scholarly journals Effect of Variation of Temperature Field on the Process of Thermal Consolidation of Tailings Pond “Zelazny Most”

2015 ◽  
Vol 36 (2) ◽  
pp. 57-65
Author(s):  
Monika Bartlewska-Urban ◽  
Tomasz Strzelecki
Keyword(s):  
Temperature Field ◽  
Laboratory Tests ◽  
Loss Of Stability ◽  
Effective Parameters ◽  
Strength Criteria ◽  
Temperature Changes ◽  
Tailings Pond ◽  
Phase Medium ◽  
Thermal Consolidation ◽  
Hydrotechnical Structure

Abstract The following study presents numerical calculations for establishing an impact of temperature changes on the process of distortion of bi–phase medium. The Biot consolidation equations with Kelvin–Voigt rheological skeleton were used for that purpose. The process was exemplified by thermal consolidation of post floatation dump “–elazny Most”. We analyzed the behavior of the landfill under the action of its own weight, forces of floating filtration and temperature gradient. Values of certain effective parameters of model were obtained during laboratory tests on material obtained from the landfill. The remaining data for mediums with similar characteristics were taken from literature. The results obtained from the stress state in the landfill allow the magnitude of plasticity potential to be specified based on known strength criteria. Change in the value sign of the plasticity potential clearly testifies to the emergence of an area of plasticity of material from landfill, however, this does not indicate the loss of stability of this hydrotechnical structure.

scholarly journals Procedure for determining the thermoelastic state of a reinforced concrete bridge beam strengthened with methyl methacrylate

2021 ◽  
Vol 4 (7(112)) ◽  
pp. 26-33
Author(s):  
Vitalii Kovalchuk ◽  
Yuliya Sobolevska ◽  
Artur Onyshchenko ◽  
Olexandr Fedorenko ◽  
Oleksndr Tokin ◽  
...  
Keyword(s):  
Temperature Field ◽  
Reinforced Concrete ◽  
Methyl Methacrylate ◽  
Concrete Beam ◽  
Vertical Direction ◽  
Reinforced Concrete Beam ◽  
Temperature Stresses ◽  
Temperature Changes ◽  
Structural Reinforcement ◽  
Elasticity Module

This paper reports the analysis of methods for determining temperature stresses and deformations in bridge structures under the influence of climatic temperature changes in the environment. A one-dimensional model has been applied to determine the temperature field and thermoelastic state in order to practically estimate the temperature fields and stresses of strengthened beams taking into consideration temperature changes in the environment. The temperature field distribution has been determined in the vertical direction of a reinforced concrete beam depending on the thickness of the structural reinforcement with methyl methacrylate. It was established that there is a change in the temperature gradient in a contact between the reinforced concrete beam and reinforcement. The distribution of temperature stresses in the vertical direction of a strengthened reinforced concrete beam has been defined, taking into consideration the thickness of the reinforcement with methyl methacrylate and the value of its elasticity module. It was established that the thickness of the reinforcement does not have a significant impact on increasing stresses while increasing the elasticity module of the structural reinforcement leads to an increase in temperature stresses. The difference in the derived stress values for a beam with methyl methacrylate reinforcement with a thickness of 10 mm and 20 mm, at elasticity module E=15,000 MPa, is up to 3 % at positive and negative temperatures. It has been found that there is a change in the nature of the distribution of temperature stresses across the height of the beam at the contact surface of the reinforced concrete beam and methyl methacrylate reinforcement. The value of temperature stresses in the beam with methyl methacrylate reinforcement and exposed to the positive and negative ambient temperatures increases by three times. It was established that the value of temperature stresses is affected by a difference in the temperature of the reinforced concrete beam and reinforcement, as well as the physical and mechanical parameters of the investigated structural materials of the beam and the structural reinforcement with methyl methacrylate

Analytic Methods of Main Cable Initial Curve Calculation in Variable Temperature Field

2010 ◽  
Vol 163-167 ◽  
pp. 307-312
Author(s):  
Xiang Ren
Keyword(s):  
Temperature Field ◽  
Variable Temperature ◽  
Suspension Bridge ◽  
Horizontal Component ◽  
Length Variation ◽  
Calculation Methods ◽  
Initial Curve ◽  
Temperature Changes ◽  
Main Cable ◽  
Cable Forces

In order to study temperature effect on initial curve of main cable, three different temperature models were built about temperature changes of main cable along span direction, and iteration calculation methods to find initial curve of main cable in variable temperature field was proposed based on the theory that the length of non-stress wire strand is persistence in unloaded cable station and construction completion station. The catenary equation in variable temperature field was deduced and the suspender length variation as well as horizontal component of cable forces were calculated based on the catenary equation. Taking some suspension bridge for an example, suspender length variation, horizontal component of the cable forces and node coordinate under three different temperature models were calculated by iteration calculation methods.

