Study on Friction Coefficient of Spiral Case with Cushion Layer in Large-Scale Hydropower Plant

2011 ◽  
Vol 71-78 ◽  
pp. 4248-4251
Author(s):  
Jian Wei Zhang ◽  
Yi Na Zhang ◽  
Shu Fang Yuan
Keyword(s):  
Coefficient Of Friction ◽  
Large Scale ◽  
Water Pressure ◽  
Structural Type ◽  
Hydropower Plant ◽  
Finite Element Program ◽  
Spiral Case ◽  
Element Program ◽  
Cushion Layer ◽  
Elastic Cushion

Elastic cushion layer between the steel spiral case and surrounding concrete is often used as a structural type in large-scale hydropower plant in China. In view of the uncertainty of the optimal elastic coefficient of friction and the transfer mechanism of internal water pressure to the surrounding concrete, Spiral case with cushion layer of large-scale hydropower plant is simulated with ANSYS nonlinear finite element program, considering the slip contact characteristics between steel spiral case and the surrounding concrete, the more reasonable coefficient of friction between the steel spiral case and concrete is studied. This provides reliable theoretical analysis for the design of large-scale hydropower plants.

Effect of Cushion Layers on Mechanical Characteristics of Spiral Case Structure in Hydropower Station

2013 ◽  
Vol 351-352 ◽  
pp. 897-900
Author(s):  
Bo Liu ◽  
Jian Hua Liu ◽  
Zhe Wang
Keyword(s):  
Mechanical Characteristics ◽  
Poisson Ratio ◽  
Water Pressure ◽  
Deformation Modulus ◽  
Hydropower Station ◽  
Finite Element Program ◽  
Load Bearing ◽  
Spiral Case ◽  
Element Program ◽  
Cushion Layer

The effects of deformation modulus, thickness and range of cushion layer on mechanical characteristics of spiral case in hydropower station has been analyzed using the finite element program ANSYS and nonlinear contact theory. The result shows that when cushion layer scope and poisson ratio is fixed, as the elastic modulus of cushion layer decreases, the deformation and stress of spiral case increases, surrounding concrete load-bearing ratio of water pressure reduces. If the cushion layer deformation modulus is fixed and the range of cushion layer extends to 10 degree site bellow the waist of spiral case, the steel spiral case stress decrease, the radial stress transferred from the spiral case to surrounding concrete increase by about from 0.01MPa to 0.03MPa, and load-bearing ratio of concrete increase, when the cushion layer Poisson ratio increases from 0.25 to 0.35.

Predicting the behaviour of storage cells in early Condeep structures

2016 ◽  
Vol 43 (7) ◽  
pp. 643-656 ◽  
Author(s):  
Amr I.I. Helmy ◽  
Michael P. Collins
Keyword(s):  
Cell Wall ◽  
Size Effect ◽  
Shear Failure ◽  
Water Pressure ◽  
Scale Model ◽  
Finite Element Program ◽  
3 Dimensional ◽  
Stress Strain Relation ◽  
Element Program ◽  
Storage Cells

RASP, also now called VecTor6, is a nonlinear finite element program for the analysis of reinforced concrete structures that uses 3-dimensional stress–strain relation of cracked concrete based on the modified compression field theory. RASP was used to predict the behavior of a 3-dimensional 1:13 scale model of a typical upper dome-cell wall junction of a storage cell in an early Condeep structure. It predicted a flexure-shear failure at the top of the cell wall when it was subjected to a pressure differential equivalent to 129–134 m head of water. Yet, there was deviation between the theoretical and the observed response of the model since the analysis ignored the detrimental effect of water pressure in the cracks. Before applying the results of the pressure test on the scale model to the prototype structure the size effect in shear was examined. It was concluded that because the failure was triggered by flexural yielding the size effect in shear was not significant for this case.

