the mechanical behavior of prestressed reactive powder concrete (RPC) box girders ,the flexural behavior tests of two prestressed RPC box girders were carried out .T he force characteristic of RPC box girders and the influence of transverse prestressing force to its flexural performance were studied .The results show that the prestressed RPC box girders display a good deformation capacity ,with a maximal deflection of 1/50 of its span .The crack width and the short‐time stiffness of the RPC box girders can be calculated according to the formula in Technical Specif ication for Fiber Reinforced Concrete Structures (CECS 38 :2004) , with a coefficient of 0 .4 and 0 .2 considering influence from steel fiber , respectively . The transverse prestressing force in the top plate of RPC box girders has little influence on the flexural bearing capacity , but the force can make a more uniform strain distribution of the compressive concrete so as to reduce the shear‐lag effect and increase the ductility of the specimen .By applying a transverse prestressing force of 2 .95 M Pa (only 3 .1% of the RPC prism compressive strength of 94 MPa) at the top plate ,the effective distribution width of box girder increases by 10% ,and ductility index of specimen increases by 3% .The calculated formula to evaluate the cracking moment and the ultimate moment of a prestressed RPC box girders is proposed and verified by the experimental results .%为研究预应力活性粉末混凝土(RPC )箱梁的正截面受力性能,进行了2片预应力RPC箱梁的抗弯性能试验,研究了RPC箱梁的受力变形特征以及顶板横向预应力对其抗弯性能的影响。结果表明:预应力RPC箱梁具有良好的变形能力,其极限变形可超过跨径的1/50;RPC箱梁正常使用阶段的裂缝宽度和短期刚度可参照《纤维混凝土结构技术规程》(CECS 38:2004)的相应公式计算,其中的钢纤维影响系数可分别取为0

  12. Energy flow in plate assembles by hierarchical version of finite element method

    DEFF Research Database (Denmark)

    Wachulec, Marcin; Kirkegaard, Poul Henning

    method has been proposed. In this paper a modified hierarchical version of finite element method is used for modelling of energy flow in plate assembles. The formulation includes description of in-plane forces so that planes lying in different planes can be modelled. Two examples considered are: L......-corner of two rectangular plates an a I-shaped plate girder made of five plates. Energy distribution among plates due to harmonic load is studied and the comparison of performance between the hierarchical and standard finite element formulation is presented....

  13. Pre-oxidized and nitrided stainless steel alloy foil for proton exchange membrane fuel cell bipolar plates. Part 2: Single-cell fuel cell evaluation of stamped plates

    Science.gov (United States)

    Toops, Todd J.; Brady, Michael P.; Tortorelli, Peter F.; Pihl, Josh A.; Estevez, Francisco; Connors, Daniel; Garzon, Fernando; Rockward, Tommy; Gervasio, Don; Mylan, William; Kosaraju, Sree Harsha

    Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr 2N, CrN, TiN, V 2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited by the pre-oxidized/nitrided Fe-20Cr-4V, which exhibited ∼5-20% better peak power output than untreated Fe-20Cr-4V, 2205, and 904L metal stampings. Durability was assessed for pre-oxidized/nitrided Fe-20Cr-4V, 904L metal, and graphite plates by 1000+ h of cyclic single-cell fuel cell testing. All three materials showed good durability with no significant degradation in cell power output. Post-test analysis indicated no metal ion contamination of the membrane electrode assemblies (MEAs) occurred with the pre-oxidized and nitrided Fe-20Cr-4V or graphite plates, and only a minor amount of contamination with the 904L plates.

  14. The Design and Construction of 160T Girder Station%160T提梁站设计与施工

    Institute of Scientific and Technical Information of China (English)

    邓洪钧

    2012-01-01

      Guangshen Coastal Expressway Shenzhen Girder Station uses the steel pipe piles combined with Bailey girders in the construction.The headroom of the girder stations and the cast-in-place box girder is 7m, and the span is 17.25m. This paper makes a brief description of the installation method of the girder station%  广深沿江高速深圳段提梁站施工采用钢管桩结合贝雷梁形式。提梁站与现浇箱梁净空高度7m,跨度为17.25m,文章就提梁站的安装方法作简要介绍。

  15. Closure technique for the hybrid girder cable stayed bridge of Edong Bridge

    Institute of Scientific and Technical Information of China (English)

    Liu Minghu; Tan Hao; Xu GuoPing; Zhao Canhui

    2012-01-01

    Based on Edong Yangtze River Bridge, which is the second longest hybrid girder cable stayed bridge with 926 m long main span, the influencing factors and crucial techniques of the main span closure method for long span hybrid girder cable stayed bridge are studied. After theoretical analysis, numerical evaluation and practical test, the loading assistant closure method is employed in Edong Yangtze River Bridge. The loading assistant closure method, with better thermal adaptability and less influence on bridge line and the forced status, can meet the requirements of the unstressed state control method. Based on the mentioned advantages, the loading assistant closure method is applicable to long span hybrid girder cable stayed bridges. The conclusion can provide a reference for the further design of the similar brid~es.

  16. 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

  17. Lateral static and dynamic characteristics of thin-walled box girder

    Institute of Scientific and Technical Information of China (English)

    CAN Yan-an; ZHOU Guang-chun

    2009-01-01

    To analyze the static and dynamic behaviors of the thin-walled box girder in its lateral webs in consideration of shear lag effect and shear deformation, an approach based on the minimum potential principle is introduced in this paper. Both static and dynamic response equations as well as the corresponding natural boundary conditions of the box girder are deduced. Meanwhile, three generalized displacement functions:w(x), U(x) and 0(x) are employed and their differences in the calculus of variation are quantitatively investigated. The comparison of finite shell element results with analytical results of calculation examples validates the feasibility of the proposed approach.

  18. Early results for treatment of two- and three-part fractures of the proximal humerus using Contours PHP (proximal humeral plate).

    Science.gov (United States)

    Biazzo, Alessio; Cardile, Carlo; Brunelli, Luca; Ragni, Paolo; Clementi, Daniele

    2017-04-28

    The management of displaced 2- and 3-part fractures of the proximal humerus is controversial, both in younger and in elderly patients. The purpose of this paper is to evaluate the functional results of the Contours Proximal Humerus Plate (OrthofixR, Bussolengo,Verona, Italy), for the treatment of displaced 2- and 3-part fractures of the proximal humerus. We retrospectively reviewed 55 patients with proximal humerus fractures, who underwent osteosynthesis with Contours Proximal Humerus Plate from December 2011 to March 2015. We had 21 patients with 2-part fractures and with an average age of 67.1 years and 34 patients with 3-part fractures, with average age of 63.6 years. The average union time was 3 months. The mean Constant score was 67 for 2-part fracture group and 64.9 for 3-part fracture group. The difference was not statistically significant (p = 0.18). The overall complication rate was 14.5 %. Six patients underwent additional surgery (10.9%). The most frequent major complication was secondary loss of reduction following varus collapse of the fracture (2 cases). In these patients, there was loss of medial hinge integrity due to impaction and osteoporosis. The placement of the main locking screw in the calcar area to provide inferomedial support is the rational of the Contours Proximal Humerus Plate. Osteosynthesis with Contours Proximal Humerus Plate is a safe system for treating displaced 2- and 3-part fractures of the proximal humerus, with good functional results and complication rates comparable to those reported in the literature.

  19. Features of Three- and Four-Part Proximal Humeral Fractures and Outcome of Internal Fixation Using the Philos® Locking Plate

    Directory of Open Access Journals (Sweden)

    Ali Sadighi

    2017-03-01

    Full Text Available Background: Proximal humeral fractures are among common types of fractures and remain a challenging issue for surgical management. This study aimed to assess the clinical outcomes and complication rates of three- vs. four-part proximal humeral fractures, treated with internal fixation using the Philos® plate. Material and Methods: In this cohort study, a total of 30 consecutive patients with three-part or four-part proximal humeral fractures based on the Neer classification were included. Surgical treatment was performed with open reduction and internal fixation using the Philos® plate. The constant score was evaluated 6 months later in follow-up. The P<0.05 was considered significant. Results: Four-part fractures were mainly caused by trauma from above, while insults of opposite direction were responsible for more than half of 3 part fractures (P=0.01. Open fractures were only observed in patients with a four-part fracture (P=0.018. No significant differences were noticed regarding gender, cause, and side of the fracture. The presence of other fractures, fracture of the implant, reduction loss, avascular necrosis (AVN of humerus head, rotator cuff injury, and revision surgery were significantly higher in patients with four-part fractures. The mean constant score was 81.40±11.61 and 65.09±16.09 for three-part and four-part fractures, respectively (P=0.006. Conclusion: Open reduction and internal fixation with Philos® plate yield acceptable results in both types of fractures, however, the prognosis of this intervention is poorer four-part fractures.

  20. 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.

  1. Experimental Evaluation of the Post-ultimate Strength Behavior of a Ship's Hull Girder in Waves

    Institute of Scientific and Technical Information of China (English)

    Weijun Xu; Kazuhiro Iijima; Ryota Wada; Masahiko Fujikubo

    2012-01-01

    Experimental investigations into the collapse behavior of a box-shape hull girder subjected to extreme wave-induced loads are presented.The experiment was performed using a scaled model in a tank.In the middle of the scaled model,sacrificial specimens with circular pillar and trough shapes which respectively show different bending moment-displacement characteristics were mounted to compare the dynamic collapse characteristics of the hull girder in waves.The specimens were designed by using finite element (FE)-analysis.Prior to the tank tests,static four-point-bending tests were conducted to detect the load-carrying capacity of the hull girder.It was shown that the load-carrying capacity of a ship including reduction of the capacity after theultimate strength can be reproduced experimentally by employing the trough type specimens.Tank tests using these specimens were performed under a focused wave in which the hull girder collapses under once and repetitive focused waves.It was shown from the multiple collapse tests that the increase rate of collapse becomes higher once the load-carrying capacity enters the reduction path while the increase rate is lower before reaching the ultimate strength.

  2. A new solution of measuring thermal response of prestressed concrete bridge girders for structural health monitoring

    Science.gov (United States)

    Jiao, Pengcheng; Borchani, Wassim; Hasni, Hassene; Lajnef, Nizar

    2017-08-01

    This study develops a novel buckling-based mechanism to measure the thermal response of prestressed concrete bridge girders under continuous temperature changes for structural health monitoring. The measuring device consists of a bilaterally constrained beam and a piezoelectric polyvinylidene fluoride transducer that is attached to the beam. Under thermally induced displacement, the slender beam is buckled. The post-buckling events are deployed to convert the low-rate and low-frequency excitations into localized high-rate motions and, therefore, the attached piezoelectric transducer is triggered to generate electrical signals. Attaching the measuring device to concrete bridge girders, the electrical signals are used to detect the thermal response of concrete bridges. Finite element simulations are conducted to obtain the displacement of prestressed concrete girders under thermal loads. Using the thermal-induced displacement as input, experiments are carried out on a 3D printed measuring device to investigate the buckling response and corresponding electrical signals. A theoretical model is developed based on the nonlinear Euler-Bernoulli beam theory and large deformation assumptions to predict the buckling mode transitions of the beam. Based on the presented theoretical model, the geometry properties of the measuring device can be designed such that its buckling response is effectively controlled. Consequently, the thermally induced displacement can be designed as limit states to detect excessive thermal loads on concrete bridge girders. The proposed solution sufficiently measures the thermal response of concrete bridges.

  3. Numerical Investigation on Aerodynamic Force of Streamlined Box Girder with Uniform Air Suction

    Directory of Open Access Journals (Sweden)

    Tang Ke

    2014-06-01

    Full Text Available In the present study, the flow around a streamlined box girder with uniform air suction has been investigated numerically. Two-dimensional incompressible unsteady Reynolds averaged Navier-Stokes (URANS equations are solved in conjunction with the SST k −ω turbulence model in simulations. Taking the Great Belt Bridge girder as an example, cases of different suction positions on the girder section were discussed. The effect of the suction ratio and the angle of attack (AOA of wind also were investigated. The result showed that the aerodynamic drag force was influenced by the uniform suction through either upper surface or lower surface of the box girder. The larger the suction ratio was, the more the drag-reducing could be. The suction position and AOA had a comprehensive effect on the drag force. The vortex shedding frequency was also affected by air suction. For the aerodynamic lift force and moment, air suction showed no obvious influence. If necessary, using a combined suction scheme to reduce the aerodynamic drag force or to control the flow wake would be more efficient in engineering design.

  4. Deflection monitoring for a box girder based on a modified conjugate beam method

    Science.gov (United States)

    Chen, Shi-Zhi; Wu, Gang; Xing, Tuo

    2017-08-01

    After several years of operation, a box girder bridge would commonly experience excessive deflection, which endangers the bridge’s life span as well as the safety of vehicles travelling on it. In order to avoid potential risks, it is essential to constantly monitor the defection of box girders. However, currently, the direct deflection monitoring methods are limited by the complicated environments beneath the bridges, such as rivers or other traffic lanes, which severely impede the layouts of the sensors. The other indirect deflection monitoring methods mostly do not thoroughly consider the inherent shear lag effect and shear deformation in the box girder, resulting in a rather large error. Under these circumstances, a deflection monitoring method suiting box girders is proposed in this article, based on the conjugate beam method and distributed long-gauge fibre Bragg grating (FBG) sensor. A lab experiment was conducted to verify the reliability and feasibility of this method under practical application. Further, the serviceability under different span-depth ratios and web thicknesses was examined through a finite element model.

  5. Research and Application of Positioning Method of Electroplating Plating Part%电镀镀件定位方法研究与应用

    Institute of Scientific and Technical Information of China (English)

    宋晓群; 尹勇; 李卉

    2013-01-01

    The plating parts often fall into the water during electroplating in manual electroplating production line.It can cause scrap for a long time. On the basis of the application of RFID technology, we proposed a location method. Each plating only corresponds to a label, then we calculate labels and reference tag distance that can quickly locate the plated position. The application of this method reduces plating factory's losses and improves the work efficiency of electroplating enterprises.%在手工电镀生产线电镀的过程中,镀件经常掉入水中,时间过长容易造成镀件报废。文章在应用RFID技术的基础上,提出一个区域定位方法,每个镀件唯一对应一个标签,计算标签与参考标签的距离,能够迅速定位镀件位置。该定位方法的应用减少了电镀厂的损失,提高了电镀企业的工作效率。

  6. A new GPS velocity field for the Pacific Plate - Part 2: implications for fault slip rates in western California

    Science.gov (United States)

    DeMets, C.; Márquez-Azúa, Bertha; Cabral-Cano, Enrique

    2014-12-01

    Lower and upper bounds for present deformation rates across faults in central California between the San Andreas Fault and Pacific coast are estimated from a new Global Positioning System (GPS) velocity field for central, western California in light of geodetic evidence presented in a companion paper for slow, but significant deformation within the Pacific Plate between young seafloor in the eastern Pacific and older seafloor elsewhere on the plate. Transects of the GPS velocity field across the San Andreas Fault between Parkfield and San Juan Buatista, where fault slip is dominated by creep and the velocity field thus reveals the off-fault deformation, show that GPS sites in westernmost California move approximately parallel to the fault at an average rate of 3.4 ± 0.4 mm yr-1 relative to the older interior of the Pacific Plate, but only 1.8 ± 0.6 mm yr-1 if the Pacific Plate frame of reference is corrected for deformation within the plate. Modelled interseismic elastic deformation from the weakly coupled creeping segment of the San Andreas Fault is an order-of-magnitude too small to explain the southeastward motions of coastal sites in western California. Similarly, models that maximize residual viscoelastic deformation from the 1857 Fort Tejon and 1906 San Francisco earthquakes mismatch both the rates and directions of GPS site motions in central California relative to the Pacific Plate. Neither thus explains the site motions southwest of the San Andreas fault, indicating that the site motions measure deformation across faults and folds outboard of the San Andreas Fault. The non-zero site velocities thus constitute strong evidence for active folding and faulting outboard from the creeping segment of the San Andreas Fault and suggest limits of 0-2 mm yr-1 for the Rinconada Fault slip rate and 1.8 ± 0.6 to 3.4 ± 0.4 mm yr-1 for the slip rates integrated across near-coastal faults such as the Hosgri, San Gregorio and San Simeon faults.

  7. Construction of stiffening girder for Akashi straits bridge. Installation with use of latest bridging technology; Akashi kaikyo ohashi hoko keta kasetsu koji. Saishin kakyo gijutsu wo kushishite kasetsu

    Energy Technology Data Exchange (ETDEWEB)

    Oe, S. [Honshu-Shikoku Bridge Authority, Tokyo (Japan)

    1996-05-25

    The Akashi straits bridge is the Kobe-Naruto route of the bridge connecting Honshu and Shikoku; the bridge links Kobe in Hyogo prefecture with Awaji Island and, when completed, it will be a 3-span 2-hinge suspension bridge with the longest center effective span in the world. This report centers on the outline of the construction of stiffening girders for the Akashi straits bridge and especially on the characteristics of the engineering method newly employed. As the method of installing the stiffening girders, an overhang installation of face bars was employed which was a time-tested method. As the installing direction of the side spans, it was decided to install them from the anchorage to the tower. At the beginning, six large block installations were performed. A special balance was developed for the installation of short hanger parts for the purpose of enhancing safety and reduction in the process. A rubber-tired transporting truck was adopted for transporting members of framework on the bridge. GPS survey was used as a method for surveying the configuration. The subject engineering method was based on the construction of suspension bridge stiffening trusses in the past Honshu-Shikoku connecting bridge and reinforced with the improvements as above. Since the bridge is in the middle of construction, a subsequent report will hopefully be made on the actual results of the installation and the spanning after the closure. 8 figs., 2 tabs.

  8. Vortex Simulation of Axisymmetrical Flows in Cylindrical Geometries.Part II:Application to Pipes Incorporating an Orifice Plate

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    The Random Vortex Method extended to an axisymmetrical flow is used in the study of the flow field inside pipes incorporating an orifice plate with different contraction ratios and different inlet velocity profiles.Three test-cases,each having experimental measurements available in the literature,are studied,.In particular,instantaneous and average velocity fields along with the turbulent statistics for high Reynolds number flows are computed and compared to the corresponding experimental results These comparisons show the ability and the limitations of the method.The results of the numerical simulations are used in the physical analysis of the flow fields and thus allow for a better understanding of the dynamics of the flow in pipes incorporating an orifice plate.

  9. Strengthening and repair of steel-concrete composite girders using CFRP laminates

    Science.gov (United States)

    Tavakkolizadeh, Mohammadreza

    The use of advanced composite materials for rehabilitation and repair of deteriorating infrastructure has been embraced worldwide. The conventional techniques for strengthening of substandard bridges are costly, time consuming and labor intensive. A total of 38 specimens made of steel and carbon fibers were prepared and tested to investigate the possibility of galvanic corrosion. Two simulated aggressive environments and three different amounts of epoxy coating were used. Potentiodynamic polarization and galvanic corrosion tests were conducted. The results of the experiments showed the existence of galvanic corrosion however the rate of such corrosion could be decreased significantly by epoxy coating. A total of 21 specimens made of S 5 x 10 A36 steel beams were prepared and tested to determine the effectiveness of CFRP patch on fatigue life of notched beam. The results showed that not only CFRP patch tends to extend the fatigue life of a detail more than three times, but also it decreases the crack growth rate significantly. To investigate the effectiveness of the epoxy bonded CFRP sheets in repair and retrofit of composite girders, a total of six large-scale steel-concrete composite girders made of W 14 x 30 A36 steel beam and 7.5 cm. thick by 91 cm wide concrete slab were prepared and tested. Three different numbers of CFRP layers and three different damage level in Range were considered. The retrofitting test results showed that epoxy bonded CFRP Sheet increased the ultimate load carrying capacity of composite girders and the behavior can be conservatively predicted by traditional methods. The repair test results showed that epoxy bonded CFRP sheet could restore the ultimate load carrying capacity and stiffness of damaged steel-concrete composite girders. The ultimate capacity of the repaired beam was predicted by traditional methods of analysis of steel-concrete composite beams, which was fairly conservative. Guidelines and procedures for design of Steel

  10. Effects of processing on microstructure and mechanical properties of a titanium alloy (Ti–6Al–4V) fabricated using electron beam melting (EBM), part 1: Distance from build plate and part size

    Energy Technology Data Exchange (ETDEWEB)

    Hrabe, Nikolas, E-mail: nhrabe@gmail.com [National Institute of Standards and Technology (NIST), 325 Broadway, Stop 647, Boulder, CO 80305-3328 (United States); Quinn, Timothy, E-mail: timothy.quinn@nist.gov [National Institute of Standards and Technology (NIST), 325 Broadway, Stop 647, Boulder, CO 80305-3328 (United States)

    2013-06-20

    Selective electron beam melting (EBM) is a layer-by-layer additive manufacturing technique that shows great promise for fabrication of medical devices and aerospace components. Before its potential can be fully realized, however, a comprehensive understanding of processing–microstructure–properties relationships is necessary. Titanium alloy (Ti–6Al–4V) parts were built in a geometry developed to allow investigation of the following two intra-build processing parameters: distance from the build plate and part size. Microstructure evaluation (qualitative prior-β grain size, quantitative α lath thickness), tensile testing, and Vickers microhardness were performed for each specimen. Microstructure and mechanical properties, including microhardness, were not found to vary as a function of distance from the build plate, which was hypothesized to be influenced by the build plate preheating associated with the EBM process. Part size, however, was found to influence ultimate tensile strength (UTS) and yield strength (YS) by less than 2% over the size range investigated. A second order effect of thermal mass might also have influenced these results. Differences were observed between the EBM Ti–6Al–4V microstructure of this work and the expected acicular or Widmanstätten microstructure normally achieved through annealing above the β transus. Therefore, a different relationship between α lath thickness and mechanical properties might be expected.

  11. 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.

  12. HULL GIRDER PROGRESSIVE COLLAPSE ANALYSIS USING IACS PRESCRIBED AND NLFEM DERIVED LOAD - END SHORTENING CURVES

    Directory of Open Access Journals (Sweden)

    Stanislav Kitarović

    2016-06-01

    Full Text Available This paper considers the hull girder ultimate strength of a bulk carrier at its midship section, as determined by an incremental-iterative progressive collapse analysis method prescribed by the International Association of Classification Societies Common Structural Rules for Bulk Carriers. In addition to the originally prescribed load – end shortening curves, curves determined by the nonlinear finite element method analysis (considering the influence of the idealized initial geometrical imperfections are also considered. Results obtained by both sets of curves are compared and discussed on both local (structural components load – end shortening curve and global (hull girder ulti-mate bending capacity and collapse sequence level, for both sagging and hogging cases.

  13. Wireless Impedance Sensor with PZT-Interface for Prestress-Loss Monitoring in Prestressed Concrete Girder

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Khac Duy; Lee, So Young; Kim, Jeong Tae [Pukyong National University, Busan (Korea, Republic of)

    2011-12-15

    Ensuring the designed prestress force is very important for the safety of prestressed concrete bridge. The loss of prestress force in tendon could significantly reduce load carrying capacity of the structure. In this study, an automated prestress-loss monitoring system for prestressed concrete girder using PZT-interface and wireless impedance sensor node is presented. The following approaches are carried out to achieve the objective. Firstly, wireless impedance sensor nodes are designed for automated impedance-based monitoring technique. The sensor node is mounted on the high-performance Imote2 sensor platform to fulfill high operating speed, low power requirement and large storage memory. Secondly, a smart PZT-interface designed for monitoring prestress force is described. A linear regression model is established to predict prestress-loss. Finally, a system of the PZT-interface interacted with the wireless sensor node is evaluated from a lab-scale tendon-anchorage connection of a prestressed concrete girder.

  14. Structural Optimization of Steel Cantilever Used in Concrete Box Girder Bridge Widening

    Directory of Open Access Journals (Sweden)

    Qian Wang

    2015-01-01

    Full Text Available The structural optimization method of steel cantilever used in concrete box girder bridge widening is illustrated in this paper. The structural optimization method of steel cantilever incorporates the conceptual layout design of steel cantilever beam based on the topological theory and the determination of the optimal location of the transverse external prestressed tendons which connect the steel cantilever and the box girder. The optimal design theory and the analysis process are illustrated. The mechanical model for the prestressed steel cantilever is built and the analytical expression of the optimal position of the transverse external tendon is deduced. At last the effectiveness of this method is demonstrated by the design of steel cantilevers which are used to widen an existing bridge.

  15. 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.

  16. Bar Simulation Method for Analysis on Long-term Behavior of Reinforced Concrete Box Girder%配筋混凝土箱梁长期受力性能的比拟杆分析

    Institute of Scientific and Technical Information of China (English)

    方志; 伍琼芳; 曹国辉

    2012-01-01

    为使配筋混凝土箱梁长期受力性能的分析趋于简便,将线弹性匀质箱梁短期弯曲性能分析的比拟杆法推广应用于其长期受力性能的分析.引入按龄期调整的有效弹性模量来考虑箱梁混凝土徐变的影响,基于换算截面的原理来考虑箱梁配筋的影响,建立能综合考虑箱梁受力特征和配筋影响的混凝土箱梁长期受力性能分析的比拟杆法.对一根预应力混凝土模型箱梁进行长达l001d的徐变试验,并用其结果对所提方法的适用性进行验证.结果表明:混凝土箱梁长期受力性能的比拟杆法计算结果与试验结果之间吻合较好.与试验值相比,t0~1001d时段内箱梁顶板混凝土压应变的计算值相差7%~11%、跨中截面长期挠曲变形的计算结果相差9%~17%.随着持荷时间的增长,箱梁顶板的剪力滞系数逐渐减小,持荷1001d后剪力滞系数减小了7.1%.%In order to develop a simple method to determine the long-term behavior of the reinforced concrete box girder structure with the shear lag effect of box girder involved, a new bar simulation method was presented in which the Age-adjusted Effective Modulus was used to consider the effects of concrete creep and the principle of transformed section was used to consider the effects of reinforcement. The results of the method were testified by the long-term performance test of a prestressed concrete simply-supported box girder under sustained loading of 1001d. The results show as follows:The developed method can give a reasonable prediction to the creep reponse of the concrete box girder; compared with the measured values, the predicted compressive strain in the top plate and the long-term deflection at the mid-span of the tested box girder is of error range of (7~11)% and (9~17)% respectively;the shear lag coefficient of the top plate of the box girder reduces gradually in extension of the sustained loading period and till by 7. 1% after 1001d.

  17. 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.

  18. 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.

  19. 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.

  20. Shear and shear friction of ultra-high performance concrete bridge girders

    Science.gov (United States)

    Crane, Charles Kennan

    Ultra-High Performance Concrete (UHPC) is a new class of concrete characterized by no coarse aggregate, steel fiber reinforcement, low w/c, low permeability, compressive strength exceeding 29,000 psi (200 MPa), tensile strength ranging from 1,200 to 2,500 psi (8 to 17 MPa), and very high toughness. These properties make prestressed precast UHPC bridge girders a very attractive replacement material for steel bridge girders, particularly when site demands require a comparable beam depth to steel and a 100+ year life span is desired. In order to efficiently utilize UHPC in bridge construction, it is necessary to create new design recommendations for its use. The interface between precast UHPC girder and cast-in-place concrete decks must be characterized in order to safely use composite design methods with this new material. Due to the lack of reinforcing bars, all shear forces in UHPC girders have to be carried by the concrete and steel fibers. Current U.S. codes do not consider fiber reinforcement in calculating shear capacity. Fiber contribution must be accurately accounted for in shear equations in order to use UHPC. Casting of UHPC may cause fibers to orient in the direction of casting. If fibers are preferentially oriented, physical properties of the concrete may also become anisotropic, which must be considered in design. The current research provides new understanding of shear and shear friction phenomena in UHPC including: (1) Current AASHTO codes provide a non-conservative estimate of interface shear performance of smooth UHPC interfaces with and without interface steel. (2) Fluted interfaces can be created by impressing formliners into the surface of plastic UHPC. AASHTO and ACI codes for roughened interfaces are conservative for design of fluted UHPC interfaces.(3) A new equation for the calculation of shear capacity of UHPC girders is presented which takes into account the contribution of steel fiber reinforcement. (4) Fibers are shown to preferentially

  1. Waffle production: influence of batter ingredients on sticking of waffles at baking plates-Part II: effect of fat, leavening agent, and water.

    Science.gov (United States)

    Huber, Regina; Schoenlechner, Regine

    2017-05-01

    Fresh egg waffles are continuously baked in tunnel baking ovens in industrial scale. Waffles that partly or fully stick to the baking plates cause significant product loss and increased costs. The aim of this study was, therefore, to investigate the effect of different recipe ingredients on the sticking behavior of waffles. In this second part, ingredients investigated were different leavening agents (sodium acid pyrophosphate, ammonium bicarbonate, magnesium hydroxide carbonate, or monocalcium phosphate), different fat sources (rapeseed oil, cocos fat, butter, or margarine), and different water sources (tap water 12°dH and distilled water). Within the different types of fats, solid fats with high amount of short-chain fatty acids (cocos fat or butter) decreased the number of sticking waffles compared to liquid oils (rapeseed oil). Regarding leavening agents, magnesium hydroxide carbonate and ammonium bicarbonate were superior to sodium acid pyrophosphate or monocalcium phosphate. Between the two water sources, effects were small.

  2. Academic Plate Spinning: the Difficulties of Balancing Full Time Degree Study With a Part-Time Job

    OpenAIRE

    Richardson, Mark; Evans, Carl; Gbadamosi, Gbolahan

    2013-01-01

    The study examined full-time students engaged in part-time work during term time. A qualitative approach was used to examine how students cope with simultaneously managing the two activities, and how part-time working affects their academic study. Semi-structured interviews were used to obtain data from a sample of 30 undergraduate business students. The findings confirm that students merely satisfice many aspects of their lives, with reading time and assignment preparation being key areas th...

  3. Development of 70/30 Poly-L-DL-Lactic Acid Filaments for 3D Printers (Part 2): Mechanical and Surface Properties of Bioabsorbable Printed Plates for Biomedical Applications

    Science.gov (United States)

    Fernandes, Daniel J.; Vidal, Rafael; Assayag, Ariel; de Biasi, Ronaldo S.; Elias, Carlos N.

    2017-01-01

    The mechanical, chemical, roughness and wettability properties of 70/30 poly (L,DL-lactide acid) three-dimensional (3D)-printed surgical plates made with extruded polymer filaments developed in the first part of this work were investigated. The plates were printed with horizontal (HRZ) and vertical (VRT) running layer orientations and evaluated by tensile, Fourier transform infrared (FTIR), optical perfilometry and wettability tests before and after degradation in simulated body fluid (SBF) for 21 days. The results show that the ultimate tensile strength (UTS) of HRZ plates before immersion in SBF was higher (34.1 MPa) than that of VRT plates (31.8 MPa). The Young's modulus ( E) of HRZ plates and VRT plates are similar (4 GPa). After immersion in SBF, the UTS of HRZ plates dropped to 20.5 MPa and E decreased to 3.3 GPa. VRT were not tested after SBF immersion due to the large degradation. FTIR analysis showed no evidence of chemical change in the plates after immersion in SBF. The roughness parameter R3z of VRT surfaces (19.54 µm) was higher than that of the HRZ surfaces (12.80 µm). The roughness parameters increased after degradation in SBF ( p = 0.7048). The contact angles of HRZ surfaces before immersion in SBF (66.28°) were higher than after immersion in SBF (18.12°); the same behavior was also observed in VRT plates.

  4. Design of a Maglev Vibration Test Platform for the Research of Maglev Vehicle-girder Coupled Vibration Problem

    Directory of Open Access Journals (Sweden)

    Zhou Danfeng

    2017-01-01

    Full Text Available The maglev vehicle-girder coupled vibration problem has been encountered in many maglev test or commercial lines, which significantly degrade the performance of the maglev train. In previous research on the principle of the coupled vibration problem, it has been discovered that the fundamental model of the maglev girder can be simplified as a series of mass-spring resonators of different but related resonance frequencies, and that the stability of the vehicle-girder coupled system can be investigated by separately examining the stability of each mass-spring resonator – electromagnet coupled system. Based on this conclusion, a maglev test platform, which includes a single electromagnetic suspension control system, is built for experimental study of the coupled vibration problem. The guideway of the test platform is supported by a number of springs so as to change its flexibility. The mass of the guideway can also be changed by adjusting extra weights attached to it. By changing the flexibility and mass of the guideway, the rules of the maglev vehicle-girder coupled vibration problem are to be examined through experiments, and related theory on the vehicle-girder self-excited vibration proposed in previous research is also testified.

  5. Study about Ultimate Bearing Capacity of Large Steel Box Girder under the Action of Shear Force%剪力作用下大型钢箱梁极限承载力研究

    Institute of Scientific and Technical Information of China (English)

    王龙奉; 吕彭民; 徐田

    2015-01-01

    The rules about the ultimate bearing capacity of the welded box girder in the current GB5001 7-2003 “Structural Design Specification”are faulty.The influences of the material non-linearity, geometrical non-linearity and the initial defect are considered in this paper.The arc length increment method obtained by revising Newton-Raphson formula is used to solve the ultimate bearing capacity of welded box girder under the action of the shear force,and the correctness of the calculation method is validated through the model tests.The formula used to calculate the stable ultimate bearing capacity under the action of the shear force of the box girder is summarized through large of simulation calculations.The method relates di-rectly the ultimate bearing capacity to the height to thickness ratio of the web and width to thickness ratio of the wing plate,which has the reference value to calculate and design the stable ultimate bearing capacity of the welded box girder.%现行 GB50017-2003《钢结构设计规范》对焊接箱形截面梁极限承载力规定还比较粗糙,本文考虑材料非线性、几何非线性和箱梁初始缺陷的影响,采用对 Nweton-Raphson 公式进行修正的弧长增量法求解剪力作用下焊接箱梁极限承载力,并通过模型试验,验证了计算方法的正确性。通过大量的数值模拟仿真计算,归纳总结出了箱形截面梁在剪力作用下稳定极限承载力计算公式。该公式把极限承载力与腹板高厚比、翼板宽厚比直接关联起来,对焊接箱形截面梁稳定极限承载力的计算及设计具有参考价值。

  6. Scattering of guided SH_wave by a partly debonded circular cylinder in a traction free plate

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiaomin

    2001-01-01

    [1]Ying, C.F., Truell, R., Scattering of plane longitudinal wave by a spherical obstacle in an isotropically elastic solid, J.Appl.Phys., 1956, 27(9): 1086.[2]Norris, A.N., Yang, Y., Shear wave scattering from a debonded fiber, in Elastic Waves and Ultrasonic Nondestructive Evaluation (eds.Datta, S.K., Achenbach, J.D., Rajapakes, Y.S.), Amsterdam: Elsevier Science Publishers, 1990, 437-440.[3]Sinclair, A.N., Anddison, R.C., Acoustic diffraction spectrum of a SiC fiber in a solid elastic medium, J.Acoust.Soc.Am., 1993, 94(2): 1126.[4]Huang, W., Brisuda, S., Rokhlin, S.I., Ultrasonic wave scattering from fiber_matrix interphases, J.Acoust.Soc.Am., 1995, 97(2): 807.[5]Huang, W., Wang, Y.J., Rokhlin, S.I., Oblique scattering of an elastic wave from a mutilayered cylinder in a solid: Transfer_matrix approach, J.Acoust.Soc.Am., 1996, 99(5): 2742.[6]Lu, Y., Guided antiplane shear wave propagation in layers reinforced by periodically spaced cylinders, J.Acoust.Soc.Am., 1996, 99(4): 1937.[7]Rokhlin, S.I., Diffraction of Lamb waves by a finite crack in an elastic layer, J.Acoust.Soc.Am., 1980, 67(4): 1157.[8]Rokhlin, S.I., Resonance phenomena of Lamb waves scattering by a finite crack in a solid layer, J.Acoust.Soc.Am., 1981, 69(4): 922.[9]Abduljabbar, Z., Datta, S.K., Shah, A.H., Diffraction of horizontally polarized shear waves by normal cracks in a plate, J.Appl.Phys., 1983, 54(2): 461.[10]Rokhlin, S.I., Lamb wave interaction with lap_shear adhesive joints: theory and experiment, J.Acoust.Soc.Am., 1991, 89(6): 2758.[11]Al_Nassar, Y.N., Datta, S.K., Shah, A.H., Scattering of Lamb waves by a normal rectangular strip of weldment, Ultrasonics, 1991, 29(2): 125.[12]Alleyne, D.N., Cawley, P., The interaction of Lamb waves with defects, IEEE Trans.Ultrason Ferroelectr.Frequency Control, 1992, 39(3): 381.[13]Nielsen, E.D., Scattering by a cylindrical post of complex permittivity in a waveguide, IEEE Trans.on Microwave Theory and

  7. 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.

  8. Methods for determination of ultimate load of eccentrically patch loaded steel I-girders

    Directory of Open Access Journals (Sweden)

    Šćepanović, B.

    2014-12-01

    Full Text Available Experimental tests show that most eccentrically patch loaded steel I-girders have a collapse mode quite different from that of centrically loaded girders. Concerning engineering practice, the most important difference between collapse modes is in ultimate load. The reduction in ultimate load with an increase in load eccentricity is obvious in some eccentrically loaded girders. Under certain circumstances, for a certain combination of influential parameters, eccentrically loaded girders behave as if loaded in the web plane, with no or no significant reduction in ultimate load due to load eccentricity. Dealing with such a big number of mutually dependant parameters that influence collapse mode and level of ultimate load reduction due to load eccentricity, still without theoretical formulation of collapse mechanism, two approaches for ultimate load determination are analysed: empirical mathematical expressions and artificial neural networks forecast models. Results of two procedures are compared. Recommendations for application in engineering practice are given.Las pruebas experimentales muestran que la mayoría de vigas en I de acero cargadas excéntricamente tienen un modo de colapso muy diferente del de las vigas cargadas centradas. En cuanto a la práctica de ingeniería, la diferencia más importante entre los modos de colapso es la carga final. La reducción de la carga última con un aumento de la excentricidad de carga es evidente en algunas vigas cargadas excéntricamente, mientras que bajo ciertas circunstancias, para una determinada combinación de parámetros influyentes, las vigas cargadas excéntricamente se comportan como si se carga en el plano del alma, con ninguna reducción significativa en la carga última debido a la carga excéntrica. Se analizan dos métodos para la determinación de la carga máxima: expresiones matemáticas empíricas y redes neuronales artificiales. Los resultados de ambos procedimientos se comparan. Se

  9. A Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 1: Structure, Properties, and Performance Correlations

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available Passive air-breathing microbial fuel cells (MFCs are a promising technology for energy recovery from wastewater and their performance is highly dependent on characteristics of the separator that isolates the anaerobic anode from the air-breathing cathode. The goal of the present work is to systematically study the separator characteristics and its effect on the performance of passive air-breathing flat-plate MFCs (FPMFCs. This was performed through characterization of structure, properties, and performance correlations of eight separators in Part 1 of this work. Eight commercial separators were characterized, in non-inoculated and inoculated setups, and were examined in passive air-breathing FPMFCs with different electrode spacing. The results showed a decrease in the peak power density as the oxygen and ethanol mass transfer coefficients in the separators increased, due to the increase of mixed potentials especially at smaller electrode spacing. Increasing the electrode spacing was therefore desirable for the application of diaphragms. The highest peak power density was measured using Nafion®117 with minimal electrode spacing, whereas using Nafion®117 or Celgard® with larger electrode spacing resulted in similar peak powers. Part 2 of this work focuses on numerical modelling of the FPMFCs based on mixed potential theory, implementing the experimental data from Part 1.

