scholarly journals SIMULATION OF WATER DIFFUSION AND HEAT CONDUCTION IN CONCRETE MEMBER USING MATHEMATICAL MODEL FOR CEMENT HYDRATION AND MICROSTRUCTURE FORMATION

2021 ◽  
Vol 86 (784) ◽  
pp. 848-859
Author(s):  
Hisashi SUGIYAMA
Keyword(s):  
Mathematical Model ◽  
Heat Conduction ◽  
Cement Hydration ◽  
Water Diffusion ◽  
Microstructure Formation ◽  
Concrete Member

scholarly journals Modeling of Hygro-Mechanical Behaviour through Raffia vinifera Fiber during the Water Diffusion Phenomenon

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Harrond Nimjieu Takoudjou ◽  
Nicodème R. Sikame Tagne ◽  
Peguy R. Nwagoum Tuwa ◽  
Médard Fogue ◽  
Ebenezer Njeugna
Keyword(s):  
Mathematical Model ◽  
Natural Fibers ◽  
Mathematical Expression ◽  
Water Diffusion ◽  
Integration Rule ◽  
Diffusion Phenomenon ◽  
Kinetics Of ◽  
Industrial Context ◽  
Fiber Radius ◽  
Model Expression

In an industrial context where the use of friendly materials is encouraged, natural fibers of vegetable origin become more solicited for the reinforcement of composite materials. This work deals with the modeling of the hygro-mechanical behavior through raffia vinifera fiber during the diffusion phenomenon. The modeling of water diffusion through the raffia vinifera fiber is described by Fick’s second law and taking into account the swelling phenomenon of the fiber. The equation obtained is solved numerically by the finite difference method, and the evolution of the fiber radius as a function of time is obtained. By applying the Leibniz integration rule, a mathematical expression to predict the evolution of this radius as a function of time is proposed. It is observed numerically and analytically an increase of the dimensionless fiber radius with time up to a critical value after what one observes the saturation. This model allowed us to propose a mathematical model describing the absorption kinetics of the raffia vinifera fiber through its absorption ratio. By comparing the results of this model with the experimental results from the literature, one observes a good agreement. Moreover, the induced stresses in the fiber during the water diffusion can also be estimated with the proposed mathematical model expression of fiber. These stresses increase with time and can reach between 5 and 7 GPa. The results of this work can be used to predict the behavior of the raffia vinifera fiber inside a composite material during its development.

scholarly journals Nonlocal Thermodynamics: Mathematical Model of Two-Dimensional Thermal Conductivity

2021 ◽  
Vol 321 ◽  
pp. 03005
Author(s):  
George Kuvyrkin ◽  
Inga Savelyeva ◽  
Daria Kuvshinnikova
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Heat Conduction ◽  
Numerical Solution ◽  
Complex Structure ◽  
Modern World ◽  
Nonlocal Term ◽  
Material Structure ◽  
Two Dimensional ◽  
Differential Heat

Nonlocal models of thermodynamics are becoming more and more popular in the modern world. Such models make it possible to describe materials with a complex structure and unique strength and temperature properties. Models of nonlocal thermodynamics of a continuous medium establish a relationship between micro and macro characteristics of materials. A mathematical model of thermal conductivity in nonlocal media is considered. The model is based on the theory of nonlocal continuum by A.K. Eringen. The interaction of material particles is described using local and nonlocal terms in the law of heat conduction. The nonlocal term describes the effect of decreasing the influence of the surrounding elements of the material structure with increasing distance. The effect of nonlocal influence is described using the standard non-locality function based on the Gaussian distribution. The nonlocality function depends on the distance between the elements of the material structure. The mathematical model of heat conduction in a nonlocal medium consists of an integro-differential heat conduction equation with initial and boundary conditions. A numerical solution to the problem of heat conduction in a nonlocal plate is obtained. The numerical solution of a two-dimensional problem based on the finite element method is described. The influence of nonlocal effects and material parameters on the thermal conductivity in a plate under highintensity surface heating is analyzed. The importance of nonlocal characteristics in modelling the thermodynamic behaviour of materials with a complex structure is demonstrated.