Experimental measurement and finite element analysis of the deformation of a high-pressure sluice gate

2000 ◽  
Vol 27 (4) ◽  
pp. 655-670
Author(s):  
Chuen-Shii Chou ◽  
Shou-Chih Lou
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Water Pressure ◽  
Sluice Gate ◽  
Water Release ◽  
Element Analysis ◽  
Finite Element Program ◽  
Safety Monitoring System ◽  
Element Program ◽  
Water Height

The deformation of a high-pressure sluice gate under an orthogonal water pressure load of 0.539 MPa (i.e., 55 m water height), acting upon the upstream side of a gate leaf, was studied numerically and experimentally. The sluice gate was installed at the end of a water-release tunnel in the Nan-Hwa Reservoir, Nan-Hwa, Taiwan, R.O.C. The numerical results obtained using the ANSYS 5.5.2 finite element program agreed reasonably well with the experimental data. The deformation of this high-pressure sluice gate under water pressure loads of 0.736 MPa (i.e., 75 m water height) and 0.931 MPa (i.e., 95 m water height) was predicted by ANSYS 5.5.2. The research reported here may provide a method for establishing a safety monitoring system for any high-pressure gate and provide engineers with useful information to evaluate the possibility of increasing the capacity of an existing reservoir.Key words: sluice gate leaf, finite element method (FEM), strain gauge, water pressure.

Friction Force and Stresses Analysis for Contact of Assembled Details

2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Friction Force ◽  
Sliding Friction ◽  
Friction Model ◽  
Contact Interface ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Element Program

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

scholarly journals Analysis of Pore Water Pressure and Piping of Hydraulic Well

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 502
Author(s):  
Jinman Kim ◽  
Heuisoo Han ◽  
Yoonhwa Jin
Keyword(s):  
Numerical Analysis ◽  
Water Level ◽  
Pore Water ◽  
Large Scale ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Hydraulic Gradient ◽  
Water Levels ◽  
Seepage Velocity ◽  
Seepage Analysis

This paper shows the results of a field appliance study of the hydraulic well method to prevent embankment piping, which is proposed by the Japanese Matsuyama River National Highway Office. The large-scale embankment experiment and seepage analysis were conducted to examine the hydraulic well. The experimental procedure is focused on the pore water pressure. The water levels of the hydraulic well were compared with pore water pressure data, which were used to look over the seepage variations. Two different types of large-scale experiments were conducted according to the installation points of hydraulic wells. The seepage velocity results by the experiment were almost similar to those of the analyses. Further, the pore water pressure oriented from the water level variations in the hydraulic well showed similar patterns between the experiment and numerical analysis; however, deeper from the surface, the larger pore water pressure of the numerical analysis was calculated compared to the experimental values. In addition, the piping effect according to the water level and location of the hydraulic well was quantitatively examined for an embankment having a piping guide part. As a result of applying the hydraulic well to the point where piping occurred, the hydraulic well with a 1.0 m water level reduced the seepage velocity by up to 86%. This is because the difference in the water level between the riverside and the protected side is reduced, and it resulted in reducing the seepage pressure. As a result of the theoretical and numerical hydraulic gradient analysis according to the change in the water level of the hydraulic well, the hydraulic gradient decreased linearly according to the water level of the hydraulic well. From the results according to the location of the hydraulic well, installation of it at the point where piping occurred was found to be the most effective. A hydraulic well is a good device for preventing the piping of an embankment if it is installed at the piping point and the proper water level of the hydraulic well is applied.

Mechanical Property Analysis and Numerical Simulation of Honeycomb Sandwich Structure’s Core

2013 ◽  
Vol 631-632 ◽  
pp. 518-523 ◽  
Author(s):  
Xiang Li ◽  
Min You
Keyword(s):  
Numerical Simulation ◽  
Elastic Constants ◽  
Sandwich Structure ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Finite Element Program ◽  
Honeycomb Sandwich ◽  
Calculation Results ◽  
Element Program ◽  
Typical Satellite

Owing to the lack of a good theory method to obtain the accurate equivalent elastic constants of hexagon honeycomb sandwich structure’s core, the paper analyzed mechanics performance of honeycomb sandwich structure’s core and deduced equivalent elastic constants of hexagon honeycomb sandwich structure’s core considering the wall plate expansion deformation’s effect of hexagonal cell. And also a typical satellite sandwich structure was chose as an application to analyze. The commercial finite element program ANSYS was employed to evaluate the mechanics property of hexagon honeycomb core. Numerical simulation analysis and theoretical calculation results show the formulas of equivalent elastic constants is correct and also research results of the paper provide theory basis for satellite cellular sandwich structure optimization design.

Finite Element Analysis on the Deformation of Energy-Saving Wire-Mesh Frame Wallboard

2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Energy Saving ◽  
Theoretical Basis ◽  
Steel Wire ◽  
Wire Mesh ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
Influence Degree

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.

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