  10. Reverse Design for Metal Plate Parts Based on Parameterization%基于参数化的钣金零件逆向设计

    Institute of Scientific and Technical Information of China (English)

    李阳; 成思源; 杨雪荣; 张湘伟

    2015-01-01

    The point cloud data of the metal plate parts were obtained by using the articulated arm scanner system. The point cloud data were imported into the reverse software. Through point cloud processing, polygon processing and parameterization design, NURBS surface of the parts was constructed. Finally, the surface model was modified in forward software to get an ideal surface, with relatively higher quality and more fitting its features and original design ideas. By experiments, it is verified that the design requirement of date revert to original parts can be met by using the parameterization technology, so as to improve design efficiency.%通过关节臂测量机对钣金零件模型进行扫描得到其点云数据,将点云数据导入逆向软件中,经过点处理、多边形处理、参数化设计得到钣金零件的NURBS曲面,最后再经过正向软件的修改得到相对质量较高、符合零件本身特性和设计思想的理想曲面。通过实例验证了采用参数化技术可以还原零件数据的设计需求,以提高设计效率。

  11. 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。

  12. Double Girder Bridge Crane with Double Cycling: Scheduling Strategy and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2014-01-01

    Full Text Available This paper introduces a novel quay crane design, double girder bridge crane (DGBC. DGBC is capable of handling containers of two adjacent bays simultaneously, avoiding crane collisions, saving travelling and reposition cost, and eventually improving terminal efficiency. This problem is formulated as a resource-constrained project scheduling with objective to minimize the maximum completion time. A two-stage heuristic algorithm is proposed in which an operating sequences on each bay is obtained by double cycling, and the integrated timetable for both bays is constructed by solving resource conflicts using the proposed minimum cost strategy. We examine effectiveness and performance of applying DGBC with double cycling. A case study is presented to illustrate how DGBC works with the two-stage method. Three extreme cases with respective conflict types are investigated to develop the performance bounds of DGBC with double cycling. The results show that DGBC can significantly improve terminal productivity, and outperforms single girder crane in both makespan and the lift operation percentage. The highest DGBC efficiency does not require maximum double cycles in two bay schedules; rather the integrated timetable for two bays is the main contribution to the DGBC performance as it yields better cooperation between two spreaders and the driver.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  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. 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.

  20. 钢桁腹预应力混凝土组合梁桥的剪滞效应%Study on Shear-lag Effect of Steel Truss-web and Pre-stressed Concrete Composite Girder Bridge

    Institute of Scientific and Technical Information of China (English)

    刘朵; 张建东; 刘钊

    2013-01-01

    The steel truss-web and pre-stressed concrete composite girder bridge consists of two parts :steel truss-web and top-and-bottom concrete board .Because the distribution of shear deformation is non-uniform ,the composite box girder bridge has the obvious shear-lag effect under longitudinal bending .Taking a steel truss-web and pre-stressed concrete composite girder bridge for example ,the shear-lag effect and the distribution law of effective width are analyzed by the fi-nite element model of space ,and the effects of top-and-bottom thickness and steel pipe thickness on the shear-lag effect are studied here so as to provide references for the similar design in the future .%钢桁腹预应力混凝土组合梁桥在截面形式上采用桁式腹杆和混凝土顶底板,由于剪切变形的不均匀性,使得组合箱梁在纵向弯曲时产生较为明显的剪滞效应。以某钢桁腹混凝土组合梁桥为例,利用空间实体模型分析了剪滞效应和有效宽度分布规律,并研究了顶底板厚度及钢管壁厚对剪滞效应的影响,为今后同类桥型的设计提供参考。

  1. 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.

  2. Energy flow in plate assembles by hierarchical version of finite element method

    DEFF Research Database (Denmark)

    Wachulec, Marcin; Kirkegaard, Poul Henning

    method has been proposed. In this paper a modified hierarchical version of finite element method is used for modelling of energy flow in plate assembles. The formulation includes description of in-plane forces so that planes lying in different planes can be modelled. Two examples considered are: L......The dynamic analysis of structures in medium and high frequencies are usually focused on frequency and spatial averages of energy of components, and not the displacement/velocity fields. This is especially true for structure-borne noise modelling. For the analysis of complicated structures......-corner of two rectangular plates an a I-shaped plate girder made of five plates. Energy distribution among plates due to harmonic load is studied and the comparison of performance between the hierarchical and standard finite element formulation is presented....

  3. Numerical simulation for local failure of a steel box girder under blast loading%钢箱梁爆炸冲击局部破坏的数值模拟

    Institute of Scientific and Technical Information of China (English)

    蒋志刚; 朱新明; 严波; 姚术健

    2013-01-01

    The local failure of a steel box girder under blasting loads of vehicle bomb (TNT equivalent 100-500kg)was investigated with the nonlinear finite element software LS-DYNA and the fluid-solid coupling method ALE Multimaterial formulations.The results showed that there are two local failure modes of a steel box girder,one is that the deck and bottom plates rupture locally; the other is that the deck plate ruptures locally and the bottom plate does not rupture but has a local large plastic deformation; the main failure modes of diaphragms are large bending plastic deformation and rupture; the failure parameters increase nonlinearly with increase in explosive TNT equivalent; the impact effect of shock wave within the box on the bottom plate and diaphragms is less than the impact effect of the deck's fragments,the latter is the main cause of the local large plastic deformation and rupture of the bottom plate and diaphragms.%运用LS-DYNA非线性有限元软件,采用ALE多物质流-固耦合算法,研究了汽车炸弹(TNT当量100~500 kg)桥面爆炸冲击作用下钢箱梁的局部破坏.结果表明,钢箱梁局部破坏模式有两种:(1)桥面板和底板均破口;(2)桥面板破口,底板产生局部塑性大变形.隔板的主要破坏模式为弯曲塑性大变形和破口.破坏参数随炸药当量的增加呈非线性增加.箱体内冲击波对底板、隔板的冲击作用相对较小,顶板破片的冲击作用是底板和隔板产生局部塑性大变形和破口的主要原因.

  4. Hemiarthroplasty versus angle-stable locking compression plate osteosynthesis in the treatment of three- and four-part fractures of the proximal humerus in the elderly : design of a randomized controlled trial

    NARCIS (Netherlands)

    Verbeek, Paul A.; van den Akker-Scheek, Inge; Wendt, Klaus W.; Diercks, Ron L.

    2012-01-01

    Background: The optimal surgical management of dislocated three- and four-part fractures of the proximal humerus in elderly patients remains unclear. Most used techniques are hemiarthroplasty and angle-stable locking compression plate osteosynthesis. In the current literature there is no evidence av

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. A compilation of research on self-consolidating concrete for prestressed bridge girders

    Science.gov (United States)

    Torres, Eduardo S.

    This thesis is composed of three research papers, for each paper a separate chapter is used, which investigates various aspects for the production of SCC utilizing materials available in the state of Wisconsin. Chapter one provides a summary of the current state-of-the-art and practice of technical documentation and specifications related to material properties and test methods for prestressed SCC bridge girders. Chapter two provides an experimental program designed to investigate the effect of material constituents on performance of SCC mixtures. From this experimental program specific mixture parameters were recommended for the application of SCC in Wisconsin DOT projects. Finally, chapter three consisted in monitoring samples of five SCC mixtures batched at three different precast plants from Wisconsin. Creep and shrinkage readings were taken for a period of 112 days to investigate the effect of specific mixture parameters of selected mixtures with performance desired by the Wisconsin DOT and precast plants. (Abstract shortened by ProQuest.).

  10. Load Test and Model Calibration of a Horizontally Curved Steel Box-Girder Bridge

    Directory of Open Access Journals (Sweden)

    Freydoon Rezaie

    2015-12-01

    Full Text Available In this paper, full scale load test of a horizontally curved steel box-girder bridge is carried out in order to detect structural defects, which reportedly result in unwanted vibrations in nearby buildings. The bridge is tested under the passage of six heavy vehicles at different speeds, so as to determine its static and dynamic responses. A total number of one hundred and two (102 sensors are used to measure the displacements, strains, and accelerations of different points of the bridge. It is observed that the bridge vibrates at a fundamental frequency of 2.6 Hz intensively and the first mode of vibration is torsional instead of flexural. The dominant frequency of vibration of the nearby buildings is computed to be approximately 2.5Hz using rational formulas. Thus, nearness of the fundamental frequency of the bridge to those of the adjacent buildings may be causing resonance phenomenon. However, in static load tests, low ranges of strain and displacement illustrated adequate structural capacity and appropriate safety under static loads. Numerical models are created using ANSYS and SAP2000 software products, so as to design the loading test and calibrate the finite element models. The connections of the transversal elements to the girders, transversal element spacing, and changes of the stiffness values of the slabs were found to be the most influential issues in the finite elements calibration process. Finally, considering the total damage of all members, the final health score of the bridge was evaluated as 89% indicating that the bridge is in a very good situation.

  11. 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)

  12. 弯扭耦合下曲线混凝土箱梁截面应力状态的受力机理分析%Analysis of Stress Mechanism of Cross Section of Curved PC Box Girder Under the Action of Bending-Torsion Coupling

    Institute of Scientific and Technical Information of China (English)

    何庆华; 卫星

    2013-01-01

    曲线箱形梁兼具弯梁桥与箱形梁两者的特点,由于曲率的影响,竖向荷载作用下曲线箱梁弯矩与扭矩互相耦合同时存在.根据国内外既有研究成果,对曲线箱形梁空间受力特点及影响因素进行了总结.以60m单跨单箱形截面曲线混凝土简支梁为例,利用有限元软件TDV建立空间板单元模型,分析自重作用下,不同曲线半径下主梁截面正应力及剪应力分布,根据弯曲变形与应变的关系,比较曲线梁桥与直线梁桥正应力横向分布规律,提出用应力增大系数来表征曲线内外侧弧长不同引起的应力变化.研究结果表明,除了受剪力滞后效应影响,曲线箱梁桥截面正应力分布还与内外侧弧长不等引起的应力增大系数有关.%Curved box girder has both characters of curved girder and box girder, and the coupling effect between bending moment and torsion moment caused by the curvature under vertical load should be taken into account. Based on research results of curved girder at home and abroad, the spatial mechanical characters and influencing factors of curved box girder were summarized in this thesis. Choosing a 60m single-span curved PC simply supported girder with single cell boxed cross-section as the example, spatial plate element models were established by TDV finite element software. Then the distributions of normal stress and shear stress of cross-section of main girder with different curve radius under the action of dead load were analyzed. Afterwards, according to the relationship between bending deformation and strains, and by comparing the transverse distributions of normal stress of curved bridge with that of straight bridge, the thesis put forward a view point that the stress variation caused by the arc length difference between the internal arc and external arc of the curve can be expressed by a magnification coefficient. Analysis results show that, except the effect of shear lag, the distributions of

  13. 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.

  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. Acoustic Nondestructive Testing and Measurement of Tension for Steel Reinforcing Members: Part 2 - Field Testing

    Science.gov (United States)

    2014-09-01

    steel beam-and-girder designs, but a significant problem is that the anchor tendons (i.e., rods) are inaccessible for expedient inspection and repair . A...embedded in concrete. Acoustic waves are nondestructive. They can travel long distances through engineered structures and can be used to thoroughly...complete post-tensioned anchorage system includes tendons (bars/rods or strands), anchorage devices or bearing plates, ducts, end caps, grout tubes

  16. A Technology for Gold Plating on Beryllium Bronze Parts%铍青铜零件电镀金工艺

    Institute of Scientific and Technical Information of China (English)

    刘志强

    2011-01-01

    在铍青铜基体上采用镍作为中间层然后镀金是传统的镀覆方法.有些应用场合不允许采用镀镍而直接镀金,必须解决镀层与基体结合力的问题.分析铍青铜的特性和镀金层结合力不良的原因,提出了一种铍青铜直接电镀金的工艺流程和工艺参数,包括热处理疏松氧化层、微腐蚀、除钝化膜、镀金及封闭处理等工序,解决了铍青铜氧化层的去除及镀金层与基体结合力的问题,使产品质量稳定.%The traditional way of electroplating on beryllium bronze substrate use nickel coating as an intermediate layer before gold plating. In some cases, direct gold plating is needed, and the adhesion problem should be resolved. In this paper, the characteristics of beryllium bronze and affecting factor on adhesion were firstly discussed. And then a new gold plating technique on beryllium bronze including process and parameters of heat treatment loosening oxidation layer, micro corrosion, removal of passivation film,gold plating and sealing treatment was put forward. The problems on the removal of oxidation layer and adhesion between gold plating and substrate were resolved, and the gold plating had a stable performance.

  17. Aluminum Manganese Molten Salt Plating

    Science.gov (United States)

    2006-06-01

    Dry fixture thoroughly with the air gun. Be especially careful to dry water out of crevices. Note: water is a contaminant to the plating process...easily destroyed if blown with the air. Be especially careful to dry water out of crevices. Note: water is a contaminant to the plating process and...especially careful to dry water out of crevices. 13. Carefully remove part from fixture. If residual plating solution is present at attachments points

  18. 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.

  19. Analysis of the contribution of sedimentation to bacterial mass transport in a parallel plate flow chamber Part II : Use of fluorescence imaging

    NARCIS (Netherlands)

    Li, Jiuyi; Busscher, Henk J.; van der Mei, Henny C.; Norde, Willem; Krom, Bastiaan P.; Sjollema, Jelmer

    2011-01-01

    Using a new phase-contrast microscopy-based method of analysis, sedimentation has recently been demonstrated to be the major mass transport mechanism of bacteria towards substratum surfaces in a parallel plate flow chamber (J. Li, H.J. Busscher, W. Norde, J. Sjollema, Colloid Surf. B. 84 (2011)76).

  20. Analysis of the contribution of sedimentation to bacterial mass transport in a parallel plate flow chamber Part II: Use of fluorescence imaging

    NARCIS (Netherlands)

    Li, J.Y.; Busscher, H.J.; Mei, van der H.C.; Norde, W.; Krom, B.P.; Sjollema, J.

    2011-01-01

    Using a new phase-contrast microscopy-based method of analysis, sedimentation has recently been demonstrated to be the major mass transport mechanism of bacteria towards substratum surfaces in a parallel plate flow chamber (J. Li, H.J. Busscher, W. Norde, J. Sjollema, Colloid Surf. B. 84 (2011)76).

  1. Behaviors of Precast Fabricated Box Girder Bridge using Reactive Powder Concrete%预制装配式活性粉末混凝土箱梁桥的结构性能

    Institute of Scientific and Technical Information of China (English)

    魏亚雄; 方志

    2016-01-01

    A new kind of ultra-high performance cement-based material,RPC (Reactive Powder Concrete),can significantly reduce the weight of structure and decrease the inertia load,when applying to build the prefabricated beam of bridge.It has lower shrinkage and high durability after hot water cu-ring.Base on a project of a 4 ×30 m prefabricated PC continuous box girder bridge,a prefabricated box girder bridge with the same span using RPC was designed.Its mechanical properties were studied and a comparative study of the economy of the PC and RPC bridges were carried out.The results showed that, both the overall and the local mechanical properties of the RPC bridge met the specification requirements, and its stress level or deformation during service even had more safety margin.The plate section of girder became thinner,and the consumption of concrete and prestressd tendons decreased by 25.4% and 27.5%.Therefore,the prefabricated RPC box girder bridge was proven to be a favorable plan and can be applied widely in the future.%超高性能活性粉末混凝土 RPC(Reactive Powder Concrete)应用于装配式梁桥中,不仅能有效减轻结构自重、增加结构抵抗使用荷载的有效性,还能充分发挥其在热养护条件下收缩徐变小且耐久性好的优点,是一种极具应用前景的新型水泥基材料。以一座4×30 m 的普通预应力混凝土装配式连续箱梁桥为背景,提出了同等跨径的 RPC 装配式箱梁桥方案,对其结构的受力性能进行了分析,并将二者的经济性能进行了比较。结果表明:提出的 RPC 箱梁桥整体和局部受力性能均满足现行规范要求,使用阶段应力以及变形尚有较大的安全储备;采用RPC 可令主梁板件厚度减小,使混凝土和预应力筋用量分别减少25.4%和27.5%。因此,预制装配式 RPC 箱梁桥作为一种可供选择的优选方案,具有良好的推广应用前景。

  2. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  3. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  4. Effect of sensor placement on operational modal analysis of steel girder bridges

    Science.gov (United States)

    Whelan, Matthew J.; Gangone, Michael V.; Janoyan, Kerop D.

    2011-04-01

    With the advent and development of low-cost wireless structural health monitoring systems, the task of routinely assessing the in-service condition of highway bridges through distributed sensor-based measurements is an increasingly feasible component of bridge safety and management practice. Bridge monitoring encompasses placement of often a limited number of distributed sensors across a relatively large and complex structural system. Consequently, the selection of proper sensor locations is imperative to extraction of the most value from the recorded measurements. An experimental investigation is presented wherein sensor placement on the superstructure girders or primary beams is contrasted to the response measured on the surface of the bridge deck. The effect on the dataset richness, as evidenced by the modal content, is presented and conclusions regarding optimal placement for this structure type are presented. To affirm the plausibility of the observed responses and conclusions drawn, a finite element analysis is also performed on a model developed from the as-built drawings.

  5. 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.

  6. 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.

  7. 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.

  8. 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

    为实现箱桁组合梁铁路斜拉桥动力特性的精准模拟计算,对箱桁组合梁开口断面斜拉桥空间杆系模型、空间板梁组合模型和空间板壳模型3种有限元建模方法进行研究。以某跨径布置为(98+140+406+406+140+98) m的三塔双主跨箱桁组合梁铁路斜拉桥为背景,采用子空间迭代方法对比分析了不同模型的模态特性,并在此基础上计算了不同模型主梁单位长度的等效质量及其惯性矩。研究结果表明:3种模型计算得到的模态分析结果基本吻合,空间板梁组合模型和空间板壳模型得到的频率及主梁等效质量基本相同,但空间杆系模型不能准确得到高阶侧弯模态的主梁等效均布质量。作为特例,进一步对无桁架钢箱梁开口断面斜拉桥的动力特性进行分析,结果表明:空间板梁组合模型和空间板壳模型吻合良好,但空间杆系模型得到的1阶扭转模态下的主梁等效均布质量惯性矩误差接近9%;桁架对主梁的侧弯基频影响较小,但能提高主梁的竖弯基频和扭转基频,有利于桥梁抗风。%To realize the accurate simulation calculation of the dynamic performance of box‐truss composite girder railway cable‐stayed bridge ,the three finite element modeling schemes of the box‐truss composite girder cable‐stayed bridge with open cross section are studied ,including the spatial bar element model ,combined space plate and beam element model and spatial shell ele‐ment model .A three‐pylon two main spans box‐truss composite girder railway cable‐stayed bridge with span arrangement of (98+140+406+406+140+98) m was taken as the study background . The sub‐spatial iterative method was used to comparatively analyze the modal characteristics of the different models ,and based on w hich the unit length equivalent mass and inertia moment of the different main girder models were calculated .The results of the

  9. Creep-fatigue evaluation method for weld joint of Mod.9Cr-1Mo steel Part II: Plate bending test and proposal of a simplified evaluation method

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Masanori, E-mail: ando.masanori@jaea.go.jp; Takaya, Shigeru, E-mail: takaya.shigeru@jaea.go.jp

    2016-12-15

    Highlights: • Creep-fatigue evaluation method for weld joint of Mod.9Cr-1Mo steel is proposed. • A simplified evaluation method is also proposed for the codification. • Both proposed evaluation method was validated by the plate bending test. • For codification, the local stress and strain behavior was analyzed. - Abstract: In the present study, to develop an evaluation procedure and design rules for Mod.9Cr-1Mo steel weld joints, a method for evaluating the creep-fatigue life of Mod.9Cr-1Mo steel weld joints was proposed based on finite element analysis (FEA) and a series of cyclic plate bending tests of longitudinal and horizontal seamed plates. The strain concentration and redistribution behaviors were evaluated and the failure cycles were estimated using FEA by considering the test conditions and metallurgical discontinuities in the weld joints. Inelastic FEA models consisting of the base metal, heat-affected zone and weld metal were employed to estimate the elastic follow-up behavior caused by the metallurgical discontinuities. The elastic follow-up factors determined by comparing the elastic and inelastic FEA results were determined to be less than 1.5. Based on the estimated elastic follow-up factors obtained via inelastic FEA, a simplified technique using elastic FEA was proposed for evaluating the creep-fatigue life in Mod.9Cr-1Mo steel weld joints. The creep-fatigue life obtained using the plate bending test was compared to those estimated from the results of inelastic FEA and by a simplified evaluation method.

  10. Pre-oxidized and nitrided stainless steel alloy foil for proton exchange membrane fuel cell bipolar plates: Part 1. Corrosion, interfacial contact resistance, and surface structure

    Science.gov (United States)

    Brady, M. P.; Wang, H.; Turner, J. A.; Meyer, H. M.; More, K. L.; Tortorelli, P. F.; McCarthy, B. D.

    Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr 2N, CrN, TiN, V 2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2× the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride particles for the treated Fe-20Cr-4V, but near continuous chromia for treated 2205 stainless steel, which was linked to the variation in ICR values. Promising corrosion resistance was observed under simulated aggressive PEMFC anode- and cathode-side bipolar plate conditions for both materials, although ICR values were observed to increase. The implications of these findings for stamped bipolar plate foils are discussed.

  11. Perpendicular construction of bridge girder for long span suspension bridge under a rapid stream; Kyuchoryuka ni okeru chodai tsuribashi no hokoketa chokka tsuri koho no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, J.; Sakamoto, M.; Nakao, T.; Koga, N. [Honshu-Shikoku Bridge Authority, Tokyo (Japan)

    1996-06-20

    Perpendicular construction of bridge girder for a long span suspension bridge, which is to be constructed over the Kurushima Channel, an international route, has been investigated. For the construction of suspension bridge over channels, the overhang construction is generally employed. Bridge girder perpendicular construction, in which unit girder block is lifted from a carrier barge and directly constructed by means of lifting beams located at main cable, is a superb method in terms of cost, time, and safety. It is necessary to stay the carrier barge during the anchoring of girder block and lifting beams. Mooring of the carrier barge is required under a rapid stream, which results in the trouble of under way ships. A propulsion positioning system has been developed for the bridge girder carrier barge, by which the position/propulsion of four thrusters equipped at each corner of the barge can be automatically controlled. Thus, the perpendicular construction of bridge girder has been developed, in which mooring is not required even under the rapid stream. The position of barge can be maintained within a range of {plus_minus}2.5 m even under a rapid stream with a speed of 3 kn. The quick joint can be certainly connected for about one minute in the horizontal movement within {plus_minus}2.5 m and vertical movement within 0.5 m. For this perpendicular construction, the construction time can be shortened to around 16 to 17 minutes, which has been usually taken for three hours. 2 refs., 17 figs., 4 tabs.

  12. Study on Fatigue Behavior of Anchorage of Cable and Girder of Long Span Cable-Stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A full scale model test is done and a FEM model is established toinvestigate the fatigue behavior of the Nancha cable-stayed bridge of the Nanjing Second Yangtz River Bridge, a long span steel bridge with a main span of 628 m. The results of test and FEM are analyzed and compared. It is shown that they are in good agreement. It is verified that the fatigue characteristic of the anchorage structure of cable and girder of the bridge satisfies the requirements specified by Chinese, British and American codes.

  13. Girder deformation related phase errors on the undulators for the European X-Ray Free Electron Laser

    Directory of Open Access Journals (Sweden)

    Yuhui Li

    2015-06-01

    Full Text Available In long gap tunable undulators, strong magnetic forces always lead to some amount of gap-dependent girder deformation and resulting gap-dependent phase errors. For the undulators for the European XFEL, this problem has been investigated thoroughly and quantitatively. Using the different gap dependencies of suitable shims and pole height tuning, a method is presented which can be applied to reduce the overall gap dependence of the phase error if needed. It is exemplified by tuning one of the undulator segments for the European X-Ray Free Electron Laser back to specs.

  14. 肱骨近端解剖锁定钢板与解剖钢板治疗肱骨Neer三、四部分骨折的疗效比较%Comparison of proximal humerus locking plate and anatomical plate for Neer three-and four-part of proximal humeral fractures

    Institute of Scientific and Technical Information of China (English)

    朱豪东; 蔡新新; 郭云峰; 郑柏生; 周卓谦

    2015-01-01

    目的:探讨肱骨近端解剖钢板与肱骨近端解剖锁定钢板治疗老年肱骨近端 Neer三、四部分骨折的功能及疗效差异。方法收集有完整随访资料的151例老年Neer 三、四部分骨折患者,按手术方式分为肱骨近端解剖钢板组(A 组,65例)和肱骨近端解剖锁定钢板组(B 组,86例),在随访过程采用Constant 评分及Neer 评分评价并比较两组疗效。结果 B 组平均愈合时间显著短于A 组(P<0.05)。两组的术后1年和术后2年功能比较:B 组Neer 评分的疼痛、功能、活动度及总分均显著优于 A 组(P<0.05);B 组 Constant 评分的疼痛、日常生活活动、主动活动及总分显著优于 A 组(P<0.05)。结论肱骨近端解剖钢板与肱骨近端解剖锁定钢板均可用于老年Neer 三、四部分骨折,但解剖锁定钢板愈合更快,功能恢复更好,临床推荐优先使用。%Objective To investigate the effect of proximal humerus locking plate and proximal humerus anatomical plate on complex 3- and 4-part fractures of the proximal humerus (Neer classification) in the elders. Methods 151 cases of proximal humeral fractures were included in the study and divided into proximal humerus anatomical plate group (A group, n=65 cases) and proximal humerus locking plate group (B group, n=86 cases) according to different operation methods. The patients of A group underwent fracture fixation by anatomical plate and those in B group received fracture fixation by locking proximal humerus plate. The treatment effect was evaluated in two groups and compared between two groups by Neer score and Constant score. Results The mean humerus healing time of B group was significant superior to A group (P<0.05). Neer score, constant score, pain , function , activity and total score of shoulder in B group were significant superior to those in A group in 1 year and 2 years after operation (P<0.05). Conclusion Proximal humerus

  15. Trial Production of QSn4-4-2.5 Bronze Plates for Auto Parts%汽车青铜QSn4-4-2.5板材的试制

    Institute of Scientific and Technical Information of China (English)

    张文芹

    2001-01-01

    The technology for producing QSn4-4-2.5 bronze plates for auto parts is explored with reference to the influence of the production program on the properties of the plates.%本文依据国内某用户的要求,对QSn4-4-2.5板材生产从锭坯的熔铸工艺和加工工艺进行探索,并论述了该合金板材生产的工艺制度对其产品性能的影响。

  16. 适用于输配电行业的铜件镀银工艺%Silver plating process for copper parts used in power transmission and distribution industry

    Institute of Scientific and Technical Information of China (English)

    茅红裕

    2011-01-01

    介绍了适用于输配电铜及铜合金件镀银工艺,其流程主要包括化学除油、盐酸活化、混酸酸洗、氰化镀铜、氰化镀银、电解钝化.说明了各工艺的操作条件及注意事项.给出了银镀层变色后的处理,不合格品的褪镀方法,以及镀层抗变色性能、结合力和显微硬度的测试方法.指出了该工艺对环保方面的要求.针对实际生产中遇到的漏镀和镀层有少量颗粒的问题,提出了改进措施.%A process for silver plating on copper parts used in power transmission and distribution industry was introduced. Its process flow is mainly composed of chemical degreasing, hydrochloric acid activating, mixed acid pickling,cyanide copper plating, cyanide silver plating, and electrolytic passivating. The operation conditions and problems needing attention were described. The treatment of tarnished coatings, the removal of rejected coatings, and the methods for testing of tarnish resistance, adhesion strength, and microhardness were given. The requirements of environmental protection were pointed out. Some countermeasures for preventing skip plating and a small amount of particles existing on coatings during practical production were presented.

  17. 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.

  18. 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.

  19. Life-Cycle Monitoring of Long-Span PSC Box Girder Bridges through Distributed Sensor Network: Strategies, Methods, and Applications

    Directory of Open Access Journals (Sweden)

    Zheheng Chen

    2015-01-01

    Full Text Available Structural health monitoring (SHM has attracted much attention in recent years, which enables early warnings of structural failure, condition assessments, and rational maintenance/repair strategies. In the context of bridges, many long-span steel bridges in China have been installed with the SHM systems; however, the applications of the SHM in prestressed concrete (PSC bridges are still rather limited. On the other hand, the PSC box girder bridges are extensively used in highway and railway systems and premature damage of these bridges is often reported, resulting in considerable maintenance and/or replacement costs. First, this paper presents a state-of-art review on the SHM of long-span PSC bridges. Monitoring strategies, methods, and previous applications for these bridges are summarized and discussed. In order to well capture the behavior of the bridge during its whole life and to maximize the use of sensors, a life-cycle monitoring strategy is proposed, in which the sensor layout is determined according to requirements for construction monitoring, completion test, and in-service monitoring. A case study is made on a three-span PSC box girder bridge in China. The system configuration, sensor layout, and data communications, and so forth, are presented. The up-to-date monitored structural responses are analyzed and compared with the design values.

  20. Waffle production: influence of batter ingredients on sticking of fresh egg waffles at baking plates-Part I: effect of starch and sugar components.

    Science.gov (United States)

    Huber, Regina; Schoenlechner, Regine

    2017-05-01

    Fresh egg waffles are a sweet convenience product typically baked from eggs, water, sugar, flour, fat, leavening agents, emulsifiers, preservatives, and flavors. In industrial production, waffles are baked continuously in high amounts of up to 200 kg raw material per hour. Therefore, it is important that the waffles do not stick onto the baking plates, which can cause significant product loss and increased costs due to interruption of the baking process, required cleaning procedures, and restarting of the energy-consuming start-up phase. Sticking of waffles is greatly influenced not only by baking plate material, release agent, baking temperature, and time, but also by the batter ingredients. In this study, effects of different starches and sugar components were investigated. Within the selected starches, potato starch demonstrated the highest effects on increasing waffle stability and releasing properties compared to wheat and lupine flour (less than 7% sticking waffles). Rice flour performed worst, with almost 50% of sticking waffles. Most of these waffles were broken during take-off, due to their crumbly texture. Within the sugar components, glycerine was better suitable than sorbitol and crystal sugar was superior compared to powdered sugar. They required less take-off force. It could be demonstrated that waffles with increased stability and texture were those that showed the least number of sticking waffles, thus the main aim of batter ingredients was to improve waffle quality. Waffle quality was influenced by batter parameters, significant correlations could be found, for example, a positive correlation between pH- and L-value, negative correlations between pH- and a-value, or density and aw-value. This resulted in significant correlations with take-off-force, which was correlated with L*- and b*-value (negative) and positive to a*-value. Sticking behavior was strongly associated with b*-value (positive) and to a*-value (negative).

  1. Hemiarthroplasty versus angle-stable locking compression plate osteosynthesis in the treatment of three- and four-part fractures of the proximal humerus in the elderly: design of a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Verbeek Paul A

    2012-02-01

    Full Text Available Abstract Background The optimal surgical management of dislocated three- and four-part fractures of the proximal humerus in elderly patients remains unclear. Most used techniques are hemiarthroplasty and angle-stable locking compression plate osteosynthesis. In the current literature there is no evidence available presenting superior results between hemiarthroplasty and angle-stable locking compression plate osteosynthesis in terms of speed of recovery, pain, patient satisfaction, functional outcome, quality of life or complications. Methods/Design A randomized controlled multicenter trial will be conducted. Patients older than 60 years of age with a dislocated three- or four-part fracture of the proximal humerus as diagnosed by X-rays and CT-scans will be included. Exclusion criteria are a fracture older than 14 days, multiple comorbidity, multitrauma, a pathological fracture, previous surgery on the injured shoulder, severely deranged function caused by a previous disease, "head-split" proximal humerus fracture and unwillingness or inability to follow instructions. Participants will be randomized between surgical treatment with hemiarthroplasty and angle-stable locking compression plate osteosynthesis. Measurements will take place preoperatively and 3 months, 6 months, 9 months, 12 months and 24 months postoperatively. Primary outcome measure is speed of recovery of functional capacity of the affected upper limb using the Disabilities of Arm, Shoulder and Hand score (DASH. Secondary outcome measures are pain, patient satisfaction, shoulder function, quality of life, radiological evaluation and complications. Data will be analyzed on an intention-to-treat basis, using univariate and multivariate analyses. Discussion Both hemiarthroplasty and angle-stable locking compression plate osteosynthesis are used in the current treatment of dislocated three-and four-part fractures of the proximal humerus. There is a lack of level-1 studies comparing

  2. Create Your Plate

    Medline Plus

    Full Text Available ... A A A Listen En Español Create Your Plate Create Your Plate is a simple and effective ... and that your options are endless. Create Your Plate! Click on the plate sections below to add ...

  3. 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.

  4. 桥式起重机轻量化主梁结构模型试验研究%Structural Model Test of Lightweight Girder of Bridge Crane

    Institute of Scientific and Technical Information of China (English)

    焦洪宇; 周奇才; 李英; 陈庆樟; 许广举

    2015-01-01

    针对桥式起重机主梁的轻量化设计方案对主梁强度、静态刚度的影响问题,基于相似理论和弹性静力学,采用方程分析法推导出原型主梁与相似主梁应力场相似的相似准则.依据主梁结构形式及受力特点,设计切实可行的主梁结构模型试验方案,开展轻量化主梁结构模型试验研究.结果表明,轻量化主梁在跨中截面腹板下半部分的弯曲正应力有一定程度的增加,腹板上半部分的弯曲正应力(绝对值)有小幅度下降;轻量化主梁在跨端截面的切应力增加幅度较大;轻量化主梁的最大挠度有所下降.依据《起重机设计规范》对轻量化主梁进行强度和静态刚度校核.在满足主梁强度、静态刚度要求的前提下,周期性去除腹板上的部分材料实现主梁轻量化设计具有一定的可行性.%In order to research the influence of girder's lightweight plan on strength and static rigidity, similarity criterions between prototype girder and similarity girder are derived from equational analysis based on similarity theory and elastostatics. The scheme of structural model test is designed reasonably and the study of structural model test is carried out. Results show that bending normal stress of upper half of web at midspan of lightweight girder increases to some extent and bending normal stress of bottom half of web decreases within a narrow range. Shear stress at the end-span declines by a great margin. The maximum deflection of lightweight girder comes down. The strength and static rigidity of lightweight girder are checked based on design rules for cranes. It is feasible to wipe off some material periodically in order to realize the lightweight design of girder on the premise of satisfying the strength and static rigidity.

  5. 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

  6. Application of Welding box girder flange by Using RAPID Welding Technology%RAPID焊接工艺技术在箱型梁翼缘板焊接的应用

    Institute of Scientific and Technical Information of China (English)

    程国志; 于连康

    2016-01-01

    RA PID焊接技术是目前比较先进的一项焊接工艺技术,它是利用数字控制的电弧曲线参数,进一步压缩电弧,使得电弧热量更集中、更具备熔透能力的一种高速焊接技术。由于其高速、高熔深的焊接工艺特性,被用于单面焊接双面成型的钢结构焊接上,可显著提高焊接生产效率。在铝电解多功能机组生产制造的专业厂,其天车主梁的焊接工艺技术一直是采取MAG焊接工艺技术,焊接质量及效率低。应用RAPID焊接工艺技术对箱型梁翼缘板焊接,与M AG焊接工艺技术在焊接质量、效率、经济性等方面进行对比、分析总结,可知,RAPID焊接工艺技术应用在天车主梁翼缘板的焊接中,综合经济效益较MAG焊接工艺有着显著的提高。%RAPID welding technology is an advanced high speed welding technology , the arc curve parame‐ters of w hich is controlled by digital technology , further compressed arc made the arc heat more concen‐trated , and had more penetration ability . Because of its welding technology properties of high speed and high penetration ,it is used for steel structure which is single -sided welding but double -sided molding , significantly improved the efficiency of welding production .In most aluminum electrolysis multifunctional unit manufacturing plants , the crane girder welding technology has been adopt MAG welding technology , welding quality and efficiency is low . After comparing , analyzing and summarizing the welding technology between RAPID and MAG about welding box beam wing flange , found that the RAPID welding technolo‐gy is better than MAG in welding quality , efficiency , economy and so on . RAPID welding technology used in crane girder flange plate welding , the comprehensive economic benefits is significantly improved than that of MAG welding technology .

  7. Thermally Nitrided Stainless Steels for Polymer Electrolyte Membrane Fuel Cell Bipolar Plates: Part 2: Beneficial Modification of Passive Layer on AISI446

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Heli [National Renewable Energy Laboratory (NREL); Brady, Michael P [ORNL; More, Karren Leslie [ORNL; Meyer III, Harry M [ORNL; Turner, John [National Renewable Energy Laboratory (NREL)

    2004-01-01

    Thermal nitridation of AISI446 mod-1 superferritic stainless steel for 24 h at 1100 C resulted in an adherent, inward growing surface layer based on (Cr, Fe){sub 2}N{sub 1-x} (x = 0--0.5). The layer was not continuous, and although it resulted in low interfacial contact resistance (ICR) and good corrosion resistance under simulated polymer electrolyte membrane fuel cell (PEMFC) cathodic conditions; poor corrosion resistance was observed under simulated anodic conditions. Nitridation for 2 h at 1100 C resulted in little nitrogen uptake and a tinted surface. Analysis by SEM, XPS, and AES suggested a complex heterogeneous modification of the native passive oxide film by nitrogen rather than the desired microns-thick exclusive Cr-rich nitride layer. Surprisingly, this modification resulted in both good corrosion resistance under simulated cathodic and anodic conditions and low ICR, well over an order of magnitude lower than the untreated alloy. Further, little increase in ICR was observed under passivating polarization conditions. The potential of this phenomenon for PEMFC bipolar plates is discussed.

  8. EMPIRICAL STUDY OF CAR LICENSE PLATES RECOGNITION

    Directory of Open Access Journals (Sweden)

    Nasa Zata Dina

    2015-01-01

    Full Text Available The number of vehicles on the road has increased drastically in recent years. The license plate is an identity card for a vehicle. It can map to the owner and further information about vehicle. License plate information is useful to help traffic management systems. For example, traffic management systems can check for vehicles moving at speeds not permitted by law and can also be installed in parking areas to se-cure the entrance or exit way for vehicles. License plate recognition algorithms have been proposed by many researchers. License plate recognition requires license plate detection, segmentation, and charac-ters recognition. The algorithm detects the position of a license plate and extracts the characters. Various license plate recognition algorithms have been implemented, and each algorithm has its strengths and weaknesses. In this research, I implement three algorithms for detecting license plates, three algorithms for segmenting license plates, and two algorithms for recognizing license plate characters. I evaluate each of these algorithms on the same two datasets, one from Greece and one from Thailand. For detecting li-cense plates, the best result is obtained by a Haar cascade algorithm. After the best result of license plate detection is obtained, for the segmentation part a Laplacian based method has the highest accuracy. Last, the license plate recognition experiment shows that a neural network has better accuracy than other algo-rithm. I summarize and analyze the overall performance of each method for comparison.

