Research on the Vehicle Effects of the Assembled Bridge by Influence Surface

2014 ◽  
Vol 889-890 ◽  
pp. 1410-1413
Author(s):  
Dong Liang ◽  
Zi Shuo Li ◽  
Hui Cai Shen
Keyword(s):  
Distribution Coefficient ◽  
Calculation Method ◽  
New Method ◽  
Accurate Calculation ◽  
Transverse Distribution ◽  
Bridge Safety ◽  
Influence Line ◽  
Vehicle Load

Accurate calculation of the vehicle load is the foundation for the middle and small bridge safety. Longitudinal influence line and transverse distribution coefficient are used in traditional calculation method of vehicle load. This method brings a little big error because of the simplification. A new method based on influence surface is offered in this paper. The analysis results show that the new method can meet more accurate demand.

Error Analysis of Lane Loading Effects on T-Girder Bridge

2014 ◽  
Vol 487 ◽  
pp. 328-331
Author(s):  
Dong Liang ◽  
Hui Cai Shen ◽  
Zi Shuo Li
Keyword(s):  
Traditional Method ◽  
3D Fem ◽  
Fem Model ◽  
Transverse Distribution ◽  
Girder Bridges ◽  
Influence Line ◽  
Vehicle Load ◽  
Loading Effects ◽  
Girder Bridge ◽  
The Moment

The transverse distribution of lane loading is one of the most concern for the assembly prefabricated T-girder bridges. Longitudinal influence line and transverse distribution coefficient are used in the traditional calculation method of lane loading effects. But, many research results show this method brings a little big error because of the simplification. Along with the advance of computer technology in mathematics, it is not difficult to use the 3D FEM model to calculate the inner force that caused by vehicle load in girder bridge. In this paper, some comparatively accurate 3D FEM models are established to analyze the lane loading effects on the simply supported T-girder bridge. The results show that the moment and shear force of each girder are quite different between traditional method and 3D FEM model. The results indicate that the traditional method in current code is non-conservative.

scholarly journals The Method of High Accuracy Calculation of Robot Trajectory for the Complex Curves

2020 ◽  
Vol 28 (4) ◽  
pp. 247-252
Author(s):  
Alexander Lozhkin ◽  
Pavol Bozek ◽  
Konstantin Maiorov
Keyword(s):  
Calculation Method ◽  
Geometric Modeling ◽  
Classical Method ◽  
Geometric Model ◽  
New Method ◽  
Approximation Methods ◽  
Linear Transformations ◽  
Design Quality ◽  
Complex Curves ◽  
Internal Properties

AbstractThe geometric model accuracy is crucial for product design. More complex surfaces are represented by the approximation methods. On the contrary, the approximation methods reduce the design quality. A new alternative calculation method is proposed. The new method can calculate both conical sections and more complex curves. The researcher is able to get an analytical solution and not a sequence of points with the destruction of the object semantics. The new method is based on permutation and other symmetries and should have an origin in the internal properties of the space. The classical method consists of finding transformation parameters for symmetrical conic profiles, however a new procedure for parameters of linear transformations determination was acquired by another method. The main steps of the new method are theoretically presented in the paper. Since a double result is obtained in most stages, the new calculation method is easy to verify. Geometric modeling in the AutoCAD environment is shown briefly. The new calculation method can be used for most complex curves and linear transformations. Theoretical and practical researches are required additionally.

An Accurate Calculation Method for Two-dimensional Incompressible Laminar Boundary Layers, Including Cases with Regions of Sharp Pressure Gradient

1977 ◽  
Vol 28 (3) ◽  
pp. 149-162 ◽  
Author(s):  
N Curle
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Calculation Method ◽  
Boundary Layer Separation ◽  
Pressure Gradients ◽  
Accurate Calculation ◽  
Boundary Layer Equations ◽  
Laminar Boundary Layers ◽  
Displacement Thickness ◽  
Type Boundary

SummaryThe paper develops and extends the calculation method of Stratford, for flows in which a Blasius type boundary layer reacts to a sharp unfavourable pressure gradient. Whereas even the more general of Stratford’s two formulae for predicting the position of boundary-layer separation is based primarily upon an interpolation between only three exact solutions of the boundary layer equations, the present proposals are based upon nine solutions covering a much wider range of conditions. Four of the solutions are for extremely sharp pressure gradients of the type studied by Stratford, and five are for more modest gradients. The method predicts the position of separation extremely accurately for each of these cases.The method may also be used to predict the detailed distributions of skin friction, displacement thickness and momentum thickness, and does so both simply and accurately.

