scholarly journals Study on stress simulation of concrete floor on transversely isotropic equivalent pile foundation during construction period

2019 ◽  
Vol 275 ◽  
pp. 03005
Author(s):  
Min Yuan ◽  
Sheng Qiang ◽  
Minjie Hu ◽  
Yedong Zhang ◽  
Hongdan Wang
Keyword(s):  
Numerical Simulation ◽  
Elastic Modulus ◽  
Calculation Result ◽  
Pile Foundation ◽  
Volume Ratio ◽  
Transversely Isotropic ◽  
Ratio Method ◽  
Calculation Error ◽  
Construction Period ◽  
Concrete Floor

In the concrete pouring process of large pumping stations, the pile foundation plays an important role in supporting the upper structures, and also has a certain constraint on the concrete floor. In the numerical simulation calculation of construction period, to simplify the pre-processing, the volume ratio method is sometimes applied to regard the pile and surrounding soil foundation as the equivalent pile foundation, while the anisotropy of pile foundation is ignored, which will result in large calculation error of the horizontal stress of the concrete floor. Aiming at this problem, the anisotropy theory of materials is adopted in this paper to simulate the temperature field and stress field of the concrete floor both on non-equivalent pile foundation and equivalent pile foundation during construction period after compiling corresponding calculation program. The results show that when the ratio α of the horizontal elastic modulus to the vertical elastic modulus of equivalent pile foundation is about 1/20, the calculation result of the transversely isotropic equivalent pile foundation is approximately equal to the calculation result of the non-equivalent pile foundation (exact solution). It may provide some reference to similar engineering numerical simulation.

Numerical Simulation on the Regular Pattern of the Lateral Friction Transmission of the Pile in the Incline under the Pulling Force

2014 ◽  
Vol 501-504 ◽  
pp. 248-253
Author(s):  
Liu Yong Cheng ◽  
Shan Xiong Chen ◽  
Xi Chang Xu ◽  
Xiao Jie Chu ◽  
Tong Bing Lei
Keyword(s):  
Numerical Simulation ◽  
Bearing Capacity ◽  
Pile Foundation ◽  
Influence Factors ◽  
Great Influence ◽  
Regular Pattern ◽  
Slope Gradient ◽  
Pulling Force ◽  
Lateral Friction

The regular pattern of the lateral friction transmission is one of the most critical influences on the ultimate uplift bearing capacity. The pile foundation in the incline under the pulling force has a wide variety of characteristics which is different with the normal pile. Numerical simulation is done by the use of FLAC3D in this paper. The regular pattern of the lateral friction transmission of the pile in the incline under the pulling force is studied. And the influence factors on the lateral friction transmission such as the slope gradient, the length and location of piles are discussed. The results show that the incline has a great influence on the lateral friction transmission. The lateral friction which is away from the incline-side is about 30% to 50% bigger than the incline-side. The slope gradient and the location of piles all have a great influence on the lateral friction transmission.

Numerical Simulation of Condenser Throat Combining with Low-Pressure Exhaust Hood for 600MW Thermal Power Unit

2012 ◽  
Vol 614-615 ◽  
pp. 77-82
Author(s):  
Jian Li ◽  
Li Zhang ◽  
Si Ping Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Calculation Result ◽  
Thermal Power ◽  
Low Pressure ◽  
Exhaust Hood ◽  
Combined Model ◽  
Real Condition ◽  
Reasonable Result

In order to obtain the more real condition of the flow field at condenser throat the flow field of condenser throat is numerical simulated by the FLUENT commercial software, alone or coupling with the low-pressure exhaust hood. The results show that the flow field of condenser throat is strongly influenced by low-pressure exhaust hood, the frustum’s diffuse-angle, the low-pressure heater and the injection of the exhaust steam from the small turbine. The velocity distribution at the outlet of the throat isn’t uniform. The calculation result of combined model is also different from the single calculation result of condenser throat. Combined numerical simulation obtains more reasonable result.

Investigation of Strength in G4-73 Type Centrifugal Fan Impeller

2011 ◽  
Vol 383-390 ◽  
pp. 5669-5673
Author(s):  
Song Ling Wang ◽  
Zhe Sun ◽  
Zheng Ren Wu
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Calculation Result ◽  
Working Condition ◽  
Equivalent Stress ◽  
Centrifugal Fan ◽  
The Finite Element Method ◽  
Total Displacement ◽  
Maximum Equivalent Stress

For the large centrifugal fan impeller, its working condition generally is bad, and its geometry generally is complex. So its displacements and stresses distribution are also complex. In this paper, we can obtain the fan impeller’s displacements and stresses distribution accurately through numerical simulation in G4-73 type centrifugal fan impeller using the finite element method software ANSYS. The calculation result shows that the maximum total displacement of the impeller is m, it occurs on the position of the half of the blade near the outlet of the impeller; and the maximum equivalent stress of the impeller is 193 MPa, it occurs on the contacted position of the blade and the shroud near inlet of the impeller. Furthermore, check the impeller strength, the result shows that the strength of the impeller can meet the requirement.