  9. Thin plate neotectonic models of the Australian plate

    Science.gov (United States)

    Burbidge, D. R.

    2004-10-01

    Thin plate finite element models of the neotectonic deformation of the Australian plate have been calculated in order to estimate the stress and strain rate within the plate, specifically concentrating on the Australian continent. The model includes plate-bounding faults, an anelastic brittle-ductile layered rheology and the option of laterally varying elevation and heat flow. The results of the models are compared to (1) the velocity of geodetic benchmarks on the Australian plate, (2) the spreading rate of the mid-oceanic ridges along the Australian plate's margins, (3) the direction of the maximum horizontal principal stress, (4) the stress regime within the plate, and (5) the crustal thickness estimated from the depth to the base of Mohorovicic discontinuity's transition zone. A variety of models are tested with a wide range of input parameters. The model with the smallest misfit with observations predicts that the strain rate for most of the Australian continent is approximately 10-17 s-1. This model has a slightly lower strain rate in the central Australia and is higher off the northern coast of Australia than for the rest of the continent. Strain rates of this magnitude would be difficult to observe from geodetic or geologic data for most parts of Australia but would be enough to generate much of the seismicity that has been observed over the last century.

  10. Finite element model updating of multi-span steel-arch-steel-girder bridges based on ambient vibrations

    Science.gov (United States)

    Hou, Tsung-Chin; Gao, Wei-Yuan; Chang, Chia-Sheng; Zhu, Guan-Rong; Su, Yu-Min

    2017-04-01

    The three-span steel-arch-steel-girder Jiaxian Bridge was newly constructed in 2010 to replace the former one that has been destroyed by Typhoon Sinlaku (2008, Taiwan). It was designed and built to continue the domestic service requirement, as well as to improve the tourism business of the Kaohsiung city government, Taiwan. This study aimed at establishing the baseline model of Jiaxian Bridge for hazardous scenario simulation such as typhoons, floods and earthquakes. Necessities of these precaution works were attributed to the inherent vulnerability of the sites: near fault and river cross. The uncalibrated baseline bridge model was built with structural finite element in accordance with the blueprints. Ambient vibration measurements were performed repeatedly to acquire the elastic dynamic characteristics of the bridge structure. Two frequency domain system identification algorithms were employed to extract the measured operational modal parameters. Modal shapes, frequencies, and modal assurance criteria (MAC) were configured as the fitting targets so as to calibrate/update the structural parameters of the baseline model. It has been recognized that different types of structural parameters contribute distinguishably to the fitting targets, as this study has similarly explored. For steel-arch-steel-girder bridges in particular this case, joint rigidity of the steel components was found to be dominant while material properties and section geometries relatively minor. The updated model was capable of providing more rational elastic responses of the bridge superstructure under normal service conditions as well as hazardous scenarios, and can be used for manage the health conditions of the bridge structure.

  11. Ultimate Strength of a Ship’s Hull Girder in Plastic and Buckling Modes.

    Science.gov (United States)

    1980-06-01

    drawn for deep - web -frame plate panels, of low slenderness ratio, simple supported and edges kept straight. It should be noted, however, that the range...H.-G., "Notes on the Buckling and Post-buckling Behaviour of Deep Web Frames," J. Marine Tech., July 1972. V. 62 [34] Timoshenko, S., "Stability of

  12. Indonesian Landforms and Plate Tectonics

    Directory of Open Access Journals (Sweden)

    Herman Th. Verstappen

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v5i3.103The horizontal configuration and vertical dimension of the landforms occurring in the tectonically unstable parts of Indonesia were resulted in the first place from plate tectonics. Most of them date from the Quaternary and endogenous forces are ongoing. Three major plates – the northward moving Indo-Australian Plate, the south-eastward moving SE-Asian Plate and the westward moving Pacific Plate - meet at a plate triple-junction situated in the south of New Guinea’s Bird’s Head. The narrow North-Moluccan plate is interposed between the Asia and Pacific. It tapers out northward in the Philippine Mobile Belt and is gradually disappearing. The greatest relief amplitudes occur near the plate boundaries: deep ocean trenches are associated with subduction zones and mountain ranges with collision belts. The landforms of the more stable areas of the plates date back to a more remote past and, where emerged, have a more subdued relief that is in the first place related to the resistance of the rocks to humid tropical weathering Rising mountain ranges and emerging island arcs are subjected to rapid humid-tropical river erosions and mass movements. The erosion products accumulate in adjacent sedimentary basins where their increasing weight causes subsidence by gravity and isostatic compensations. Living and raised coral reefs, volcanoes, and fault scarps are important geomorphic indicators of active plate tectonics. Compartmental faults may strongly affect island arcs stretching perpendicular to the plate movement. This is the case on Java. Transcurrent faults and related pull-apart basins are a leading factor where plates meet at an angle, such as on Sumatra. The most complicated situation exists near the triple-junction and in the Moluccas. Modern research methods, such as GPS measurements of plate movements and absolute dating of volcanic outbursts and raised coral reefs are important tools. The mega-landforms resulting

  13. Indonesian Landforms and Plate Tectonics

    Directory of Open Access Journals (Sweden)

    Herman Th. Verstappen

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v5i3.103The horizontal configuration and vertical dimension of the landforms occurring in the tectonically unstable parts of Indonesia were resulted in the first place from plate tectonics. Most of them date from the Quaternary and endogenous forces are ongoing. Three major plates – the northward moving Indo-Australian Plate, the south-eastward moving SE-Asian Plate and the westward moving Pacific Plate - meet at a plate triple-junction situated in the south of New Guinea’s Bird’s Head. The narrow North-Moluccan plate is interposed between the Asia and Pacific. It tapers out northward in the Philippine Mobile Belt and is gradually disappearing. The greatest relief amplitudes occur near the plate boundaries: deep ocean trenches are associated with subduction zones and mountain ranges with collision belts. The landforms of the more stable areas of the plates date back to a more remote past and, where emerged, have a more subdued relief that is in the first place related to the resistance of the rocks to humid tropical weathering Rising mountain ranges and emerging island arcs are subjected to rapid humid-tropical river erosions and mass movements. The erosion products accumulate in adjacent sedimentary basins where their increasing weight causes subsidence by gravity and isostatic compensations. Living and raised coral reefs, volcanoes, and fault scarps are important geomorphic indicators of active plate tectonics. Compartmental faults may strongly affect island arcs stretching perpendicular to the plate movement. This is the case on Java. Transcurrent faults and related pull-apart basins are a leading factor where plates meet at an angle, such as on Sumatra. The most complicated situation exists near the triple-junction and in the Moluccas. Modern research methods, such as GPS measurements of plate movements and absolute dating of volcanic outbursts and raised coral reefs are important tools. The mega-landforms resulting

  14. 铜陵公铁两用长江大桥桁片式钢桁梁立体试拼装工艺%Techniques for Trial Vertical Assembly of Steel Truss Girder of Tongling Changjiang River Rail-cum-Road Bridge

    Institute of Scientific and Technical Information of China (English)

    邵天吉; 余本俊

    2014-01-01

    铜陵公铁两用长江大桥为五跨连续钢桁梁三索面斜拉桥,钢桁梁采用板桁结合形式,由3片主桁、上层正交异性公路板式桥面、下层正交异性铁路钢箱桥面及横联构成。钢桁梁采用整体焊接式桁片结构,每2个节间的主桁上、下弦杆,斜杆,竖杆通过整体节点焊接成桁片上桥安装。为验证制造工艺和精度并指导实桥施工,选取3.5个连续节间钢桁梁在工厂内一次完成立体试拼装。由于主桁桁片采用水平拼装制作工艺,采用800 t龙门吊机2×200 t吊钩提升加横移对桁片进行90°转体翻身后试拼装。试拼装过程中设置了抗推拉刚性斜撑增强桁片与铁路桥面的稳定性;在斜杆件加垫片,通过调整间隙控制桥梁预拱度。试拼装过程中设置了测量控制网,检测结果满足设计和验收标准,达到了立体试拼装目的。%The Tongling Changjiang River Rail‐cum‐Road Bridge is a five‐span continuous steel truss girder cable‐stayed bridge with three cable planes .The steel truss girder is the combined or‐thotropic steel plates and steel trusses structure ,containing three main trusses ,the upper ortho‐tropic steel plate deck for vehicles ,the lower orthotropic railway steel box deck and lateral brac‐ings .The steel truss girder is a integrally‐welded truss structure ,the upper and lower chords ,di‐agonal struts and vertical struts of the main trusses in every two blocks are welded by integral nodes to be truss block for assembling on the bridge .In order to verify the manufacturing tech‐nique and precision and to direct the construction of the real bridge ,the steel truss girder in 3 .5 continuous blocks were selected to conduct one‐time trial vertical assembly in the factory .The main truss blocks were fabricated by the horizontal assembling technique ,the 800 t overhead lift‐ing gantry with two lifting hooks of 200 t was adopted to lift and horizontally

  15. FRP 加固 RC 连续梁桥抗震性能试验研究%Tests for aseismic performances of a RC continuous girder bridge retrofitted by FRP jacket

    Institute of Scientific and Technical Information of China (English)

    林元铮; 田石柱

    2016-01-01

    Taking a reinforced concrete continuous girder bridge as the study object,retrofitting the plastic region of piers with FRP jacket,the aseismic performances of the bridge structure were studied with hybrid tests.The fixed pier bearing most seismic action was taken as a test element and physically tested in a lab while the other parts of the bridge structure were taken as calculation elements and simulated numerically with OpenSees.After integrating and combining different parts with the hybrid test platform--OpenFresco,the dynamic responses of the overall bridge structure under seismic action were obtained.At last,the test results and Open Sees finite element analysis ones were compared.The results showed that the aseismic performances of the RC continuous girder bridge can be improved effectively after retrofitted with FRP jacket,and the test results agree well with those of finite element analysis.%以某钢筋混凝土连续梁桥作为研究对象,对其桥墩进行了塑性铰区的 FRP 抗震加固,采用混合试验技术研究了该桥梁结构的抗震性能。将连续梁桥结构承担主要地震作用的固定墩作为试验单元,进行真实的物理试验;将桥梁结构其余部分作为计算单元通过有限元软件 OpenSees 进行模拟,通过 OpenFresco 混合试验平台集成协调,完成了该连续梁桥的抗震混合试验。最后将试验结果与 OpenSees 有限元分析结果进行了对比。研究结果表明,FRP 抗震加固能够有效改善桥梁的抗震性能;试验结果与有限元分析结果吻合较好。

  16. Saudi License Plate Recognition Algorithm Based on Support Vector Machine

    Institute of Scientific and Technical Information of China (English)

    Khaled Suwais; Rana Al-Otaibi; Ali Alshahrani

    2013-01-01

    License plate recognition (LPR) is an image processing technology that is used to identify vehicles by their license plates. This paper presents a license plate recognition algorithm for Saudi car plates based on the support vector machine (SVM) algorithm. The new algorithm is efficient in recognizing the vehicles from the Arabic part of the plate. The performance of the system has been investigated and analyzed. The recognition accuracy of the algorithm is about 93.3%.

  17. Plate tectonics

    Digital Repository Service at National Institute of Oceanography (India)

    Chaubey, A.K.

    of magnetic reversals. Matuyama's study, based on available age information of the rock samples, has revealed that during early part of the Quaternary period the earth's magnetic field was reversely magnetized and that has gradually changed over to normal...). While Heirtzler et al. (1968) proposed a magnetic polarity reversal time scale for the Late Cretaceous to 211 Recent, about 75 Ma (anomaly 32), based on the distribution of oceanic magnetic anomalies on a few long magnetic profiles. This time...

  18. 轻型钢结构吊车梁优化设计%Optimization Design of Crane Girder in Portal Frame Buildings

    Institute of Scientific and Technical Information of China (English)

    石永久

    2001-01-01

    This paper investigates the design method of crane girders applied in portal frame buildings.An optimal design approach was proposed to reduce the grider weight and fabricate the crane girder economically.Finally some design examples were given to illustrate the efficiency of the proposed method.%通过分析和研究单层门式刚架轻型钢结构厂房中的吊车梁设计,总结了轻型钢结构吊车梁的优化设计方法和节点连接构造,对合理设计吊车梁,降低用钢量提出了设计建议。

  19. 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

  20. Construction technology points for box-girder fabrication and installation engineering%箱梁预制与安装工程施工技术要点

    Institute of Scientific and Technical Information of China (English)

    李慧萍

    2011-01-01

    Taking He-Yun highway box-girder fabrication project as the example,it summarizes the construction technology points for box-girder fabrication and installation engineering,respectively describes the fabrication plant layout,steel reinforcement preparation,pre-stressed tension,duct jacking and other critical construction procedures and attentions,which has provided certain guidance for future similar project.%以河运高速公路箱梁预制项目为例,针对箱梁预制及安装工程施工技术要点进行了总结,分别阐述了预制厂的布置,钢筋加工,预应力张拉,孔道压浆等关键工序施工步骤及注意事项,为今后同类项目提供了一定指导。

  1. Optimization of Post-Tensioned Box Girder Bridges with Special Reference to Use of High-Strength Concrete Using AASHTO LRFD Method

    Directory of Open Access Journals (Sweden)

    Byungik Chang

    2012-01-01

    Full Text Available With the Federal Highway Administration-mandated implementation of the LRFD specifications, many state departments of transportation (DOTs have already started implementing LRFD specifications as developed by the AASHTO. Many aspects of the LRFD specifications are being investigated by DOTs and researchers in order for seamless implementation for design and analysis purposes. This paper presents the investigation on several design aspects of post-tensioned box girder bridges designed by LRFD Specifications using conventional or High-Strength Concrete (HSC. A computer spreadsheet application was specifically developed for this investigation. It is capable of analysis, design, and cost evaluation of the superstructure for a cast-in-place post-tensioned box girder bridge. Optimal design of a post-tensioned box girder is achievable by correct selection of design variables. Cost evaluation of superstructures with different geometrical and material configurations has led to the development of optimum design charts for these types of superstructures. Variables used to develop these charts include, among others, span length, section depth, web spacing, tendon profile, and concrete strength. It was observed that HSC enables the achievement of significantly longer span lengths and/or longer web spacing that is not achievable when using normal strength concrete.

  2. 矿用汽车车架纵梁成形模开发研究%Mine Car Frame Girder Mold Development Research

    Institute of Scientific and Technical Information of China (English)

    向小汉

    2013-01-01

    To mine car frame girder for forming process analysis, with AutoForm software rebound calculation, the results of the analysis according to the rebound in ThinkDesign to girder local for the springback compensation, in the mold structure design also takes into account to springback control. Through the forming process of the optimization and reasonable die structure design, got to meet quality requirements of the girder products, and meet the needs of the mass production.%对矿用汽车车架纵梁进行成形工艺分析,用AutoForm软件进行回弹计算,根据回弹分析结果用ThinkDesign对纵梁局部进行回弹补偿,在模具结构设计中也考虑到对回弹的控制。通过成形工艺的优化和合理的模具结构设计,得到了满足质量要求的纵梁产品,并满足了批量生产的需要。

  3. Tratamento das fraturas femorais subtrocantéricas com placas de bloqueio lateral da parte proximal do fêmur The treatment of femoral subtrochanteric fractures with the proximal lateral femur locking plates

    Directory of Open Access Journals (Sweden)

    Sun-Jun Hu

    2012-12-01

    Full Text Available OBJETIVO: Estudar o desfecho de fraturas subtrocantéricas de quadril tratadas com placa de bloqueio lateral da parte proximal do fêmur. MÉTODO: Revisamos retrospectivamente os resultados clínicos de 48 casos de fraturas subtrocantéricas tratadas com placas de bloqueio lateral da parte proximal do fêmur de janeiro de 2008 a maio de 2010. Registrou-se o progresso da consolidação da fratura, assim como a ocorrência de complicações. A função da articulação do quadril foi avaliada pelo índice social de Harris e o escore de mobilidade de Parker-Palmer, um ano após a cirurgia. RESULTADO: Quarenta e cinco pacientes foram acompanhados até a união da fratura ou a revisão da cirurgia. Entre os 45 pacientes, 43 atingiram a união da fratura sem outra intervenção. Trinta e oito fraturas consolidaram sem perda da posição no acompanhamento de um ano. Não houve casos de perfuração da cabeça do fêmur pelo parafuso. O escore médio do índice social de Harris foi 86,5 ± 9,8 (73 ~95. A média do escore de mobilidade de Parker e Palmer foi 7,4 ± 2,1 (3~ 9. CONCLUSÃO: A placa de bloqueio lateral da parte proximal do fêmur é o tipo de fixação interna estável e efetiva para tratar as fraturas subtrocantéricas de quadril e tem a vantagem de fixação estável, em especial em fratura da parede lateral do fêmur. Nível de evidência IV, Série de Casos.OBJECTIVE: To study the outcome of subtrochanteric hip fractures treated by using a proximal lateral femur locking plate. METHOD: We retrospectively reviewed the clinical results of 48 cases of femoral subtrochanteric fractures treated with proximal lateral femur locking plates from Jan 2008 to May 2010. The progress of fracture healing, as well as the occurrence of complications, was recorded. The function of the hip joint was evaluated by Harris social index and the Parker and Palmer mobility score at 1 year after the operation. RESULT: 45 patients were followed up until fracture

  4. Processless offset printing plates

    Directory of Open Access Journals (Sweden)

    Sanja Mahović Poljaček

    2015-06-01

    Full Text Available With the implementation of platesetters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today. This paper presents some of the processless printing plates.

  5. 斜拉桥主梁大型 0 号块施工技术%Construction Techniques for Massive No .0 Main Girder Block of Cable-Stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    付浩; 严杰; 尹振君; 潘立泉

    2015-01-01

    武汉西四环汉江特大桥主桥为(77+100+360+100+77 ) m预应力混凝土梁斜拉桥 ,主梁为π形结构 ,两边为单箱双室、中间为纵横梁加桥面板结构形式.主梁0号块宽44 m、长22 m ,采用钢管桩贝雷梁支架现浇施工.支架由底模系统、横梁(贝雷梁)、桩顶分配梁、砂筒、钢管支架组成 ,支架施工完后采用反力架预压钢管桩 ,边箱室顶板底模采用透水模板布施工.通过混凝土配合比优化 ,配制高耐久性、稳定性的C55高性能混凝土 ,并采用天泵和地泵从两个方向分层浇筑 ,桥面纵、横坡采用提浆整平机控制.在0号块混凝土强度成长期预张拉横向预应力 ,纵向预应力待1号和1′号块施工完采用连接器连接构成整束一次性张拉 ;预应力采用智能张拉系统张拉、智能压浆系统压浆.实践表明 ,该桥采用该施工技术成功克服了支架不均匀沉降 ,有效控制了裂纹的产生 ,保证了主梁0号块的施工质量与施工安全.%The main bridge of the Hanjiang River Bridge on the west Fourth Ring Road in Wu-han is a prestressed concrete girder cable-stayed bridge with span arrangement of (77+100+360+100+77) m.The two edge boxes (two-cell single box structure) together with the central lattice beam covered with deck slabs form theπ-shaped main girder.The No.0 block of the main girder , cast on scaffolds made up of steel pipe piles and bailey trusses ,is 44 m wide and 22 m long.The scaffolds are composed of the chassis ,floor beam (bailey truss) ,pile-top distributive beam ,sand bailer and steel pipe supports.After the completion of the construction of the scaffolds ,the steel pipe piles were pre-compressed using reaction frame ,and the chassis for the top plate of edge boxes are constructed by using permeable formwork cloth.During the concreting ,the concrete mixing proportion was optimized ,the C55 high-performance concrete with sound durability and stability was prepared ,and the layered

  6. EFFECTIVE STIFFNESS METHOD FOR CALCULATING DEFLECTION OF CORRUGATED WEB GIRDER%波形钢腹板梁变形计算的有效刚度法

    Institute of Scientific and Technical Information of China (English)

    聂建国; 李法雄; 樊健生

    2012-01-01

    By introducing a shear rotation function accounting for the shear deformation in the webs, the paper presents a beam theory model of corrugated web girder, where the flexural behavior of corrugated web girder is modeled as the combination of truss action and bending action between upper flange and lower flange. Then analytical solutions for simply supported corrugated steel web girders and cantilever corrugated steel web girders are derived under uniformly distributed load and concentrated load, and the analytical solutions are well verified through a comparison with FEM results. In order to determine the deformation of corrugated web girders for the purpose of practical design, a simplified design method to calculate the deflection of corrugated web girders considering web shear deformation is presented by introducing an importance parameter. The deflections calculated by this method agree well with those obtained from experiments. According to the comparison of calculated deflections among different design methods for corrugated web girders, the simplified method presented in this study has good accuracy and is convenient to use.%为研究波形钢腹板剪切变形对波形钢腹板梁受力行为的影响,引入腹板剪切变形转角函数,将波形钢腹板梁的弯曲行为分解为桁架作用和弯曲作用,建立一个能够考虑波形钢腹板剪切变形的波形钢腹板梁理论模型,推导了简支和悬臂波形钢腹板梁在不同类型荷载作用下的变形解析解,采用有限元方法验证了理论模型和解析解的正确性和适用性。根据变形等效原理,引入重要影响参数对波形钢腹板梁的变形解析解进行简化,提出了考虑腹板剪切行为的波形钢腹板梁变形简化计算方法——有效刚度法。用该文提出的有效刚度法计算波形钢腹板梁在正常使用极限状态下的变形值和试验结果吻合良好,为波形钢腹板梁在正常使用极限状态下的

  7. 铝件镀银出现“黑斑”的原因及其消除%Cause of black spots appeared on surface of silver plated aluminum parts and its elimination

    Institute of Scientific and Technical Information of China (English)

    裴城关

    2011-01-01

    某批次铝零件在镀银后喷漆加工过程中出现了黑斑.从原材料、电镀和喷漆加工工艺等方面对黑斑产生的原因进行了讨论,通过表面和截面形貌观察、电镜分析、能谱分析等方法对黑斑与正常镀银层进行了对比,确定了黑斑为镀银层被硫元素污染所致,并找出了镀银层变色的原因,排除了故障.%Black spots appeared on the surface of a batch of aluminum parts during paint spraying after silver plating. The cause producing such black spots was discussed from the aspects of raw materials as well as processes of electroplating and spraying. A comparison between black spot and normal silver deposit was made by surface and section morphologies observation, scanning electron microscopy and energy-dispersive spectroscopy. It is ascertained that sulfur contamination of silver deposit results in the formation of black spots. The cause leading to silver deposits tarnishing is found out and the trouble is eliminated.

  8. 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

  9. Long-term monitoring of a PSC box girder bridge: Operational modal analysis, data normalization and structural modification assessment

    Science.gov (United States)

    Cury, Alexandre; Cremona, Christian; Dumoulin, John

    2012-11-01

    For reliable performance of vibration-based damage detection algorithms, it is important to distinguish abnormal changes in modal parameters caused by structural damage from normal changes due to environmental fluctuations. This paper firstly addresses the modeling of temperature effects on modal frequencies of a PSC box girder bridge located on the A1 motorway in France. Based on a six-month monitoring experimental program, modal frequencies of the first seven mode shapes and temperatures have been measured at three hour intervals. Neural networks are then introduced to formulate regression models for quantifying the effect of temperature on modal parameters (frequencies and mode shapes). In 2009, this bridge underwent a strengthening procedure. In order to assess the effect of strengthening on the vibration characteristics of the bridge, modal properties had to be corrected from temperature influence. Thus, the first goal is to assess the changes on the vibration signature of this bridge induced by the strengthening. For this purpose, classical statistical analysis and clustering methods are applied to the data recorded over the period after strengthening. The second goal is to evaluate the influence of temperature effects on the clustering results. It comes that the temperature correction significantly improves the confidence in the novelty detection and in the strengthening efficiency.

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

    Science.gov (United States)

    Yang, Caiqian; Wu, Zhishen; Zhang, Yufeng

    2008-06-01

    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.

  11. Geometry control of long-span continuous girder concrete bridge during construction through finite element model updating

    Science.gov (United States)

    Wu, Jie; Yan, Quan-sheng; Li, Jian; Hu, Min-yi

    2016-04-01

    In bridge construction, geometry control is critical to ensure that the final constructed bridge has the consistent shape as design. A common method is by predicting the deflections of the bridge during each construction phase through the associated finite element models. Therefore, the cambers of the bridge during different construction phases can be determined beforehand. These finite element models are mostly based on the design drawings and nominal material properties. However, the accuracy of these bridge models can be large due to significant uncertainties of the actual properties of the materials used in construction. Therefore, the predicted cambers may not be accurate to ensure agreement of bridge geometry with design, especially for long-span bridges. In this paper, an improved geometry control method is described, which incorporates finite element (FE) model updating during the construction process based on measured bridge deflections. A method based on the Kriging model and Latin hypercube sampling is proposed to perform the FE model updating due to its simplicity and efficiency. The proposed method has been applied to a long-span continuous girder concrete bridge during its construction. Results show that the method is effective in reducing construction error and ensuring the accuracy of the geometry of the final constructed bridge.

  12. CMS Resistive plate Champers

    CERN Document Server

    Zainab, Karam

    2013-01-01

    There are many types of gas detectors which are used in CERN in LHC project, There is a main parts for the gas detectors which must be in all gas detectors types like Multiwire proportional chambers, such as the micromesh gaseous structure chamber (the MicroMegas), Gas-electron multiplier (GEM) detector, Resistive Plate Champers... Compact Muon Solenoid (CMS) experiment detecting muons which are powerful tool for recognizing signatures of interesting physics processes. The CMS detector uses: drift tube (DT), cathode strip chamber (CSC) and resistive plate chamber (RPC). Building RPC’s was my project in summer student program (hardware). RPC’s have advantages which are triggering detector and Excellent time resolution which reinforce the measurement of the correct beam crossing time. RPC’s Organized in stations :  RPC barrel (RB) there are 4 stations, namely RB1, RB2, RB3, and RB4  While in the RPC endcap (RE) the 3 stations are RE1, RE2, and RE3. In the endcaps a new starion will be added and this...

  13. 解剖重建锁定钢板固定治疗肱骨近端三、四部分骨折脱位%Management of proximal humeral Neer 3-part and 4-part fracture dislocations with anatomic reconstruction locking plate

    Institute of Scientific and Technical Information of China (English)

    杨国勇; 向明; 胡晓川; 陈杭; 杨顺; 唐浩琛

    2012-01-01

    Objective To analyze the therapeutic effect of open reduction with internal fixation (ORIF) and anatomic reconstruction locking plate in treatment of Neer 3-part and 4-part fracture dislocations of proximal humerus. Methods The study involved 30 patients with Neer 3-part and 4-part fracture dislocations treated with anatomic reconstruction locking plate from September 2004 to December 2007.Twenty patients had complete follow-up data.The treatment methods included locking proximal humeral plate (LPHP) in seven patients and proximal humeral internal locking system (PHILOS) in 13.There were 15 males and five females,at age range of 29-84 years (average 52.5 years),including nine patients younger than 65 years and 11 older than 65 years.According to Neer classification,there were 15 patients with 3-part fracture dislocations including 12 anterior and three posterior dislocations and five patients with 4-part fracture dislocations including four anterior and one posterior dislocations. VAS and Constant scoring system were adopted to evaluate the shoulder joint function postoperatively. Results All 20 patients were followed up for 36-71 months ( average 51 months),which showed avascular necrosis of humeral head in six patients (30%),plating loosening in two,screw penetration in six,nonunion in two and infection in two.The mean visual analogue score (VAS) was 2.55 poiuts and the mean Constant score for the shoulder was 80.8.According to the Neer shoulder functional evaluation standard,eight patients were graded as excellent,six as good,three as fair and three as poor,with excellence rate of 70%.Conclusions Although the anatomic reconstruction locking plate and ORIF can cause a high incidence of avascular necrosis of humeral head in the treatment of Neer 3-part and 4-part fracture dislocations of proximal humerus,especially for the patients older than 65 years.However,there is no obvious correlation between necrosis of humeral head and shoulder function

  14. Create Your Plate

    Medline Plus

    Full Text Available ... steps to get started: Using your dinner plate, put a line down the middle of the plate. ... vegetables . Now in one of the small sections, put grains and starchy foods. See this list of ...

  15. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... 2016 Articles from Diabetes Forecast® magazine: wcie-meal-planning, In this section Food Planning Meals Diabetes Meal ...

  16. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal ... Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook ...

  17. Food guide plate

    Science.gov (United States)

    ... chips or cookies. VEGETABLES: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Vegetables can be raw, fresh, ... as a snack. FRUITS: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Fruits can be fresh, canned, ...

  18. Growth Plate Fractures

    Science.gov (United States)

    ... the most widely used by doctors is the Salter-Harris system, described below. Type I Fractures These ... incidence of growth plate fractures peaks in adolescence. Salter-Harris classification of growth plate fractures. AAOS does ...

  19. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  20. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  1. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets you still choose the foods you want, but changes the portion sizes so you are getting larger ...

  2. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... Sleeve Custom jerseys for your Tour de Cure team benefits the cause. Ask the Experts: Learn to ...

  3. LICENSE PLATE LOCALIZATION USING GABOR FILTERS AND NEURAL NETWORKS

    Directory of Open Access Journals (Sweden)

    Sami Ktata

    2013-01-01

    Full Text Available Vehicle License Plate Detection (LPD is an important step for the vehicle plate recognition which can be used in the intelligent transport systems. Many methods have been proposed for the detection of license plates based on: Mathematical morphology, Discrete Wavelet Transform, Hough Transform and others. In general, an LPR system includes four main parts: Vehicle image acquisition, license plate detection, character segmentation and character recognition. In this study, we present a robust method for extracting and detecting license plates, from simple images of Tunisian vehicles, based on Gabor filters and neural networks. The proposed method is designed to perform recognition of any kind of license plates under any environmental conditions.

  4. Aerodynamic stability study of a long-span prestressed concrete cable-stayed bridge. Aerodynamic behavior of edge box girder under uniform flow; Chodai PC shachokyo no taifu anteisei ni kansuru kenkyu. Ichiyoryuchu ni okeru edge girder keishiki no kuriki tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, T. [Obayashi Corp., Tokyo (Japan)

    1999-01-10

    In recent years, the construction of long-span bridges is on the increase. Prestressed concrete cable-stayed bridges are dynamically very efficient structures of relatively low cost that blend in well with the landscape. Maintenance is also easy. Consequently, the adoption of edge box girders for cable-stayed bridges is increasing worldwide, but problems related to the aerodynamic stability of the structure have emerged. The aerodynamic stability of edge box girders for a prestressed concrete cable-stayed bridge was investigated under uniform flow conditions by conducting several wind tunnel experiments. As a result, the section of the bridge deck was optimized to prevent torsional flutter within an angle of attack varying from -5 to +5 degrees. It is therefore possible to guarantee the aerodynamic stability of long-span prestressed concrete cable-stayed bridges. (author)

  5. Accelerated plate tectonics.

    Science.gov (United States)

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  6. 武黄客专700t预制简支箱梁架设施工技术%On construction technique for erection of 700 t prestressed simply supported box girder along Wuhan-Huangshi special passenger line

    Institute of Scientific and Technical Information of China (English)

    魏巍

    2011-01-01

    Taking the erection of 700 t prestressed simply supported box girder along Wuhan-Huangshi special passenger line as the example, the paper sums up the erection equipment and structure characteristic of the box girder and its performance, and illustrates the construction craft of the erection for the box girder and the key points for bearing' s perfusion, so as to accumulate relative experience and direct the engineering prac- tice.%以武黄客运专线700t预制简支箱梁架设为例,对箱梁架设设备及其结构特点和性能作了归纳,重点对箱梁架设施工工艺及支座灌注要点进行了阐述,以积累相关施工经验,指导工程实践。

  7. Create Your Plate

    Medline Plus

    Full Text Available ... Reset Plate Share Create Your Plate ! Share: Seven Simple Steps to Create Your Plate It's simple and effective for both managing diabetes and losing ... en.html Have Type 2 Diabetes? Our free program will help you live well. More from diabetes. ...

  8. Obliquity along plate boundaries

    Science.gov (United States)

    Philippon, Mélody; Corti, Giacomo

    2016-12-01

    Most of the plate boundaries are activated obliquely with respect to the direction of far field stresses, as roughly only 8% of the plate boundaries total length shows a very low obliquity (ranging from 0 to 10°, sub-orthogonal to the plate displacement). The obliquity along plate boundaries is controlled by (i) lateral rheological variations within the lithosphere and (ii) consistency with the global plate circuit. Indeed, plate tectonics and magmatism drive rheological changes within the lithosphere and consequently influence strain localization. Geodynamical evolution controls large-scale mantle convection and plate formation, consumption, and re-organization, thus triggering plate kinematics variations, and the adjustment and re-orientation of far field stresses. These geological processes may thus result in plate boundaries that are not perpendicular but oblique to the direction of far field stresses. This paper reviews the global patterns of obliquity along plate boundaries. Using GPlate, we provide a statistical analysis of present-day obliquity along plate boundaries. Within this framework, by comparing natural examples and geological models, we discuss deformation patterns and kinematics recorded along oblique plate boundaries.

  9. 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

  10. 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

  11. Corrosion Reason Analysis on Galvanized Parts of Steel Plate Barn in a Port%某码头钢板仓镀锌件腐蚀原因分析

    Institute of Scientific and Technical Information of China (English)

    李咏梅; 李建三; 刘钧泉

    2011-01-01

    Corrosion occurred on the surface of galvanized steel barn in a port,and three types of corrosion were found by the realty investigation.Corrosion reasons were analyzed by macro examination,zinc mass test and EDS.The results show that the zinc mass satisfied the requirement of design and had no relation with the corrosion.The main corrosion reason for the galvanized steel plate barn were in the high concentration of corrosive medium of the port environment,couple corrosion cell formed between zinc coating and the cutting edge,and the oxygen concentration different cell formed in the crevice between the galvanized parts and the ground or concrete.%某码头钢板仓镀锌件发生腐蚀生锈现象,通过现场调查对镀锌件的腐蚀形态进行分析发现,钢板仓镀锌件的腐蚀主要有3种形态。采用宏观分析、镀锌层质量试验以及腐蚀产物能谱分析等方法对镀锌件的腐蚀原因进行了分析。结果表明:钢板仓镀锌件发生腐蚀与镀锌层质量无关,钢板仓镀锌件发生腐蚀主要是由于钢板仓所在码头环境腐蚀性介质含量较高,镀锌层与切口处的钢铁形成了电偶腐蚀电池,以及镀锌件与地面或混凝土支座接触部位形成了氧浓差腐蚀电池所致。

  12. 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.

  13. Vehicle License Plate Character Segmentation

    Institute of Scientific and Technical Information of China (English)

    Mei-Sen Pan; Jun-Biao Yan; Zheng-Hong Xiao

    2008-01-01

    Vehicle license plate (VLP) character segmentation is an important part of the vehicle license plate recognition system (VLPRS). This paper proposes a least square method (LSM) to treat horizontal tilt and vertical tilt in VLP images. Auxiliary lines are added into the image (or the tilt-corrected image) to make the separated parts of each Chinese character to be an interconnected region. The noise regions will be eliminated after two fusing images are merged according to the minimum principle of gray values.Then, the characters are segmented by projection method (PM) and the final character images are obtained. The experimental results show that this method features fast processing and good performance in segmentation.

  14. Fatigue behaviour of welded joints assembled by longitudinal corrugated plates

    Institute of Scientific and Technical Information of China (English)

    王志宇; 王清远; 刘永杰; 孙美

    2015-01-01

    Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of the fatigue behaviour of welded details in such structures becomes an important issue for the design. The typical welded details were represented as welded joints assembled by longitudinal corrugated plates. All the experiments were performed under fatigue loading using a servo-control testing machine. The test results from the failure mode observation with the aid of infrared thermo-graph technology show that the failure manner of these welded joints is comparable to that of the corrugated steel web beams reported previously. It is indicated from the stiffness degradation analysis that the welded joints with larger corrugation angle have higher stiffness and greater stiffness degradation in the notable stiffness degradation range. It is shown from the testS−N relations based on the free regression and forced regression analyses that there is a good linear dependence between lg(N) and lg(ΔS). It is also demonstrated that the proposed fracture mechanics analytical model is able to give a prediction slightly lower but on the safe side for the mean stresses at 2 million cycles of the test welded joints.

  15. Angular shear plate

    Science.gov (United States)

    Ruda, Mitchell C [Tucson, AZ; Greynolds, Alan W [Tucson, AZ; Stuhlinger, Tilman W [Tucson, AZ

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  16. Strengthening Effect Analysis of RC T-Sectional Girders Strengthened with CFRP Sheets%CFRP布加固钢筋混凝土T梁效果分析

    Institute of Scientific and Technical Information of China (English)

    何广宝

    2014-01-01

    Because of many advantage, such as f being light, high strength and corrosion resistance,car-bon fiber reinforced polymer is widely used in old bridge reinforcement. However, the study on theoretical analysis and numerical simulation is relatively delayed due to its complex mechanical properties com-pared common reinforced concrete girders. The finite element software ANSYS is used to establish an nu-merical simulation model of RC T-sectional girders strengthened with CFRP sheets in the article. The problem of convergence of nonlinear Finite Element Analysis (FEA) is solved in the numerical simulation analysis. The midspan deflection and maximum stress of T-sectional girder after reinforcement reduce by 11.6% and 20.7% respectively compared to initial girder, but the ultimate capacity increases by 52%, which demonstrates that CFRP sheets can improve the mechanical performance of RC beams.%碳纤维复合材料具有轻质、高强以及耐腐蚀等优点,在旧桥加固工程中得到广泛应用,但由于其力学性能和破坏模式比普通钢筋混凝土梁复杂,在理论和数值分析方面的研究相对滞后。依托某T型钢筋混凝土桥梁加固实例,运用ANSYS有限元软件建立模型进行分析,解决了CFRP布加固构件非线性数值求解难以收敛的问题。加固后T型梁的跨中挠度和最大应力相比于加固前分别下降了10.4%和17.1%了,然而极限承载力提升了52%,这表明CFRP布加固可以很好地改善钢筋混凝土梁的受力性能。

  17. The delicate analysis of shear lag effect on trapezoidal box girders%梯形箱梁剪力滞后效应的精细化分析

    Institute of Scientific and Technical Information of China (English)

    甘亚南; 石飞停

    2014-01-01

    引入剪滞翘曲应力自平衡条件的影响,考虑了剪切变形和剪滞效应等因素,设置了三个不同的剪滞纵向位移差函数以准确反映梯形箱梁不同宽度翼板的剪滞变化幅度,提出了一种能对工程中常用箱梁静力学特性分析的精确解法。本文以能量变分原理为基础建立了薄壁箱梁的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。算例中,分析了不同荷载形式、跨宽比和悬臂板长度等因素对箱梁静力学特性的影响,结果显示出引入剪滞翘曲应力自平衡条件的必要性。%In consideration of self-equilibrium condition for shear lag warping stress ,shear deformation and shear lag effect ,three different longitudinal displacement difference functions are employed to accu-rately reflect the amplitude of change of shear lag in the trapezoidal box girders with various widths of wing slabs ,and a new warping displacement mode of trapezoidal thin-walled box girders is chosen to meet the axial self-equilibrium condition for corresponding stress ,a more accurate approach is proposed to analyze the mechanical characteristics of trapezoidal box girders generally used in engineering .Based on the minimum potential principle ,the governing differential equations and related natural boundary conditions are induced ,the closed-form solutions of generalized displacements are obtained .The varia-tions of stress of trapezoidal box girders ,caused by the change of factors such as self-equilibrium condi-tion ,type of loading and ratio of span and width are discussed ,the importance about the introduction of self-equilibrium condition is proved .

