Comparison and analysis of the results of grillage method and single beam method to continuous box girder with variable width

2017 ◽  
Author(s):  
Ying Zhou ◽  
Yasha Ji
Keyword(s):  
Box Girder ◽  
Single Beam ◽  
Beam Method ◽  
Comparison And Analysis ◽  
Grillage Method

scholarly journals A Study on Calculation Theory and Method of Transverse Distribution Coefficient of the Corrugated Steel Web Box Girder Based on the "Modified Rigid Jointed Beam Method"

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Wang Jie
Keyword(s):  
Distribution Coefficient ◽  
Load Distribution ◽  
Internal Force ◽  
Transverse Load ◽  
Box Girder ◽  
Steel Box Girder ◽  
Calculation Process ◽  
Beam Method ◽  
Corrugated Steel Web ◽  
Girder Bridge

Abstract: The PC box girder Bridge with corrugated steel web, as a new kind of bridge structure, has different mechanical properties from that of the ordinary concrete box girder bridge. Due to the late development of the corrugated steel web pre-stressed box girder structure, the domestic experts have made little research on the transverse load distribution of PC box Girder Bridge with corrugated steel webs. Whether the method of calculating the transverse distribution coefficient in the classical box girder theory can be applied to the corrugated steel web composite box girder and how to further improve the calculation theory and method of the transverse load distribution of the steel box girder bridge need urther study. method of the transverse load distribution of the steel box girder bridge need further study.Based on the "traditional rigid jointed process and the programming ideas of the transverse distribution coefficient of corrugated steel web composite box girder of the "modified rigid jointed beam method".beam method" and the existing research, this paper proposes the "modified rigid-jointed beam method" in combination with the specific internal force distribution of corrugated steel web composite box girder. The computational scheme and formula of mechanics, the calculation process and the programming ideas of the transverse distribution coefficient of corrugated steel web composite box girder of the "modified rigid jointed beam method".

Research on Extending Span of Box Girder Bridge with Corrugated Steel Webs up to 300m

2019 ◽  
Author(s):  
Dong Xu ◽  
Xiangyong Duanmu ◽  
Yafan Zhou
Keyword(s):  
Limit State ◽  
Ultimate Limit State ◽  
Beam Model ◽  
Box Girder ◽  
Single Beam ◽  
Stability Performance ◽  
Rigid Frame ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Under Construction

<p>In order to promote the application of steel-concrete composite structure in mountainous areas in China, a conceptual design for a PC continuous rigid frame box-girder bridge with corrugated steel webs and main span of 300 m was performed in the present paper. The combined corrugated steel web was proposed to increase the compressive area and improve the stability performance; thus, the self-weight of the composite box-girder bridge is significantly reduced. Flexural capacity of the whole section had been calculated with a single-beam model for the ultimate limit state (ULS). For the service limit state (SLS) design, the calculation for the composite box-girder bridge was conducted with the spatial grid model (SGM), from which 27 complete checking stresses in three layers (i.e. outside, inside and middle planes) of concrete plates and steel webs in every cross-section could be obtained. The stress history under construction stage was incorporated into the results obtained by SGM. Moreover, the stress states and stability performance for the composite box-girder bridge constructed were evaluated. The present investigation can provide references for the design and construction of the composite box-girder bridge with corrugated steel webs for long spans.</p>

Mechanism of Zn Vapour Suppressed by Al In Laser Lap Welding of High Strength Zinc Coated Sheet Steel

2010 ◽  
Vol 37-38 ◽  
pp. 634-642 ◽  
Author(s):  
Shi Quan Zhou ◽  
Zhen Guo Peng
Keyword(s):  
Binary Alloy ◽  
Sheet Steel ◽  
Travel Speed ◽  
Laser Fusion ◽  
Single Beam ◽  
Dual Beam ◽  
Beam Method ◽  
Laser Lap Welding ◽  
Lap Welding ◽  
Coated Sheet

The basic feasibility of laser fusion welding for prefabrication and assembly of zinc-coated sheet steel auto body components has been demonstrated in a significant number of prior studies. For trouble-free high volume manufacturing, however, one leading key technical concern remains incompletely resolved. In lap or similar weld joint geometries, venting of trapped Zn vapour can seriously disturb the molten weld pool and give rise to gross fusion defects. In this paper, the technical status of the issue has been reviewed, and various experiments were planned to explore Al foil as an interlayer and dual beam laser for suppressing Zn vapour. The results have shown that the welding processing is very sTable when the lap 1+1 mm sheet steel is welded by using Nd-Yag laser at 3KW power and 4m/min travel speed (defined as single beam) with 75μm Al foil as interlayer. However, if first using 2KW power and 4m/min travel speed, secondly using 3KW power and4m/min travel speed (defined as dual beam), only 25 μm Al foil can stabilize welding fusion pool. It is found that Al foil just store the Zn vapour in the single beam method and cannot mix with Zn to form Al-Zn binary alloy, because the laser heating is too fast that Zn has been vaporized before Al was melted. But Al can mix with Zn to form Al-Zn binary alloy in the dual beam method, therefore, the boiling temperature is raised to about 1600°C. So that, in laser lap welding of Zn coated (galvanized) sheet steel, the Al-Zn alloy will be more effective than Al metal for stabilizing welding process.