Numerical Analysis of Lining Temperature Field of Hydraulic Tunnel under the Highway

2010 ◽  
Vol 163-167 ◽  
pp. 1505-1509
Author(s):  
Xiao Yun Jia ◽  
Bao Long Lin
Keyword(s):  
Temperature Field ◽  
Numerical Analysis ◽  
Structural Characteristics ◽  
Crack Control ◽  
Temperature Changes ◽  
Finite Element Software ◽  
Concrete Crack ◽  
Geological Conditions ◽  
North Water ◽  
The Difference

Based on the geological conditions of culvert of the South to North Water Transfer Project, lining temperature field of hydraulic tunnel for crack control is simulated by finite element software—ANSYS. According to numerical analysis results of lining temperature field, considering terrain condition, structural characteristics and climate, some engineering measures are taken during construction. Internal temperature of concrete is controlled effectively, concrete crack caused by temperature changes is solved successfully, and construction quality is assured. The difference of measuring data in-situ and calculating data is very small, which illustrate that calculated model is correct and parameters are reasonable. The results can act as reference for the design and construction of similar projects later.

Temperature Effect Analysis of the Twin Towers Concrete Cable-Stayed Bridge for Construction Control

2013 ◽  
Vol 671-674 ◽  
pp. 1055-1063
Author(s):  
Gui Zhen Wang ◽  
Ying Min Li
Keyword(s):  
Temperature Field ◽  
Temperature Effect ◽  
Great Influence ◽  
Internal Force ◽  
Construction Control ◽  
Effect Analysis ◽  
Temperature Changes ◽  
Distribution Rule ◽  
Cable Force ◽  
Main Girder

It exists a great influence on deformation and internal force of large span bridge when temperature changes, the influence of the temperature must be considered and try to avoid in the process of construction control. Under monitoring to the construction process of Tieluoping super-large bridge on the scene, the influence law on internal force of Tieluoping Bridge is analyzed considering temperature effect, and the influence considering the sunshine temperature difference on cable tower deviation and stress is obtained, and the size of influence of main girder elevation, cable force and strain because of temperature field and distribution rule internal temperature field are clear. It provides powerful help for the smooth construction.

scholarly journals Stability of a nonlinear thermoelastic plate

2021 ◽  
Vol 2131 (2) ◽  
pp. 022023
Author(s):  
G I Volokitin ◽  
D V Moiseev
Keyword(s):  
Temperature Field ◽  
Circular Plate ◽  
Small Deformation ◽  
Loss Of Stability ◽  
Lateral Compression ◽  
Thermoelastic Plate ◽  
Inhomogeneous Temperature ◽  
Inhomogeneous Temperature Field

Abstract The problem of loss of stability of a circular plate under lateral compression in an inhomogeneous temperature field is considered. The theory of superposition of a small deformation on a finite one is used. A similar approach to the study of the equilibrium bifurcation of nonlinear thermoelastic bodies was used in the following works.

The study of the filtration of liquids in the elastic-plastic regime with the integral law of fracture of rocks

2003 ◽  
Vol 3 ◽  
pp. 271-275
Author(s):  
B.H. Khudjuyerov ◽  
I.E. Shodmonov ◽  
E.C. Holier
Keyword(s):  
Solid Particles ◽  
Oil Fields ◽  
Loss Of Stability ◽  
Two Phase ◽  
Elastic Plastic ◽  
Local Character ◽  
Pressure Decrease ◽  
Phase Medium ◽  
Porosity And Permeability ◽  
Non Local

As experience shows the development of deep oil fields with terrigenous reservoirs along with irreversibility of deformation there is a loss of stability of the formation's skeleton, i.e. he collapses in zones of strong pressure decrease. Particles of rock then are carried out from the formation by a flow of liquid. In this case, the composition of the liquid changes, a two-phase medium consisting of a liquid and a solid particles. In this paper we propose generalized dependencies of the variation porosity and permeability in the elastic-plastic mode of filtration The liquid taking into account the removal of the destroyed particles from the formation, where it is taken into account non-local character of the removal of the destroyed particles in time.