A new mathematical model of heat conduction processes

1990 ◽  
Vol 42 (2) ◽  
pp. 210-216 ◽  
Author(s):  
V. I. Fushchich ◽  
A. S. Galitsyn ◽  
A. S. Polubinskii
Keyword(s):  
Mathematical Model ◽  
Heat Conduction

Comprehesive Solution of Heat Conduction Problem Using Mathematical Model of Heat and Mass Transfer in Permafrost Soils

2014 ◽  
Vol 50 (6) ◽  
pp. 262-266 ◽  
Author(s):  
L. A. Duginov ◽  
N. B. Kutvitskaya ◽  
M. A. Magomedgadzhieva ◽  
E. A. Melˈnikova ◽  
M. Kh. Rozovskii
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat Conduction ◽  
Heat And Mass Transfer ◽  
Heat Conduction Problem ◽  
Permafrost Soils

Dispersion and Absorption of SBR Latex in the System of Mono-Dispersed Cement Particles in Water

2013 ◽  
Vol 687 ◽  
pp. 347-353 ◽  
Author(s):  
Xiao Xin Shi ◽  
Ru Wang ◽  
Pei Ming Wang
Keyword(s):  
Cement Hydration ◽  
Single Layer ◽  
Optical Microscope ◽  
Solution Phase ◽  
Environmental Scanning ◽  
Cement Particle ◽  
Microstructure Formation ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Cement Based Materials

This paper investigates the dispersion of cement particles in water at different mix proportions using optical microscope, and the dispersion and absorption of SBR latex in the system of mono-dispersed cement particles in water using environmental scanning electron microscope (ESEM). The results show that the mono-dispersed cement can be well obtained at the water to cement ratio (mw/mc) of 10:1. The ESEM images present that SBR latex is dispersed on the surface of the cement particles as well as the solution phase. SBR latex does not prefer to be absorbed on the cement particles in spite of their opposite electric charge but chooses to be dispersed in the system proportionally. In addition, SBR particles are single-layer absorbed on the surface of cement particles in all the SBR latex to cement ratios (mp/mc). Several SBR particles absorbed on the surface of cement particle get close enough to form groups at the mp/mc of 15% and 20%. The results of this paper provide some bases for analyzing the influence of polymer on cement hydration and the microstructure formation of polymer-modified cement-based materials in a new view.

Studi Perpindahan Panas Material pada Sistem Koordinat Segitiga

2017 ◽  
Vol 1 ◽  
pp. 114
Author(s):  
Imam Basuki ◽  
C Cari ◽  
A Suparmi
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Conduction ◽  
Partial Differential Equations ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Numerical Solution ◽  
Difference Method ◽  
The Finite Difference Method ◽  
The Mathematical Model

<p class="Normal1"><strong><em>Abstract: </em></strong><em>Partial Differential Equations (PDP) Laplace equation can be applied to the heat conduction. Heat conduction is a process that if two materials or two-part temperature material is contacted with another it will pass heat transfer. Conduction of heat in a triangle shaped object has a mathematical model in Cartesian coordinates. However, to facilitate the calculation, the mathematical model of heat conduction is transformed into the coordinates of the triangle. PDP numerical solution of Laplace solved using the finite difference method. Simulations performed on a triangle with some angle values α and β</em></p><p class="Normal1"><strong><em> </em></strong></p><p class="Normal1"><strong><em>Keywords:</em></strong><em>  heat transfer, triangle coordinates system.</em></p><p class="Normal1"><em> </em></p><p class="Normal1"><strong>Abstrak</strong> Persamaan Diferensial Parsial (PDP) Laplace  dapat diaplikasikan pada persamaan konduksi panas. Konduksi panas adalah suatu proses yang jika dua materi atau dua bagian materi temperaturnya disentuhkan dengan yang lainnya maka akan terjadilah perpindahan panas. Konduksi panas pada benda berbentuk segitiga mempunyai model matematika dalam koordinat cartesius. Namun untuk memudahkan perhitungan, model matematika konduksi panas tersebut ditransformasikan ke dalam koordinat segitiga. Penyelesaian numerik dari PDP Laplace diselesaikan menggunakan metode beda hingga. Simulasi dilakukan pada segitiga dengan beberapa nilai sudut  dan  </p><p class="Normal1"><strong> </strong></p><p class="Normal1"><strong>Kata kunci :</strong> perpindahan panas, sistem koordinat segitiga.</p>

Mathematical model of gas-charged accumulator considering heat conduction

2018 ◽  
Vol 2018 (0) ◽  
pp. YC2018-081
Author(s):  
Kazushi SANADA ◽  
Shuce ZHANG ◽  
Shuto MIYASHITA
Keyword(s):  
Mathematical Model ◽  
Heat Conduction
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