Research of Flow Mechanism and Numerical Simulation on the Post-Prestressed Duct Grouting

2013 ◽  
Vol 405-408 ◽  
pp. 1567-1573
Author(s):  
Geng Xu ◽  
Ren Jun Yan ◽  
Chang Lian She ◽  
Lin Zhi Xu ◽  
Lin Xu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Reference Value ◽  
Control Program ◽  
Simulation Method ◽  
Construction Process ◽  
Height Difference ◽  
Grouting Pressure ◽  
Parameters Analysis ◽  
Complex Construction ◽  
The Relationship

Post-prestressed duct grouting is a complex construction process and it is affected by many factors. Since there are no clear cognitive relations to the influencing factors of the grouting quality, it is hard to make the best control program during the construction. By the theoretical applicability and parameters analysis through the grouting process, this article used the numerical simulation method to analyze the grouting process and obtained the correspondence between the initial velocity, grouting pressure and grouting quality. To the height difference and bending in the duct, the relationship between volume and forming quality were analyzed, the results has reference value to the design of duct gas vent.

Research on Relationship between Weight Filter Function and Stiffness Filter Function

2011 ◽  
Vol 411 ◽  
pp. 580-583
Author(s):  
Zhen Shang ◽  
Yun Kang Sui
Keyword(s):  
Numerical Simulation ◽  
Topology Optimization ◽  
Least Squares Method ◽  
Simulation Method ◽  
Homogenization Method ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
Filter Function ◽  
The Impact ◽  
The Relationship

Combined with the homogenization method and the least squares method, the filter function with the form of power function is studied in the Independent Continuum Map (ICM) method. Then, the numerical simulation method is used to study the relationship between a weight filter function and a stiffness filter function. Finally, the impact of the filtration function on the efficiency of topology optimization is showed by examples. It is important to further research structural topology optimization.

Numerical Simulation of Stimulated Volume in Low-Permeability Reservoir

2013 ◽  
Vol 734-737 ◽  
pp. 1415-1419
Author(s):  
Zhen Yu Liu ◽  
Tian Tian Cai ◽  
Hu Zhen Wang ◽  
Cheng Yu Zhang
Keyword(s):  
Numerical Simulation ◽  
Reference Value ◽  
Simulation Method ◽  
Fracture Network ◽  
Gas Production ◽  
Low Permeability ◽  
Flow State ◽  
Low Permeability Reservoir ◽  
Complex Fracture ◽  
Low Permeability Reservoirs

There is an increasing focus on the effective methods to develop low-permeability reservoirs, especially for ultra-low permeability reservoirs. It is hard to achieve the expected stimulation effect only on the traditional single fracturing, because of the poor supply ability from the matrix to fracture in low-permeability reservoirs. Volume stimulating to reservoir, achieving short distance from matrix to fracture because of producing fracture network. So the volume fracturing technology proposed for increasing oil or gas production, this technology is suitable for low porosity and low permeability reservoir. The conventional simulation method can't describe the complex fracture network accurately,but this paper established hydraulic fracturing complex fracture model based on the finite element numerical simulation method , making the simulated complex fracture more close to the real description,it can accurately describe the flow state in the reservoir and cracks.It has an important reference value to the low permeability reservoirs.

Numerical Simulation of Diaphragm Wall-Pile-Soil Interaction

2013 ◽  
Vol 438-439 ◽  
pp. 829-833
Author(s):  
Long Chen ◽  
Xi Hua Chu ◽  
Yuan Jie Xu
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Diaphragm Wall ◽  
Elastic Model ◽  
Construction Process ◽  
Design Requirement ◽  
Existing Structures ◽  
Ground Deformations ◽  
Ground Stress ◽  
Diaphragm Walls

The construction of underground infrastructures often requires to excavate in close vicinity of existing structures. In these conditions, the main design requirement is that of limiting ground deformations caused by excavation to ensure the safety of the structure. The diaphragm wall was used to meet this requirement on the background of a hydropower station in China. In this paper, a series of 3D finite element analyses was carried out for modeling the installation of diaphragm walls based on ABAQUS. The contact pair between the wall, the pile and soil was built by the master-slave method. The elastic model is adopted for the diaphragm wall and the pile, the elastic-plastic model based Mohr-Coulomb was applied to soil. The construction process and the running state were also simulated to estimate whether the plan was appropriate while considering the initial ground stress. The results obtain by numerical simulation agree with the observed data, the deformation process can be satisfactorily modeled. So this simulation method of the diaphragm wall can be used as reference for similar hydraulic projects.