  18. 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.

  19. 考虑腹板剪切行为的波形钢腹板梁理论模型%Theory Model of Corrugated Steel Web Girder Considering Web Shear Behavior

    Institute of Scientific and Technical Information of China (English)

    聂建国; 李法雄

    2011-01-01

    为研究波形钢腹板剪切变形对波形钢腹板梁受力行为的影响,引入腹板剪切变形转角函数,将波形钢腹板梁的弯曲行为分解为桁架作用和弯曲作用,建立一个能够考虑波形钢腹板剪切变形的波形钢腹板梁理论模型。推导了端部无约束条件下简支波形钢腹板梁在均布荷载和端部约束条件下简支波形钢腹板梁在跨中集中荷载作用下的解析解,采用有限元方法验证了理论模型和解析解的正确性和适用性。研究结果表明:端部约束条件对主梁变形影响很小;波形钢腹板的剪切变形对主梁变形影响显著,在常见波形钢腹板梁桥尺寸范围内,由腹板剪切变形引起的主梁挠度占总挠度的10%~30%。%In order to study the influence of shear deformation of forcing behavior for corrugated steel web,shear rotation function of calculating shear deformation in the web was introduced,a theory model of corrugated steel web girder was presented.In the model,bending behavior of corrugated steel web girder could be divided into truss action and bending action between upper-flange and sub-flange.Then,analytical solutions for the cases of simply-supported corrugated steel web girder without end restraint sustaining under uniform distribution load and simply-supported corrugated steel web girder with end restraint under sustaining mid-span concentrated load were derived,validity and usability of the analytical solution and the model were well proved by finite element method.Results show that the end constraint conditions have little effect on the deformation of the main girder.However,the shear deformation of corrugated steel web has great impact on the deformation of main girder.In the common size ranges of bridge with corrugated steel web girders,the proportion of main girder deflection caused by shear deformation in the web may reach 10% to 30% of total deflection.

  20. Highly curved microchannel plates

    Science.gov (United States)

    Siegmund, O. H. W.; Cully, S.; Warren, J.; Gaines, G. A.; Priedhorsky, W.; Bloch, J.

    1990-01-01

    Several spherically curved microchannel plate (MCP) stack configurations were studied as part of an ongoing astrophysical detector development program, and as part of the development of the ALEXIS satellite payload. MCP pairs with surface radii of curvature as small as 7 cm, and diameters up to 46 mm have been evaluated. The experiments show that the gain (greater than 1.5 x 10 exp 7) and background characteristics (about 0.5 events/sq cm per sec) of highly curved MCP stacks are in general equivalent to the performance achieved with flat MCP stacks of similar configuration. However, gain variations across the curved MCP's due to variations in the channel length to diameter ratio are observed. The overall pulse height distribution of a highly curved surface MCP stack (greater than 50 percent FWHM) is thus broader than its flat counterpart (less than 30 percent). Preconditioning of curved MCP stacks gives comparable results to flat MCP stacks, but it also decreases the overall gain variations. Flat fields of curved MCP stacks have the same general characteristics as flat MCP stacks.

  1. Study the vibration and dynamic response of the dipole girder system for CSNS/RCS

    OpenAIRE

    Renhong, Liu; Min, Wang; Junsong, Zhang; GuangYuan, Wang

    2015-01-01

    China Spallation Neutron Source is a high intensity proton accelerator based facility, and its accelerator complex includes two main parts an H- linac and a rapid cycling synchrotron. The RCS accumulates the 80MeV proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25Hz. The dipole of the CSNS RCS is operated at a 25 Hz sinusoidal alternating current which causes severe vibrate. The vibration will influence the long term safety and reliable operation of the magnet. The dipole...

  2. 无氰镀铜的实验研究与生产应用进展(一)%Advances in experimental study and production practice of cyanide-free copper plating-Part I

    Institute of Scientific and Technical Information of China (English)

    袁诗璞

    2009-01-01

    The unfeasibility of dip plating of copper on iron and steel workpiece from a bright acid copper sulfate bath and the features of acid copper plating process characterized by the combination of dip plating with electrodeposition were analyzed. The latest progress in the studies of acid copper brightener, iron and steel activation principle, and complexing agent for cyanide-free alkaline copper plating were introduced. It is pointed out that cyanide-free HEDP copper plating bath has chemical activation effect and pre-dipping can improve the adhesion of deposit to substrate.%分析了基于硫酸盐光亮酸性镀铜体系的钢铁件浸镀铜工艺工业化应用的不可行性,以及浸镀与电沉积相结合的酸性镀铜工艺的特点.介绍了酸铜光亮剂、钢铁件活化原理、无氰碱铜配位荆等研究的最新进展.指出HEDP无氰碱铜镀液具有化学活化作用,以及预浸能提高镀层结合力.

  3. Creation of the Cocos and Nazca plates by fission of the Farallon plate

    Science.gov (United States)

    Lonsdale, Peter

    2005-08-01

    Throughout the Early Tertiary the area of the Farallon oceanic plate was episodically diminished by detachment of large and small northern regions, which became independently moving plates and microplates. The nature and history of Farallon plate fragmentation has been inferred mainly from structural patterns on the western, Pacific-plate flank of the East Pacific Rise, because the fragmented eastern flank has been subducted. The final episode of plate fragmentation occurred at the beginning of the Miocene, when the Cocos plate was split off, leaving the much reduced Farallon plate to be renamed the Nazca plate, and initiating Cocos-Nazca spreading. Some Oligocene Farallon plate with rifted margins that are a direct record of this plate-splitting event has survived in the eastern tropical Pacific, most extensively off northern Peru and Ecuador. Small remnants of the conjugate northern rifted margin are exposed off Costa Rica, and perhaps south of Panama. Marine geophysical profiles (bathymetric, magnetic and seismic reflection) and multibeam sonar swaths across these rifted oceanic margins, combined with surveys of 30-20 Ma crust on the western rise-flank, indicate that (i) Localized lithospheric rupture to create a new plate boundary was preceded by plate stretching and fracturing in a belt several hundred km wide. Fissural volcanism along some of these fractures built volcanic ridges (e.g., Alvarado and Sarmiento Ridges) that are 1-2 km high and parallel to "absolute" Farallon plate motion; they closely resemble fissural ridges described from the young western flank of the present Pacific-Nazca rise. (ii) For 1-2 m.y. prior to final rupture of the Farallon plate, perhaps coinciding with the period of lithospheric stretching, the entire plate changed direction to a more easterly ("Nazca-like") course; after the split the northern (Cocos) part reverted to a northeasterly absolute motion. (iii) The plate-splitting fracture that became the site of initial Cocos

  4. 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。

  5. Experimental investigation on prestressed concrete slabs for two- or three-girders bridges; Shoshuketa kyoryoyo PC yukaban ni kansuru jikken kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, F.; Yabe, J.; Ogaki, K.; Sakugawa, K.; Ito, A.; Takeuchi, K.; Tomoda, T. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

    1996-01-20

    Rationalization and labor-saving in the construction of bridges are the pending problems arising from the shortage of skilled construction workers, shortened time usable for construction, and demand for lower cost. Under the circumstances, experiment and study were conducted about the PC slab for two- or three-girder bridges. On the assumption of a PC slab located between two main girders, the interval 6 meters long, specimens near the real size were subjected to experiments. Springs were attached to the free sides so that load tests might be conducted under boundary conditions equivalent to those of a finite continuous slab along the direction of the bridge length as in case of a real bridge. It was found that a partial slab model of limited dimensions was usable when a long span slab experiment was necessary. A PC slab, unlike an RC slab, regained its elastic behavior when the load was removed even after the appearance of cracks. Crack producing loads fell within the range which could generally be estimated by calculation, and the PC slab was capable of restoring its original state upon unloading even after the production of cracks. The PC slab, as compared with the RC slab, demonstrated a greater ultimate strength, but the strength was not affected by the size of the prestress. In case of a PC slab on a long span, the bend fracture precedes and the ultimate strength is determined by the bend strength. 9 refs., 9 figs., 5 tabs.

  6. On construction technique of arc model at box girder web%箱梁外腹板圆弧模施工技术

    Institute of Scientific and Technical Information of China (English)

    梁见

    2012-01-01

    Combining with the arc model construction of the continuous box girder web at Yijiang Bridge at Wuhu, the paper undertakes the mould installation by adopting various method according to the parameters of the web arc and the field fact, and mainly introduces the technique, including the making and the consolidation of the box girder arc models with two different parameters, so as to have better reference and direction for the similar bridge construction.%结合芜湖弋江桥连续箱梁外腹板圆弧模施工技术,根据外腹板圆弧半径大小,结合现场实际情况,通过采取不同方法进行模板制安施工,详细介绍了两种不同圆弧半径的箱梁圆弧模板的制作、加固等技术,对同类型桥梁施工具有较强的借鉴和指导作用。

  7. 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.

  8. Generalized Fibonacci zone plates

    CERN Document Server

    Ke, Jie; Zhu, Jianqiang

    2015-01-01

    We propose a family of zone plates which are produced by the generalized Fibonacci sequences and their axial focusing properties are analyzed in detail. Compared with traditional Fresnel zone plates, the generalized Fibonacci zone plates present two axial foci with equal intensity. Besides, we propose an approach to adjust the axial locations of the two foci by means of different optical path difference, and further give the deterministic ratio of the two focal distances which attributes to their own generalized Fibonacci sequences. The generalized Fibonacci zone plates may allow for new applications in micro and nanophotonics.

  9. 连续箱梁的日照温差应力计算研究%Study on Calculation of Sunshine Thermal Stress in Continuous Box-girders

    Institute of Scientific and Technical Information of China (English)

    陈权; 王丽娟; 张元海; 诸昌钤

    2009-01-01

    According to the harmonious condition of deformation and the assumption of plane section, the general formula for calculating sunshine thermal stress of continuous box girders was derived. Then based on the existing experimental results and the modes of sunshine thermal gradients in the present code for design of railway and highway bridges, the practical calculating formula of thermal stress was presented. The method and formula for calculating secondary thermal bending moment were provided tnnzekew continuous box girders based on the three-moment equation of skew continuous beam. The corresponding programmaing was fulfilled. The thermal stresses in figh and skew continuous box girders were calculated through engineering practice and good agreement was achieved compared with those of ANSYS calculation. The longitudinal distribution pattern of the thermal stress in continuous box girder bridges was ascertained. It is put forward that (1) much attention should be paid to the checking calculation for nonnal stress and crack resistance at midspan cross-section of central span in the design of prestrssed concrete continuous box girder bridges; (2) the checking calculation for crack resistance of inclined cross -section near gravity axis in internal support area should also be treated seriously.%根据变形协调条件及平截面假定,首先推导了连续箱梁日照温差总应力的一般公式,并针对试验观测资料及我国铁路桥梁和公路桥梁设计规范中的不同日照温差梯度模式,给出了温度应力的实用计算公式.为了能够进一步应用于斜交连续箱梁,以斜交连续梁的三力矩方程为基础,给出了温度次弯矩的计算方法及公式.编制了相应温度应力分析程序,结合工程实例分别对正交和斜交连续箱梁的温度应力进行了计算分析,并与ANSYS有限元计算结果进行对比.通过分析连续箱梁日照温差应力沿梁跨方向的分布规律,提出在设计预应力混凝

  10. Treatment Measures for Empty Bearing of Arc Steel Box Girder with Cross Slope for Rotating Structure%旋转结构找横坡弧形钢箱梁支座托空处理措施

    Institute of Scientific and Technical Information of China (English)

    李粤东; 夏崇滔; 张翼; 巫正伟

    2014-01-01

    钢箱梁结构因其自身的特性在市政工程建设得到大量运用,钢箱梁吊装施工中空间就位及空形态的控制问题较为突出,其中带纵坡的弧形钢箱梁通过旋转结构找横坡就使得钢箱梁在施工过程中整体空间形态要有控制技术难度更高,极易造成钢箱梁支座托空。该文结合工程实例,就有纵坡且旋转结构找横坡弧形钢箱梁吊装后产生支座托空的处理措施进行论述。%Steel box girder structure is widely applied nowadays for its virtues, but the controlling problems in space location and spatial form in its con-struction are severe, and the finding of cross slope through rotating structure by arc steel box girder with longitudinal slope renders controlling technology of steel box girder over spatial form harder, easily causing empty bearing of steel box girder. The treatment measures for such problem are presented in de-tail.

  11. Blue Willow Story Plates

    Science.gov (United States)

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  12. Create Your Plate

    Medline Plus

    Full Text Available ... In Memory In Honor Become a Member En Español Type 1 Type 2 About Us Online Community ... Page Text Size: A A A Listen En Español Create Your Plate Create Your Plate is a ...

  13. Create Your Plate

    Medline Plus

    Full Text Available ... Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning ... Planning Meals Diabetes Meal Plans and a Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets ...

  14. 钢箱梁电弧喷铝防腐涂层无损检测图像分析%Image analysis of arc sprayed aluminum anticorrosive coating on steel box girder based on nondestructive test

    Institute of Scientific and Technical Information of China (English)

    刘丽娜; 刘涛

    2015-01-01

    为研究钢箱梁电弧喷铝防腐涂层防腐机理,预测其防腐寿命,加工制作钢板试样,表面电弧喷铝涂层,进行室内加速腐蚀试验。通过平板扫描仪采集对象图像,观测腐蚀发展过程。采用基于二值化图像的图像处理技术提取腐蚀形貌图像特征参数,并结合规范评定涂层腐蚀损伤级别。研究结果表明:基于二值化图像的图像处理技术可以有效区分涂层腐蚀与未腐蚀区域,实现涂层腐蚀面积定量化分析,为防腐涂层腐蚀等级评定提供新的思路,并估算200μm喷铝涂层实际海洋大气环境下的寿命为63.6年。%To study the anticorrosion mechanism of arc-sprayed aluminum anticorrosive coating on steel box girder and to predict the anticorrosive life of the coating,steel plates were manufactured and painted with aluminum on the surfaces to carry out indoor accelerated corrosion test. Corrosion image of the organic protection coating was collected by a flat scanner to observe its corrosion process. The blistering area was extracted through image processing technology to evaluate the corrosion grade. The results demonstrate that the image processing technology based on binary image can distinguish the corrosion areas from the non-corrosion areas so as to realize quantitative analysis for coating corrosion area. With the help of this technology,a new way has been presented for assessing the corrosion grade of anticorrosive coatings and the service life of 200μm aluminum coating has been estimated to be 63.6 years in the actual marine atmospheric environment.

  15. 箱型桥梁结构的面板声学贡献分析%Application of panel acoustic contribution theory in study of noise fro m simply -supprted box girder in high speed rail way

    Institute of Scientific and Technical Information of China (English)

    刘林芽; 付奇川; 邵文杰; 李纪阳

    2015-01-01

    Taking the high speed railway 32 m concrete simply -supported box bridge as the research object,the theses used finite element software to set up for high speed railway track -bridge analysis model.Then,based on the theory of vehicle -track -bridge coupling vibration,this paper analyzed the vertical vibration of the struc-ture of the bridge.A vertical vibration response was finally gotten as boundary conditions,which we use in the boundary element model of box girder structure noise prediction.At the same time,based on panel acoustic con-tribution analysis theory,the box beam body panel pressure contribution analysis and panel acoustic power analy-sis were done.In this way,we determined the largest position of body radiation noise for box beam .The results of the study show that if the train speeds up to 200 km /h on the elevated rail,box beam body radiation noise mainly occur within the range of 0 -100 Hz,of which 20 Hz and 42 Hz are prominent peak.Meanwhile,by the panel acoustic contribution analysis,we come to the conclusion that the part of main radiation noise comes from the box girder roof and the two flank flange panel.%以高速铁路32 m 混凝土简支箱型桥梁为研究对象,通过有限元软件建立了轨道-桥梁分析模型,采用车辆-轨道-桥梁耦合振动理论,分析了桥梁结构的竖向振动,并将得到的竖向振动响应作为边界条件,导入到箱梁边界元模型中预测箱梁结构噪声。同时基于面板声学贡献分析理论,进行了箱梁梁体的面板声压贡献分析和声功率贡献分析,确定箱梁梁体辐射噪声的最大部位。研究结果表明:列车以200 km/h 的速度运行在高架轨道上时,箱梁梁体辐射噪声主要集中0-100 Hz 范围内,其中在20 Hz 和42 Hz 左右有比较突出峰值。同时由面板声学贡献分析可知箱梁梁体主要辐射噪声的部位是箱梁的顶板和两侧翼缘板下面板。

  16. Improvements in Cold-Plate Fabrication

    Science.gov (United States)

    Zaffetti, Mark A.; Taddey, Edmund P.; Laurin, Michael B.; Chabebe, Natalia

    2012-01-01

    Five improvements are reported in cold-plate fabrication. This cold plate is part of a thermal control system designed to serve on space missions. The first improvement is the merging of the end sheets of the cold plate with the face sheets of the structural honeycomb panel. The cold plate, which can be a brazed assembly, uses the honeycomb face sheet as its end sheet. Thus, when the honeycomb panel is fabricated, the face sheet that is used is already part of the cold plate. In addition to reducing weight, costs, and steps, the main benefit of this invention is that it creates a more structurally sound assembly. The second improvement involves incorporation of the header into the closure bar to pass the fluid to a lower layer. Conventional designs have used a separate header, which increases the geometry of the system. The improvement reduces the geometry, thus allowing the cold plate to fit into smaller area. The third improvement eliminates the need of hose, tube, or manifold to supply the cooling fluid externally. The external arrangement can be easily damaged and is vulnerable to leakage. The new arrangement incorporates an internal fluid transfer tube. This allows the fluid to pass from one cold plate to the other without any exposed external features. The fourth improvement eliminates separate fabrication of cold plate(s) and structural members followed by a process of attaching them to each other. Here, the structural member is made of material that can be brazed just as that of the cold plate. Now the structural member and the cold plate can be brazed at the same time, creating a monolithic unit, and thus a more structurally sound assembly. Finally, the fifth improvement is the elimination of an additional welding step that can damage the braze joints. A tube section, which is usually welded on after the braze process, is replaced with a more structurally sound configuration that can be brazed at the same time as the rest of the cold plate.

  17. 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 .

  18. A modified feeding plate for a newborn with cleft palate.

    Science.gov (United States)

    Erkan, Mustafa; Karaçay, Seniz; Atay, Arzu; Günay, Yumuşhan

    2013-01-01

    Objectives : Cleft palate is a common congenital maxillofacial defect. We wish to present the fabrication of a modified feeding plate that will adapt to the changing palatal and velopharyngeal morphology during function. Case Report : A neonate with unilateral cleft lip and palate was referred to our clinic for the fabrication of a feeding plate. Intraoral examination revealed a cleft involving the uvula and the soft palate, with an alveolar defect on the left side. An impression was taken and a dental cast was obtained. A 1-mm Bioplast clear soft plate was pressed on the model. After trimming the edges of the plate, several retentive holes were made for its attachment to the hard plate. With the Bioplast soft plate replaced on the cast, plaster was used to cover parts of the soft plate that were not to come in contact with the hard plate. Biocryl resin was put on the retentive holes and 2-mm Biocryl C Rosa-transparent plate was pressed. The edges of the plate were cut, trimmed, and polished. Conclusion : This modified feeding plate effectively obstructed the soft palate defect. The adaptation of the flexible bulb of the appliance with the soft palate was excellent. Evaluation with nasoendoscopy revealed the synchronized movement of the bulb of the appliance with the soft palate during swallowing. Soft extension of the feeding plate eliminated the risk of irritation, and the baby accepted the appliance easily.

  19. Parameters Inversion on Bird Constitutive Model Part Ⅰ:Study on Experiment of Bird Striking on Plate%鸟体本构模型参数反演I:鸟撞平板试验研究

    Institute of Scientific and Technical Information of China (English)

    刘军; 李玉龙; 郭伟国; 石霄鹏; 彭刚; 叶彪

    2011-01-01

    为了结合数值模拟得到鸟撞过程中的鸟体本构模型参数,对鸟撞平板进行了试验研究.鸟体质量分别为1.8kg和3.6 kg,平板材料采用厚度为10 mm和14 mm的LYl2铝合金和厚度为4.5 mm和8.0 mm的45#钢,鸟体撞击速度为70、120、170 m/s,共进行了16组鸟撞试验.采用动态数据采集系统获得了鸟撞过程中平板的位移和应变及撞击支反力等物理量的时间历程数据,运用高速摄像系统记录了鸟撞平板动响应变形的全过程.试验结果表明:每组两次试验从撞击速度到试验结果重复性均很好;鸟撞作用时间为ms量级,属冲击动力学行为,且鸟体与平板之间存在强烈的耦合作用;平板变形较大,中心点最大位移是平板厚度的7.9倍;撞击速度越高,鸟体的流体特性越明显.%In order to obtain the mechanical parameters of the bird during the process of bird striking, numerical simulations and experiments of bird striking on plate are studied in the paper. The bird mass is 1.8 kg and 3. 6 kg respectively, and the plate is made by LY12 aluminium alloy with the thickness of 10 mm and 14 mm and 45# steel with the thickness of 4.5 mm and 8.0 mm. Sixteen groups of experiments are performed in the present paper with the bird velocity at 70,120,170 m/s,respectively. The histories of displacement-time and strain-time of plate as well as the force-time are measured by the dynamic data acquisition system, and the whole process of dynamic response during bird striking on plate is recorded by highspeed camera system. The results of the experiments indicate that the repeatability of the impacting velocities and the measured results for twice experiments in one group are very good. The reaction time of bird striking is millisecond, so its behavior belongs to impact dynamics; there exists strong coupling between the bird and the plate. The deformation of the plate is very big and the ratio of the plate displacement at the center point to the

  20. Influence of expander components on the processes at the negative plates of lead-acid cells on high-rate partial-state-of-charge cycling. Part II. Effect of carbon additives on the processes of charge and discharge of negative plates

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, D.; Nikolov, P.; Rogachev, T. [Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Street, bl. 10, Sofia 1113 (Bulgaria)

    2010-07-15

    Lead-acid batteries operated in the high-rate partial-state-of-charge (HRPSoC) duty rapidly lose capacity on cycling, because of sulfation of the negative plates. As the battery operates from a partially discharged state, the small PbSO{sub 4} crystals dissolve and precipitate onto the bigger crystals. The latter have low solubility and hence PbSO{sub 4} accumulates progressively in the negative plates causing capacity loss. In order to suppress this process, the rate of the charge process should be increased. In a previous publication of ours we have established that reduction of Pb{sup 2+} ions to Pb may proceed on the surface of both Pb and carbon black particles. Hence, the reversibility of the charge-discharge processes improves, which leads to improved cycle life performance of the batteries in the HRPSoC mode. However, not all carbon forms accelerate the charge processes. The present paper discusses the electrochemical properties of two groups of carbon blacks: Printex and active carbons. The influence of Vaniseprse A and BaSO{sub 4} (the other two components of the expander added to the negative plates) on the reversibility of the charge-discharge processes on the negative plates is also considered. It has been established that lignosulfonates are adsorbed onto the lead surface and retard charging of the battery. BaSO{sub 4} has the opposite effect, which improves the reversibility of the processes on cycling and hence prolongs battery life in the HRPSoC duty. It has been established that the cycle life of lead-acid cells depends on the type of carbon black or active carbon added to the negative plates. When the carbon particles are of nano-sizes (<180 nm), the HRPSoC cycle life is between 10,000 and 20,000 cycles. Lignosulfonates suppress this beneficial effect of carbon black and activated carbon additives to about 10,000 cycles. Cells with active carbons have the longest cycle life when they contain also BaSO{sub 4} but no lignosulfonate. A summary of

  1. Pixelated neutron image plates

    Science.gov (United States)

    Schlapp, M.; Conrad, H.; von Seggern, H.

    2004-09-01

    Neutron image plates (NIPs) have found widespread application as neutron detectors for single-crystal and powder diffraction, small-angle scattering and tomography. After neutron exposure, the image plate can be read out by scanning with a laser. Commercially available NIPs consist of a powder mixture of BaFBr : Eu2+ and Gd2O3 dispersed in a polymer matrix and supported by a flexible polymer sheet. Since BaFBr : Eu2+ is an excellent x-ray storage phosphor, these NIPs are particularly sensitive to ggr-radiation, which is always present as a background radiation in neutron experiments. In this work we present results on NIPs consisting of KCl : Eu2+ and LiF that were fabricated into ceramic image plates in which the alkali halides act as a self-supporting matrix without the necessity for using a polymeric binder. An advantage of this type of NIP is the significantly reduced ggr-sensitivity. However, the much lower neutron absorption cross section of LiF compared with Gd2O3 demands a thicker image plate for obtaining comparable neutron absorption. The greater thickness of the NIP inevitably leads to a loss in spatial resolution of the image plate. However, this reduction in resolution can be restricted by a novel image plate concept in which a ceramic structure with square cells (referred to as a 'honeycomb') is embedded in the NIP, resulting in a pixelated image plate. In such a NIP the read-out light is confined to the particular illuminated pixel, decoupling the spatial resolution from the optical properties of the image plate material and morphology. In this work, a comparison of experimentally determined and simulated spatial resolutions of pixelated and unstructured image plates for a fixed read-out laser intensity is presented, as well as simulations of the properties of these NIPs at higher laser powers.

  2. Plate removal following orthognathic surgery.

    Science.gov (United States)

    Little, Mhairi; Langford, Richard Julian; Bhanji, Adam; Farr, David

    2015-11-01

    The objectives of this study are to determine the removal rates of orthognathic plates used during orthognathic surgery at James Cook University Hospital and describe the reasons for plate removal. 202 consecutive orthognathic cases were identified between July 2004 and July 2012. Demographics and procedure details were collected for these patients. Patients from this group who returned to theatre for plate removal between July 2004 and November 2012 were identified and their notes were analysed for data including reason for plate removal, age, smoking status, sex and time to plate removal. 3.2% of plates were removed with proportionally more plates removed from the mandible than the maxilla. 10.4% of patients required removal of one or more plate. Most plates were removed within the first post-operative year. The commonest reasons for plate removal were plate exposure and infection. The plate removal rates in our study are comparable to those seen in the literature.

  3. Anisotropic elastic plates

    CERN Document Server

    Hwu, Chyanbin

    2010-01-01

    As structural elements, anisotropic elastic plates find wide applications in modern technology. The plates here are considered to be subjected to not only in plane load but also transverse load. In other words, both plane and plate bending problems as well as the stretching-bending coupling problems are all explained in this book. In addition to the introduction of the theory of anisotropic elasticity, several important subjects have are discussed in this book such as interfaces, cracks, holes, inclusions, contact problems, piezoelectric materials, thermoelastic problems and boundary element a

  4. Plating in Top Agar

    OpenAIRE

    sprotocols

    2014-01-01

    1. Warm plates to room temperature before use. Cold plates causes the top agar to solidify irregularly. DO not warm plates to 37° as the top agar will take forever to solidify. - Prepare top agar as the appropriate liquid medium with 0.7% agar. Keeping 100 mL bottles is convenient. For phages, use λ top agar, which is less rich and yields bigger plaques. - Melt top agar in the microwave completely. Allow the agar to boil after liquification; incompletely melted agar looks liquid, but is...

  5. Influence of expander components on the processes at the negative plates of lead-acid cells on high-rate partial-state-of-charge cycling. Part I: Effect of lignosulfonates and BaSO{sub 4} on the processes of charge and discharge of negative plates

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, D.; Nikolov, P.; Rogachev, T. [Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Street, bl. 10, Sofia 1113 (Bulgaria)

    2010-07-15

    This study investigates the influence of the organic expander component (Vanisperse A) and of BaSO{sub 4} on the performance of negative lead-acid battery plates on high-rate partial-state-of-charge (HRPSoC) cycling. Batteries operating in the HRPSoC mode should be classified as a separate type of lead-acid batteries. Hence, the additives to the negative plates should differ from the conventional expander composition. It has been established that lignosulfonates are adsorbed onto the lead surface and thus impede the charge processes, which results in impaired reversibility of the charge-discharge processes and hence shorter cycle life on HRPSoC operation, limited by sulfation of the negative plates. BaSO{sub 4} exerts the opposite effect: it improves the reversibility of the processes in the HRPSoC mode and hence prolongs the cycle life of the cells. The most pronounced effect of BaSO{sub 4} has been registered when it is added in concentration of 1.0 wt.% versus the leady oxide (LO) used for paste preparation. It has also been established that BaSO{sub 4} lowers the overpotential of PbSO{sub 4} nucleation. The results of the present investigation indicate that BaSO{sub 4} affects also the crystallization process of Pb during cell charging. Thus, BaSO{sub 4} eventually improves the performance characteristics of lead-acid cells on HRPSoC cycling. (author)

  6. 合蚌客专350km/h单线试验箱梁工艺试验研究%Study on Process Test for Box Girder of Hefei-Bengbu Dedicated Passenger Railway 350 km/h Single-Track Line

    Institute of Scientific and Technical Information of China (English)

    郭晓明

    2012-01-01

    时速350公里客运专线单线后张法单箱单室预应力混凝土简支箱梁属首次应用。为验证其各项指标,进行了4孔箱梁的试验工作;通过对箱梁的各项工艺试验进行研究,充分验证箱梁的设计。%The post-tensioning method single-cell pre-stressed concrete simple box girder for 350 km/h dedicated passenger railway single-track line is used for the first time.To verify its performance indexes,four-truss box girder test is carried out,studies on box girder process tests fully verify the design of box girder.

  7. 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

  8. 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。

  9. 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.

  10. Design of Norway HAKRDANGER Steel Box Girder Bridge Coating Process%挪威HAKRDANGER大桥钢箱梁涂装工艺设计

    Institute of Scientific and Technical Information of China (English)

    李连缀; 李敏风

    2011-01-01

    The anti-corrosion matching scheme and performance of the Norwegian HAKRDANGER bridge steel box girder inside and outside were introduced. The design of coating process including surface treatment, arc spraying zinc process, spray construction process equipment and related technical parameters requirements were introduced in detail.%介绍了挪威HAKRDANGER大桥钢箱梁内外侧防腐配套方案及性能。着重介绍了涂装工艺设计,包括表面处理、电弧喷锌工艺、喷漆施工等工艺设备及相关技术参数要求等。

  11. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... but changes the portion sizes so you are getting larger portions of non-starchy vegetables and a ...

  12. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... 4/Box) Taking the guesswork out of portion control has never been easier. It can be a ...

  13. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  14. MyPlate

    Science.gov (United States)

    ... our stage of life, situations, preferences, access to food, culture, traditions, and the personal decisions we make over time. All your food and beverage choices count. MyPlate offers ideas and ...

  15. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: September ...

  16. Designing Assemblies Of Plates

    Science.gov (United States)

    Williams, F. W.; Kennedy, D.; Butler, R.; Aston, G.; Anderson, M. S.

    1992-01-01

    VICONOPT calculates vibrations and instabilities of assemblies of prismatic plates. Designed for efficient, accurate analysis of buckling and vibration, and for optimum design of panels of composite materials. Written in FORTRAN 77.

  17. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning What Can I Eat? Making Healthy Food Choices Diabetes Superfoods Non-starchy Vegetables Grains and Starchy Vegetables ...

  18. Create Your Plate

    Medline Plus

    Full Text Available ... Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning ... serving of dairy or both as your meal plan allows. Choose healthy fats in small amounts. For ...

  19. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Diabetes Get Started Safely Get And Stay Fit Types of Activity Weight Loss Assess Your Lifestyle ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  20. Create Your Plate

    Medline Plus

    Full Text Available ... Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... been easier. It can be a challenge to manage portion control wherever you are. Now, our best- ...

  1. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  2. Create Your Plate

    Medline Plus

    Full Text Available ... Carbohydrates Carbohydrate Counting Make Your Carbs Count Glycemic ... to manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  3. Origami - Folded Plate Structures

    OpenAIRE

    Buri, Hans Ulrich

    2010-01-01

    This research investigates new methods of designing folded plate structures that can be built with cross-laminated timber panels. Folded plate structures are attractive to both architects and engineers for their structural, spatial, and plastic qualities. Thin surfaces can be stiffened by a series of folds, and thus not only cover space, but also act as load bearing elements. The variation of light and shadow along the folded faces emphasizes the plas...

  4. Fractal multifiber microchannel plates

    Science.gov (United States)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

  5. 客货共线1-156m简支钢桁结构分析%Structural analysis of 156 m simply supported steel truss girder

    Institute of Scientific and Technical Information of China (English)

    郝云杉

    2012-01-01

    The simply supported steel truss girder is widely used in railway bridge, because of definite stress, lower structural height, light weight and short construction period. Huanglin Hancheng Houma railway 156 m simply supported steel truss girder is the most span length in China. The bridge uses the triangle web member system without vertical members, which main truss members are box sections, the web members are box sections and H-shape sections. In the plane of the upper chords, the crisscross top lateral bracings are arranged which use I-shape sections. MIDAS Civil 2010 is use to establish the three-dimensional finite element model, calculate internal forces of main truss elements, stress, fatigue stress range and natural vibration period.%简支钢桁梁桥因其受力明确、结构高度低、自重轻以及施工周期短等优点,在铁路桥梁中得到了越来越广泛的采用.黄韩侯铁路单线l-156m栓焊下承式简支钢桁梁是目前国内最大跨度的简支钢桁梁结构.该桥主桁采用无竖杆的三角形腹杆体系,主桁弦杆均采用箱形截面;腹杆采用箱形截面和H形截面;上、下均采用交叉式平纵联,采用工字型截面.采用MIDAS Civil 2010建立该桥三维有限元模型,计算其主桁杆件内力、应力、疲劳应力幅,及全桥自振周期.

  6. Petroleum and natural gas geology and plate tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Koebel, B.

    1984-01-01

    Several processes of oil and gas geology are studied in connection with plate-tectonical processes. Thus it becomes clear, that there is a distinct difference between the Paleozoic development of the European plate and the Mesozoic development. One can state, that the Paleozoic development is essentially influenced by the positions of the mobile belts and the cratonized parts of the plates. The development during Meso-Caenozoic is mainly characterized by crustal processes in the result of the disintegration of Pangaea.

  7. Key Technology of the Fabrication and Erection of Steel-concrete Composite Girder on Integral Span of Hong Kong-Zhuhai-Macao Bridge%港珠澳大桥钢-混组合梁制造及安装关键技术

    Institute of Scientific and Technical Information of China (English)

    王艳峰; 潘军

    2015-01-01

    港珠澳大桥浅水区非通航孔桥上部结构采用钢-混组合连续梁。文中主要从桥面板预制、钢主梁整孔制造、钢主梁桥面板组合、组合梁整孔运架,以及组合梁体系转换技术方面阐述了组合梁整孔制造整孔架设技术,体现了大型构件海上施工的“大型化、标准化、工厂化、装配化”理念。%The non-navigable bridge in the shallow water area of the Hong Kong-Zhuhai-Macao Bridge is made of steel-concrete composite structure in the form of continuous box girder structure.This arti-cle expounded the technology of integral fabrication and erection on box girder from fabrication of the precast concrete bridge deck,fabrication of integral span on box girder,combined with steel box gird-er and bridge deck,transport and erection on composite girder,stress system transformation on com-posite girder.It shows the advanced construction concept which is″large-scale,industrialized,stand-ardized and assembled″ in the marine construction.

  8. Bending and stretching of plates

    CERN Document Server

    Mansfield, E H; Hemp, W S

    1964-01-01

    The Bending and Stretching of Plates deals with elastic plate theory, particularly on small- and large-deflexion theory. Small-deflexion theory concerns derivation of basic equations, rectangular plates, plates of various shapes, plates whose boundaries are amenable to conformal transformation, plates with variable rigidity, and approximate methods. Large-deflexion theory includes general equations and some exact solutions, approximate methods in large-deflexion theory, asymptotic large-deflexion theories for very thin plates. Asymptotic theories covers membrane theory, tension field theory, a

  9. 覆膜竹胶模板在现浇箱梁施工中的应用%Application of Coated Bamboo Rubber Template in Situ Box Girder Construction

    Institute of Scientific and Technical Information of China (English)

    王培国

    2012-01-01

    The materials of coated bamboo rubber template is light, its processing and demolition is convenient, and it is easy to operate. So it is widely used in the external and internal model construction of situ box girder. This paper, combined with the actual situ box girder construction, discussed characteristics, scope, process, operation points of coated bamboo rubber template in more detail, for the reference in construction.%覆膜竹肢模板具有材质轻、加工及安拆方便、操作简便特点,广泛用于现浇箱梁外、内模施工,本文结合现浇箱粱施工实际,对覆膜竹胶模板的特点、适用范围、工艺流程、操作要点进行了较为详细的论述,以供施工参考.

  10. 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

  11. 大跨径梁桥长期挠度的控制技术研究%Control Technology of Long-term Deflection for Long-span Girder Bridge

    Institute of Scientific and Technical Information of China (English)

    黄新哲

    2011-01-01

    This paper analyzed the development of large-span girder bridge, based on the problems of long-term deflection in large-span girder bridge, put forward the causes of long-term deflection and control measures by an example of a bridge, to provide reference for the relevant project officers.%文章就大跨梁桥发展概况进行了剖析,针对大跨梁桥长期挠度的问题现象,以某大桥为例提出了长期挠度成因及控制措施新途径,以供相关工程人员参考.

  12. Design of Composite Girder with Non-standard Span on Harbin-Dalian Passenger Dedicated Line%哈大铁路客运专线变跨结合梁设计

    Institute of Scientific and Technical Information of China (English)

    孙宗磊

    2012-01-01

    结合哈大客运专线沈大段桥梁非标准跨度的特点,从适用、景观、施工控制等方面介绍哈大客运专线变跨结合梁的设计过程,对结合梁外形选择、结构断面选择、施工方案以及计算方法进行了详细介绍.%In view of the characteristics of the bridge with non-standard span on Shenyang-Dalian section of Harbin-Dalian Passenger Dedicated Line, this paper introduces the design process of the composite girder with non-standard span on Harbin - Dalian Passenger Dedicated Line in terms of applicability,landscape and construction control, and explains in detail the selection of girder profile, structural cross-section, construction scheme and calculation method.