Numerical Simulation of Squeezed Branch and Plate Pile Subjected to Vertical and Lateral Loads

2014 ◽  
Vol 926-930 ◽  
pp. 597-600
Author(s):  
Xiao Juan Gao ◽  
Yue Hui Li
Keyword(s):  
Numerical Simulation ◽  
Elastic Modulus ◽  
Bearing Capacity ◽  
Lateral Load ◽  
Vertical Load ◽  
Lateral Loads ◽  
Load Bearing Capacity ◽  
The Mean ◽  
Bearing Behavior ◽  
Pile Length

Based on the theoretical analysis results, the bearing behavior of squeezed and branch pile under vertical load and lateral load was analyzed in this paper. The mean works include the influence of vertical load on the pile lateral bearing capacity and influence of the lateral load on the vertical load bearing capacity. The factors influence the bearing capacity of pile such as elastic modulus of soil around and under pile bottom, pile length, plate position are also analyzed.

Numerical Simulation of Steam Reforming of Methanol in Micro-Channel Reactor

2005 ◽  
Author(s):  
Wenzhi Cui ◽  
Longjian Li ◽  
Tien-Chien Jen ◽  
Qinghua Chen ◽  
Quan Liao
Keyword(s):  
Numerical Simulation ◽  
Steam Reforming ◽  
Hydrogen Generation ◽  
Volume Ratio ◽  
Micro Channel ◽  
Microchannel Reactor ◽  
Fuel Processing ◽  
Reaction Heat ◽  
Steam Reforming Of Methanol ◽  
Hot Air

On-board hydrogen generation from hydrocarbon fuels, such as methanol, natural gas, gasoline and diesel, etc., will be technically feasible in the near future for fuel cell powered vehicles. Among all the fuel processing methods, steam reforming is considered as the most widely used method of hydrogen reforming for the lower reactive temperature, pressure and higher hydrogen ratio in reformate. A laminate micro-channel catalytic reactor was designed for the purpose of hydrogen generation from hydrocarbons. The depth of the reaction channel is 0.5 mm, and the length and width are 50 mm and 40 mm, respectively. The same geometry is designed for the heating channels. A metal sheet is placed between reacting and heating channels to separate them. Piling up alternately the two channels is to buildup the laminate microchannel reactor. Numerical simulation has been conducted in one reactive unit, i.e., one reacting channel and one heating channel. The reactant is the solution of methanol and water mixing with a certain ratio. And the reaction heat is provided by hot air flow with a temperature of 600K. A 2D steady model of the reforming reactive processes was developed and solved numerically. The ratio of water and methanol is set to be at 1.3. The conversion rate of methanol was nearly 100% at the outlet of reactor, while the volume ratio of hydrogen is 51.4% with the selectivity of CO2 reaches 49.2%. Detail results showed that the 50 mm long reacting channel could be divided into four different regimes along with the reacting course. In the first regime (0-5mm), methanol in the reactants is almost completely converted and CO is mainly generated in the third one (15-20mm), while reactions in the other two regimes are indiscoverable. The reasons leading to such phenomena are clarified in this paper.

Numerical Simulation of Deformation Pattern to Pile Raft Foundation

2011 ◽  
Vol 71-78 ◽  
pp. 4460-4462
Author(s):  
Ya Dong Chen ◽  
Xu Dong Wang ◽  
Yue Xin She ◽  
Jiang Dong Cai
Keyword(s):  
Numerical Simulation ◽  
Displacement Field ◽  
Pile Foundation ◽  
Deformation Pattern ◽  
Single Pile ◽  
Deep Foundation ◽  
Raft Foundation ◽  
Study Results ◽  
Good Consistency ◽  
Foundation Failure

ABAQUS is used to study the load-settlement characteristic and soil displacement field of the pile raft foundation. Numerical results are compared to the outputs from model test. The study results show that good consistency is obtained from the comparison of results between numerical simulation and model tests. Small pile space will weaken the single pile bearing capacity. The compress region is mainly centralized in the soil beneath the pile tip to the 3b space pile raft foundation, which presents a massive deep foundation failure pattern. As the increase of pile space, the compress region under cap shifts upward. The displacement influence depth of 6b space pile foundation is smaller than 3b space pile raft foundation, and it is destroyed by the lateral squeeze of the soil around piles.

Research of NOx Emissions Characteristic of Engine Fuelled with M40

2011 ◽  
Vol 382 ◽  
pp. 22-25
Author(s):  
Xin Guang Li ◽  
Bing Yuan Han ◽  
Rong Hai Yang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Simulation Model ◽  
Compression Ratio ◽  
Gasoline Engine ◽  
Volume Ratio ◽  
Nox Emissions ◽  
Cylinder Pressure ◽  
Variable Parameters ◽  
Vehicle Engine

A numerical simulation model for gasoline engine was established by GT-POWER in order to study the NOx emissions characteristic of vehicle engine fuelled with M40 (the methanol and the gasoline in volume ratio 40∶60) and was validated by Experimental data. Based on the model, the variable parameters study including air-fuel radio, compression radio and ignition advance angle were carried out. The model results showed that the compression radio and the air-fuel radio played an important role during the NOx emissions characteristic. There is a significant improvement of the NOx emissions with the compression ratio increases. The cylinder pressure increased with the improvement of the compression ratio brought out the NOx emissions rise. With the improvement of the air-fuel ratio, NOx emissions increased first and then decreased. A larger ignition advance angle can increase the pressure and the temperature of the cylinder.

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