The Meticulous Analysis of Skew Beam Based on the Space Skew Beam Element Method

2014 ◽  
Vol 578-579 ◽  
pp. 220-224
Author(s):  
Xiang Feng Xu ◽  
Feng Zhang ◽  
Guang Zhi Qi
Keyword(s):  
Stiffness Matrix ◽  
Beam Element ◽  
Finite Element Models ◽  
Single Beam ◽  
Skew Bridge ◽  
Proposed Model ◽  
Minimum Potential ◽  
Space Beam Element ◽  
Beam Bridge ◽  
Grillage Method

When a skew bridge is analyzed, it is difficult to treat skew boundary conditions with general space beam element in single beam calculation of skew beam bridge. The stiffness of skew bridge cannot be simulated efficiently. In order to improve the accuracy of skew bridge, the stiffness matrix of the space skew beam element is derived based on the principle of minimum potential in this paper, this element is suitable for single beam of skew bridge and grillage method. A corresponding program is completed by Visual C++, the calculated results of different finite element models are compared, so the validity of the proposed model in this paper is validated. This paper can provide reference for plane and space calculation of the skew bridge design.

Measurements of nondegenerate optical nonlinearity using a two‐color single beam method

1991 ◽  
Vol 59 (21) ◽  
pp. 2666-2668 ◽  
Author(s):  
H. Ma ◽  
A. S. L. Gomes ◽  
Cid B. de Araujo
Keyword(s):  
Optical Nonlinearity ◽  
Single Beam ◽  
Beam Method

An optical study of turbulence

1970 ◽  
Vol 43 (3) ◽  
pp. 607-635 ◽  
Author(s):  
G. E. Roe
Keyword(s):  
Refractive Index ◽  
Power Spectrum ◽  
Power Spectra ◽  
Mean Flow ◽  
Cavendish Laboratory ◽  
Turbulent Region ◽  
Single Beam ◽  
Beam Method ◽  
A New Technique ◽  
Spatial Power Spectrum

This paper describes theoretical and experimental work carried out at the Cavendish Laboratory of the University of Cambridge. The main object of the work was to develop a new technique for measuring the structure of fluid turbulence.A parallel beam of light is passed through the turbulent region, containing refractive index fluctuations, and analyzed on exit by gratings of periodic transmissivity. Two forms of analysis yield (a) the spatial power spectrum of the refractive index fluctuations in the turbulence, and (b) the velocity distribution within the beam aperture. The method does not disturb the fluid physically, does not depend on the existence of a mean flow velocity, and works well in liquids.One of the limitations of this single-beam method is that it produces information averaged along the path length of the beam in the turbulence, and to overcome this a cross-beam technique, using two beams intersecting at right-angles, has been developed in theory. This method gives the spatial power spectrum of the refractive index fluctuations, as does the single beam method, but the results are characteristic only of the volume of intersection of the beams.The paper first discusses the theory of the single-beam and crossed-beam techniques, and then experimental results obtained with the single-beam method.The turbulent region investigated was a rectangular tank of water, heated from below and cooled from above, producing convective turbulence of high Rayleigh number (4·1 × 108), a system difficult to analyze by conventional methods of measurement, such as the hot-wire anemometer.Spectral density functions (power spectra) of refractive index, and hence in this case temperature fluctuations, have been measured, as have velocity distributions. Statistical analysis of the results also gives useful information about the Eulerian time scale of the turbulent field.

Application on Grillage Method in Box Girder Bridges

2013 ◽  
Vol 438-439 ◽  
pp. 886-890
Author(s):  
Jian Ping Feng ◽  
Xue Long Zhang ◽  
Zheng Zhu ◽  
Ping Ming Huang ◽  
Di Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Plate Element ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Finite Element Software ◽  
Girder Bridges ◽  
Bridge Structures ◽  
Grillage Method

Grillage method was an effective method for analyzing bridge structures. In order to validate the grillage method met the requirements of engineering precision in calculation about box girder bridges, the grillage model and the plate element model of the bridge were built by using the finite element software Midas/Civil; under the premise of the same loading location and the load value, the deflection values and the stress values calculated from the two models were compared, and the corresponding error ranges were obtained. The results show that the differences between them meet the engineering accuracy and using the grillage method in box girder bridges is reasonable.

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