Practical Constitutive Model in the Application of Arch Dam Shape Design Calculation

2011 ◽  
Vol 105-107 ◽  
pp. 857-861
Author(s):  
Hong Wang ◽  
Chong Jin ◽  
Xiao Zhou Xia ◽  
Hong Yuan
Keyword(s):  
Constitutive Model ◽  
Mechanical Performance ◽  
Water Pressure ◽  
Safety Margin ◽  
Least Square Method ◽  
High Water ◽  
Arch Dam ◽  
Least Square ◽  
Design Calculation ◽  
High Arch Dam

A fitting curve of stress-strain relation given is applied in numerical analyzing based on Legendre orthogonal polynomial and least square method. The nonlinear constitutive model is employed to examine the shape of an arch dam. For the asymmetries and high water pressure, the safety of High Arch Dam is one of key issues in the design and construction of High Arch Dam. The simulation results show that the basic mechanical performance index is symmetrical distribution. The dam mainly bears pressure and no obvious tensile stress exists in the dam when water level is normal. Material yields in dam heel when 1.4 times overloading is considered. It can be concluded that the dam is reliable and the safety margin is satisfactory.

Stress-Seepage Fully Coupling Model for High Arch Dam

2014 ◽  
Vol 513-517 ◽  
pp. 4025-4029 ◽  
Author(s):  
Lei Gan ◽  
Zhen Zhong Shen ◽  
Rui Wang ◽  
Qing Fu Huang
Keyword(s):  
Water Pressure ◽  
Element Model ◽  
High Water ◽  
Displacement Component ◽  
Arch Dam ◽  
Similar Distribution ◽  
Displacement Fields ◽  
High Arch Dam ◽  
Coupled Effect ◽  
Stress And Displacement Fields

Based on M language offered by Comsol Multiphysics analysis platform, a 3-D finite element model of a high arch dam was established. In this paper, a practical engineering was taken to be as a case.The coupled seepage-stress field was compared with uncoupled condition under normal storage level. The seepage, stress and displacement fields of the dam were analyzed for discussing the coupled effect. The results show the similar distribution of seepage, stress and displacement fields in the two conditions. However, compared to the uncoupled one, the potential distribution of seepage field is close to downstream, each displacement component increases at different rates, the tensile stress of the upstream rock and the compressive stress of the downstream rock both increases in the coupled condition, which enhances the uplift pressure in the foundation. So the coupled effect of seepage and stress is not beneficial for the dam safety, which cannot be ignored under high water pressure.

The Numerical Calculation of Vibration Frequency of High Arch Dam Structure on the Condition of Earthquake

2012 ◽  
Vol 170-173 ◽  
pp. 2188-2192
Author(s):  
Ke Feng Zhang ◽  
Zhi Xiang Cao ◽  
Zheng Bing Xia
Keyword(s):  
Natural Frequency ◽  
Coefficient Of Variation ◽  
Stochastic Dynamics ◽  
Water Pressure ◽  
Random Variable ◽  
Arch Dam ◽  
High Arch Dam ◽  
Ground Acceleration ◽  
Average Value ◽  
The Mathematical Model

The dynamic response mechanism of the high arch dam structure is very complicated under the strong earthquake, based on the theory of stochastic dynamics analysis, starting from the basic dynamics equations of structure, the mathematical model of natural frequency of the structure is established by considering random variable of dynamic role of water pressure, earthquake ground acceleration and elastic modulus of the structure. The model numerical results show that the natural frequency of average value and coefficient of variation have a certain correlation and the common characteristics of random is affected by random input variable, and the different vibration mode has average value and coefficient of variation, and the average value of variation has a certain change rule, but coefficient of variation changes small.

Analysis on the Stress of Arch Dam Heel

2014 ◽  
Vol 919-921 ◽  
pp. 1216-1221
Author(s):  
Chun Tao Wang ◽  
Hui Lv ◽  
You Ping Wu
Keyword(s):  
Finite Element ◽  
Model Experiment ◽  
Water Pressure ◽  
Arch Dam ◽  
Elastic Theory ◽  
High Arch Dam ◽  
Stress Curve ◽  
Element Density ◽  
Set Up

Because of the characteristic of the elastic theory, the stress on dam heel is infinite, which makes the stress larger and larger with the increasing of finite element density. In view of this the dam heel stress tendency method is presented. This method uses the envelope of stress curves to replace real stress curve. In order to verify the method, Xiaowan high arch dam model under the water pressure has been set up, while the FEA modal is set up at the same time. The result of model experiment is close to the result form dam heel stress tendency method, which shows that the method is correct.