  13. Anterior cervical plating

    Directory of Open Access Journals (Sweden)

    Gonugunta V

    2005-01-01

    Full Text Available Although anterior cervical instrumentation was initially used in cervical trauma, because of obvious benefits, indications for its use have been expanded over time to degenerative cases as well as tumor and infection of the cervical spine. Along with a threefold increase in incidence of cervical fusion surgery, implant designs have evolved over the last three decades. Observation of graft subsidence and phenomenon of stress shielding led to the development of the new generation dynamic anterior cervical plating systems. Anterior cervical plating does not conclusively improve clinical outcome of the patients, but certainly enhances the efficacy of autograft and allograft fusion and lessens the rate of pseudoarthrosis and kyphosis after multilevel discectomy and fusions. A review of biomechanics, surgical technique, indications, complications and results of various anterior cervical plating systems is presented here to enable clinicians to select the appropriate construct design.

  14. High-frequency techniques for RCS prediction of plate geometries and a physical optics/equivalent currents model for the RCS of trihedral corner reflectors, parts 1 and 2

    Science.gov (United States)

    Balanis, Constantine A.; Polka, Lesley A.; Polycarpou, Anastasis C.

    Formulations for scattering from the coated plate and the coated dihedral corner reflector are included. A coated plate model based upon the Uniform Theory of Diffraction (UTD) for impedance wedges was presented in the last report. In order to resolve inaccuracies and discontinuities in the predicted patterns using the UTD-based model, an improved model that uses more accurate diffraction coefficients is presented. A Physical Optics (PO) model for the coated dihedral corner reflector is presented as an intermediary step in developing a high-frequency model for this structure. The PO model is based upon the reflection coefficients for a metal-backed lossy material. Preliminary PO results for the dihedral corner reflector suggest that, in addition to being much faster computationally, this model may be more accurate than existing moment method (MM) models. An improved Physical Optics (PO)/Equivalent Currents model for modeling the Radar Cross Section (RCS) of both square and triangular, perfectly conducting, trihedral corner reflectors is presented. The new model uses the PO approximation at each reflection for the first- and second-order reflection terms. For the third-order reflection terms, a Geometrical Optics (GO) approximation is used for the first reflection; and PO approximations are used for the remaining reflections. The previously reported model used GO for all reflections except the terminating reflection. Using PO for most of the reflections results in a computationally slower model because many integrations must be performed numerically, but the advantage is that the predicted RCS using the new model is much more accurate. Comparisons between the two PO models, Finite-Difference Time-Domain (FDTD) and experimental data are presented for validation of the new model.

  15. License plate detection algorithm

    Science.gov (United States)

    Broitman, Michael; Klopovsky, Yuri; Silinskis, Normunds

    2013-12-01

    A novel algorithm for vehicle license plates localization is proposed. The algorithm is based on pixel intensity transition gradient analysis. Near to 2500 natural-scene gray-level vehicle images of different backgrounds and ambient illumination was tested. The best set of algorithm's parameters produces detection rate up to 0.94. Taking into account abnormal camera location during our tests and therefore geometrical distortion and troubles from trees this result could be considered as passable. Correlation between source data, such as license Plate dimensions and texture, cameras location and others, and parameters of algorithm were also defined.

  16. Casimir force between metal plate and dielectric plate

    Institute of Scientific and Technical Information of China (English)

    刘中柱; 邵成刚; 罗俊

    1999-01-01

    The Casimir effect between metal plate and dielectric plate is discussed with 1+1-dimensional potential model without using cut-off method. Calculation shows that the Casimir force between metal plate and dielectric plate is determined not only by the potential V0, the dielectric thickness and the distance α between the metal plate and dielectric plate, but also by the dimension of the vessel. When α is far less than the dimension of the vessel, the Casimir force Fc∝α(-1); conversely Fc∝α-2. This result is significant for Casimir force experiment.

  17. On slope consolidation effect with combination of anti-sliding pile and lattice girder%抗滑桩--格构梁联合加固边坡效果分析

    Institute of Scientific and Technical Information of China (English)

    赵志强; 姚成

    2012-01-01

    According to the application of the combined support structure with the anti-sliding pile and lattice girder in the slope treatment, the paper points out the idea of considering the deformation coordination of the anchor cable, the anti-sliding pile and the lattice girder, adopts the finite element software., ABAQUS to undertake the simulation, and concludes the deformation coordination design methods with the anti-sliding pile, the lattice girder and the anchor cable can enhance the slope consolidation effect after the comparative analysis of the results.%针对边坡治理中应用的支护结构——抗滑桩与格构梁联合支护,在设计方法上提出了考虑锚索、抗滑桩、格构梁三者变形协调的思想;利用有限元软件ABAQUS模拟,通过计算结果对比分析,得到了考虑抗滑桩、格构梁以及桩上锚索三者变形协调的设计方法更有利于边坡加固效果的结论。

  18. 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.

  19. Manufacture Process of Steel Box Girder for RP Gantry in Some Nuclear Power Station%某核电站RP龙门架箱形钢结构梁制作工艺

    Institute of Scientific and Technical Information of China (English)

    展之芳

    2014-01-01

    In steel structure project, fabrication process of steel box girder is complex, so it is difficult to control welding deformation. This paper introduced the fabrication process of steel box girder for RP gantry in nuclear power station from the material, assembly, welding and correction. The fabrication process ensures the overall geometry of box girder, and guarantees the effective control of welding deformation and welding quality, achieves a certain economic benefits.%钢结构工程中,箱形钢梁制作工艺复杂,焊接变形控制困难。通过从下料、组装、焊接、矫正等方面详细介绍了核电站RP龙门架箱形钢结构梁的制作工艺过程,该过程保证了箱形钢梁的整体几何尺寸,同时又保证了焊接质量并有效控制了焊接变形,取得了一定经济效益。

  20. Construction technology of steel structure shelter with elevated platform arc variable-section box girder%高架站弧形变截面箱梁钢结构雨篷施工技术

    Institute of Scientific and Technical Information of China (English)

    王志峰

    2015-01-01

    Combining with urban rail transit steel structure shelter with variable section box girder as an example,the paper studies construction quality control and limited hoisting construction of steel structure shelter with elevated platform arc variable-section box girder,and solves difficul-ties occurring in quality control and field limitation hoisting process of variable section box girder installation,which has accumulated experience for similar engineering.%结合某市城市轨道交通变截面箱梁钢结构雨篷施工实例,对高架站变截面箱梁钢结构雨篷制作质量控制及场地受限吊装施工展开了技术研究,解决了变截面箱形梁制作安装过程中质量控制及场地受限时吊装过程中的难题,为其他类似工程积累了经验。

  1. Design and Analysis of Simple Supported Box Girder on Ballastless Single Track of High Speed Railway%高速铁路无砟轨道单线简支箱梁结构设计与分析

    Institute of Scientific and Technical Information of China (English)

    杨鹏健

    2015-01-01

    结合350km/h高速铁路常用跨度无砟轨道单线简支箱梁通用参考图设计,介绍该箱梁在梁高、桥面宽度、二期恒载、支座横向中心距、梁端构造等方面的受力分析以及从景观性、经济性方面阐述腹板斜率、外轮廓圆弧倒角等细部构造,并通过计算分析选定合理值。%Based on the General Reference Drawing for Simple Supported Box Girder with Common Span on Balastless Single Track for 350 km/h High Speed Railways, this paper focuses on the analysis of stresses with respect to girder height, bridge deck width, secondary dead load, transverse center distance of bearing, girder end structure, and web slope and arc chamfering of outer contour and other micro structures are illustrated in terms of outlook and economy. Furthermore, reasonable values for these parameters are determined through calculation.

  2. 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.

  3. Computational modelling of long bone fractures fixed with locking plates - How can the risk of implant failure be reduced?

    LENUS (Irish Health Repository)

    Nassiri, M

    2013-03-01

    The Locking Compression Plate (LCP) is part of a new plate generation requiring an adapted surgical technique and new thinking about commonly used concepts of internal fixation using plates. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability and the risk of implant failure can best be controlled.

  4. Nuclear reactor alignment plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  5. Wave Damping over a Perforated Plate with Water Chambers

    Institute of Scientific and Technical Information of China (English)

    ZHU Shutang

    2006-01-01

    The movement of waves propagating over a horizontally submerged perforated plate with waterfilled chambers bellow the plate was investigated by using linear potential theory. The analytical solution was compared with laboratory experiments on wave blocking. The analysis of the wave energy dissipation on the perforated bottom surface shows that the effects of the perforated plate on thewave motion depend mainly on the plate porosity, the wave height, and the wave period. The wave number is a complex number when the wave energy dissipation on the perforated plate is considered. The real part of the wave number refers to the spatial periodicity while the imaginary part represents the damping modulus. The characteristics of the wave motion were explored for several possible conditions.

  6. Smaller plates, less food waste

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg; Schmidt, Karsten; Skov, Laurits Rhoden

    With roughly one-third of food produced for human consumption lost or wasted globally (about 1.3 billion tons per year), the impact on the environment cannot be anymore neglected. Actions at all points in the production chain are now urgent, including reductions in food waste at home, by retailer...... the hypothesis that dishware size plays an important role in the amount of food wasted among Danish adults in a self-service eating setting. This finding has PHN implications: slight changes in the foodscape can contribute to sustainable food consumption goals....... was to investigate whether the size of the dishware would non-reflectively influence the amount of foods taken from an “ad-libitum” buffet and the resulting amount of waste. Sample consisted of Danish business leaders that took part in a congress in Copenhagen, Denmark. Two buffet tables were set up on two separate....... All food waste was collected in designated trash bags (different colour in each floor) and weighted in bulk by students. Smaller plates appear to have decreased food waste by 26% compared to the standard sized plates at a single serving in a self-service eating setting. This pilot study supports...

  7. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are ... Fitness Home Food MyFoodAdvisor Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten ...

  8. Create Your Plate

    Medline Plus

    Full Text Available ... Create Your Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... year of delicious meals to help prevent and manage diabetes. Healthy Recipes: ... to your day with this guide. Ways to Give: Wear Your Cause on Your Sleeve - ...

  9. Create Your Plate

    Medline Plus

    Full Text Available ... tax-deductible gift today can fund critical diabetes research and support vital diabetes education services that improve the ... way to manage your blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ...

  10. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are ... Fitness Home Food MyFoodAdvisor Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten ...

  11. Create Your Plate

    Medline Plus

    Full Text Available ... tax-deductible gift today can fund critical diabetes research and support vital diabetes education services that improve the ... way to manage your blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ...

  12. Create Your Plate

    Medline Plus

    Full Text Available ... unsweetened tea or coffee. Featured Product Precise Portions® Go Healthy Travel Pack (4/Box) Taking the guesswork ... you are. Now, our best-selling, sectioned to-go plate with easy-sealing lid is offered in ...

  13. Create Your Plate

    Medline Plus

    Full Text Available ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing lid is offered in a 4-pack. Whether ... Research & Practice We Are Research Leaders We Support Your Doctor ...

  14. INL HIP Plate Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  15. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals > Create Your Plate Share: Print Page Text Size: A A A Listen En Español Create ... somewhere in between, you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: ... Cost of Diabetes Advocate Toolkit Call to Congress Research & ...

  16. [Flow of molten metal in denture base in horizontal centrifugal casting procedure. (Part 2) Flow, inflow volume and casting time of molten metal passing through several sprues into model denture plate mold (author's transl)].

    Science.gov (United States)

    Okamura, H

    1978-10-01

    Two types of spruing methods were used in the casting of the denture type model pattern (thickness, 0.43 mm). Flow of molten metal in the mold was filmed by the improved system of Part 1. When three sprues were attached to the pattern vertically, molten metal passed through each sprue gate flowed being affected by the direction of gravity and revolution of casting machine, and gathered at the lower part of the mold. Next molten metal filled the mold from the lower part to the upper part. In this spruing type, molten metal turned its direction of flow several times. At the middle stage of casting, the inflow volume per unit time (inflow rate), v (mm3/10-2)s)was evaluated as v = 12.36 + 5.16A-0.16 A2 (A: total cross-sectional areas of sprues). The inflow rate increased with increase of the area of the sprues, but it saturated. When the main sprue and the subsprues were attached at the posterior border, the molten metal filled the mold from the lower part to the upper part quietly. In this spruing type, the casting mold was set facing its sprue gates downwards. The inflow rate at the middle stage of casting was evaluated as v = 21.05 + 1.79 C (C: the cross-sectional area of the main sprue). The inflow rate increased linearly with increase of the area of the main sprue.

  17. 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

  18. Investigating the impact of non-linear geometrical effects on wind turbine blades—Part 1: Current status of design and test methods and future challenges in design optimization

    DEFF Research Database (Denmark)

    Jensen, Find Mølholt; Puri, Amit S.; Dear, John P.

    2011-01-01

    This article is the first part of a three-article series and it deals with full-scale tests of a load-carrying box girder. The two other articles present more details on smaller sub-component levels as well as cap specimens (article 2) and shear webs (article 3). This article also links to the two...... may also have a significant impact on present wind turbine blades. In this article, a 34 m long load-carrying box girder has been tested in static flap-wise bending, and it has been demonstrated that, for this design, the Brazier effect is a critical phenomenon of great relevance for the ultimate...

  19. 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.

  20. Composition of the continental plates

    Science.gov (United States)

    Gilluly, J.

    1954-01-01

    The structures of continental plates and of oceanic basins suggested by several seismologists are utilized to estimate the relative volumes of sial and sima in the earth's crust. It seems that sial of the composition of the average igneous rock constitutes fully 26% and perhaps as much as 43% of the total crust. This ratio is far higher than seems likely if the sial had been entirely derived through fractional crystallization of a basaltic magma. The relative paucity of intermediate rocks as compared with granite and gabbro in the crust points in the same direction. The tentative conclusion is reached that the sial owes a large part of its volume to some process other than fractional crystallization of basalt-possibly to the emanation of low-melting constituents such as water, silica, potassa, soda, and alumina directly from the mantle to the crust. ?? 1954 Springer-Verlag.

  1. 大跨结构箱形曲梁的平面内整体稳定性能分析%Analysis of In-plane Stability Performance of Large Span Steel Structure Curved Box-girders

    Institute of Scientific and Technical Information of China (English)

    王元清; 刘莉媛; 丁大益; 石永久; 完海鹰

    2012-01-01

    In order to study the in-plane stability performance of the arc axis both ends hinged curved box-girders, numerical method theory was carried out using finite element software ABAQUS. Two-dimensional curved girder models were established to simulate the in-plane stability of curved box-girders. Influences of different central angles, different slenderness ratio, and different initial geometric imperfections on the in-plane stability performances of the curved box-girder were considered. The differences and laws of the numerical solution and classic theoretical solution of the elastic buckling factor were gained. Effects on the stability factor and regularization slenderness ratio of the initial geometric imperfections were given, and the form of axial load-moment curve was calculated as well. The design formulae for calculating the in-plane stability of arc axis curved box-girders can provide theoretical basis and suggestions for the future design.%为研究两端铰接圆弧轴线箱形截面曲梁的平面内整体稳定性能,采用数值方法对其进行了理论研究,采用ABAQUS有限元软件建立了二维的曲梁模型,模拟曲梁的平面内稳定问题.研究了不同圆心角、不同长细比,以及不同大小的初始几何缺陷对圆弧轴线箱形截面曲梁平面内稳定性能的影响,得到了弹性屈曲系数的数值解与经典理论解的差异和规律,给出了初始几何缺陷对稳定系数和正则化长细比关系曲线的影响,并且计算得到了该形式曲梁的轴力-弯矩关系曲线.提出的圆弧轴线箱形截面曲梁平面内稳定的设计公式可为今后的设计提供理论依据和建议.

  2. LOWLID FORMATION AND PLATE TECTONICS ON EXOPLANETS

    Science.gov (United States)

    Stamenkovic, V.; Noack, L.; Breuer, D.

    2009-12-01

    The last years of astronomical observation have opened the doors to a universe filled with extrasolar planets. Detection techniques still only offer the possibility to detect mainly Super-Earths above five Earth masses. But detection techniques do steadily improve and are offering the possibility to detect even smaller planets. The observations show that planets seem to exist in many possible sizes just as the planets and moons of our own solar system do. It is only a natural question to ask if planetary mass has an influence on some key habitability factors such as on plate tectonics, allowing us to test which exoplanets might be more likely habitable than others, and allowing us to understand if plate tectonics on Earth is a stable or a critical, instable process that could easily be perturbed. Here we present results derived from 1D parameterized thermal evolution and 2D/3D computer models, showing how planetary mass influences the propensity of plate tectonics for planets with masses ranging from 0.1 to 10 Earth masses. Lately [2, 3] studied the effect of planetary mass on the ability to break plates and hence initiate plate tectonics - but both derived results contradictory to the other. We think that one of the reasons why both studies [2, 3] are not acceptable in their current form is partly due to an oversimplification. Both treated viscosity only temperature-dependent but neglected the effect pressure has on enlarging the viscosity in the deep mantle. More massive planets have therefore a stronger pressure-viscosity-coupling making convection at high pressures sluggish or even impossible. For planets larger than two Earth masses we observe that a conductive lid (termed low-lid) forms above the core-mantle boundary and thus reduces the effective convective part of the mantle when including a pressure-dependent term into the viscosity laws as shown in [1]. Moreover [2, 3] use time independent steady state models neglecting the fact that plate tectonics is a

  3. MyPlate Food Guide

    Science.gov (United States)

    ... Choosing the Right Sport for You Shyness MyPlate Food Guide KidsHealth > For Teens > MyPlate Food Guide Print ... other sugary drinks. Avoid oversized portions. continue Five Food Groups Different food groups meet different nutrition needs. ...

  4. What Are Growth Plate Injuries?

    Science.gov (United States)

    ... plate injuries are:  Falling down  Competitive sports (like football)  Recreational activities. Other reasons for growth plate injuries are:  Child abuse  Injury from extreme cold (for ...

  5. Experimental Study on Structure-Borne Noise of Railway 32 m Simply-Supported Concrete Box-Girder%铁路32 m混凝土简支箱梁结构噪声试验研究

    Institute of Scientific and Technical Information of China (English)

    李小珍; 张迅; 刘全民; 张志俊; 李亚东

    2013-01-01

    以32 m单线和双线单室混凝土简支箱梁为对象,通过噪声试验、结构有限元和声学有限元分析,研究箱梁结构噪声的声辐射特性、峰值频率产生的原因及评价方法.结果表明:列车通过桥梁时,离箱梁表面较远处的噪声级起伏不大,可采用稳态算法简化分析;混凝土箱梁的结构噪声主要分布在250 Hz以下,且随频率的增加而迅速衰减,因此理论预测时可将250 Hz作为截止频率;单线和双线箱梁的2个噪声峰值频率分别为63和160 Hz,以及50和315 Hz,二者均在第1个峰值频率处达到最大声压级,且此峰值频率处的噪声具有明显的有调性;不同箱室尺寸箱梁的结构噪声声辐射差异较大,车速并不是噪声的第一决定因素;混凝土箱梁结构噪声的峰值频率出现在声辐射效率和振动响应均较大处,因此应避免结构振动模态和空腔声学模态重合而导致空腔共鸣引起的噪声被放大;建议修订铁路噪声相关规范时,考虑混凝土箱梁低频结构噪声的危害.%Based on the study objects of single-and double-track simply-supported concrete box-girders with only one cell and a span of 32 m,this paper investigated the sound radiation characteristics of structure-borne noise,reasons leading to peak frequency and evaluation methods by field measurements,structural and acoustical finite element analysis.The results show that:during a train runs across bridge,the noise far away from the box-girder surface fluctuates slightly,which means that simplified steady-state acoustic analysis is feasible; structure-borne noise from concrete box-girder dominates in the frequency lower than 250 Hz and decreases rapidly with increasing frequency,accordingly,250 Hz can be regarded as the upper limiting frequency for theoretical prediction; the two frequencies of peak noise of single-and doubletrack box-girder are 63 and 160 Hz,as well as 50 and 315 Hz,respectively,and the noise reaches

  6. Controlling Laminate Plate Elastic Behavior

    OpenAIRE

    Mareš, T.

    2004-01-01

    This paper aims to express the relation of a measure of laminate plate stiffness with respect to the fiber orientation of its plies. The inverse of the scalar product of the lateral displacement of the central plane and lateral loading of the plate is the measure of laminate plate stiffness. In the case of a simply supported rectangular laminate plate this measure of stiffness is maximized, and the optimum orientation of its plies is searched.

  7. High-frequency seismic radiation during Maule earthquake (Chile, 27/02/2010, Mw 8.8) inferred by backprojection of P waves: evidence of activation of two distinct zones at the downdip part of the plate interface

    Science.gov (United States)

    Palo, M.; Tilmann, F. J.; Krueger, F.; Ehlert, L.; Lange, D.; Rietbrock, A.; Jenkins, J.; Hicks, S. P.

    2013-12-01

    zones of the subduction interface at different depths, the deeper of which is characterised by a large number of repeating event clusters (Rietbrock, Jenkins et al., this session). Thus, our backprojection analysis in combination with the aftershock distribution demonstrates the existence of a peculiar doubled downdip transition from seismogenic behaviour to stable sliding. We suspect fluids released from the downgoing plate to be the cause of the transitions in frictional behaviour because of (1) the co-location of high Vp/Vs ratios with the deep interface seismicity, (2) systematic decrease of depth of onset of deeper seismicity with younging incoming plate age, (3) patchy occurrence along-strike of deeper seismicity.

  8. Microchannel plate streak camera

    Science.gov (United States)

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  9. Electronic Equipment Cold Plates

    Science.gov (United States)

    1976-04-01

    equations for such a flow regiae. For laainar flow and Moderate teaperature differwwe« between the well «nd coolant, a aodifled Sieder -Tate...con- figuration. The heat-transfer coefficients, therefore, were determined by using both the Sieder -Tate and McAdams equations and the coaputed...values used In the analytical predictions. As with th* previous cold Plates, the Sieder -Tate equation gave too low of values for the heat- transfer

  10. Elastic plate spallation

    Science.gov (United States)

    Oline, L.; Medaglia, J.

    1972-01-01

    The dynamic finite element method was used to investigate elastic stress waves in a plate. Strain displacement and stress strain relations are discussed along with the stiffness and mass matrix. The results of studying point load, and distributed load over small, intermediate, and large radii are reported. The derivation of finite element matrices, and the derivation of lumped and consistent matrices for one dimensional problems with Laplace transfer solutions are included. The computer program JMMSPALL is also included.

  11. Plate Tearing by a Cone

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1997-01-01

    The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisaton of the damage, which...

  12. Plate Tearing by a Cone

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisation of the damage, which...

  13. Highly adhesive metal plating on Zylon fiber via iodine pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Fatema, Ummul Khair [Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567 (Japan); Gotoh, Yasuo, E-mail: ygotohy@shinshu-u.ac.jp [Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567 (Japan)

    2011-11-01

    Highly adhesive metal plating was performed on poly(p-phenylene-2,6-benzobisoxazole) fiber named Zylon via iodine pretreatment followed by electroless plating. First, iodine components were selectively doped into the inner part of the fiber near the surface through iodine vapor exposure. The doped iodine was converted to palladium iodide particles by treating with palladium chloride solution. After the reduction of the iodide to metal palladium particles, electroless copper plating was conducted on the fiber. A uniform copper layer was deposited on the fiber surface and exhibited high durability in durability tests such as ultrasonic exposure, tape peeling-off, and corrosion in NaCl solution. This durability was attributed to the palladium particles formed at the fiber surface that served as an anchor for the plated layer as well as an electroless plating catalyst. The plated fibers also possessed electrical conductivity. Although the tensile strength of the Zylon fiber decreased from 5.8 to 4.9 GPa after undergoing the pretreatment and plating processes, the light shielding effect improved the light resistance of the plated fibers in terms of tensile properties. After 18 days of xenon lamp exposure, the plated fibers retained 74% of its initial strength, whereas that of untreated fibers decreased to 43%.

  14. Finite Element Analysis of Reinforced Concrete Plate Impacted by Block

    Institute of Scientific and Technical Information of China (English)

    LUO Xiaoyang; Pascal PERROTIN; YAN Quansheng

    2006-01-01

    A new concept of structurally dissipating rock-shed (SDR) was developed by the lab of Tonello IC and LOCIE-ESIGEC (France).To decide the dimension of the plate used in SDR,an ANSYS model which could simulate the impact of rock in the centre of the plate was established by Fabien Delhomme.By using this model,some finite element analyses are carried out in the present paper Firstly,a plate impacted by a block is numerically simulated,the numerical results obtained from different mesh sizes are compared and the accuracy of the finite element model is verified.Then,the dynamic response of the plate impacted at the boundary and in the medium part is computed.By analyzing the stress in rebar,the most dangerous region of impact of plate was found.For a rectangular plate,the most dangerous region is at the corner of the plate when a block drops in.Finally,the whole deformation process of the plate under dropping block was simulated and a simplified definition (effect zone) to describe the deformation process in different positions of plate was given.From this study,it is found that the impact only affects heavily within the effect zone.

  15. Enrichment of nitrogen-15 by Nitrox system. Part 2: determination of the fractionation factor, height of an equivalent theoretical plate and production of nitric acid enriched in nitrogen-15; Enriquecimento de nitrogenio-15 pelo sistema Nitrox. Parte 2: determinacao do fator de fracionamento, altura equivalente de uma placa teorica e producao de acido nitrico enriquecido em nitrogenio-15

    Energy Technology Data Exchange (ETDEWEB)

    Ducatti, Carlos [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Fisica e Biofisica; Matsui, Eichii [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1997-12-01

    The expression S = f(alpha, P,L,N{sub o},N{sub p}) showed here, allows the simultaneous determination of the isotopic fractionation factor ({alpha}) by Nitrox System and the number of theoretical plates (s) of the column in countercurrent. For the experimental conditions utilized, room temperature, atmospheric pressure, column packing with stainless steel. Gauze spiral type of ({theta} o,4x h 0,4) cm, feed flow (1,4{+-}0,2) cm{sup 3}/min, feed concentration (4,7 {+-} 0,2)M and (0,369{+-} 0,001) atoms % {sup 15}N, the isotopic fractionation factor of HNO{sub 3}/NO system was {alpha} = 1,062 {+-} 0,001. The total number of theoretical plate (s) and height of an equivalent theoretical plate (HETP) of the isotopic exchange column was 45,3 {+-} 7,1 and (9,1 {+-} 1,6) cm, respectively. It was also vefified that the production of H {sup 15} NO{sub 3} in the isotopic exchange column shows a comprise relationship subject to the same time interval, which means to withdrow little quantity of H{sup 15} NO{sub 3} subject to low concentration (130 cm{sup 3} H{sup 15} NO{sub 3}/week; 2.0 atoms % {sup 15} N). (author). 7 refs., 6 tabs., 3 figs.

  16. The Layout Optimization of Main and Secondary Girder Floor System%主次梁楼盖体系的布置优化

    Institute of Scientific and Technical Information of China (English)

    楼世雄; 朱杰江; 张磊

    2016-01-01

    In this paper, the layout of main and secondary girder roof system has been optimized by the composition of the floor optimization program.The structure model and internal force analysis are made by calling ETABS software, the optimization for the secondary beam number, the section size of main and secondary beam and the floor thickness is made by LINGO software, which are both under the Visual Basic (.NET 4.0) plat-form, and through this program, the optimal floor layout is achieved.%编制楼盖优化程序,对主次梁楼盖体系进行布置优化。在Visual Basic (.NET 4.0)平台下调用ETABS进行建模和内力分析,调用LINGO优化求解器对次梁数量、主次梁截面尺寸以及楼板厚度进行优化,得到楼盖最优布置。

  17. 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。

  18. 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.

  19. Multi-part mask for implanting workpieces

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Aaron P.; Carlson, Charles T.

    2016-05-10

    A multi-part mask has a pattern plate, which includes a planar portion that has the desired aperture pattern to be used during workpiece processing. The multi-part mask also has a mounting frame, which is used to hold the pattern plate. Prior to assembly, the pattern plate has an aligning portion, which has one or more holes through which reusable alignment pins are inserted. These alignment pins enter kinematic joints disposed on the mounting frame, which serve to precisely align the pattern plate to the mounting frame. After the pattern plate has been secured to the mounting frame, the aligning portion can be detached from the pattern plate. The alignment pins can be reused at a later time. In some embodiments, the pattern plate can later be removed from the mounting frame, so that the mounting frame may be reused.

  20. Dynamics of Shells and Fluid-Loaded Plates.

    Science.gov (United States)

    Wang, Zhang

    This thesis is composed of two parts. The first part is concerned with wave propagation on elastic structures in vacuum. An asymptotic approximation is obtained for the dispersion relation of flexural waves propagating in an infinite, flat plate, with material and/or geometric properties periodic in one direction. A matrix approach is proposed to investigate waves in circular cylindrical thin shells joined with circular plates. Both the general propagator matrix and S-matrix formalisms are presented, with emphasis on the latter. The second part is devoted to structures with ambient fluid loading. The Green's function for a fluid-loaded plate under line loading is expressed as a sum of five fluid-loaded plate waves and an acoustic wave with magnitude given by an infinite integral, similar to a branch cut integral. A scattering matrix approach is presented to solve wave propagation problems on fluid-loaded plates with attached ribs. The low frequency asymptotic dispersion relation for a fluid-loaded plate with infinite number of equally spaced identical ribs is derived, from which an equation of motion for the plate is inferred which is valid also at low frequencies.

  1. Dynamic Behaviors of Axially Moving Viscoelastic Plate with Varying Thicknessn

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yinfeng; WANG Zhongmin

    2009-01-01

    Structural components of varying thickness draw increasing attention these days due to economy and light-weight considerations. In view of the absence of research in vibration analysis of viscoelastic plate with varying thickness, this study devotes to investigate the dynamic behaviors of axially moving viscoelastic plate with varying thickness. Based on the thin plate theory and the two-dimensional viscoelastic differential constitutive relation, the differential equation of motion of the axially moving viscoelastic rectangular plate is derived, the plate constituted by Kelvin-Voigt model has linearly varying thickness in the y-direction. The dimensionless complex frequencies of axially moving viscoelastic plate with four edges simply supported are calculated by the differential quadrature method, curves of real parts and imaginary parts of the first three-order dimensionless complex frequencies versus dimensionless moving speed are obtained, the effects of the aspect ratio, thickness ratio, the dimensionless moving speed and delay time on the dynamic behaviors of the axially moving viscoelastic rectangular plate with varying thickness are analyzed. When other parameters keep constant, with the decrease of thickness ratio, the real parts of the first three-order natural frequencies decrease, and the critical divergence speeds of various modes decrease too, moreover, whether the delay time is large or small, the frequencies are all complex numbers.

  2. Plate tectonics conserves angular momentum

    Directory of Open Access Journals (Sweden)

    C. Bowin

    2009-03-01

    Full Text Available A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4 E+27 kgm2s−1. Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates. Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth. The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant velocity on the crests of convection cells driven by rising heat. These results imply that spreading centers are primarily passive reactive

  3. Vehicle License Plate Recognition Syst

    Directory of Open Access Journals (Sweden)

    Meenakshi,R. B. Dubey

    2012-12-01

    Full Text Available The vehicle license plate recognition system has greater efficiency for vehicle monitoring in automatic zone access control. This Plate recognition system will avoid special tags, since all vehicles possess a unique registration number plate. A number of techniques have been used for car plate characters recognition. This system uses neural network character recognition and pattern matching of characters as two character recognition techniques. In this approach multilayer feed-forward back-propagation algorithm is used. The performance of the proposed algorithm has been tested on several car plates and provides very satisfactory results.

  4. Using plate mapping to examine portion size and plate composition for large and small divided plates.

    Science.gov (United States)

    Sharp, David E; Sobal, Jeffery; Wansink, Brian

    2014-12-01

    Does the size of a plate influence the serving of all items equally, or does it influence the serving of some foods - such as meat versus vegetables - differently? To examine this question, we used the new method of plate mapping, where people drew a meal on a paper plate to examine sensitivity to small versus large three-compartment divided plates in portion size and meal composition in a sample of 109 university students. The total drawn meal area was 37% bigger on large plates than small plates, which showed that the portion of plate coverage did not differ by plate size. Men and women drew bigger vegetable portions and men drew bigger meat portions on large plates when compared to small plates. These results suggest that men and women are differentially sensitive to plate size for overall meal size and for meal composition. Implications for decreasing portion size and improving meal balance are that plate size may influence portion size and change the proportions of foods served.

  5. [Angle-fixed plate fixation or double-plate osteosynthesis in fractures of the proximal humerus: a biomechanical study].

    Science.gov (United States)

    Hessmann, Martin H; Korner, Jan; Hofmann, Alexander; Sternstein, Werner; Rommens, Pol M

    2008-06-01

    Internal fixation of fractures of the proximal humerus needs a high stability of fixation to avoid secondary loss of fixation. This is especially important in osteoporotic bone. In an experimental study, the biomechanical properties of the angle-fixed Philos plate (internal fixator) and a double-plate osteosynthesis using two one-third tubular plates were assessed. The fracture model was an unstable three-part fracture (AO type B2). Eight pairs of human cadaveric humeri were submitted to axial load and torque. In the first part of the study, it was assessed to which degree the original stiffness of the humeri could be restored after the osteotomy by the osteosynthesis procedure. Subsequently, subsidence during 200 cycles of axial loading and torque was analysed. During axial loading, the Philos plate was significantly stiffer and showed less irreversible deformation. Two double-plate fixations, but none of the Philos plate osteosynthesis, failed. During torsion, there were no significant differences between the two implants. From the biomechanical point of view, the angle-fixed Philos plate represents the implant of choice for the surgical fixation of highly unstable three-part fractures of the proximal humerus, as the internal fixator system is characterised by superior biomechanical properties.

  6. The Installation Plans of Impervious Cover Plates in the Joint Parts of Composite Geomembrane and Concrete Structure%复合土工膜与混凝土结构接头部位防渗盖片安装方案

    Institute of Scientific and Technical Information of China (English)

    黎逢先

    2014-01-01

    近年来,土工合成材料得到了大量应用,它的应用成效引起了工程技术人员的高度重视。笔者结合具体的实例工程,对混凝土结构接头部位的防渗盖片安装进行了分析。%In recent years, geosynthetics get a lot of applicati-ons, and the effect of application has caused great at ention of the engineering and technical personnel. The author combines with the specific project examples to analysis the instal ation of impervious cover plates in the concrete structure joint part.

  7. Temperature field of steel plate cooling process after plate rolling

    Directory of Open Access Journals (Sweden)

    Huijun Feng, Lingen Chen, Fengrui Sun

    2015-01-01

    Full Text Available Based on numerical calculation with Matlab, the study on cooling process after plate rolling is carried out, and the temperature field distribution of the plate varying with the time is obtained. The effects of the plate thickness, final rolling temperature, cooling water temperature, average flow rate of the cooling water, carbon content of the plate and cooling method on the plate surface and central temperatures as well as final cooling temperature are discussed. For the same cooling time, the plate surface and central temperatures as well as their temperature difference increase; with the decrease in rolling temperature and the increase in average flow rate of the cooling water, the plate surface and central temperatures decrease. Compared with the single water cooling process, the temperature difference between the plate centre and surface based on intermittent cooling is lower. In this case, the temperature uniformity of the plate is better, and the corresponding thermal stress is lower. The fitting equation of the final cooling temperature with respect to plate thickness, final rolling temperature, cooling water temperature and average flow rate of the cooling water is obtained.

  8. Real Plates and Dubious Microplates

    Science.gov (United States)

    Kogan, M. G.; Steblov, G. M.

    2008-12-01

    From the onset of plate tectonics, the existence of most of the plates was never put in doubt, although the boundaries of some plates, like Africa, were later revised. There are however, two microplates in northeast Asia, the Amurian and Okhotsk, whose existence and the sense of rotation was revised several times. The rms value of plate-residual GPS velocities is 0.5-0.9 mm/a for sets of stations representing the motion of the following plates: Antarctic, Australian, Eurasian, North American, Nubian, Pacific, and South American. This value can be regarded as an upper bound on deviation of real plates from infinite stiffness. The rms value of plate-residual GPS velocities is 1.2-1.8 mm/a for the Indian, Nazca, and Somalian plates. Higher rms values for India and Nazca are attributed to the noisier data. The higher rms value for Somalia appears to arise from the distributed deformation to the east of the East African Rift; whether this statement is true can only be decided from observations of denser network in the future. From the analysis of plate-residual GPS velocities, the Canadian Arctic and northeastern Siberia belong to the North American plate. The detailed GPS survey on Sakhalin Island shows that the Sea of Okhotsk region also belongs to the North American plate while the region to the west of it belongs to the Eurasian plate. These results provide a constraint on the geometry of the North American plate and put in doubt the existence of smaller plates in northeast Asia.

  9. Plate Full of Color

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Plate Full of Color teaches the value of eating a variety of colorful and healthy foods.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  10. Dynamics of Tectonic Plates

    CERN Document Server

    Pechersky, E; Sadowski, G; Yambartsev, A

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces.

  11. Dynamics of Tectonic Plates

    OpenAIRE

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend ...

  12. Regeneration of ciliary comb plates in the ctenophore Mnemiopsis leidyi. i. morphology.

    Science.gov (United States)

    Tamm, Sidney L

    2012-01-01

    Regeneration of missing body parts in model organisms provides information on the mechanisms underlying the regeneration process. The aim here is to use ctenophores to investigate regeneration of their giant ciliary swimming plates. When part of a row of comb plates on Mnemiopsis is excised, the wound closes and heals, greatly increasing the distance between comb plates near the former cut edges. Video differential interference contrast (DIC) microscopy of the regeneration of new comb plates between widely separated plates shows localized widenings of the interplate ciliated groove (ICG) first, followed by growth of two opposing groups of comb plate cilia on either side. The split parts of a new plate elongate as their bases extend laterally away from the ICG widening and continue ciliogenesis at both ends. The split parts of a new plate grow longer and move closer together into the ICG widening until they merge into a single plate that interrupts the ICG in a normal manner. Video DIC snapshots of dissected gap preparations 1.5-3-day postoperation show that ICG widenings and/or new plates do not all appear at the same time or with uniform spacing within a gap: the lengths and distances between young plates in a gap are quite variable. Video stereo microscopy of intact animals 3-4 days after the operation show that all the new plates that will form in a gap are present, fairly evenly spaced and similar in length, but smaller and closer together than normal. Normal development of comb plates in embryos and growing animals is compared to the pattern of comb plate regeneration in adults. Comb plate regeneration differs in the cydippid Pleurobrachia that lacks ICGs and has a firmer mesoglea than Mnemiopsis. This study provides a morphological foundation for histological, cellular, and molecular analysis of ciliary regeneration in ctenophores. Copyright © 2011 Wiley Periodicals, Inc.

  13. A PROBLEM OF CUTTING OFF THE LAMINATED SEMIS TYPE PLATE

    Directory of Open Access Journals (Sweden)

    Florin Ciofu

    2012-11-01

    Full Text Available A problem often coped on many domains such as wood manufacturing, glass, plastics and metallic platework industry, is the shaping or cutting off a big plate in many pieces. With this purpose there are algorithms of optimizing for positioning the parts following to be cut off from a row plate. From mathematical point of view, in positioning the parts on a raw plate the number of solutions increase four times evrey time a new part is added, and in case of finding the best solution for about few hundreds of pieces or parts would require years of processing on the most performant computers nowadays – for an analogy remember the famous story with the rice beads which the King had to pay to the master teaching him the chess: twice more for each square of the chessboard; for the total quantity assessment, King ascertained that the crops in his whole life wouldn’t have been enough.