scholarly journals High-precision Joint 2D Traveltime Calculation for Seismic Processing

2018 ◽  
Vol 22 (4) ◽  
pp. 327-334 ◽  
Author(s):  
Hui Sun ◽  
Fanchang Meng ◽  
Zhihou Zhang ◽  
Cheng Gao ◽  
Mingchen Liu
Keyword(s):  
High Precision ◽  
Calculation Method ◽  
Numerical Models ◽  
New Method ◽  
Fast Marching Method ◽  
Surrounding Area ◽  
Fast Marching ◽  
Seismic Processing ◽  
Grid Nodes ◽  
Marching Method

Fast Marching Method (FMM) boasts high calculation efficiency and strong adaptability and stability while being applied to seismic traveltime. However, when it is applied to the largescale model, the calculation precision of FMM is insufficient. FMM has poor calculation precision near the source, which is an essential reason for the low accuracy of the whole algorithm. This paper puts forward a joint traveltime calculation method to address the problem. Wavefront Construction (WFC) with a relatively high calculation accuracy rather than FMM is adopted for calculation of the grid nodes’ traveltime near the source. After that, FMM is used to calculate the seismic traveltime in the remaining area. Joint traveltime calculation method greatly improves the calculation accuracy of the source’s surrounding area and the calculation accuracy of FMM. According to the new method, FMM is still adopted for the calculation of most grid nodes in the model, so the high calculation efficiency of FMM is maintained. Multiple numerical models are utilized to verify the above conclusions in the paper. 

The Study on the Linking-Up of Free-Form Surface Fiber Placement Track Based on Mesh Creating

2008 ◽  
Vol 392-394 ◽  
pp. 682-687 ◽  
Author(s):  
Zhong Xi Shao ◽  
Hong Ya Fu ◽  
De Cai Li
Keyword(s):  
Projective Plane ◽  
Calculation Method ◽  
New Method ◽  
Free Form ◽  
Parallel Projection ◽  
Reference Vector ◽  
Fiber Placement ◽  
Vertex Point ◽  
Free Form Surface ◽  
Pass Through

When using meshing creating method of FP (fiber placement) track, once the track point falls at some vertex point of mesh element, in the meantime the vertex point happens to be shared by several mesh elements, there needs a reasonable calculation method to select next mesh element which the FP track will pass through. Then it comes to the problem on linking of FP tracks. In order to solve it, in this paper, the author puts forward a new method, in which parallel projection theory is used, project need analytical mesh element and FP reference vector to a sound projective plane, on which the mesh element be selected and the FP track be calculated, then the FP track would be projected back to the placement surface. Program using this method realized a reasonable joint at the shared vertex point of meshing elements, which the FP direction has little change, and the mutation of track doesn’t come forth. So, the correctness of the method, which putted forward in this paper, is proved.

Research of the Chamfer Millers for the Gears

2011 ◽  
Vol 179-180 ◽  
pp. 960-966
Author(s):  
Hu Ran Liu
Keyword(s):  
Machine Tool ◽  
Product Quality ◽  
Tool Life ◽  
Calculation Method ◽  
Design Principle ◽  
New Method ◽  
Milling Machine ◽  
Batch Production ◽  
Machining Quality ◽  
The Past

In order to improve productivity and product quality and reduce cost, over the past many years, producers made great efforts to find the new method of chamfering. One of the methods is the chamfer milling cutter, on the milling machine tool. This method is suited for medium and small batch production. The tool life is long, the machining quality is stable. In this thesis, the principle of meshing between gear and the rake is applied. The chamfer miller design principle and calculation method is put forward.

The Design and Study of Roller Curvature for the Tube or Bar Straightener

2010 ◽  
Vol 145 ◽  
pp. 394-398
Author(s):  
Da Chao Hu ◽  
Hao Min Chen
Keyword(s):  
Calculation Method ◽  
New Method ◽  
Working Process ◽  
Shape Curve ◽  
Curve Equation ◽  
Roll Shape

The straightener roll should be in contact with the tube or bar in line during the working process. The traditional calculation method using roll-shape curve equation was extremely complex, so this paper presents a new method of determining roll-shape curvature in the condition of the tube or bar contacted with roller in line. By comparison, this calculation method is simple and easy. Moreover, this method guarantees the quality of product with the required accuracy. This method presents a new way in straightener roller design.

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