Effects of tool eccentralization on cement-bond-log measurements: Numerical and experimental results

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. D181-D191 ◽  
Author(s):  
Ruo-Long Song ◽  
Ji-Sheng Liu ◽  
Xiu-Mei Lv ◽  
Xiu-Tian Yang ◽  
Ke-Xie Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Quality Evaluation ◽  
Horizontal Wells ◽  
Simulation Method ◽  
Experimental Results ◽  
Vertical Wells ◽  
The World ◽  
Fluid Channel ◽  
The Relationship

The cement-bond log (CBL) is a conventional and widely used cement quality evaluation technology for vertical wells. With the increase in horizontal wells around the world, the existing cement evaluation technologies are not appropriate. We have explored the possibilities of utilizing CBL in horizontal wells through investigating the effects of a noncentralized tool on CBL measurements. The parallel finite-difference numerical simulation method and experiments in calibration wells were adopted in the study. The numerical and experimental results matched very well, and indicated that the CBL amplitude decreases linearly with increasing tool eccentricity in a well with free pipe (i.e., a cased but uncemented well). For a standard pipe with a diameter of 5.5 in (139.7 mm) and a thickness of 7.72 mm, an eccentricity of [Formula: see text] (17% of the maximum eccentricity) could cause the CBL amplitude to be reduced by about 20%. The numerical simulations of CBL in wells with fluid channels in the cement showed that tool eccentralization could either increase or reduce the CBL amplitude relative to a centered tool, depending on the channel azimuth relative to eccentered direction. To explain this phenomenon, we investigated numerically the polarizations of casing waves in a well with free pipe and in a well with a fluid channel, and casing waves at higher frequencies in a well with free pipe. The relationship between the CBL amplitude and the percentage of cemented area for a borehole-centered tool was also studied. Our results provided some insights into understanding CBL measurements in horizontal wells.

scholarly journals Influence of Backing Plate Support Conditions on Armor Ceramic Protection Efficiency

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3427
Author(s):  
Bowen Zhang ◽  
Yangwei Wang ◽  
Shaofeng Du ◽  
Zhikun Yang ◽  
Huanwu Cheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Composite Ceramic ◽  
Simulation Method ◽  
Mechanical Support ◽  
Protection Efficiency ◽  
Positive Correlation ◽  
Backing Plate ◽  
The World ◽  
Support Conditions ◽  
The Relationship

The bilayer composite ceramic armor is widely used in the world, while the protection efficiency of the armor ceramic in it still confuses researchers. This study applied a numerical simulation method to produce a general equation that describes the relationship between the protection efficiency of the armor ceramic and the supporting conditions of the backing plate, thereby enhancing the current understanding of the composite ceramic armor. The results indicated that the protection efficiency of the armor ceramic can be divided into three parts: (1) the basic protection efficiency, (2) the increment efficiency caused by inertial support, and (3) the increment efficiency caused by mechanical support. The inertial support is related to the density and thickness of the backing plate, and the mechanical support is related to the elastic modulus and yield strength of the backing plate materials. The inertial support exhibited a positive correlation with the protection efficiency of the armor ceramic before it reached the Scr; after that, the protection efficiency of the armor ceramic would remain stable. In addition, the mechanical support showed a linear, positive correlation with the backing plate stress at ε0.

Numerical Simulation of Safety Rod and its Drive Mechanism in Sodium-Cooled Fast Reactor During Scram Action

2018 ◽  
Author(s):  
Li Yan ◽  
Hu Wenjun ◽  
Ren Lixia
Keyword(s):  
Numerical Simulation ◽  
Fast Reactor ◽  
Simulation Method ◽  
Drive Mechanism ◽  
Pipe System ◽  
The Core ◽  
Hydraulic Method ◽  
Drop Time ◽  
China Experimental Fast Reactor ◽  
The Relationship

Safety rod and its drive mechanism is one of the shutdown systems in sodium-cooled fast reactor, which must be quickly inserted into the core to achieve emergency shutdown in the event of an accident. Therefore, it is necessary to study the falling process of safety rod. In this paper, the numerical simulation method is used to analyze the falling process of safety rod and its drive mechanism in China Experimental Fast Reactor. According to the flow path of the safety rod and its drive mechanism, the pipe system hydraulic method is used to model the safety rod and its drive mechanism and calculate the hydraulic force of the safety rod and its drive mechanism during the falling process. The relationship between time, displacement, velocity and acceleration is presented. The drop time of safety rod is calculated, which is compared with the experimental results. The factors that affect the drop process are analyzed and a sensitivity analysis is presented.

scholarly journals Numerical Simulation and Accuracy Verification of Surface Morphology of Metal Materials Based on Fractal Theory

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4158
Author(s):  
Xiaokai Mu ◽  
Wei Sun ◽  
Chong Liu ◽  
Bo Yuan ◽  
Yunlong Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Fractal Dimension ◽  
Surface Morphology ◽  
Fractal Theory ◽  
Surface Profile ◽  
Reference Value ◽  
Fractal Dimensions ◽  
Current Method ◽  
Simulation Method ◽  
Surface Morphologies