  14. Looking for Plate Tectonics in all the wrong fluids

    Science.gov (United States)

    Davaille, Anne

    2017-04-01

    Ever since the theory of Plate Tectonics in the 1960's, the dream of the geomodeler has been to generate plate tectonics self-consistently from thermal convection in the laboratory. By selfconsistenly, I mean that the configuration of the plate boundaries is in no way specified a priori, so that the plates develop and are wholly consumed without intervention from the modeler. The reciepe is simple : put a well-chosen fluid in a fishtank heated from below and cooled from above, wait and see. But the « well-chosen » is the difficult part... and the interesting one. Plate tectonics is occuring on Earth because of the characteristics of the lithosphere rheology. The latter are complex to estimate as they depend on temperature, pressure, phase, water content, chemistry, strain rate, memory and scale. As a result, the ingredients necessary for plate tectonics are still debated, and it would be useful to find an analog fluid who could reproduce plate tectonics in the laboratory. I have therefore spent the last 25 years to try out fluids, and I shall present a number of failures to generate plate tectonics using polymers, colloids, ketchup, milk, chocolate, sugar, oils. To understand why they failed is important to narrow down the « well-chosen » fluid.

  15. Shrinking of the Cocos and Nazca Plates due to Horizontal Thermal Contraction and Implications for Plate Non-rigidity and the Non-closure of the Pacific-Cocos-Nazca Plate Motion Circuit

    Science.gov (United States)

    Gordon, R. G.; Kreemer, C.

    2015-12-01

    Plate rigidity is the central tenet of plate tectonics. Mounting evidence suggests, however, that significant intraplate deformation occurs in oceanic lithosphere due to horizontal thermal contraction, the rate of which decreases as ≈ 1/age [Kumar & Gordon 2009]. Support for this hypothesis comes from the azimuths of submarine transform faults, which are fit significantly better assuming shrinking plates than by assuming rigid plates [Mishra & Gordon 2015]. Previously we estimated the intraplate velocity field of the Pacific plate accounting for horizontal thermal contraction. The ≈2 mm/yr southeastward motion predicted for the northeastern part of the plate relative to the Pacific-Antarctic Rise may contribute to the non-closure of the Pacific-North America plate motion circuit. In a reference frame in which fix the oldest portion of the Pacific plate, some sites on the plate move up to ≈2 mm/yr [Kreemer & Gordon 2014]. Here we present intraplate velocity fields of the Cocos and Nazca plates and discuss their implications for the non-rigidity of plates and the non-closure of the Pacific-Cocos-Nazca plate circuit, which fails closure by a stunning 14 ±5 mm/yr [DeMets et al. 2010]. If we fix the oldest part of the Cocos plate, intraplate velocities of up to ≈2 mm/yr are estimated, with the fastest motion occurring at the northern end of the plate. If we fix the oldest part of the Nazca plate, displacement rates up to 2 mm/yr are estimated, with the fastest motion occurring in the northeasternmost portion of the plate. In the velocity fields for both plates, the lithosphere adjacent to transform faults along the East Pacific Rise tends to move to the south, which would skew the azimuths of the transform faults clockwise of the values expected for rigid plates, which is the same as the sense of misfit between observed azimuths of transform faults and the azimuths calculated from the MORVEL global set of relative angular velocities [DeMets et al. 2010]. Direct

  16. Rapid Prototyping Bipolar Plate of PEMFC by Gelcasting

    Institute of Scientific and Technical Information of China (English)

    LUO Bing; CHEN Shang-wei; HUANG Ming-yu; WANG Lian-jun

    2006-01-01

    Bipolar plate is one key component of proton exchange membrane fuel cell (PEMFC). According to this paper, mesocarbon microbeads were used as raw materials for forming the green bodies of bipolar plates with complex flow channels by gelcasting technique. Then, the final bipolar plates would be gained after the green parts were died, burned out and sintered. Meanwhile, its properties are researched and evaluated by the test of flexible strength and electric resistivity. The resultant flexural strength of sintered sample is 67 Mpa and the electric resistivity is 52 μΩ·m.

  17. Model Test of Continuous Composite Box Girder in Hong Kong-Zhuhai-Macao Bridge%港珠澳大桥组合连续箱梁模型试验研究

    Institute of Scientific and Technical Information of China (English)

    刘沐宇; 毛玉东; 邓晓光; 徐镜; 张强; 卢志芳

    2014-01-01

    A two-span composite continuous box girder (2 × 8.5 m) test model was designed based on the HZMB shallow water non-navigable bridge according to principle of similitude.Gradation loading test and finite element modeling were researched based on the actual construction process and operation load.The experimental results show that under 100% and 150% normal operation loads,the measured value of each key strain and deflection measure point in steel girder and concrete is linear,and the connection between the shear studs of cluster type and concrete slab is well.In addition,the unloading spring-back strain and deflection is small.In a word,for the high safety capacity and excellent structural overall performance,the continuous composite box girder bridge should be popularized and applied.%以港珠澳大桥组合连续箱梁为研究背景,基于相似原理设计制作了2×8.5m的钢-混组合连续箱梁试验模型.根据实桥施工过程和运营荷载,对试验模型开展分级加载试验和有限元模拟.结果表明:正常运营和150%运营荷载下,集束式剪力钉和混凝土板连接良好,钢箱梁、混凝土板应变和挠度呈线性增长,且卸载回弹良好,表明钢-混组合连续箱梁桥受力安全储备高,结构整体性能好,值得推广应用.

  18. Localised Plate Motion on Venus

    Science.gov (United States)

    Ghail, R. C.

    1996-03-01

    The volcanic and tectonic features observed in Dali Vinculum, Parga Vinculum and Imdr Regio are concentrated at long, narrow, curvilinear zones, with relatively minor volcanism and tectonism between these zones. These zones, whilst more diffuse than terrestrial plate boundaries, nevertheless define the margins of tectonic plates. In contrast to Earth, however, it appears that venusian plates are neither created nor destroyed by lateral motion. Rather, plates are thinned and intruded at vincula plate boundaries, vertically accreted by small-scale intra-plate (planitia) volcanism and perhaps destroyed by delamination of thickened crust in tesserae and montane regions such as Thetis Regio and Ishtar Terra. The diversity in age both between and within these three areas together with the evidence for infrequent, small scale resurfacing in the planitiae are difficult to reconcile with a non-uniformitarian geological process.

  19. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  20. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  1. Development of Aircraft Sandwich Parts

    Directory of Open Access Journals (Sweden)

    J. Křena

    2000-01-01

    Full Text Available The presented paper shows the design and development process of sandwich parts. A spoiler plate and a main landing gear door are developed. Sandwich parts are made of C/E composite facings and a foam core. FE models have been used for optimization of structures. Emphasis has been placed on deformations of parts under a few load cases. Experimental tests have been used for a verification of structure parts loaded by concentrated forces.

  2. Local stress analysis of flat steel box girder with circular arc lower desk%圆弧形底面扁平钢箱梁局部应力分析

    Institute of Scientific and Technical Information of China (English)

    饶瑞; 黄小峰; 林桢楷

    2011-01-01

    A flat steel box girder with circular arc lower desk was analyzed by two steps with two models, a whole bridge model established by larger scale elements and a segment model established by little scale elements. The whole bridge model was analyzed firstly to determine the boundary condition for the segment mod el. Then the local stress distributions of the upper desk and the lower desk were studied based on the segment model with the obtained boundary condition under the dead load and the living load. It is found that shear lag effects are significant in the upper and the lower desk and that effects of the ribs on the mid - span section are larger then that on the section near the pier. Comparisons of the lower desk stress dlstributions between two kinds of the flat steel box girder show that stress distributions of the girder with fold line lower desk are uniform than that of the girder with circular arc lower desk.%采用从整体到局部、从粗放到精细的两阶段两尺度分析方法,对国内首个圆弧形底面扁平钢箱梁在运营状态下的局部应力进行分析.用大尺度单元建立全桥模型,用小尺度单元建立梁段模型.通过分析全桥模型获得梁段模型的边界约束力.在此基础上,利用梁段模型研究钢箱梁在恒载和活载作用下项、底板的应力响应.研究表明:圆弧形底面扁平钢箱梁顶、底板均存在剪力滞现象,U肋对跨中截面应力分布的影响大于墩顶附近截面.圆弧形底面钢箱梁的底板正应力不均匀程度略大于折线形底面钢箱梁.

  3. 叶梁缠绕机张力控制系统建模与设计%Modelling and Design of Tension Control System for Girder Winding Machine

    Institute of Scientific and Technical Information of China (English)

    陈云军; 蒋秀明; 杨公源

    2012-01-01

    Periodic tension disturbances and large tension variations occur in a winding cycle due to the rectangle shape of the section of girder. The location of key parameters which affect tension control accuracy through the establishment of mathematical models for winding and unwinding, combined with application of the predictive control, the identification of system and an dynamic compensation method, plus the adoption of the master/slave control mode which is based on industrial control computer high performance programmable multi-axis controller (PMAC) and tension controller (TO, can effectively solve the problem. The ±4% dynamic tension accuracy of the tension control system has been proven. The work meets the demands of the enterprise, and has yielded obvious economic and social benefits.%缠绕构件叶梁的横截面为矩形,缠绕过程中存在张力波动和切换点处张力突变现象.通过建立缠绕和放卷两大部分的数学模型,找出影响张力变化的几个关键因素,融合预测控制、系统辨识、动态补偿等控制算法,采用计算机+多轴运动控制器+张力控制器(IPC+PMAC+TC)的主从控制模式,有效避免了缠绕过程中切换点处的张力跳变问题.运行状况表明,该系统张力动态控制精度为±4%,满足企业的使用要求,取得了明显的经济效益和社会效益.

  4. Glass-bead peen plating

    Science.gov (United States)

    Graves, J. R.

    1974-01-01

    Peen plating of aluminum, copper, and nickel powders was investigated. Only aluminum was plated successfully within the range of peen plating conditions studied. Optimum plating conditions for aluminum were found to be: (1) bead/powder mixture containing 25 to 35% powder by weight, (2) peening intensity of 0.007A as measured by Almen strip, and (3) glass impact bead diameter of at least 297 microns (0.0117 inches) for depositing-100 mesh aluminum powder. No extensive cleaning or substrate preparation is required beyond removing loose dirt or heavy oil.

  5. Intermittent plate tectonics?

    Science.gov (United States)

    Silver, Paul G; Behn, Mark D

    2008-01-04

    Although it is commonly assumed that subduction has operated continuously on Earth without interruption, subduction zones are routinely terminated by ocean closure and supercontinent assembly. Under certain circumstances, this could lead to a dramatic loss of subduction, globally. Closure of a Pacific-type basin, for example, would eliminate most subduction, unless this loss were compensated for by comparable subduction initiation elsewhere. Given the evidence for Pacific-type closure in Earth's past, the absence of a direct mechanism for termination/initiation compensation, and recent data supporting a minimum in subduction flux in the Mesoproterozoic, we hypothesize that dramatic reductions or temporary cessations of subduction have occurred in Earth's history. Such deviations in the continuity of plate tectonics have important consequences for Earth's thermal and continental evolution.

  6. VISAS AND GREEN PLATES

    CERN Multimedia

    2000-01-01

    From 3 April 2000, all questions relating to visa requests for Switzerland, France, or Russia for a member of the personnel must be addressed to Ms. Agnita Querrou (telephone 72838, office 5-2-019, e-mail Agnita.Querrou@cern.ch).The Users' Office continues to deal with requests for letters of invitation and questions concerning visas for users in EP Division.Questions relating to removals, requests for green plates, to privileges of members of the personnel and to the importation of vehicles are still dealt with by Ms Zuzana Miller (telephone 79257, office 33-1-017, e-mail Zuzana.Muller@cern.ch) and Ms Joëlle Belleman (telephone 73962, office 33-1-019, e-mail Joelle.Belleman@cern.ch).

  7. 肱骨近端内固定锁室系统接骨板治疗肱骨近端外翻嵌插四部分骨折的疗效分析%Early results for treatment of valgus impacted four-part proximal humerus fractures using the PHILOS plate system

    Institute of Scientific and Technical Information of China (English)

    曲巍; 傅重洋; 鲁明; 蒋华军; 汤欣; 张卫国; 吕德成

    2010-01-01

    Objective To evaluate the clinical results of open reduction and internal fixation of valgus impacted four-part proximal humerus fractures with the AO proximal humeral internal locking system (PHILOS). Methods Eleven patients (mean age 42 years) with four-part valgus impacted fracture of the proximal humerus underwent operations. The exposure was limited tothe lateral side of the intertubercular sulcus and the periosteal continuity of the lesser tubercle was preserved. When the humeral head was reduced, autograft or allograft bone was implanted to the site of bone defects, and subsequently the PHILOS plate was used to fix the fractured bone. Results All cases were followed up 20 months after the surgery. Avascular necrosis of the humeral head was found in one case. The necrosis ratio was 9.1%. The mean angle of anterior flexion of the shoulder was 150°. The mean angles of external and internal rotation of the shoulder were 20° and Thl2, respectively. The mean JOA score was 91. Conclusion Open reduction and internal fixation with PHILOS locking plate can gain satisfactory therapeutic effects in the treatment of valgus impacted four-part proximal humerus fractures.%目的 探讨利用AO肱骨近端内固定锁室系统(proximal humeral internal locking system,PHILOS)接骨板切开复位内固定治疗肱骨近端外翻嵌插四部分骨折的术后疗效.方法 对11例平均年龄42岁的肱骨近端外翻嵌插四部分骨折的患者进行手术治疗.术中注意保护小结节内侧的骨膜连续性,仅在结节间沟外侧进行显露,肱骨头复位后骨缺损处行自体骨或同种异体骨移植,PImDS接骨板板内固定.结果 经平均20个月的随访发现1例肱骨头坏死,坏死率为9.1%.肩关节平均前屈上举150°、外旋20°、内旋Th12,JOA评分平均91分.结论 利用PHILOS接骨板切开复位内固定治疗肱骨近端外翻嵌插四部分骨折取得了良好的疗效.

  8. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    2008-01-01

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  9. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  10. The New Plating Process on Plastics

    Institute of Scientific and Technical Information of China (English)

    MakotoImamura; JunOkada; KazuyaSatoh

    2004-01-01

    This process does not use general electroless plating solution containing formaldehyde(carcinogen) and phosphate(the object of waste water regulation). Furthermore. we succeeded in developing a new electroless copper plating solution which is usable semi-permanently by using the special reducing agent, The electroless deposition forms a very thin conductive film on substrate. Therefore, it can prevent some appearance defects (e.g. pits. pin-holes, laminations and inclusions) that occur in the conventional ones. In addition, it is possible to eliminate electroplating of copper from the process by applying the exclusive nickel solution in electroplating. Therefore, the obtained metal parts can be recycled as high quality stainless steel. Given this copper elecltoplating-free process, 25μ m-thick nickel deposition at the stage of electroplating, at least, enables the metal layers to show properties as versatile as those of the conventional(its total thickness is 25μm in the comparative conventional process).

  11. The New Plating Process on Plastics

    Institute of Scientific and Technical Information of China (English)

    Makoto Imamura; Jun Okada; Kazuya Satoh

    2004-01-01

    This process does not use general electroless plating solution containing formaldehyde(carcinogen) and phosphate(the object of waste water regulation). Furthermore, we succeeded in developing a new electroless copper plating solution which is usable semi-permanently by using the special reducing agent. The electroless deposition forms a very thin conductive film on substrate. Therefore, it can prevent some appearance defects (e.g. pits, pin-holes, laminations and inclusions) that occur in the conventional ones. In addition, it is possible to eliminate electroplating of copper from the process by applying the exclusive nickel solution in electroplating. Therefore, the obtained metal parts can be recycled as high quality stainless steel. Given this copper electroplating-free process, 25μ m-thick nickel deposition at the stage of electroplating, at least, enables the metal layers to show properties as versatile as those of the conventional(its total thickness is 25μ m in the comparative conventional process).

  12. Plate tectonics, damage and inheritance.

    Science.gov (United States)

    Bercovici, David; Ricard, Yanick

    2014-04-24

    The initiation of plate tectonics on Earth is a critical event in our planet's history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately 3 billion years ago) suggests that plates and plate boundaries became widespread over a period of 1 billion years. The reason for this time lag is unknown but fundamental to understanding the origin of plate tectonics. Here we suggest that when sufficient lithospheric damage (which promotes shear localization and long-lived weak zones) combines with transient mantle flow and migrating proto-subduction, it leads to the accumulation of weak plate boundaries and eventually to fully formed tectonic plates driven by subduction alone. We simulate this process using a grain evolution and damage mechanism with a composite rheology (which is compatible with field and laboratory observations of polycrystalline rocks), coupled to an idealized model of pressure-driven lithospheric flow in which a low-pressure zone is equivalent to the suction of convective downwellings. In the simplest case, for Earth-like conditions, a few successive rotations of the driving pressure field yield relic damaged weak zones that are inherited by the lithospheric flow to form a nearly perfect plate, with passive spreading and strike-slip margins that persist and localize further, even though flow is driven only by subduction. But for hotter surface conditions, such as those on Venus, accumulation and inheritance of damage is negligible; hence only subduction zones survive and plate tectonics does not spread, which corresponds to observations. After plates have developed, continued changes in driving forces, combined with inherited damage and weak zones, promote increased tectonic complexity, such as oblique subduction, strike-slip boundaries that are subparallel to plate motion, and spalling of minor plates.

  13. 某预应力混凝土箱梁桥悬臂施工中底板纵向裂缝成因分析及处理措施%Analysis of Causes Inducing Longitudinal Cracks in Base Slabs During Cantilever Construction of A Prestressed Concrete Box Girder Bridge and Treating Measures

    Institute of Scientific and Technical Information of China (English)

    胡志红; 王攀; 邹红丹

    2015-01-01

    The bridge cited as an example in this study is a combined prestressed concrete con-tinuous beam and rigid-frame composite box girder bridge with span arrangement of(80+2 × 150+80) m.The box girder adopts the two-cell single box cross section with straight diaphragms ,cas-ted in situ in cantilevers using form travelers.During the construction of the first 8 sections ,longi-tudinal cracks were found in the base slabs of the box girder.ANSYS was used to establish the fi-nite element models of the No.1 and No.2 box girder sections and calculate the stress distribution condition of the girder under 4 load cases.By analyzing the distributive law of the cracks in the base slabs of the girder ,the transverse stress and temperature during the curing of the box girder concrete were monitored.and the causes inducing longitudinal cracks in the base slabs of the box girder was analyzed.The results of the analysis indicate that the gradient thermal loading effect in-side the concrete takes the major responsibility for longitudinal cracks.T hen the measures for in-tensifying the transverse prestressing tendons in the base slabs of box girder were proposed.The curing of base slabs should also be given enough attention.By using the aforementioned measures , no marked longitudinal cracks were found in the base slabs of the box girder during the construc-tion monitoring of the girder sections.%某预应力混凝土连续梁-刚构组合箱梁桥跨径布置为(80+2 × 150+80 ) m ,箱梁为直腹板单箱双室截面 ,采用挂篮悬臂现浇施工 ,在前8个节段的施工过程中 ,箱梁底板出现了纵向裂缝.采用ANSYS建立1号、2号节段箱梁实体有限元模型 ,计算4种荷载工况下箱体的应力分布情况 ,并监测箱梁混凝土养护过程中的横向应力和温度 ,分析了箱梁底板纵向裂缝开裂原因.分析得出混凝土内部的梯度温度荷载效应是底板产生纵向裂缝的主要原因 ,提出加强箱梁底板的横向配筋及

  14. Casimir Effect for Dielectric Plates

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We generalize Kupisewska method to the three-dimensional system and another derivation of the Casimir effect between two dielectric plates is presented based on the explicit quantization of the electromagnetic field in the presence of dielectrics, where the physical meaning of "evanescent mode" is discussed. The Lifshitz's formula is rederived perfect metallic plates will the evanescent modes become unimportant.

  15. Micro-channel plate detector

    Science.gov (United States)

    Elam, Jeffrey W.; Lee, Seon W.; Wang, Hsien -Hau; Pellin, Michael J.; Byrum, Karen; Frisch, Henry J.

    2015-09-22

    A method and system for providing a micro-channel plate detector. An anodized aluminum oxide membrane is provided and includes a plurality of nanopores which have an Al coating and a thin layer of an emissive oxide material responsive to incident radiation, thereby providing a plurality of radiation sensitive channels for the micro-channel plate detector.

  16. Gold plating on spectacle frames.

    Science.gov (United States)

    Kenny, I; Mitchell, J W; Walsh, G

    1997-05-01

    An investigation was carried out into the thickness and standard of application of the plating and lacquer coatings applied to three metal spectacle frames. All conform to BS 6625 (1991) for plating thickness, but there was considerable variation in regularity and porosity.

  17. Plate shell structures of glass

    DEFF Research Database (Denmark)

    Bagger, Anne

    . This modelling technique is used to model a plate shell structure with a span of 11.5 meters in the FE software \\textsc{Abaqus}. The structure is analyzed with six different connection details with varying stiffness characteristics, to investigate the influence of these characteristics on the structural effects...... University, a script has been developed for an automated generation of a given plate shell geometry and a corresponding finite element (FE) model. A suitable FE modelling technique is proposed, suggesting a relatively simple method of modelling the connection detail's stiffness characteristics....... Based on these investigations, and FE analysis of other plate shell models, the structural behaviour is described. Possible methods of estimating the stresses in a given plate shell structure are proposed. The non-linear behaviour of a plate shell structure is investigated for varying parameters...

  18. The moving plate capacitor paradox

    Science.gov (United States)

    Davis, B. R.; Abbott, D.; Parrondo, J. M. R.

    2000-03-01

    For the first time we describe an apparent paradox concerning a moving plate capacitor driven by thermal noise from a resistor. A demon restores the plates of the capacitor to their original position, only when the voltage across the capacitor is small—hence only small forces are present for the demon to work against. The demon has to work harder than this to avoid the situation of perpetual motion, but the question is how? We explore the concept of a moving plate capacitor, driven by noise, a step further by examining the case where the restoring force on the capacitor plates is provided by a simple spring, rather than some unknown demon. We display simulation results with interesting behavior, particularly where the capacitor plates collide with each other.

  19. SAMI Automated Plug Plate Configuration

    CERN Document Server

    Lorente, Nuria P F; Goodwin, Michael

    2012-01-01

    The Sydney-AAO Multi-object Integral field spectrograph (SAMI) is a prototype wide-field system at the Anglo-Australian Telescope (AAT) which uses a plug-plate to mount its 13 x 61-core imaging fibre bundles (hexabundles) in the optical path at the telescope's prime focus. In this paper we describe the process of determining the positions of the plug-plate holes, where plates contain three or more stacked observation configurations. The process, which up until now has involved several separate processes and has required significant manual configuration and checking, is now being automated to increase efficiency and reduce error. This is carried out by means of a thin Java controller layer which drives the configuration cycle. This layer controls the user interface and the C++ algorithm layer where the plate configuration and optimisation is carried out. Additionally, through the Aladin display package, it provides visualisation and facilitates user verification of the resulting plates.

  20. Underwater electrical discharge in plate to plate configuration

    Science.gov (United States)

    Stelmashuk, Vitaliy

    2016-09-01

    Two main configurations of high voltage electrodes submersed in water have been used for an electrical discharge generation: pin to pin and pin to plate. An electrical breakdown between plate electrodes is generally difficult to reproduce, because there is a uniform and weak electric field. One major advantage of using plate electrodes is their greater ``wear hardness'' to high-energy discharges. The plate electrodes can withstand extremely high energy deposition at which the pin electrode is quickly destroyed. The electrical discharge between plate electrodes can be initiated by creating an inhomogeneity in the electrical field. Two methods of discharge initiation between plate electrodes are proposed for this aim: 1) focusing of a shock wave in the interelectrode region; 2) a bubble injection into the electrode gap. The shock wave creates favourable conditions for the electrical breakdown between the two plate electrodes: it causes that numerous microbubbles of dissolved air start to grow and serve as locations for streamer initiation. In the second method the gas bubble is injected from the one of the electrodes, which has a gas inlet hole on the lateral face for this purpose. A ``volcano'' like morphology of positive streamers are observed in the experiments with weak electric field. The authors are grateful to MEYS grant INGO LG 15013.

  1. Finite Element Analysis of Circular Plate using SolidWorks

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yeo Jin; Jhung, Myung Jo [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2011-10-15

    Circular plates are used extensively in mechanical engineering for nuclear reactor internal components. The examples in the reactor vessel internals are upper guide structure support plate, fuel alignment plate, lower support plate etc. To verify the structural integrity of these plates, the finite element analyses are performed, which require the development of the finite element model. Sometimes it is very costly and time consuming to make the model especially for the beginners who start their engineering job for the structural analysis, necessitating a simple method to develop the finite element model for the pursuing structural analysis. Therefore in this study, the input decks are generated for the finite element analysis of a circular plate as shown in Fig. 1, which can be used for the structural analysis such as modal analysis, response spectrum analysis, stress analysis, etc using the commercial program Solid Works. The example problems are solved and the results are included for analysts to perform easily the finite element analysis of the mechanical plate components due to various loadings. The various results presented in this study would be helpful not only for the benchmark calculations and results comparisons but also as a part of the knowledge management for the future generation of young designers, scientists and computer analysts

  2. Shunting Process Analysis of the 3-Girder-Switch with Fixed Rotating Center for Rail Transit%城市轨道交通用三段定心式道岔的转辙过程分析

    Institute of Scientific and Technical Information of China (English)

    袁亦竑

    2011-01-01

    介绍了国内首组城市轨道交通用三段定心式道岔在研制过程中的转辙分析过程.以三开道岔为例,通过自编程序对道岔转辙过程进行模拟,得到了转辙全过程中道岔各梁段的运动情况,找到了转辙过程中加速度变化的最大位置,为道岔转辙机构的具体设计提供了参考.%This article made a brief introduction to shunting process analysis in developing the 3-girder-switch with fixed rotating center of the Chinas first group for rail transit. Taking a 3 - way switch as an example, we simulated shunting process by the software which was developed by ourselves. We gained the kinematics conditions of all the girders during the shunting process of the switch, and finally found out the place where the maximum of the acceleration changing rate was located. The results can provide a reference for the specific design of the shunting device of the switch.

  3. On analysis of construction technique of prestressed concrete continuous box girder at curve section%谈曲线段预应力混凝土连续箱梁施工技术

    Institute of Scientific and Technical Information of China (English)

    贺喜萍

    2011-01-01

    结合具体工程实例,针对曲线段预应力混凝土连续箱梁施工技术进行了探讨,分别阐述了桥孔平面线形处理,弦弧差调整,墩顶连续端的处理,基桩坐标的确定等内容,以期指导今后同类工程,保证曲线段预应力混凝土箱梁平面线形美观。%Combining with the factual project examples,the paper explores the construction technique of the prestressed concrete continuous box girder at curve section,illustrates the treatment of the plane alignment of bridge holes,the adjustment of chord and arc difference,and the treatment of the continuous ends of pier tops,and the identification of the coordinate of foundation piles,so as to direct the similar projects and ensure the beauty of the plane lines of the prestressed concrete continuous box girder at curve section.

  4. 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。

  5. Current status of research on fatigue damage in steel box girder of cable-supported bridge in China%我国缆索支承桥梁钢箱梁疲劳损伤研究现状

    Institute of Scientific and Technical Information of China (English)

    吉伯海

    2014-01-01

    针对钢桥运营安全亟需关注的热点问题之一---缆索支承桥梁钢箱梁的安全性、耐久性,回顾我国钢箱梁疲劳损伤相关研究概况及主要成果,分析总结过去研究中存在的难点与热点问题,并对今后的发展方向提出了展望与建议。%The safety and durability of the steel box girder of cable-supported bridges has become a compelling subject in steel bridge safety operation. This paper provides a review on the research status and main results of fatigue damage in steel box girders in China, presents an analysis of the difficulties and pressing issues in previous research, and puts forward prospects and suggestions for the future development.

  6. 预应力混凝土连续宽箱梁偏载系数研究%Research of Unbalanced Coefficient of Prestressed Concrete Continuous Wide Box Girder

    Institute of Scientific and Technical Information of China (English)

    辛慧; 赵玲

    2014-01-01

    Taking prestressed concrete single box multi-cells continuous wide box Girder Bridge at Tongqi street Nantong city as the background, the paper establishes entity unit spa-tial finite element models. There is a comparison between calculated value which is got though increasing the coefficient of normal stress in each location point of box Girder min-span calculation section and the value calculated by common sim-plified method. The paper discusses the feasibility of the simp-lified calculation method and offers a reference for the similar engineering design.%以南通通启路高架工程的预应力混凝土单箱多室连续宽箱梁桥为背景,建立实体单元空间有限元模型,将箱梁跨中截面各位置点的正应力增大系数计算值与常用简化计算方法所得值进行对比,探讨简化计算方法的可行性,供同类工程设计参考。

  7. 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

  8. Rigid-Plastic Post-Buckling Analysis of Columns and Quadratic Plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2008-01-01

    The objective of this paper is to show the application of a novel approach to the rigid plastic hinge and yield line theory in post-buckling analysis of slender plates and columns. The upper bound theorem of plasticity theory and the associated flow law of plasticity are used to find...... of the post-buckling behaviour. The rigid plastic theory of plates, referred to as yield line theory, involves large rigid parts of the plate mutually rotating about yielding hinge lines, however in order to accommodate in plane plastic deformations area “collapse” yield lines have been introduced. The hinge...... yield lines accommodate differential rotations of rigid parts and the area “collapse” yield lines accommodate local area changes of the rigid parts thereby preserving compatibility of the rigid parts of a plate. The approach will be illustrated for rigid plastic column analysis and for a quadratic plate...

  9. Active NE-SW Compressional Strain Within the Arabian Plate

    Science.gov (United States)

    Floyd, M. A.; ArRajehi, A.; King, R. W.; McClusky, S.; Reilinger, R. E.; Douad, M.; Sholan, J.; Bou-Rabee, F.

    2012-12-01

    Motion of the Arabian plate with respect to Eurasia has been remarkably steady over more than 25 Myr as revealed by comparison of geodetic and plate tectonic reconstructions (e.g., McQuarrie et al., 2003, GRL; ArRajehi et al., 2010, Tectonics). While internal plate deformation is small in comparison to the rate of Arabia-Eurasia convergence, the improved resolution of GPS observations indicate ~ NE-SW compressional strain that appears to affect much of the plate south of latitude ~ 30°N. Seven ~ NE-SW oriented inter-station baselines all indicated shortening at rates in the range of 0.5-2 mm/yr, for the most part with 1-sigma velocity uncertainties < 0.4 mm/yr. Plate-scale strain rates exceed 2×10-9/yr. The spatial distribution of strain can not be resolved from the sparse available data, but strain appears to extend at least to Riyadh, KSA, ~ 600 km west of the Zagros Fold and Thrust Belt that forms the eastern, collisional boundary of the Arabian plate with Eurasia (Iran). Geodetic velocities in the plate tectonic reference frame for Arabia, derived from magnetic anomalies in the Red Sea (Chu and Gordon, 1998, GJI), show no significant E-W motion for GPS stations located along the Red Sea coast (i.e., geodetic and plate tectonic spreading rates across the Red Sea agree within their resolution), in contrast to sites in the plate interior and along the east side of the plate that indicate east-directed motions. In addition, NE-SW contraction is roughly normal to ~ N-S striking major structural folds in the sedimentary rocks within the Arabian Platform. These relationships suggest that geodetically observed contraction has characterized the plate for at least the past ~ 3 Myr. Broad-scale contraction of the Arabian plate seems intuitively reasonable given that the east and north sides of the plate are dominated by active continental collision (Zagros, E Turkey/Caucasus) while the west and south sides are bordered by mid-ocean ridge spreading (Red Sea and Gulf of

  10. Development of tin-plated regenerator material

    Science.gov (United States)

    Xu, M. Y.; Morie, T.; Tsuchiya, A.

    2017-02-01

    To improve the efficiency of a cryocooler, it is vital to improve the regenerator. In general, the heat capacity of materials decreases as temperature decreases. Thus, when temperature is below 50 K, lead spheres are often used as a regenerator material. However, the pressure drop through a sphere regenerator is larger than that through a screen regenerator. To overcome this dilemma, a new, low pressure loss tin-plated screen is proposed. A comparison test was performed with a two-stage GM cryocooler by replacing part of the first stage regenerator material, bronze screens with tin-plated screens. Compared to a regenerator filled with bronze screens, the cooling capacity of the first stage increased by about 14% at 40 K and 90% at 30 K with such tin-plated screens. The ratio of the wire diameter before and after the deposition was also optimized. An optimum cooling capacity of 53.5 W at 40 K was obtained at a diameter ratio of about 1.4. The detailed experimental results are reported in this paper.

  11. Locking plates in proximal humerus fractures.

    Science.gov (United States)

    Strohm, P C; Helwig, P; Konrad, G; Südkamp, N P

    2007-12-01

    It is well known that proximal humerus fractures are among the three most frequent fracture types. Epidemiological invetsigations show that in people elder than 60 years the fracture of the proximal humerus is more frequent than fractures of the hip region (17). Over the last decades several techniques have been applied for treatment of proximal humerus fractures. Widely accepted is the initiation of a conservative treatment regimen for undisplaced fractures, however, the standard treatment for displaced fractures, especially three and four part fractures, is still the center of scientific debate. Many different implants have been tested and investigated, thus demonstrating lack of sufficient results. Over the last years the development of angle stable, locking implants started and clinical studies demonstrated encouraging results. In our clinic the locking proximal humerus plate and the PHILOS plate advanced to the implant of choice for treatment of displaced proximal humerus fractures. There are still cases of implant failure and humerus head necrosis, but most of these complications were caused by the fracture type and not an implant specific problem. However the overall results with these new implants are encouraging. Key words: locking plates, proximal humerus fracture, humerus, humerus fracture, PHILOS, PHP.

  12. The concept of locking plates.

    Science.gov (United States)

    Cronier, P; Pietu, G; Dujardin, C; Bigorre, N; Ducellier, F; Gerard, R

    2010-05-01

    After a short historical review of locking bone plates since their inception more than a century ago to the success of the concept less than 15 years ago with today's plates, the authors present the main locking mechanisms in use. In the two broad categories - plates with fixed angulation and those with variable angulation - the screw head is locked in the plate with a locknut by screwing in a threaded chamber on the plate or by screwing through an adapted ring. The authors then provide a concrete explanation, based on simple mechanical models, of the fundamental differences between conventional bone plates and locking plates and why a locking screw system presents greater resistance at disassembly, detailing the role played by the position and number of screws. The advantages of epiphyseal fixation are then discussed, including in cases of mediocre-quality bone. For teaching purposes, the authors also present assembly with an apple fixed with five locking screws withstanding a 47-kg axial load with no resulting disassembly. The principles of plate placement are detailed for both the epiphysis and diaphysis, including the number and position of screws and respect of the soft tissues, with the greatest success assured by the minimally invasive and even percutaneous techniques. The authors then present the advantages of locking plates in fixation of periprosthetic fractures where conventional osteosynthesis often encounters limited success. Based on simplified theoretical cases, the economic impact in France of this type of implant is discussed, showing that on average it accounts for less than 10% of the overall cost of this pathology to society. Finally, the possible problems of material ablation are discussed as well as the means to remediate these problems.

  13. Writing and Visualization for Teaching Plate Tectonics

    Science.gov (United States)

    Thomas, S. F.

    2004-12-01

    The Theory of Plate Tectonics is probably the most important paradigm for understanding the workings of our planet. As such it is an integral part in any Introductory Geology course. Whereas geology majors usually easily embrace the Theory of Plate Tectonics, the enthusiasm for the coherence and elegance of this theory appears to be much more subdued among the majority of non-science majors. While visual and electronic media certainly support the teaching of the theory, pretty pictures and animations are not sufficient for many non-science majors to grasp the concepts of interacting lithospheric plates. It is well known that students do better in learning scientific concepts if they create their own understanding through research and inquiry-based learning, by working in the field, manipulating real earth-science data, and through writing. Writing assignments give instructors the opportunity to assess their students' learning and to clarify misconceptions yet they also have to be willing to teach students how to craft a science paper. Most electronic media and textbook-added CD-ROMs are not useful for making the structure of a science paper transparent. I found many of the necessary ingredients for effectively teaching plate tectonics in the interactive CD-ROM, "Our Dynamic Planet", developed by Wm. Prothero together with G. Kelly (University of California at Santa Barbara). It allows students to select and manipulate real earth-science data of plate-tectonically active regions, and provides an electronic interface that lets students create graphical representations of their collected data. A downloadable Teacher's Manual provides suggestions on teaching students to write a scientific argument, rooted in sound pedagogy. Originally designed for a large oceanography class, the material was modified for use in a small introductory geology class for non-science majors. Various assignments were given to instruct students in writing a scientific argument based on their

  14. Simulation of the CMS Resistive Plate Chambers

    CERN Document Server

    Hadjiiska, R; Pavlov, B; Petkov, P; Dimitrov, A; Beernaert, K; Cimmino, A; Costantini, S; Garcia, G; Lellouch, J; Marinov, A; Ocampo, A; Strobbe, N; Thyssen, F; Tytgat, M; Verwilligen, P; Yazgan, E; Zaganidis, N; Aleksandrov, A; Genchev, V; Iaydjiev, P; Rodozov, M; Shopova, M; Sultanov, G; Ban, Y; Cai, J; Xue, Z; Ge, Y; Li, Q; Qian, S; Avila, C; Chaparro, L F; Gomez, J P; Moreno, B Gomez; Oliveros, A F Osorio; Sanabria, J C; Assran, Y; Sharma, A; Abbrescia, M; Colaleo, A; Pugliese, G; Loddo, F; Calabria, C; Maggi, M; Benussi, L; Bianco, S; Colafranceschi, S; Piccolo, D; Carrillo, C; Iorio, O; Buontempo, S; Paolucci, P; Vitulo, P; Berzano, U; Gabusi, M; Kang, M; Lee, K S; Park, S K; Shin, S; Kim, M S; Seo, H; Goh, J; Choi, Y; Shoaib, M

    2013-01-01

    The Resistive Plate Chamber (RPC) muon subsystem contributes significantly to the formation of the trigger decision and reconstruction of the muon trajectory parameters. Simulation of the RPC response is a crucial part of the entire CMS Monte Carlo software and directly influences the final physical results. An algorithm based on the parametrization of RPC efficiency, noise, cluster size and timing for every strip has been developed. Experimental data obtained from cosmic and proton-proton collisions at $\\sqrt{s}=7$ TeV have been used for determination of the parameters. A dedicated validation procedure has been developed. A good agreement between the simulated and experimental data has been achieved.