Engineering Advice for Preventing Crack on the Upstream Surface of Super-High Arch Dam

2013 ◽  
Vol 438-439 ◽  
pp. 1320-1324 ◽  
Author(s):  
Jun Feng Guan ◽  
Long Bang Qing ◽  
Wei Feng Bai ◽  
Juan Wang ◽  
Peng Lin
Keyword(s):  
Fracture Toughness ◽  
Crack Propagation ◽  
Water Pressure ◽  
Arch Dam ◽  
High Arch Dam ◽  
Propagation Length ◽  
Crack Stability ◽  
Dam Concrete ◽  
The Relationship ◽  
Crack Propagation Length

In this paper, the crack stability and crack propagation regularity of the upstream surface of super-high arch dam along the water-stop structure were analyzed in the framework of fracture mechanics. According to fracture toughness of dam concrete, the relationship between the crack propagation length and the allowable water pressure was studied. Finally, two main specific engineering suggestions for avoiding this kind of crack on the upstream surface of super-high arch dam were given: (1) the value of checking water pressure should not exceed 0.4 MPa; (2) the flange of the water-stop structure near the upstream surface of dam should be changed toward the downstream.

Direct Assessment of Effective Renal Plasma Flow from Renoscintigraphy with a Gamma Camera and an On-Line Computer

1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma
Keyword(s):  
Count Rate ◽  
Renal Plasma Flow ◽  
Early Period ◽  
Least Square Method ◽  
Least Square ◽  
Uptake Coefficient ◽  
Positive Linear Correlation ◽  
On Line ◽  
Best Fit ◽  
Plasma Activity

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.

PENGARUH KNOWLEDGE MANAGEMENT, KOMPETENSI, MOTIVASI TERHADAP KINERJA KARYAWAN

2015 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Miftahol Arifin
Keyword(s):  
Knowledge Management ◽  
Linear Regression ◽  
Significant Influence ◽  
Employee Performance ◽  
Least Square Method ◽  
Least Square ◽  
Analysis Tool ◽  
Ordinary Least Square ◽  
Competence Motivation ◽  
Performance Analyze

The purpose of this research is to analyze the influence of knowledge management on employee performance, analyze the effect of competence on employee performance, analyze the influence of motivation on employee performance). In this study, samples taken are structural employees PT.centris Kingdom Taxi Yogyakarta. The analysis tool in this study using multiple linear regression with Ordinary Least Square method (OLS). The conclusion of this study showed that the variables of knowledge management has a significant influence on employee performance, competence variables have an influence on employee performance, motivation variables have an influence on employee performance, The analysis showed that the variables of knowledge management, competence, motivation on employee performance.Keywords: knowledge management, competence, motivation, employee performance.

Peristaltic Carreau-Yasuda nanofluid flow and mixed heat transfer analysis in an asymmetric vertical and tapered wavy wall channel

2020 ◽  
Vol 1 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Mohammad Hatami ◽  
◽  
D Jing ◽  
Keyword(s):  
Heat Transfer ◽  
Least Square Method ◽  
Weissenberg Number ◽  
Least Square ◽  
Heat Transfer Analysis ◽  
Phase Method ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Nanoparticles Concentration ◽  
The Right

In this study, two-phase asymmetric peristaltic Carreau-Yasuda nanofluid flow in a vertical and tapered wavy channel is demonstrated and the mixed heat transfer analysis is considered for it. For the modeling, two-phase method is considered to be able to study the nanoparticles concentration as a separate phase. Also it is assumed that peristaltic waves travel along X-axis at a constant speed, c. Furthermore, constant temperatures and constant nanoparticle concentrations are considered for both, left and right walls. This study aims at an analytical solution of the problem by means of least square method (LSM) using the Maple 15.0 mathematical software. Numerical outcomes will be compared. Finally, the effects of most important parameters (Weissenberg number, Prandtl number, Brownian motion parameter, thermophoresis parameter, local temperature and nanoparticle Grashof numbers) on the velocities, temperature and nanoparticles concentration functions are presented. As an important outcome, on the left side of the channel, increasing the Grashof numbers leads to a reduction in velocity profiles, while on the right side, it is the other way around.

Fast noise removal algorithm for HDR image based on least square method

2009 ◽  
Vol 29 (4) ◽  
pp. 994-996
Author(s):  
De-quan SUN ◽  
Jun ZHANG ◽  
Xiao-feng LI ◽  
Hui LI
Keyword(s):  
Least Square Method ◽  
Noise Removal ◽  
Least Square ◽  
Hdr Image
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