This paper presents a numerical simulation method to determine the surface morphology characteristics of metallic materials. First, a surface profiler (NV5000 5022s) was used to measure the surface, and the morphology data thereof were characterized. Second, fractal theory was used to simulate the surface profile for different fractal dimensions D and scale coefficients G, and statistical analyses of different surface morphologies were carried out. Finally, the fractal dimension D of the simulated morphology and the actual morphology were compared. The analysis showed that the error of fractal dimension D between the two morphologies was less than 10%; meanwhile, the comparison values of the characterization parameters of the simulated morphology and the actual morphology were approximately equal, and the errors were below 6%. Therefore, the current method used to evaluate the surface morphologies of parts processed by the grinding/milling method can be replaced by the simulated method using the corresponding parameters. This method makes it possible to theorize about the surface morphologies of machined parts, and provides a theoretical basis and reference value for the surface morphology design of materials, with the potential to improve the assembly quality of products.

Construction Numerical Simulation of Cable-Supported Barrel Shell Structure Considering Construction Nonlinearity

2014 ◽  
Vol 548-549 ◽  
pp. 1748-1752
Author(s):  
Jia Li ◽  
Jing Hai Yu ◽  
Xiang Yu Yan ◽  
Hong Bo Liu
Keyword(s):  
Numerical Simulation ◽  
Shell Structure ◽  
Simulation Analysis ◽  
Mutual Influence ◽  
Reference Value ◽  
Construction Process ◽  
Analysis Method ◽  
Nonlinear Simulation ◽  
Similar Construction ◽  
Structure Layout

Based on an actual construction process, this paper put forward a nonlinear simulation analysis method, which can take the mutual influence between structural forming and the tensioning of the active-cables into account. The proposed method shows good performance in solving the problem of structure layout finding and the pre-stress calculation of pre-tensioning tendons by stages and in group. The method has clear mechanical conception and is of reference value for similar construction analysis.

Study on the Numerical Simulation of Massive Concrete Sidewall Hydration Heat under Negative Temperature Transient Boundary

2010 ◽  
Vol 163-167 ◽  
pp. 2560-2563 ◽  
Author(s):  
Dong Wei Li ◽  
Ju Hong Fan ◽  
Hai Ming Chen ◽  
Jun Hao Chen ◽  
Ren He Wang
Keyword(s):  
Numerical Simulation ◽  
Reference Value ◽  
Frozen Soil ◽  
Hydration Heat ◽  
Construction Process ◽  
Distribution Law ◽  
Massive Concrete ◽  
Frozen Wall ◽  
Concrete Hydration ◽  
The Impact

To get massive concrete sidewall hydration heat and the frozen wall’s temperature distribution law, the temperature monitor and analysis were applied in the construction process of deep frozen shaft. Combined with frozen sidewall temperature field numerical calculation finite element method, analyzed the concrete hydration heat on the impact of the artificially frozen wall in the frozen wall’s construction process. Concrete hydration heat release made rapid temperature rise of concrete, the temperature was gradually cooling down effected by the frozen wall’s low temperature and the concrete permanent supporting borders. During large release of concrete hydration heat, the frozen soil curtain was partial heating and melting, the Interface moved quickly and reached the maximum. The results showed that: the change laws of the numerical simulation and the measure point temperature were uniform, and their values were more consistent. This had a certain reference value in improving freezing construction methods and the design of deep frozen wall.

scholarly journals Numerical Simulation on the Stability of Surrounding Rock of Horizontal Rock Strata in the Tunnel

2018 ◽  
Vol 3 (12) ◽  
pp. 1189 ◽  
Author(s):  
Nian Zhang ◽  
Weihong Wang ◽  
Zhuoqiang Yang ◽  
Jianian Zhang
Keyword(s):  
Numerical Simulation ◽  
Reference Value ◽  
Simulation Method ◽  
Vertical Displacement ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Geological Condition ◽  
Deformation And Failure ◽  
The Stability ◽  
Rock Strata

Horizontal rock strata is a geological condition of rock which is often encountered in the tunnel construction, and it has an important influence on the tunnel construction, it is necessary to analyze and study the stability of horizontal rock strata in tunnel construction to ensure the tunnel construction’s safety and efficiency. By taking “Xishan Highway Tunnel” as the research object, and using the numerical simulation method, the numerical model of the tunnel has been established in the Midas/GTS to simulate the tunnel excavation under the horizontal rock strata condition，and the deformation and failure mechanism of surrounding rock and the influence factors of surrounding rock stability after are studied and analyzed. The research focused on the displacement of surrounding rock horizontal and vertical deformation, the results show that the vertical displacement of the surrounding rock is obviously greater than that of other parts during the excavation of the horizontal rock tunnel. According to the calculation results, the optimization measures of horizontal stratum tunnel construction method are put forward, which has important reference value for ensuring the construction safety and construction quality.

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