The Measurement of Thickness and Model Prediction of Hot Asphalt Mixture in the Rolling Compacting Process

2012 ◽  
Vol 204-208 ◽  
pp. 1706-1714 ◽  
Author(s):  
Xiao Chen ◽  
Jian Long Zheng
Keyword(s):  
Quality Control ◽  
Temperature Field ◽  
Deformation Theory ◽  
Asphalt Mixture ◽  
Forecast Model ◽  
Test Methods ◽  
Temperature Fields ◽  
Temperature Changes ◽  
Thickness Prediction ◽  
Measurement Of Thickness

The thickness test and models prediction methods and rheological deformation theory have an important impact on quality control in the process of hot asphalt mixture field rolling compaction. DSL30 leveling instrument are used to measure the thickness in the process of hot asphalt mixture. Pt100 and Paperless Recorder are joined to test the temperature field and results of compaction thickness and temperature changes are obtained, and the model is established for mixture rheological deformation theory and compaction thickness prediction. The results shows that: by using the thickness and temperature field test methods, relevant data of hot asphalt mixture can be gained accurately, viscoplastic rheological theory correctly reflects its deformation behavior and the thickness forecast model can efficiently show the mixture layer. In this way, new methods are provided for the asphalt pavement quality control, rheological theory and temperature fields testing.

scholarly journals Numerical model of heat transfer in three phases of the poroelastic medium

2016 ◽  
Vol 38 (2) ◽  
pp. 53-59
Author(s):  
Anna Uciechowska-Grakowicz ◽  
Tomasz Strzelecki
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Solid Phase ◽  
Irreversible Thermodynamics ◽  
Pore Fluid ◽  
Gas Filtration ◽  
Two Phase ◽  
Phase Medium ◽  
Thermal Consolidation ◽  
The Mathematical Model

Abstract In this paper, the results of numerical analysis of the thermal consolidation of a two phase medium, under the assumption of independent heat transfer in fluid and the solid phase of the medium, are presented. Three cases of pore fluid were considered: liquid, represented by water, and gas, represented by air and carbon dioxide. The mathematical model was derived from irreversible thermodynamics, with the assumption of a constant heat transfer between the phases. In the case of the accepted geometry of the classical dimensions of the soil sample and boundary conditions, the process leads to equalization of temperatures of the skeleton on the pore fluid. Heat transfer is associated with the fluid flow in the pores of the medium. In the case of gas as the pore fluid, a non-linear mathematical model of gas filtration through the pores of the medium was accepted. For the computing process, relationships between viscosity or density and temperature proposed by other authors were taken into account. Despite accepting mechanical constants of the solid phase that do not depend on temperature, the obtained model is nonlinear and develops the classical Biot–Darcy model.

The Numerical Simulation on the Temperature Field of Laser Cladding

2011 ◽  
Vol 467-469 ◽  
pp. 1372-1376
Author(s):  
Li Yun Zheng ◽  
Wen Zheng Xie ◽  
Yu Ling Li
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Simulation Model ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Temperature Changes ◽  
Finite Element Software ◽  
Depth Direction ◽  
Scanning Region

This article uses the finite element software ABAQUS in the process of laser cladding to form the numerical simulation, which establishes numerical simulation model of the temperature field of laser cladding forming the heat transfer. The results show that the laser scanning position of the cladding layer depth direction of a high temperature gradient. Simulation of temperature changes of a known point the temperature change in laser scanning region is drastic. The experimental results show that the numerical simulation model of the temperature field is reasonable. Therefore, the numerical simulation model can be used to analyze the influence of the laser cladding parameters on the temperature field and simulate remelting depth under any scanning speed.

Research on Early Cracking of the CRCP in the Tunnel under Low Temperature Difference

2013 ◽  
Vol 857 ◽  
pp. 133-140
Author(s):  
Jian Wei Liu ◽  
Dui Jia Zhao ◽  
Shao Wen Liu ◽  
Jun Min Shen
Keyword(s):  
Temperature Field ◽  
Temperature Difference ◽  
Crack Width ◽  
Cement Hydration ◽  
Concrete Strength ◽  
Concrete Pavement ◽  
Crack Spacing ◽  
Internal Temperature ◽  
Temperature Changes ◽  
Maximum Crack

Calculate and analysis influence of the temperature field for Continuously Reinforced Concrete Pavement design. The temperature and crack of pavement are tested, so that the temperature changing and early cracks development inside the tunnel have been got. Studies have shown that: the tunnel temperature changes slowly, the temperature difference is small. In the first two days after concrete paving, the internal temperature of the slab was significantly higher than the ambient temperature, 79% of early cracking appears in this stages; Panel temperature rise because of the cement hydration. Strain increases in process of the growth of the concrete strength and shrinkage, the cracks appears. The number of cracks in the first two days accounted for 50% of the total number in 7 days, only the number of the second day accounted for 37.59%. Crack width accounted for 60.5% of the total, which is mainly concentrated in 0.1 mm and 0.2 mm. The crack spacing is mainly concentrated in 2m to 8m, accounted for 76.8% of all. The maximum crack spacing is 84 m, the minimum is only 0.5m.

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