  15. Characterization of Bird Impacts on a Rigid Plate: Part 1

    Science.gov (United States)

    1975-01-01

    velocity 40 1. 27cm off center of impact. Prscinng page Madh vii r _ _ AFrFDL-TR-IS-5 LIST OF ILLUSTRATIONS (CON TD ) FIGURE PAGE 21. Impulse...velocity 234 rn/s ! I Shot No. 5190; velocity 129 m/1" B-9 AFFDL-TR-75-S APPENDIX C BIRD IMPACT CINE SEQUENCES AFFDL-TR-75-5 museu. woman nams.UUS Nae womenU

  16. FSW Numerical Simulation of Aluminium Plates by Sysweld - Part I

    OpenAIRE

    Jančo Roland; Écsi Ladislav; Élesztős Pavel

    2016-01-01

    Friction Stir Welding (FSW) is one of the most effective solid state joining processes and it has numerous potential applications in many industries. The simulation process can provide the evolution of physical quantities such as temperature, metallurgical phase proportions, stress and strain which can be easily measured during welding. The numerical modelling requires the modelling of a complex interaction between thermal, metallurgical and mechanical phenomena. The aim of this paper is to d...

  17. FSW Numerical Simulation of Aluminium Plates by SYSWELD - Part II

    OpenAIRE

    Jančo Roland; Écsi Ladislav; Élesztős Pavel

    2016-01-01

    Friction Stir Welding (FSW) is one of the most effective solid state joining processes and has numerous potential applications in many industries. The simulation process can provide the evolution of physicals quantities such as temperature, metallurgical phase proportions, stress and strain which can be easily measured during welding. The numerical modelling requires the modelling of the complex interaction between thermal, metallurgical and mechanical phenomena. The aim of this paper is to d...

  18. 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

  19. 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。

  20. PC连续箱梁合龙束横向效应%Transverse Effect of Bottom Continuity Tendons in Continuous PC Box Girder

    Institute of Scientific and Technical Information of China (English)

    项贻强; 唐国斌; 朱汉华; 晁春峰

    2011-01-01

    Bottom continuity tendons induce transverse additive effect while providing longitudinal compression during the construction of PC box girder. Taking a cross-sea bridge for example, the mechanism of bottom continuity tendon is investigated. The transverse effect and parameters study are conducted through a refined model. It is illustrated that the state of bottom flange is in a dynamic changeable process during the tensioning of bottom continuity tendons, and the transverse effect caused by the tendons is much more than that by dead loading and other prestressing tendons. The transverse effect is more sensitive to alignment and thickness of the bottom flange, as well as concrete cover of the ducts. Finally, based on the simplified frame analysis, the design method is proposed by introducing prestressing effect simplified factor and duct modified factor.%PC连续箱梁合龙束张拉不仅使底板纵向受压,同时在横向产生附加效应;以某跨海大桥为例,对底板合龙束作用机理进行探讨,并通过精细有限元模型,对施工过程中合龙束的横向效应进行分析和参数研究;结果表明,合龙束张拉过程中底板横向应力处于动态变化过程,其横向效应远大于恒载和其它预应力作用结果,同时,合龙束的横向效应对底板的线形、厚度及孔道保护层较为敏感;最后,基于横向框架法,通过引入预应力效应简化系数和孔道修正系数,提出合龙束横向效应的简化计算方法.

  1. Swing Analysis of Suspended Load System for Crane Ship of Transporting and Lifting Girders%运架梁起重船吊重摆动分析

    Institute of Scientific and Technical Information of China (English)

    胡于进; 文定旭; 王学林

    2012-01-01

    以运架梁起重船为对象,对其作业过程中吊重的非线性动力学响应进行研究。基于吊摆系统的几何约束,构建了多点吊摆系统的双摆模型,运用带乘子的拉格朗日方程建立了吊摆系统的非线性动力学模型,对规则波条件下3000吨大型起重船吊重的动力学响应进行了仿真分析。比较了线性及非线性方程下吊重的运动规律以及船舶纵摇角对双摆系统摆角的影响,讨论了变绳长的方法对吊物系统的摆幅进行控制的理论模型。同时,对提出的理论模型仿真结果与Adams刚体动力学模型结果进行了比较分析。%The crane ship of transporting and lifting girders was focused. The nonlinear dynamic response of suspended load system during operation of the crane was analyzed. A double pendulum model for the multi-point suspended load system was constructed based on the geometric constraints. Nonlinear dynamic model of the suspended pendulum was established using the Lagrange multiplier equation. A simulation of dynamic response analysis was calculated based on 3000 tons crane under the condition of regular waves. In this work, trajectory of swing laws under linear and nonlinear equations, and the effect of the ship pitching angle to the swing angle of double-pendulum system were compared respectively. The swing controlling theoretical model was discussed using method of changing the rope length. At the same time, the simulation results of the mathematical theoretical model were compared with the Adams rigid body dynamics model.

  2. Optical Near-Field Plates

    Science.gov (United States)

    2015-04-08

    color filtering and spectral imaging ,” Nat. Comm. 1, 59 (2010). 3. H.-F. Shi and L. J. Guo, “Design of Plasmonic Near Field Plate at Opitical...AFRL-OSR-VA-TR-2015-0085 OPTICAL NEAR-FILED PLATES Roberto Merlin UNIVERSITY OF MICHIGAN Final Report 04/08/2015 DISTRIBUTION A: Distribution...03-2015 Final 09/01/2009-12/31/2014 Optical Near-Field Plates FA9550-09-1-0636 erlin, Roberto, D. The University of Michigan Ann Arbor, MI 48109

  3. Plate shell structures of glass

    DEFF Research Database (Denmark)

    Bagger, Anne

    to their curved shape. A plate shell structure maintains a high stiffness-to-weight ratio, while facilitating the use of plane structural elements. The study focuses on using laminated glass panes for the load bearing facets. Various methods of generating a plate shell geometry are suggested. Together with Ghent......, such as facet size, imperfections, and connection characteristics. The critical load is compared to that of a similar, but smoothly curved, shell structure. Based on the investigations throughout the study, a set of guidelines for the structural design of plate shells of glass is proposed....

  4. THE NEW STRUCTURE OF A PLATE-PILE FOUNDATION

    Directory of Open Access Journals (Sweden)

    SAMORODOV О. V.

    2016-01-01

    Full Text Available Raising of problem. In the construction of high-rise buildings with significant loads on foundations and bedding at the base of not rocky soils tend to use the most common pile foundation to reduce the deformation and correspond to regulations [1] on the maximum permissible deformation. Monitoring of the stress-strain state (SSS pile foundations constructed buildings shows the existing reserves of bearing capacity on the one hand - soil bases of the second group of limit states, on the other - the foundation of the first group of limit states by regulating the SSS foundation during construction and exploitation. Therefore, are increasingly using more progressive structure of foundations consisting of piles and of plate, as well as methods for their construction [2 - 10], however, in their design there are a number of disadvantages associated with the ambiguity of the application of methods for the calculation of such structures, which allows to do only partial conclusions and recommendations. Purpose. Is proposing the new structure of a plate-pile foundation, which overcomes the drawbacks of the existing design solutions and methods of consruction their, as well as is proposing an engineering method of a determination of basic parameters. Conclusion. Is proposes the new structure of a plate-pile foundation and the method of a determination of basic parameters his in the design of a soil base to the maximum permissible deformation Su buildings. Efficiency of application this type plate-pile foundation obtained by rational distribution resistance between a plate and piles, when under load from the building to the first work fully incorporated plate that allows maximum deformed for plate, and then the piles - due to of the hinge connection with the plate. Thus, depending on the maximum permissible deformation for buildings resistance of plate part of a full load of more than 50%, that significantly reduces the consumption of concrete.

  5. Plate tectonics and crustal deformation around the Japanese Islands

    Science.gov (United States)

    Hashimoto, Manabu; Jackson, David D.

    1993-01-01

    We analyze over a century of geodetic data to study crustal deformation and plate motion around the Japanese Islands, using the block-fault model for crustal deformation developed by Matsu'ura et al. (1986). We model the area including the Japanese Islands with 19 crustal blocks and 104 faults based on the distribution of active faults and seismicity. Geodetic data are used to obtain block motions and average slip rates of faults. This geodetic model predicts that the Pacific plate moves N deg 69 +/- 2 deg W at about 80 +/- 3 mm/yr relative to the Eurasian plate which is much lower than that predicted in geologic models. Substantial aseismic slip occurs on the subduction boundaries. The block containing the Izu Peninsula may be separated from the rigid part of the Philippine Sea plate. The faults on the coast of Japan Sea and the western part of the Median Tectonic Line have slip rates exceeding 4 mm/yr, while the Fossa Magna does not play an important role in the tectonics of the central Japan. The geodetic model requires the division of northeastern Japan, contrary to the hypothesis that northeastern Japan is a part of the North American plate. Owing to rapid convergence, the seismic risk in the Nankai trough may be larger than that of the Tokai gap.

  6. Plate tectonics and crustal deformation around the Japanese Islands

    Science.gov (United States)

    Hashimoto, Manabu; Jackson, David D.

    1993-01-01

    We analyze over a century of geodetic data to study crustal deformation and plate motion around the Japanese Islands, using the block-fault model for crustal deformation developed by Matsu'ura et al. (1986). We model the area including the Japanese Islands with 19 crustal blocks and 104 faults based on the distribution of active faults and seismicity. Geodetic data are used to obtain block motions and average slip rates of faults. This geodetic model predicts that the Pacific plate moves N deg 69 +/- 2 deg W at about 80 +/- 3 mm/yr relative to the Eurasian plate which is much lower than that predicted in geologic models. Substantial aseismic slip occurs on the subduction boundaries. The block containing the Izu Peninsula may be separated from the rigid part of the Philippine Sea plate. The faults on the coast of Japan Sea and the western part of the Median Tectonic Line have slip rates exceeding 4 mm/yr, while the Fossa Magna does not play an important role in the tectonics of the central Japan. The geodetic model requires the division of northeastern Japan, contrary to the hypothesis that northeastern Japan is a part of the North American plate. Owing to rapid convergence, the seismic risk in the Nankai trough may be larger than that of the Tokai gap.

  7. An Offline Technique for Localization of License Plates for Indian Commercial Vehicles

    CERN Document Server

    Saha, Satadal; Nasipuri, Mita; Basu, Dipak Kumar

    2010-01-01

    Automatic License Plate Recognition (ALPR) is a challenging area of research due to its importance to variety of commercial applications. The overall problem may be subdivided into two key modules, firstly, localization of license plates from vehicle images, and secondly, optical character recognition of extracted license plates. In the current work, we have concentrated on the first part of the problem, i.e., localization of license plate regions from Indian commercial vehicles as a significant step towards development of a complete ALPR system for Indian vehicles. The technique is based on color based segmentation of vehicle images and identification of potential license plate regions. True license plates are finally localized based on four spatial and horizontal contrast features. The technique successfully localizes the actual license plates in 73.4% images.

  8. Hierarchical self-organization of tectonic plates

    OpenAIRE

    2010-01-01

    The Earth's surface is subdivided into eight large tectonic plates and many smaller ones. We reconstruct the plate tessellation history and demonstrate that both large and small plates display two distinct hierarchical patterns, described by different power-law size-relationships. While small plates display little organisational change through time, the structure of the large plates oscillate between minimum and maximum hierarchical tessellations. The organization of large plates rapidly chan...

  9. Efeito da acetilação das partículas de madeira de Eucalyptus grandis e da inclusão de partículas de polietileno e de embalagens cartonadas nas propriedades de chapas de aglomerado Effect of particle acetylation of Eucalyptus grandis wood and the inclusion of particles of polyethylene and cardboard packaging of properties in crowded plates

    Directory of Open Access Journals (Sweden)

    Fernando Vitor Oliveira

    2010-10-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da acetilação das partículas de madeira de Eucalyptus grandis e da inclusão de partículas de polietileno de baixa densidade (PEBD e de alta densidade (PEAD e de embalagens cartonadas nas propriedades de chapas de aglomerado. As partículas de madeira foram produzidas em laboratório a partir de toras que foram desdobradas em tábuas, convertidas em baguetas, depois em flocos e, finalmente, transformadas em partículas. Embalagens cartonadas e de polietino de alta e baixa densidades foram coletadas em depósitos de material reciclável e processadas em moinho de martelo. A acetilação foi realizada em autoclave com controle de pressão e temperatura. A acetilação promoveu significativa estabilização dimensional dos painéis, entretanto diminuiu algumas propriedades mecânicas. A adição de polietileno reduziu as propriedades mecânicas, em especial a flexão estática (MOR e MOE, porém, de modo geral, melhorou a estabilidade dimensional dos painéis, independentemente do tipo de partícula. No entanto, a adição de embalagens cartonadas reduziu a resistência mecânica e promoveu maior adsorção de vapor de água, inchamento em espessura e expansão linear, tanto nas chapas contendo partículas acetiladas quanto naquelas que não as continham.The objective of this study was to evaluate the effect of eucalyptus grandis particles acetylation and the addition of polyethylene of low (pebd and high density (pead and paperboard particles in the properties particleboard. Wood particles were produced in laboratory from logs that were split into plaks, baguettes and then converted into flakes and finally transformed into particles. Paperboard and polyethylene collected in recyclable material stores and processed in a hammer mil. Acetylation was performed in autoclave with pressure and temperature control. Wood particles acetylation promoted a significant stabilization of the particleboards but

  10. The multigap resistive plate chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zeballos, E. Cerron [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Crotty, I. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Hatzifotiadou, D. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Valverde, J. Lamas [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Univ. Louis Pasteur, Strasbourg (France); Neupane, S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Williams, M. C. S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Zichichi, A. [Univ. of Bologna, Bologna (Italy)

    2015-02-03

    The paper describes the multigap resistive plate chamber (RPC). This is a variant of the wide gap RPC. However it has much improved time resolution, while keeping all the other advantages of the wide gap RPC design.

  11. An efficient rectangular plate element

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new 12-parameter rectangular plate element is presented by useof the double set parameter method. The error in the energy norm is of order O(h2), one order higher than the commonly used Adini nonconforming element.

  12. Tectonics: Changing of the plates

    Science.gov (United States)

    Brandon, Alan

    2016-10-01

    The composition of Earth's crust depends on the style of plate tectonics and of the melting regimes in the mantle. Analyses of the oldest identified rocks suggest that these styles and the resulting crust have changed over Earth's history.

  13. Rhodium platings – experimental study

    Directory of Open Access Journals (Sweden)

    R. Rudolf

    2013-07-01

    Full Text Available Modern rhodium plating solutions are based on either sulphate or phosphate. Although in theory there are four possible combinations, in practice only three different rhodium electrolytes are used. These are based on dilutions of rhodium sulphate or phosphate concentrates with added sulphuric or phosphoric acid. These processes are be discussed in this paper with a demonstration of Rh platings in the Slovenian firm Zlatarna Celje d.d.

  14. Horizontal versus vertical plate motions

    Directory of Open Access Journals (Sweden)

    M. Cuffaro

    2006-07-01

    Full Text Available We review both present and past motions at major plate boundaries, which have the horizontal component in average 10 to 100 times faster (10–100 mm/yr than the vertical component (0.01–1 mm/yr in all geodynamic settings. The steady faster horizontal velocity of the lithosphere with respect to the upward or downward velocities at plate boundaries supports dominating tangential forces acting on plates. This suggests a passive role of plate boundaries with respect to far field forces determining the velocity of plates. The forces acting on the lithosphere can be subdivided in coupled and uncoupled, as a function of the shear at the lithosphere base. Higher the asthenosphere viscosity, more significant should be the coupled forces, i.e., the mantle drag and the trench suction. Lower the asthenosphere viscosity, more the effects of uncoupled forces might result determinant, i.e., the ridge push, the slab pull and the tidal drag. Although a combination of all forces acting on the lithosphere is likely, the decoupling between lithosphere and mantle suggests that a torque acts on the lithosphere independently of the mantle drag. Slab pull and ridge push are candidates for generating this torque, but, unlike these boundary forces, the advantage of the tidal drag is to be a volume force, acting simultaneously on the whole plates, and being the decoupling at the lithosphere base controlled by lateral variations in viscosity of the low-velocity layer.

  15. Horizontally oriented plates in clouds

    CERN Document Server

    Bréon, François-Marie

    2011-01-01

    Horizontally oriented plates in clouds generate a sharp specular reflectance signal in the glint direction, often referred to as "subsun". This signal (amplitude and width) may be used to analyze the relative area fraction of oriented plates in the cloud top layer and their characteristic tilt angle to the horizontal. We make use of spaceborne measurements from the POLDER instrument to provide a statistical analysis of these parameters. More than half of the clouds show a detectable maximum reflectance in the glint direction, although this maximum may be rather faint. The typical effective fraction (area weighted) of oriented plates in clouds lies between 10-3 and 10-2. For those oriented plates, the characteristic tilt angle is less than 1 degree in most cases. These low fractions imply that the impact of oriented plates on the cloud albedo is insignificant. The largest proportion of clouds with horizontally oriented plates is found in the range 500-700 hPa, in agreement with typical in situ observation of p...

  16. How mantle slabs drive plate tectonics.

    Science.gov (United States)

    Conrad, Clinton P; Lithgow-Bertelloni, Carolina

    2002-10-04

    The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction.

  17. Hollow plate girder bridge damaged hinge joints on the transverse distribution%空心板梁桥铰缝损坏对横向分布的影响

    Institute of Scientific and Technical Information of China (English)

    张立东; 孙全胜

    2015-01-01

    Through the hollow beam superstructure disease research found that very serious damage to the hinge joints. Due to changes in the stiff-ness of the hinge joints caused a bridge overall force changes that may even force the board features. With the help of Midas civil finite element analysis software to establish the finite element model to analyze the impact of the bridge damaged hinge joints transverse distribution can provide a theoretical basis for the kind of bridge maintenance and reinforcement of hinge joints.%通过对空心板梁上部结构病害调查研究发现,铰缝破坏现象十分严重,由于铰缝刚度发生变化造成了桥梁整体受力变化,甚至可能出现单板受力特征,借助Midas civil有限元分析软件建立了有限元模型,分析了铰缝损坏对桥梁横向分布的影响,可为同类桥梁铰缝维修与加固提供理论依据。

  18. 钢结构大板梁T型角焊缝超声波探伤方法选择%SELECTION OF THE METHOD FOR ULTRASONIC INSPECTION OF THE T-FILLET WELD IN STEEL PLATE GIRDER

    Institute of Scientific and Technical Information of China (English)

    刘少印; 姚富忠; 胡雪翔

    2001-01-01

    @@ 现代化钢结构厂房的建设,存在着大量的柱、梁和吊车梁等工字形大板梁的制作和安装,按图样技术条件及规范要求,大板梁翼板和腹板采用角焊接的焊缝,有些是不要求焊透的,而对一些重要的受力件,其角焊缝要求焊透.对需要焊透的角焊缝,按技术条件及规范要求需要进行检测,较早的技术规范要求用精确法对大板梁的T型角焊缝进行检验,以确保角焊缝中不存在未焊透缺陷,新的钢结构验收标准GB 50205-1995《钢结构工程施工及验收规范》明确要求用超声波检测方法对角焊缝整个截面进行检测,执行国标GB 11345-1989《钢焊缝手工超声波探伤方法和探伤结果的分类》中B级检验等级并达到Ⅱ级评定等级要求.针对这些角焊缝的超声波检测,各种教材和标准叙述了不同的探伤方法,有的规定用直探头在翼板上进行探测,而有的则规定用斜探头在翼板的内外侧进行探测,或用斜探头在腹板上进行探测.笔者在角焊缝实际探伤过程中,对各种探伤方法进行了比较,总结出了较好的T型角焊缝探伤方法,供参考.

  19. Footbridge Design with All Welded Steel Truss Girder of Nodeless Plate (H Steel)%无节点板全焊接(H型钢)钢桁梁人行桥设计

    Institute of Scientific and Technical Information of China (English)

    郭辉

    2015-01-01

    该人行桥采用无节点板全焊接(H型钢)钢桁梁结构,通过静力、动力及稳定性计算,表明该桥结构受力合理、传力明确,是结合桥址处地理环境设计的一种新型桥梁结构,具有较好的稳定性和经济性.

  20. Outcome Analysis of Locking Plate Fixation in Proximal Humerus Fracture

    Science.gov (United States)

    Pathak, Abhishek; Gaur, Sanjiv

    2016-01-01

    Introduction Proximal humerus fractures account for approximately 5% of all fractures. Stable minimally displaced fractures can be treated nonoperatively but the management of displaced fractures remain controversial with various modalities of treatment available. Locking plates provide stable fixation and enable early postoperative mobilization specially in osteoporotic proximal humerus fracture. Aim To evaluate the functional outcome of locking plate fixation and to compare the results of two approaches used for fixation. Materials and Methods This prospective study was conducted at a tertiary level hospital between September 2011 to December 2013. PHILOS plates were used for internal fixation of displaced proximal humerus fractures Neer’s type 2 part, 3 part and 4 part fractures on 26 patients (M/F ratio 1.36:1; mean age 46 years). According to Neer classification, 5,12 and 9 patients had displaced 2, 3 and 4 part fractures respectively. Deltopectoral and deltoid splitting approaches were used for fixation on 13 patients each. Functional outcome was assessed using Constant-Murley shoulder score. Graphpad software version 6.0 was used with Chi-square test and Fisher-exact test are used to compare data. The p-value .05) and all fractures were united. Conclusion Our study demonstrates that locking plate fixation gives good functional outcomes in treatment of proximal humerus fractures. There was no significant difference in the two approaches used for exposure. Our results are comparable to various studies conducted by other authors which states that locking plates provide better functional and radiological outcomes as compared to other fixation methods like Tension band wiring, percutaneous K-wire fixation, non-locking plates, intramedullary nails. PMID:27656515

  1. Geometry of the Cocos Plate Under North American Plate

    Science.gov (United States)

    Perez-Campos, X.

    2015-12-01

    The Cocos plate subducts under the North American plate with a complex geometry, and previous seismicity studies revealed some of this complexity. However, details of the geometry and the depth that the plate penetrates werelargely unknown. Since 2004, temporary experiments and the expansion of the permanent network of the Servicio Sismológico Nacional (SSN, Mexican National Seismological Service) have improved resolution of the plate geometry and have helped to map its descent into the upper mantle. Going from northwest to southeast, the Cocos plate appears to be fragmenting into north and south segments. The north segment subducts with an angle of ~30º and the south with an angle of ~10-15º. The transition is smooth near the trench and progresses to a tear at depth; this coincides with the projection of the Orozco Fracture Zone to depth. Also, this transition marks the limit of the presence to the south of an ultra slow velocity layer (USL) on top of the slab.South of this transition, the Cocos plate subducts horizontally , underplating the North American plate for a distance of ~140 to ~300 km from the trench. Along this horizontal region, silent slow events (SSE) and tectonic tremor (TT) have been observed. At a distance of 300 km from the trench (beneath central Mexico), the plate dives into the mantle with an angle of 76º to a depth of 500 km. This geometry changes abruptly to the south, marking the eastern limit of the USL. This change seems to be also characterized by a tear on the slab. Finally to the south, the Cocos plate subducts with a constant angle of 26º. This presentation summarizes the work of many contributors including A. Arciniega-Ceballos, M. Brudzinski, E. Cabral-Cano, T. Chen, R. Clayton,F. Cordoba-Montiel,P. Davis,S. Dougherty,F. Green, M. Gurnis, D. V. Helmberger, A. Husker,A. Iglesias, Y. Kim, V. Manea, D. Melgar, M. Rodríguez-Domínguez,S. K. Singh, T.-R. A. Song, C. M. Valdés-González, D. Valencia-Cabrera

  2. Biomechanical analysis of acromioclavicular joint dislocation treated with clavicle hook plates in different lengths.

    Science.gov (United States)

    Shih, Cheng-Min; Huang, Kui-Chou; Pan, Chien-Chou; Lee, Cheng-Hung; Su, Kuo-Chih

    2015-11-01

    Clavicle hook plates are frequently used in clinical orthopaedics to treat acromioclavicular joint dislocation. However, patients often exhibit acromion osteolysis and per-implant fracture after undergoing hook plate fixation. With the intent of avoiding future complications or fixation failure after clavicle hook plate fixation, we used finite element analysis (FEA) to investigate the biomechanics of clavicle hook plates of different materials and sizes when used in treating acromioclavicular joint dislocation. Using finite element analysis, this study constructed a model comprising four parts: clavicle, acromion, clavicle hook plate and screws, and used the model to simulate implanting different types of clavicle hook plates in patients with acromioclavicular joint dislocation. Then, the biomechanics of stainless steel and titanium alloy clavicle hook plates containing either six or eight screw holes were investigated. The results indicated that using a longer clavicle hook plate decreased the stress value in the clavicle, and mitigated the force that clavicle hook plates exert on the acromion. Using a clavicle hook plate material characterized by a smaller Young's modulus caused a slight increase in the stress on the clavicle. However, the external force the material imposed on the acromion was less than the force exerted on the clavicle. The findings of this study can serve as a reference to help orthopaedic surgeons select clavicle hook plates.

  3. 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.

  4. 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.

  5. 浮托顶推法架设64m钢桁梁技术%Technology of Erecting 64 m Span Steel Truss Girder with Float Tow and Jack - in Method

    Institute of Scientific and Technical Information of China (English)

    张云昭

    2011-01-01

    研究目的:浮托顶推法架设钢桁梁的施工设施主要由膺架、滑道、水上浮托支承、顶推纵移、方向及定位控制等五大系统组成.文章介绍了其工艺原理、工艺流程、操作步骤和主要安全质量措施,对修建同类桥梁具有重要的指导意义和借鉴意义.研究结论:浮托顶推法架设钢桁梁是在一般浮拖法架梁基础上的创新,它与一般浮拖法架梁的主要区别是钢梁纵移的动力不同,即采用钢桁梁后端的顶推装置代替前方的牵引设备,具有设备简单、操作方便、速度均匀、运行平稳、有利安全的特点.%Research purposes: Erecting the steel truss girder with the float tow and jack -in method needs five systems of the corbelling, slideway , bearing of uplift force, longitudinal movement by jack - in, and direction and position controller. This paper introduces the main technique principle, the technological process, operation steps and the measures of ensuring safety and quality of erecting the steel truss girder with the float toe and jack - in method for providing the reference to construction of similar bridge.Research conclusions:The float tow and jack -in method is the innovation based on the traditional float toe method. It is different from the traditional float toe method in the power to make the girder longitudinal moving. Namely, it uses the jack -in device at the rear end of steel truss to substitute the traction device in the front of the steel truss, with the features of using simply equipments, easy operation, even velocity, smooth running and ensuring the security.

  6. Unusual initial development of an esthesioneuroblastoma above the cribriform plate.

    Science.gov (United States)

    Mazzamuto, G; Bosschaert, P

    2012-01-01

    Esthesioneuroblastoma is a rare tumor localized in the superior part of the nasal cavity. Extension in the anterior cerebral fossa is sometimes observed. As we discovered in our patient, the location of the tumor above the cribriform plate was very unusual and meningioma was suspected. Features and prognosis are discussed below.

  7. Studies of the buckling of composite plates in compression

    DEFF Research Database (Denmark)

    Hayman, B.; Berggreen, Christian; Lundsgaard-Larsen, Christian

    2009-01-01

    As part of the MARSTRUCT Network of Excellence on Marine Structures, a series of studies has been carried out into the buckling of glass fibre reinforced polymer plates with in-plane compression loading. The studies have included fabrication and testing of square, laminated panels with various...

  8. Studies of the Buckling of Composite Plates in Compression

    DEFF Research Database (Denmark)

    Hayman, B.; Berggreen, Christian; Lundsgaard-Larsen, Christian

    2011-01-01

    As part of the Network of Excellence on Marine Structures (MARSTRUCT), a series of studies has been carried out into the buckling of glass-fibre-reinforced polymer plates with in-plane compression loading. The studies have included fabrication and testing of square, laminated panels with various...

  9. Avaliação da soldagem multipasse de chapas espessas de aços inoxidáveis lean duplex UNS S32304 soldadas pelos processos SMAW, GMAW e FCAW: parte 1: propriedades mecânicas Evaluation of multipass welding of thick lean duplex stainless steel UNS S32304 plates welded by SMAW, GMAW and FCAW: part 1: Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Ronaldo Cardoso Junior

    2012-12-01

    Full Text Available Os aços inoxidáveis duplex (AID vêm se apresentando como uma excelente alternativa para aplicações em que alta resistência à corrosão e alta resistência mecânica são requeridas. Contudo, os AID, incluindo os aços inoxidáveis lean duplex, apresentam soldabilidade inferior em relação aos aços inoxidáveis austeníticos. Nesse sentido, esse trabalho tem como objetivo a avaliação da soldagem multipasse de chapas 22 mm de espessura da liga inoxidável lean duplex UNS S32304, utilizando-se os processo SMAW, GMAW e FCAW e consumíveis com dois tipos de composição química, 22%Cr9%Ni3%Mo e 23%Cr7%Ni, totalizando seis experimentos. Foram empregados chanfros em V com 60º e suporte cerâmico para soldagem do passe de raiz, sendo que o aporte térmico foi mantido praticamente constante em 1,6 kJ.mm-1. Determinou-se os tempos de soldagem e a seqüência de passes, objetivando uma análise de produtividade, em seguida as juntas soldadas foram submetidas à END por raios x. Foram extraídos corpos de prova para ensaios de tração, dobramento, Charpy a -30 ºC e microdureza. A produtividade dos processos semi-automáticos se mostrou pelo menos 63 % maior que a do processo SMAW, enquanto o processo FCAW se mostrou de 6 a 18% mais rápido que o GMAW. Foram encontradas descontinuidades (porosidade consideradas aceitáveis segundo ASME B31.3 em alguns dos experimentos, que não influenciaram negativamente os resultados mecânicos, os quais se apresentaram acima requerimento do metal de base e especificado por normas de fabricação.The duplex stainless steels (DSS's have been placed as an excellent alternative for applications where high corrosion resistance and high mechanical strength are required. However, DSS's, including the lean duplex, present lower weldability than the austenitic stainless steels. Thus, this study aims to evaluate the multipass welding of 22 mm plates of lean duplex stainless steel alloy UNS S32304, using the process

  10. Temperature Uniformity of Heated Mold Plate by Oscillating Heat Pipe

    Directory of Open Access Journals (Sweden)

    Kamonpet Patrapon

    2015-01-01

    Full Text Available Uniformity of the temperature in the mold plate is of paramount important since it will affect the dimensional stability of the part produced. To provide uniform temperature to the metal plate, many factors need to be considered such as choice of heating technology, uniformity of a heat source, a type of control, etc. This paper aims to study the temperature uniformity of metal plate using closed-loop oscillating heat pipe (CLOHP as a heat transfer device. The metal plates which were P-20 with the size of 306 x 130 mm2 were used. Metal plate was gouged to a depth of 3 mm for installing the CLOHP. Distances from the heating device to the metal plate surface were 5 and 10 mm. The surface temperatures of the metal plate were controlled at 80, 90, 100, 110, 120, and 130°C. Sixteen pointa of temperature were recorded. The results were then compared to those using the heat source as the cartridge heater arranged in the similar way with the same heating capacity. Once the system entered the steady state, it was found that the temperature distribution of metal plate using the CLOHP has a deviation in the range of ± 1.00°C and ± 0.94°C at the CLOHP depth of 5 mm. and 10 mm., respectively. While those of using cartridge heater deviated in the range of ± 1.35°C and ± 1.16°C. Compare to the recommended value from the ASTM Standard that the mold surface temperature need to be in the range of ± 2.0°C, the CLOHP shows the very promising results.

  11. Analytical solution for multilayer plates using general layerwise plate theory

    Directory of Open Access Journals (Sweden)

    Vuksanović Đorđe M.

    2005-01-01

    Full Text Available This paper deals with closed-form solution for static analysis of simply supported composite plate, based on generalized laminate plate theory (GLPT. The mathematical model assumes piece-wise linear variation of in-plane displacement components and a constant transverse displacement through the thickness. It also include discrete transverse shear effect into the assumed displacement field, thus providing accurate prediction of transverse shear stresses. Namely, transverse stresses satisfy Hook's law, 3D equilibrium equations and traction free boundary conditions. With assumed displacement field, linear strain-displacement relation, and constitutive equations of the lamina, equilibrium equations are derived using principle of virtual displacements. Navier-type closed form solution of GLPT, is derived for simply supported plate, made of orthotropic laminae, loaded by harmonic and uniform distribution of transverse pressure. Results are compared with 3D elasticity solutions and excellent agreement is found.

  12. Participant report for University of North Carolina at Charlotte (USA) Hole Plate No. 132

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Hansen, Hans Nørgaard; Morace, Renate Erica

    plate [1], designed and manufactured by DTU. A measurement procedure was sent to each participant together with the hole plate to be measured. The procedure consists mainly of two parts [2]: 1) four reversal measurements, by which the systematic errors in the measuring plane (X,Y) on the CMM...

  13. Plate tectonics of the Mediterranean region.

    Science.gov (United States)

    McKenzie, D P

    1970-04-18

    The seismicity and fault plane solutions in the Mediterranean area show that two small rapidly moving plates exist in the Eastern Mediterranean, and such plates may be a common feature of contracting ocean basins. The results show that the concepts of plate tectonics apply to instantaneous motions across continental plate boundaries.

  14. 30 CFR 18.13 - Certification plate.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Certification plate. 18.13 Section 18.13... Certification plate. Each certified component shall be identified by a certification plate attached to the... characteristics of the component. The plate shall be of serviceable material, acceptable, to MSHA, and shall...

  15. 21 CFR 872.4760 - Bone plate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone plate. 872.4760 Section 872.4760 Food and... DENTAL DEVICES Surgical Devices § 872.4760 Bone plate. (a) Identification. A bone plate is a metal device... plate with screws to prevent movement of the segments. (b) Classification. Class II. ...

  16. 30 CFR 18.11 - Approval plate.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approval plate. 18.11 Section 18.11 Mineral... plate. (a)(1) The notice of approval will be accompanied by a photograph of an approval plate, bearing... number shall be added to the original approval number on the approval plate. (Example: Original approval...

  17. Beyond plate tectonics - Looking at plate deformation with space geodesy

    Science.gov (United States)

    Jordan, Thomas H.; Minster, J. Bernard

    1988-01-01

    The requirements that must be met by space-geodetic systems in order to constrain the horizontal secular motions associated with the geological deformation of the earth's surface are explored. It is suggested that in order to improve existing plate-motion models, the tangential components of relative velocities on interplate baselines must be resolved to an accuracy of less than 3 mm/yr. Results indicate that measuring the velocities between crustal blocks to + or - 5 mm/yr on 100-km to 1000-km scales can produce geologically significant constraints on the integrated deformation rates across continental plate-boundary zones such as the western United States.

  18. Plating on some difficult-to-plate metals and alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dini, J.W.; Johnson, H.R.

    1980-02-01

    Electrodeposition of coatings on metals such as beryllium, beryllium-copper, Kovar, lead, magnesium, thorium, titanium, tungsten, uranium, zirconium, and their alloys can be problematic. This is due in most cases to a natural oxide surface film that readily reforms after being removed. The procedures we recommend for plating on these metals rely on replacing the oxide film with a displacement coating, or etching to allow mechanical keying between the substrate and plated deposit. The effectiveness of the procedures is demonstrated by interface bond strengths found in ring-shear and conical-head tensile tests.

  19. Beyond plate tectonics - Looking at plate deformation with space geodesy

    Science.gov (United States)

    Jordan, Thomas H.; Minster, J. Bernard

    1988-01-01

    The requirements that must be met by space-geodetic systems in order to constrain the horizontal secular motions associated with the geological deformation of the earth's surface are explored. It is suggested that in order to improve existing plate-motion models, the tangential components of relative velocities on interplate baselines must be resolved to an accuracy of less than 3 mm/yr. Results indicate that measuring the velocities between crustal blocks to + or - 5 mm/yr on 100-km to 1000-km scales can produce geologically significant constraints on the integrated deformation rates across continental plate-boundary zones such as the western United States.

  20. Chladni's law for vibrating plates

    Science.gov (United States)

    Rossing, Thomas D.

    1982-03-01

    The normal vibrational modes of free circular plates can be classified according to the number of nodal diameters m and the number of nodal circles n. Chladni observed that the addition of one nodal circle raised the frequency f about the same amount as adding two nodal diameters, and Rayleigh pointed out that f is proportional to (m+2n)2 for large f. Waller, however, concluded that the number of nodal diameters necessary to raise the frequency as much as a nodal circle varies from two to five. We have examined data on the vibrations of flat and non-flat circular plates and fitted their vibration frequencies to the relationship f = c(m+bn)k. By proper choice of c it is possible to satisfy Chladni's law (b = 2, k = 2) over quite a wide range of frequency in flat plates. Non-flat plates such as cymbals and bells, require different choices of b and k. A brief history of Chladni patterns, and suggestions for observing and demonstrating the vibrational modes of plates are included (AIP).

  1. 船体梁刚度对波激振动影响的比较研究%Comparative study of the effect of hull-girder stiffness on springing behaviors

    Institute of Scientific and Technical Information of China (English)

    汪雪良; 顾学康; 胡嘉骏

    2016-01-01

    With the large scale development trend, the lengths of ships are constantly increasing. As a re⁃sult, high strength steel is widely used due to the demand of lightweight design of ship structures. Hull gird⁃er of the ship, in particular, becomes much more flexible than those of small and medium-sized ships. This results in different characteristics of springing behaviors of ship structures when the ship travels on the sea. In this paper, a large engineering ship is taken as the research subject in order to study its low-and high-frequency wave induced load responses in waves. Two kinds of steel girders with different trans⁃verse-section moments of inertia are used to simulate original and changed stiffness in a segmented model. The 3D hydroelasticity theory is employed to predict responses of the ship in waves, and comparison analy⁃sis is also conducted between experimental and theoretical results. It is shown that springing behavior is prone to happen with low hull-girder stiffness, and continual springing behavior will result in serious fa⁃tigue damage to ship structures. The necessity of considering the hull-girder stiffness as an important pa⁃rameter in the structural optimization design of large ships is thus verified as the effect of hull-girder stiff⁃ness on springing behaviors cannot be neglected.%船舶大型化发展的趋势使得其尺度越来越大,而结构轻量化设计的需求则使高强度钢被大量应用于其结构设计之中,相对于传统的小尺度船舶,相对刚度的下降使得船体梁变得越来越“软”,这将导致大型船舶在波浪中航行时船体结构波激振动特性发生变化。采用模型试验和理论预报的方法,研究某大型工程船在不同船体梁刚度下的低频和高频垂向波浪载荷响应。分段试验模型采用2种横剖面惯性矩的钢质梁,用以分别模拟船舶横剖面原始的和变化后的刚度。采用三维水弹性理论对该船在波浪

  2. 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

  3. 铁路混凝土箱梁箱内空腔共鸣噪声及其影响研究%Study on Cavity Resonance Noise of Railway Concrete Box-Girder and Its Influence

    Institute of Scientific and Technical Information of China (English)

    张迅; 王党雄; 李小珍

    2015-01-01

    为探讨铁路混凝土箱梁箱内空腔共鸣噪声及其影响,以某客运专线32 m预应力混凝土简支箱梁为研究对象,开展实桥振动与噪声试验,分析箱梁振动与噪声的时域特性及频谱特性。采用有限元法建立三维空腔声模型,分析箱内空腔声模态与腔内噪声峰值的关联性。采用边界元法分别建立两端封闭与两端开口的箱梁声学模型,验证箱内空腔共鸣噪声的来源及其影响。结果表明:在特定行车速度下,箱内噪声出现“拍”现象,显著增大箱内噪声,瞬时最大声压可达40 Pa,峰值频率为75.0 Hz;箱内噪声的“拍”现象来源于顶板的振动噪声,顶板的振动峰值频率与箱内空腔垂向声模态频率吻合时,箱内噪声显著增大;由于梁缝的声泄漏特性,箱内空腔共鸣噪声在梁缝处衰减较大,但其对桥梁两侧总体噪声的影响不可忽略。%In order to study the cavity resonance noise of concrete box-girder and its influence,a field test con-cerning vibration and noise of a 32 m PC simply-supported box-girder was carried out,to investigate the time-domain characteristics and frequency spectrum characteristics of vibration and noise of the box-girder.A 3D cavity acoustical model was established based on FEM to analyze the correlation between cavity acoustic mode and cavity noise peak.Two acoustical models for box-girders with closed ends and open ends,were built based on BEM,respectively,to verify the source and influence of cavity resonance noise.Results showed that the“beat”wave phenomenon of cavity noise appeared under a specific train speed,significantly increasing the cavi-ty noise,with the transient maximum sound pressure of cavity noise reaching 40 Pa and the noise peak frequen-cy being 75.0 Hz;The “beat”wave phenomenon of cavity noise derived from the vibration of deck.When the peak vibration frequency of deck matched with the frequency of vertical acoustic modal of the cavity

  4. 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

  5. 高铁板式轨道区段箱梁结构噪声辐射分析%Noise Radiation Analysis of Box-girder Structure in Slab Track Section of High Speed Railways

    Institute of Scientific and Technical Information of China (English)

    石广田; 杨新文; 张小安; 杨建近

    2015-01-01

    A high speed train-track coupling dynamics model was established using Simpack software, and the wheel/rail vertical contact force excited by track irregularity spectrum was calculated. The wheel/rail vertical force was taken as a boundary condition and applied to the finite element model (FEM) of an elevated box girder structure to calculate its surface vibration response. Then, the vibration response was taken as the acoustic boundary conditions and was applied to the bound-ary element model (BEM) of the elevated box-girder structure to analyze its sound radiation. The results show that, using the finite element method and the boundary element method, the vibration noise of the concrete simply-supported box-beam structure can be effectively calculated with shell elements. The vibration noise is mainly concentrated in the low frequency range of 0-200 Hz, and the peaks mainly appear at the central frequencies of 16 Hz, 25 Hz, 80 Hz-100 Hz. The sound pres-sure level decreases with the increase of the distance from the ground in the lateral sound field and this tendency is more ob-vious for lower frequency sound field. The sound pressure level generally increases with the increase of the distance from the ground in the vertical acoustic field, and the sound pressure level in far field area does not change obviously for the fre-quencies below 31.5 Hz. In the range of 80 Hz-100 Hz, the sound pressure levels of the field points near the girder, especial-ly above the girder, are higher than those in the other regions.%利用Simpack软件建立高速列车-轨道耦合动力学模型,计算在轨道不平顺谱激励下的轮轨垂向力,以此作为载荷边界条件施加到高架箱梁结构的有限元模型。计算了高架箱梁表面的振动响应,并利用箱梁结构振动响应作为声学边界条件。进而又采用间接边界元法对其进行声辐射分析。研究结果表明,利用板壳单元,采用有限元—边界元方法能够有效

  6. Multiregional evaluation of the SimPlate heterotrophic plate count method compared to the standard plate count agar pour plate method in water.

    Science.gov (United States)

    Jackson, R W; Osborne, K; Barnes, G; Jolliff, C; Zamani, D; Roll, B; Stillings, A; Herzog, D; Cannon, S; Loveland, S

    2000-01-01

    A new SimPlate heterotrophic plate count (HPC) method (IDEXX Laboratories, Westbrook, Maine) was compared with the pour plate method at 35 degrees C for 48 h. Six laboratories tested a total of 632 water samples. The SimPlate HPC method was found to be equivalent to the pour plate method by regression analysis (r = 0. 95; y = 0.99X + 0.06).

  7. Multiregional Evaluation of the SimPlate Heterotrophic Plate Count Method Compared to the Standard Plate Count Agar Pour Plate Method in Water

    OpenAIRE

    Jackson, R. Wayne; Osborne, Karen; Barnes, Gary; Jolliff, Carol; Zamani, Dianna; Roll, Bruce; Stillings, Amy; Herzog, David; Cannon, Shelly; Loveland, Scott

    2000-01-01

    A new SimPlate heterotrophic plate count (HPC) method (IDEXX Laboratories, Westbrook, Maine) was compared with the pour plate method at 35°C for 48 h. Six laboratories tested a total of 632 water samples. The SimPlate HPC method was found to be equivalent to the pour plate method by regression analysis (r = 0.95; y = 0.99X + 0.06).

  8. Multiple-Dynode-Layer Microchannel Plate

    Science.gov (United States)

    Woodgate, Bruce E.

    1990-01-01

    Improved microchannel-plate electron image amplifier made of stack of discrete microchannel-plate layers. New plates easier to manufacture because no need to etch long, narrow holes, to draw and bundle thin glass tubes, or to shear plates to give microchannels curvatures necessary for reduction of undesired emission of ions. Discrete dynode layers stacked with slight offset from layer to layer to form microchannel plate with curved channels. Provides for relatively fast recharging of microchannel dynodes, with consequent enhancement of performance.

  9. Ultimately Thin Metasurface Wave Plates

    CERN Document Server

    Keene, David; Durach, Maxim

    2015-01-01

    Optical properties of a metasurface which can be considered a monolayer of two classical uniaxial metamaterials, parallel-plate and nanorod arrays, are investigated. It is shown that such metasurface acts as an ultimately thin sub-50 nm wave plate. This is achieved via an interplay of epsilon-near-zero and epsilon-near-pole behavior along different axes in the plane of the metasurface allowing for extremely rapid phase difference accumulation in very thin metasurface layers. These effects are shown to not be disrupted by non-locality and can be applied to the design of ultrathin wave plates, Pancharatnam-Berry phase optical elements and plasmon-carrying optical torque wrench devices.

  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. 60 Meters Steel Box Girder Installation across Existing Railway with Bridge Machine Technique%采用架桥机进行跨既有铁路60m钢箱梁安装施工技术

    Institute of Scientific and Technical Information of China (English)

    郝晋新

    2012-01-01

    Taking Shanxi Pingyang freeway LJ26 contract section of Taiyuan hub K119 + 555 overpass bridge project as an example, for problems in large span steel box girder across existing railway construction, by comparison of the schemes pro- posed, and finally the paper selects the integral installation construction method of large span steel box girder with new bridge machine across the existing double railway electrification, and accordingly independent design and manufacture of a kind of YQXZ240t-60A3 bridge erecting machine is made. The paper introduces the composition of bridge erecting machine, and summarizes the keg construction process of the bridging machine for large span steel box beam erection construction.%以山西省平阳高速公路LJ26合同段太原枢纽K119+555跨线桥工程为例,针对大跨度钢箱梁跨既有铁路施工时遇到的难题,经方案比选,提出并最终采用新型架桥机进行上跨既有双线电气化铁路的大跨度钢箱梁的整体安装施工方法,并据此自主设计制造了一种YQXZ240t一60A3架桥机。介绍了架桥机的组成,总结了采用该架桥机进行大跨度钢箱梁架设施工的关键施工工艺。

  12. 简直转连续斜箱梁桥单梁静载试验分析%PRESTRESSED REINFORCED CONCRETE SIMPLY SUPPORTED-CONTINUOUS BOX GIRDER SINGLE STATIC LOAD EXPERIMENT AND ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    张宏祥; 曹岩

    2013-01-01

    The single static load experiment is one of the important means to identify whether the bridges can be normal operationed or not during the normal operation period. We can detect whether single static structure performance meets the requirements of design documents and specifications and guarantee the safety of bridge after the completion of the bridge by the single static load experiment This paper unifies some prestressed reinforced concrete box example. It introduced the experiment examination content, the testing sequence, and the test result analysis of the prestressed reinforced concrete box girder simply supported - continuous static load testing. We can make a correct evaluation of prestressed reinforced concrete box girder, and provide the basis for future tests by summarizing the results of static loading test%单梁静载试验是检验桥梁在正常运营期间能否保证桥梁正常运营的一个重要手段,通过对单梁静载试验,检测单梁的结构性能是否达到设计文件和规范要求,保证成桥后桥梁的安全.结合某预应力混凝土斜箱梁实例,介绍预应力钢筋混凝土简直转连续单梁静载试验的检测内容、试验步骤和试验结果分析.总结单梁静载试验结果,对预应力钢筋混凝土简直转连续梁桥作出正确的质量评估,为以后的试验提供理论依据.

  13. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./ Russian Progress Report for Fiscal Year 1997, Volume 4, Part 8 - Neutron Poison Plates in Assemblies Containing Homogeneous Mixtures of Polystyrene-Moderated Plutonium and Uranium Oxides

    Energy Technology Data Exchange (ETDEWEB)

    Yavuz, M.

    1999-05-01

    In the 1970s at the Battelle Pacific Northwest Laboratory (PNL), a series of critical experiments using a remotely operated Split-Table Machine was performed with homogeneous mixtures of (Pu-U)O{sub 2}-polystyrene fuels in the form of square compacts having different heights. The experiments determined the critical geometric configurations of MOX fuel assemblies with and without neutron poison plates. With respect to PuO{sub 2} content and moderation [H/(Pu+U)atomic] ratio (MR), two different homogeneous (Pu-U) O{sub 2}-polystyrene mixtures were considered: Mixture (1) 14.62 wt% PuO{sub 2} with 30.6 MR, and Mixture (2) 30.3 wt% PuO{sub 2} with 2.8 MR. In all mixtures, the uranium was depleted to about O.151 wt% U{sup 235}. Assemblies contained copper, copper-cadmium or aluminum neutron poison plates having thicknesses up to {approximately}2.5 cm. This evaluation contains 22 experiments for Mixture 1, and 10 for Mixture 2 compacts. For Mixture 1, there are 10 configurations with copper plates, 6 with aluminum, and 5 with copper-cadmium. One experiment contained no poison plate. For Mixture 2 compacts, there are 3 configurations with copper, 3 with aluminum, and 3 with copper-cadmium poison plates. One experiment contained no poison plate.

  14. Review of HEDP direct copper plating process on iron and steel workpiece after 30 years of development Part Ⅲ. Wastewater treatment of HEDP and other alkaline copper plating solutions%钢铁件HEDP直接镀铜工艺开发30年回顾第三部分——HEDP及其他碱性镀铜液的废水处理

    Institute of Scientific and Technical Information of China (English)

    方景礼

    2009-01-01

    比较了几种碱性无氰镀铜螯合剂的环保特性与废水处理难度,分析了氧化破坏法、化学沉淀法和离子交换法处理螯合废水的优缺点,介绍了从碱、酸铜废水中回收铜粉以及HEDP镀铜液除铜和除HEDP的高效沉淀新技术.%The environmental protection characteristics and wastewater treatment difficulty of various chelating agents used in non-cyanide alkaline copper plating were compared. The advantages and disadvantages of oxidative destruction, chemical precipitation and ion exchange method for chelating wastewater treatment were analyzed. New methods for recovering copper powder from acidic/alkaline copper-containing wastewater and the highly-efficient precipitation method for removing copper and HEDP from HEDP copper plating solution were introduced.

  15. Plate-like osteoma cutis.

    Science.gov (United States)

    Orme, Charisse M; Hale, Christopher S; Meehan, Shane A; Long, Wendy

    2014-12-16

    Osteoma cutis is the aberrant development of bone within the skin. The bone formation may be de novo (primary) or result from an injury to the skin (secondary). Here we present a healthy 53-year-old man with no known abnormalities in calcium or phosphate metabolism with plate-like osteoma cutis of the scalp. Plate- or plaque-like osteoma cutis was initially described as a congenital condition but has now been reported several times in the literature as an idiopathic process that occurs in adults. Treatment options are limited and are only required if the lesion is bothersome to the patient.

  16. Hydroelasticity of a Floating Plate

    DEFF Research Database (Denmark)

    Chen, X.; Jensen, Jørgen Juncher; Cui, W.

    2003-01-01

    The membrane forces are included in the hydroelastic analysis of a floating plate undergoing large vertical deflections in regular monochromatic multidirectional waves. The first-order vertical displacements induced by the linear wave exciting forces are calculated by the mode expansion method...... in the frequency domain. The second-order vertical displacements induced by the membrane forces are calculated by the von Karman plate theory. The results show that the membrane contribution both in terms of the axial stresses and the effect on the bending stresses can be important...

  17. Orifice plates and venturi tubes

    CERN Document Server

    Reader-Harris, Michael

    2015-01-01

    This book gives the background to differential-pressure flow measurement and goes through the requirements explaining the reason for them. For those who want to use an orifice plate or a Venturi tube the standard ISO 5167 and its associated Technical Reports give the instructions required.  However, they rarely tell the users why they should follow certain instructions.  This book helps users of the ISO standards for orifice plates and Venturi tubes to understand the reasons why the standards are as they are, to apply them effectively, and to understand the consequences of deviations from the standards.

  18. Outer rise seismicity of the subducting Nazca Plate: Plate stress distribution, fault orientation and plate hydration

    Science.gov (United States)

    Barama, Louisa

    Subduction of the Nazca plate beneath the South American plate drives frequent and sometimes large magnitude earthquakes. During the past 40 years, significant numbers of outer rise earthquakes have occurred in the offshore regions of Colombia and Chile. In this study, we investigate the distribution of stress due to lithospheric bending and the extent of faults within the subducting plate. To calculate more accurate epicenters and to constrain which earthquakes occurred within the outer rise, we use hypocentroidal decomposition to relocate earthquakes with Global Centroid Moment Tensor (GCMT) solutions occurring after 1976 offshore Colombia and Chile. We determine centroid depths of outer rise earthquakes by inverting teleseismic P-, SH-, and SV- waveforms for earthquakes occurring from 1993 to 2014 with Mw ≥ 5.5. In order to further constrain the results of the waveform inversion, we estimate depths by comparing earthquake duration, amplitude, and arrival times for select stations with waveforms with good signal to noise ratios. Our results indicate that tensional earthquakes occur at depths down to 13 km and 24 km depth beneath the surface in the Colombia and Chile regions, respectively. Since faulting within the outer rise can make the plate susceptible to hydration and mantle serpentinization, we therefore infer the extent of possible hydration of the Nazca plate to extend no deeper than the extent of tensional outer rise earthquakes.

  19. Clear double layer Bioplast feeding plate for neonates with cleft palate.

    Science.gov (United States)

    Yilmaz, R Burcu Nur; Mutlu, Meltem; Germec-Cakan, Derya

    2015-01-01

    An infant with cleft palate was referred to cleft clinic of the Orthodontic Department. The mother was concerned to feed the child because of the escape of milk from the nose. Intraoral examination revealed a large palatal cleft extending from hard to soft palate involving uvula. The impression was taken and dental cast obtained. A 3 mm soft and afterward a 1 mm hard Bioplast plate was pressed using Biostar device (Scheu-Dental Gmbh, Iserlohn, Germany) on the model. Finally, a hole was prepared on the anterior part to put a thread through it. The infant tolerated the plate immediately and encounters no difficulties during feeding. The inlaying soft Bioplast plates eliminate the risk of tissue irritation, whereas the covering hard Bioplast plate supplies endurance. The fabrication of the clear Bioplast feeding plate is easy and less time-consuming compared with acrylic plates and may be recommended in crowded and overloaded cleft centers.

  20. 基于3D打印股骨远端骨折标准件库接骨板的数字化内固定%Digital design of standard parts database for distal femoral fractures treated with plating via three-dimensional printing

    Institute of Scientific and Technical Information of China (English)

    吴长福; 郑祖高; 陈宣煌; 余正希; 张国栋; 陈旭; 林海滨; 吴献伟; 高小强

    2016-01-01

    BACKGROUND:On CT reconstruction of three-dimensional (3D) model, fracture virtual reduction and internal fixation cannot be achieved, and reasonable operation scheme cannot be formulated. Digital design can fuly meet the needs of clinical orthopedics physicians. Standard parts database can provide the possibility to choose the ideal internal fixation. 3D printing makes the reasonable operation scheme accurate in clinical implementation. OBJECTIVE:To discuss the feasibility, accuracy and minimal invasion of internal fixation in treatment of the distal femoral fracture with digital design of standard parts database by 3D printing. METHODS: (1) Nine adult lower extremity specimens were selected to take continuously thin-layer CT scanning. After Dicom images were imported into the mimics software, the model was established. According to the AO classification, they were classified into A1-3, B1-3 and C1-3 types of distal femoral fracture by virtual design. Internal fixation with plate and screw formed standard parts database virtualy. It was printed out the pilot hole of the navigation module design by three-dimensional printing forming technique. Plate and screw were inserted assisted by the module. X-ray and CT scan were taken postoperatively to access the position. (2) 30 patients with distal femoral fracture were subjected to above fixation. The operation time, intraoperative blood loss and postoperative drainage were recorded. Imaging and curative effects were evaluated during folow-up. RESULTS AND CONCLUSION: (1) Nine samples underwent X-ray and CT scan. 3D reconstruction results revealed plate position, screw entry point, nail direction, length and diameter were consistent with presetting data in Mimics software. The navigation models were designed to fit the lateral bony structure of distal femur. There were good fitting degree, good card position and good stability when the navigation was applied. It could guide plant and screw implantation. (2) In 30 cases

  1. Light splitting with imperfect wave plates.

    Science.gov (United States)

    Jackson, Jarom S; Archibald, James L; Durfee, Dallin S

    2017-02-01

    We discuss the use of wave plates with arbitrary retardances, in conjunction with a linear polarizer, to split linearly polarized light into two linearly polarized beams with an arbitrary splitting fraction. We show that for non-ideal wave plates, a much broader range of splitting ratios is typically possible when a pair of wave plates, rather than a single wave plate, is used. We discuss the maximum range of splitting fractions possible with one or two wave plates as a function of the wave plate retardances, and how to align the wave plates to achieve the maximum splitting range possible when simply rotating one of the wave plates while keeping the other one fixed. We also briefly discuss an alignment-free polarization rotator constructed from a pair of half-wave plates.

  2. Effects of a sliding plate on morphology of the epiphyseal plate in goat distal femur.

    Science.gov (United States)

    Lin, Da-sheng; Lian, Ke-jian; Hong, Jia-yuan; Ding, Zhen-qi; Zhai, Wen-liang

    2012-01-01

    The aim of this study was to observe the effects of a sliding plate on the morphology of the epiphyseal plate in goat distal femur. Eighteen premature female goats were divided randomly into sliding plate, regular plate and control groups. Radiographic analysis and histological staining were performed to evaluate the development of epiphyseal plate at 4 and 8 weeks after surgery. In the sliding plate group, the plate extended accordingly as the epiphyseal plate grows, and the epiphyseal morphology was kept essential normal. However, the phenomenon of the epiphyseal growth retardation and premature closure were very common in the regular plate group. In addition, the sliding plate group exhibited more normal histologic features and Safranin O staining compared to the regular plate group. Our results suggest that the sliding plate can provide reliable internal fixation of epiphyseal fracture without inhibiting epiphyseal growth.

  3. Effects of a Sliding Plate on Morphology of the Epiphyseal Plate in Goat Distal Femur

    Directory of Open Access Journals (Sweden)

    Da-sheng LIN, Ke-jian LIAN, Jia-yuan HONG, Zhen-qi DING, Wen-liang ZHAI

    2012-01-01

    Full Text Available The aim of this study was to observe the effects of a sliding plate on the morphology of the epiphyseal plate in goat distal femur. Eighteen premature female goats were divided randomly into sliding plate, regular plate and control groups. Radiographic analysis and histological staining were performed to evaluate the development of epiphyseal plate at 4 and 8 weeks after surgery. In the sliding plate group, the plate extended accordingly as the epiphyseal plate grows, and the epiphyseal morphology was kept essential normal. However, the phenomenon of the epiphyseal growth retardation and premature closure were very common in the regular plate group. In addition, the sliding plate group exhibited more normal histologic features and Safranin O staining compared to the regular plate group. Our results suggest that the sliding plate can provide reliable internal fixation of epiphyseal fracture without inhibiting epiphyseal growth.

  4. Dike-induced contraction along oceanic and continental divergent plate boundaries

    KAUST Repository

    Trippanera, D.

    2014-10-28

    The axis of divergent plate boundaries shows extension fractures and normal faults at the surface. Here we present evidence of contraction along the axis of the oceanic ridge of Iceland and the continental Main Ethiopian Rift. Contraction is found at the base of the tilted hanging wall of dilational normal faults, balancing part of their extension. Our experiments suggest that these structures result from dike emplacement. Multiple dike injection induces subsidence above and uplift to the sides of the dikes; the transition in between is accommodated by reverse faults and subsequent peripheral inward dipping normal faults. Our results suggest that contraction is a direct product of magma emplacement along divergent plate boundaries, at various scales, marking a precise evolutionary stage and initiating part of the extensional structures (extension fractures and normal faults). Key Points Contraction along divergent plate boundaries results from dike emplacementContraction generates extensional structures along divergent plate boundariesSurface deformation along divergent plate boundaries may be magma induced

  5. Tectonics of the Nazca-Antarctic plate boundary

    Science.gov (United States)

    Anderson-Fontana, Sandra; Larson, Roger L.; Engeln, Joseph F.; Lundgren, Paul; Stein, Seth

    1987-01-01

    A new bathymetric chart of part of the Chile transform system is constructed, based mainly on an R/V Endeavor survey from 100 deg W to its intersection with the East Ridge of the Juan Fernandez microplate. A generally continuous lineated trend can be followed through the entire region, with the transform valley being relatively narrow and well-defined from 109 deg W to approximately 104 deg 30 min W. The fracture zone then widens to the east, with at least two probable en echelon offsets to the south at 104 deg and 102 deg W. Six new strike-slip mechanisms along the Chile Transform and one normal fault mechanism near the northern end of the Chile Rise, inverted together with other plate-motion data from the eastern portion of the boundary, produce a new best-fit Euler pole for the Nazca-Antarctic plate pair, providing tighter constraints on the relative plate motions.

  6. Propagation of elastic waves in a plate with rough surfaces

    Institute of Scientific and Technical Information of China (English)

    DAI Shuwu; ZHANG Hailan

    2003-01-01

    The characteristics of Lamb wave propagating in a solid plate with rough surfacesare studied on the basis of small perturbation approximation. The Rayleigh-Lamb frequencyequation expressed with SA matrix is presented. The Rayleigh-Lamb frequency equation fora rough surface plate is different from that for a smooth surface plate, resulting in a smallperturbation Ak on Lamb wave vector k. The imaginary part of Ak gives the attenuationcaused by wave scattering. An experiment is designed to test our theoretical predications.By using wedge-shape pipes, different Lamb wave modes are excited. The signals at differentpositions are received and analyzed to get the dispersion curves and attenuations of differentmodes. The experimental results are compared with the theoretical predications.

  7. Tectonics of the Nazca-Antarctic plate boundary

    Science.gov (United States)

    Anderson-Fontana, Sandra; Larson, Roger L.; Engeln, Joseph F.; Lundgren, Paul; Stein, Seth

    1987-01-01

    A new bathymetric chart of part of the Chile transform system is constructed, based mainly on an R/V Endeavor survey from 100 deg W to its intersection with the East Ridge of the Juan Fernandez microplate. A generally continuous lineated trend can be followed through the entire region, with the transform valley being relatively narrow and well-defined from 109 deg W to approximately 104 deg 30 min W. The fracture zone then widens to the east, with at least two probable en echelon offsets to the south at 104 deg and 102 deg W. Six new strike-slip mechanisms along the Chile Transform and one normal fault mechanism near the northern end of the Chile Rise, inverted together with other plate-motion data from the eastern portion of the boundary, produce a new best-fit Euler pole for the Nazca-Antarctic plate pair, providing tighter constraints on the relative plate motions.

  8. Comment on "Intermittent plate tectonics?".

    Science.gov (United States)

    Korenaga, Jun

    2008-06-06

    Silver and Behn (Reports, 4 January 2008, p. 85) proposed that intermittent plate tectonics may resolve a long-standing paradox in Earth's thermal evolution. However, their analysis misses one important term, which subsequently brings their main conclusion into question. In addition, the Phanerozoic eustasy record indicates that the claimed effect of intermittency is probably weak.

  9. License plate recognition using DTCNNs

    NARCIS (Netherlands)

    ter Brugge, M.H; Stevens, J.H; Nijhuis, J.A G; Spaanenburg, L; Tavsanonoglu, V

    1998-01-01

    Automatic license plate recognition requires a series of complex image processing steps. For practical use, the amount of data to he processed must be minimized early on. This paper shows that the computationally most intensive steps can be realized by DTCNNs. Moreover; high-level operations like fi

  10. Corrosion resistant metallic bipolar plate

    Science.gov (United States)

    Brady, Michael P.; Schneibel, Joachim H.; Pint, Bruce A.; Maziasz, Philip J.

    2007-05-01

    A corrosion resistant, electrically conductive component such as a bipolar plate for a PEM fuel cell includes 20 55% Cr, balance base metal such as Ni, Fe, or Co, the component having thereon a substantially external, continuous layer of chromium nitride.

  11. The seismotectonics of plate boundaries

    Science.gov (United States)

    Berger, J.; Brune, J. N.; Goodkind, J.; Wyatt, F.; Agnew, D. C.; Beaumont, C.

    1981-01-01

    Research on the seismotectonics of plate boundaries is summarized. Instrumental development and an observational program designed to study various aspects of the seismotectonics of southern California and the northern Gulf of California are described. A unique superconducting gravimeter was further developed and supported under this program for deployment and operation at several sites. Work on Earth tides is also discussed.

  12. Main Girder Type Selection for Maputo Bridge in Mozambique Based on Sectional Model Wind Tunnel Test%基于节段模型风洞试验的莫桑比克马普托大桥主梁选型研究

    Institute of Scientific and Technical Information of China (English)

    周健; 樊泽民; 王骑; 孟令亮; 魏雪涛; 李元博

    2014-01-01

    为合理确定主跨680 m 的莫桑比克马普托大桥的主梁形式,利用节段模型风洞试验,分别研究了扁平钢箱梁、钢箱叠合梁和工字型叠合梁的气动性能。结果表明:扭转刚度较弱的工字型叠合梁颤振风速远低于检验风速,且涡激振动也不满足舒适性要求,在设计中不宜采用;钢箱叠合梁尽管颤振风速较高,但其在钢箱顶面凸起的混凝土桥面板会造成气流分离和漩涡脱落,可能存在较大涡激振动振幅的隐患,可在设计中选择性采用;扁平钢箱梁断面颤振临界风速高,且无明显涡激振动,为该大跨度悬索桥的优选主梁形式。试验结果还显示,若设置宽0.5 m 的风嘴导流板可进一步提高钢箱梁断面的颤振临界风速,但由于导流板直接影响造价并增加后期养护费用,而节段模型试验结果一般偏于保守,因此最后的取舍需要参考三维颤振计算或全桥气弹模型风洞试验结果。若在其斜腹板上外挂直径90 cm 的过桥水管,将显著弱化颤振性能和涡振性能,因此在设计中不宜采用。%To select a rational main girder type for the Maputo Bridge in Mozambique which is projected to have a main span of 680 m ,the aerodynamic behavior of three types of main girder ,in-cluding the flat steel box girder ,steel-concrete composite box girder and I-shaped composite girder were examined by the sectional model wind tunnel test .The results of the test indicate that the I-shaped composite girder with intrinsic low torsional stiffness is not a favorable solution in the de -sign ,for its flutter wind speed is much smaller than the testing wind speed and its vortex -induced vibration is not able to meet the requirements of physical and psychological comfort as well .The steel-concrete composite box girder can withstand higher flutter wind speed ,but the concrete deck slab humps on top of the steel box are prone to cause airflow

  13. Global Dynamic Numerical Simulations of Plate Tectonic Reorganizations

    Science.gov (United States)

    Morra, G.; Quevedo, L.; Butterworth, N.; Matthews, K. J.; Müller, D.

    2010-12-01

    We use a new numerical approach for global geodynamics to investigate the origin of present global plate motion and to identify the causes of the last two global tectonic reorganizations occurred about 50 and 100 million years ago (Ma) [1]. While the 50 Ma event is the most well-known global plate-mantle event, expressed by the bend in the Hawaiian-Emperor volcanic chain, a prominent plate reorganization at about 100 Ma, although presently little studied, is clearly indicated by a major bend in the fracture zones in the Indian Ocean and by a change in Pacific plate motion [2]. Our workflow involves turning plate reconstructions into surface meshes that are subsequently employed as initial conditions for global Boundary Element numerical models. The tectonic setting that anticipates the reorganizations is processed with the software GPlates, combining the 3D mesh of the paleo-plate morphology and the reconstruction of paleo-subducted slabs, elaborated from tectonic history [3]. All our models involve the entire planetary system, are fully dynamic, have free surface, are characterized by a spectacular computational speed due to the simultaneous use of the multi-pole algorithm and the Boundary Element formulation and are limited only by the use of sharp material property variations [4]. We employ this new tool to unravel the causes of plate tectonic reorganizations, producing and comparing global plate motion with the reconstructed ones. References: [1] Torsvik, T., Müller, R.D., Van der Voo, R., Steinberger, B., and Gaina, C., 2008, Global Plate Motion Frames: Toward a unified model: Reviews in Geophysics, VOL. 46, RG3004, 44 PP., 2008 [2] Wessel, P. and Kroenke, L.W. Pacific absolute plate motion since 145 Ma: An assessment of the fixed hot spot hypothesis. Journal of Geophysical Research, Vol 113, B06101, 2008 [3] L. Quevedo, G. Morra, R. D. Mueller. Parallel Fast Multipole Boundary Element Method for Crustal Dynamics, Proceeding 9th World Congress and 4th Asian

  14. Compact, Two-Sided Structural Cold Plate Configuration

    Science.gov (United States)

    Zaffetti, Mark

    2011-01-01

    In two-sided structural cold plates, typically there is a structural member, such as a honeycomb panel, that provides the structural strength for the cold plates that cool equipment. The cold plates are located on either side of the structural member and thus need to have the cooling fluid supplied to them. One method of accomplishing this is to route the inlet and outlet tubing to both sides of the structural member. Another method might be to supply the inlet to one side and the outlet to the other. With the latter method, an external feature such as a hose, tube, or manifold must be incorporated to pass the fluid from one side of the structural member to the other. Although this is a more compact design than the first option, since it eliminates the need for a dedicated supply and return line to each side of the structural member, it still poses problems, as these external features can be easily damaged and are now new areas for potential fluid leakage. This invention eliminates the need for an external feature and instead incorporates the feature internally to the structural member. This is accomplished by utilizing a threaded insert that not only connects the cold plate to the structural member, but also allows the cooling fluid to flow through it into the structural member, and then to the cold plate on the opposite side. The insert also employs a cap that acts as a cover to seal the open area needed to install the insert. There are multiple options for location of o-ring style seals, as well as the option to use adhesive for redundant sealing. Another option is to weld the cap to the cold plate after its installation, thus making it an integral part of the structural member. This new configuration allows the fluid to pass from one cold plate to the other without any exposed external features.

  15. Levator plate upward lift and levator muscle strength

    Science.gov (United States)

    Rostaminia, Ghazaleh; Peck, Jennifer; Quiroz, Lieschen; Shobeiri, S. Abbas

    2016-01-01

    Objective The aim of study was to compare digital palpation with the levator plate lift measured by endovaginal and transperineal dynamic ultrasound. Methods Dynamic transperineal and endovaginal ultrasound were performed as part of multicompartmental pelvic floor functional assessment. Patients were instructed to perform Kegels while a probe captured the video clip of the levator plate movement at rest and during contraction in 2D mid-sagittal posterior view. We measured the distance between the levator plate and the probe on endovaginal ultrasound as well as the distance between the levator plate and the gothic arch of the pubis in transperineal ultrasound. The change in diameter (lift) and a levator plate lift ratio (lift / rest) x 100) were calculated. Pelvic floor muscle strength was assessed by digital palpation and divided into functional and non-functional groups using the Modified Oxford Scale (MOS). Mean differences in levator plate upward lifts were compared by MOS score using student t-tests and analysis of variance (ANOVA). Results 74 women were available for analysis. The mean age was 55 (SD±11.9). When measured by vaginal dynamic ultrasound, mean values of the lift and lift/rest ratio increased with increasing MOS score (ANOVA p=0.09 and p=0.04, respectively). When MOS scores were categorized to represent non-functional (MOS 0-1) and functional (MOS 2-5) muscle strength groups, the mean values of the lift (3.2 mm vs. 4.6 mm, p=0.03) and lift/rest ratio (13% vs 20%, p=0.01) were significantly higher in women with functional muscle strength. All patients with ≥ 30% lift detected by vaginal ultrasound had functional muscle strength. Conclusions Greater levator plate lift ratio detected by dynamic endovaginal ultrasound was associated with higher muscle strength as determined by MOS. This novel measurement can be incorporated into ultrasound evaluation of the levator ani function. PMID:26333568

  16. Structural Analysis of Plate Based Tensegrity Structures

    DEFF Research Database (Denmark)

    Hald, Frederik; Kirkegaard, Poul Henning; Damkilde, Lars

    2013-01-01

    Plate tensegrity structures combine tension cables with a cross laminated timber plate and can then form e.g. a roof structure. The topology of plate tensegrity structures is investigated through a parametric investigation. Plate tensegrity structures are investigated, and a method...... for determination of the structures pre-stresses is used. A parametric investigation is performed to determine a more optimized form of the plate based tensegrity structure. Conclusions of the use of plate based tensegrity in civil engineering and further research areas are discussed....

  17. Structural Analysis of Plate Based Tensegrity Structures

    DEFF Research Database (Denmark)

    Hald, Frederik; Kirkegaard, Poul Henning; Damkilde, Lars

    2013-01-01

    Plate tensegrity structures combine tension cables with a cross laminated timber plate and can then form e.g. a roof structure. The topology of plate tensegrity structures is investigated through a parametric investigation. Plate tensegrity structures are investigated, and a method...... for determination of the structures pre-stresses is used. A parametric investigation is performed to determine a more optimized form of the plate based tensegrity structure. Conclusions of the use of plate based tensegrity in civil engineering and further research areas are discussed....

  18. Avionics Box Cold Plate Damage Prevention

    Science.gov (United States)

    Stambolian, Damon B.; Larchar, Steven W.; Henderson, Gena; Tran, Donald; Barth, Tim

    2012-01-01

    Problem Introduction: 1. Prevent Cold Plate Damage in Space Shuttle. 1a. The number of cold plate problems had increased from an average of 16.5 per/year between 1990 through 2000, to an average of 39.6 per year between 2001through 2005. 1b. Each complete set of 80 cold plates cost approximately $29 million, an average of $362,500 per cold plate. 1c It takes four months to produce a single cold plate. 2. Prevent Cold Plate Damage in Future Space Vehicles.

  19. 钢箱梁正交异性桥面板球扁钢纵肋球头朝向和黄隔板空孔的优化%Optimization of Bulb Direction and Diaphragm Cutout of Bulb Flat Ribs in Steel Orthotropic Deck of Box Girder

    Institute of Scientific and Technical Information of China (English)

    吴臻旺; 郑凯锋; 税彦斌; 张昊

    2011-01-01

    某钢箱梁正交异性桥面板行车道范围内采用球扁钢纵肋,在横隔板对应部位设置空孔让纵肋连续通过,为研究横隔板的空孔圆弧、空孔与纵肋连接端部等两个细节部位的受力特性,以某立交桥F匝道为工程背景,建立全桥有限元模型,对称荷载作用,对比横隔板对称位置空孔应力分布,分析纵肋球头朝向和背对邻近腹板两种布置对空孔受力的影响.荷栽位于不同横向位置,分析横隔板空孔面内受力.荷载位于不同纵向位置,分析横隔板空孔面外受力.对横隔板空孔圆弧半径进行参数分析.研究表明,球扁钢纵肋球头背对邻近腹板和适当增大空孔圆弧半径等措施,可明显改善横隔板空孔圆弧部位受力,但对空孔与纵肋连接端部效果不够明显,需采取进一步措施以改善该细节部位的受力性能.%Bulb flat ribs were used in the range of driveways on the steel orthotropic deck of a box girder, and cutout was set on the diaphragm to let the longitudinal ribs to pass through continuously. In order to probe into the stress characteristics of two details of diaphragm cutout, such as arc of cutout and its joint to rib, finite element analysis was carried out based on the ramp F of an overpass. With the symmetrical vehicle load action, stress distributions of symmetrical cutouts were compared, and the influences of bulb towards and/or back against the adjacent web plate on the stress characteristics of the cutout were studied respectively. For different transverse positions of vehicle load, the in-plane stress characteristics of diaphragm cutout were studied. For different longitudinal positions of vehicle load, the out-of-plane stress characteristics of diaphragm cutout were studied. Then, the parameter optimization of arc radius of cutout was carried out. The results show that the stress along the arc of the diaphragm cutout will be more appropriate when the bulb of longitudinal ribs is back

  20. BAO Plate Archive Project: Digitization, Electronic Database and Research Programmes

    Science.gov (United States)

    Mickaelian, A. M.; Abrahamyan, H. V.; Andreasyan, H. R.; Azatyan, N. M.; Farmanyan, S. V.; Gigoyan, K. S.; Gyulzadyan, M. V.; Khachatryan, K. G.; Knyazyan, A. V.; Kostandyan, G. R.; Mikayelyan, G. A.; Nikoghosyan, E. H.; Paronyan, G. M.; Vardanyan, A. V.

    2016-06-01

    The most important part of the astronomical observational heritage are astronomical plate archives created on the basis of numerous observations at many observatories. Byurakan Astrophysical Observatory (BAO) plate archive consists of 37,000 photographic plates and films, obtained at 2.6m telescope, 1m and 0.5m Schmidt type and other smaller telescopes during 1947-1991. In 2002-2005, the famous Markarian Survey (also called First Byurakan Survey, FBS) 1874 plates were digitized and the Digitized FBS (DFBS) was created. New science projects have been conducted based on these low-dispersion spectroscopic material. A large project on the whole BAO Plate Archive digitization, creation of electronic database and its scientific usage was started in 2015. A Science Program Board is created to evaluate the observing material, to investigate new possibilities and to propose new projects based on the combined usage of these observations together with other world databases. The Executing Team consists of 11 astronomers and 2 computer scientists and will use 2 EPSON Perfection V750 Pro scanners for the digitization, as well as Armenian Virtual Observatory (ArVO) database will be used to accommodate all new data. The project will run during 3 years in 2015-2017 and the final result will be an electronic database and online interactive sky map to be used for further research projects, mainly including high proper motion stars, variable objects and Solar System bodies.