The mathematical modelling of corrosion in hot dip galvanized steel reinforced concrete

2011 ◽  
Vol 2 (1) ◽  
pp. 1-12
Author(s):  
A. Hegyi ◽  
H. Vermeşan ◽  
V. Rus
Keyword(s):  
Mathematical Model ◽  
Reinforced Concrete ◽  
Numerical Model ◽  
Equation System ◽  
Galvanized Steel ◽  
Steel Reinforced Concrete ◽  
Numeric Model ◽  
Physical And Mathematical Models ◽  
Physical Phenomena ◽  
The Mathematical Model

Abstract In this paper we wish to present the numerical model elaborated in order to simulate some physical phenomena that influence the general deterioration of steel, whether hot dip galvanized or not, in reinforced concrete. We describe the physical and mathematical models, establishing the corresponding equation system, the initial and boundary conditions. We have also presented the numeric model associated to the mathematical model and the numeric methods of discretization and solution of the differential equations system that describes the mathematical model.

scholarly journals Simulations and Tests of a KRET Aerospace Penetrator

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3291
Author(s):  
Krzysztof Bieńkowski ◽  
Łukasz Kolimas ◽  
Sebastian Łapczyński ◽  
Michał Drogosz ◽  
Michał Szulborski ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Numerical Model ◽  
Boundary Conditions ◽  
Eddy Currents ◽  
Electromagnetic Properties ◽  
Laboratory Model ◽  
Engineering Data ◽  
Experimental Values ◽  
Physical Phenomena ◽  
The Mathematical Model

This manuscript presents the simulation tests of an aerospace penetrator conducted to check the device’s validity and functionality. For this work, the numerical model was created on the basis of engineering data, the laboratory model of the tube reluctance actuator was created on the basis of the numerical model, and a set of simulations were executed on the basis of both presented. Moreover, the mathematical model was supplemented by precise boundary conditions. The main goal was the analysis of the introduced device’s properties by comparing them to experimental values. Three different variants were taken into account to check the construction functionality and to study the most important parameters, e.g., the hammer displacement, hammer velocity, eddy currents and overall electromagnetic properties of the penetrator’s hammer displacement. The high-end values of the applied components were derived on the basis of the results and are presented in the summary of the concluded work. An overall method for checking the validity of the penetrator was proposed, which is cost and time effective. The model used was not limited in the representation of physical phenomena.

scholarly journals Mathematical model for reliability indicators calculation of tethered UAV hybrid navigation system

2021 ◽  
Vol 2091 (1) ◽  
pp. 012033
Author(s):  
V M Vishnevsky ◽  
K A Vytovtov ◽  
E A Barabanova ◽  
V E Buzdin
Keyword(s):  
Mathematical Model ◽  
Navigation System ◽  
Analytical Method ◽  
Mathematical Expression ◽  
Equation System ◽  
Kolmogorov Equation ◽  
Reliability Indicators ◽  
Technical Vision ◽  
The Mathematical Model ◽  
First Time

Abstract The mathematical model for reliability indicators calculation of the hybrid navigation system containing microwave and technical vision subsystems is proposed in this paper for the first time. The proposed method is based on the translation matrix concept of solutions to the Kolmogorov equation system and it allows us to obtain the mathematical expression of availability factor, downtime ratio, and other reliability indicators. Also the presented approach allows finding the reliability indicators for the cases of jump change of transition intensities caused by external influences. Besides the analytical method can be used for investigation of hybrid navigation system transient mode functioning. The results of the numerical calculations clearly demonstrated correctness of the proposed approach.

Chaotic Phenomena Induced by the Fast Plastic Deformation of Metals During Cutting

2005 ◽  
Vol 73 (2) ◽  
pp. 240-245 ◽  
Author(s):  
Zoltan Palmai
Keyword(s):  
Mathematical Model ◽  
Plastic Deformation ◽  
Shear Stress ◽  
General Structure ◽  
Equation System ◽  
Qualitative Description ◽  
Balance Equations ◽  
Different Types ◽  
Energy Equations ◽  
The Mathematical Model

In the present study the examination of chip formation is focused on the primary shear zone, which is divided into two layers, and the variation of shear stress and temperature in time are given by two mechanical balance equations and three energy equations. All the five evolution differential equations are autonomous and nonlinear. The material characteristics are determined by an exponential constitutive equation. The mathematical model is suitable for the qualitative description of different types of chips, such as continuous chips and periodic or aperiodic shear localized chips, which is demonstrated by the general structure and typical solutions of the equation system.

scholarly journals Melacak Dampak Perubahan Iklim Terhadap Kondisi Makroekonomi dengan Teori Permainan Dinamis

2018 ◽  
Vol 7 (2) ◽  
pp. 57-62
Author(s):  
Muhammad Wakhid Musthofa
Keyword(s):  
Climate Change ◽  
Economic Growth ◽  
Mathematical Model ◽  
Equation System ◽  
Output Function ◽  
Macroeconomic Conditions ◽  
System A ◽  
Economic Growth Model ◽  
The Impact ◽  
The Mathematical Model

Makalah ini membahas tentang model matematika dampak perubahan iklim terhadap kondisi makroekonomi suatu negara. Dengan mengacu pada model pertumbuhan ekonomi endogen pada suatu negara, dengan fungsi output berbentuk fungsi Cobb-Douglas akan diturunkan model matematika yang mendeskripsikan dampak perubahan iklim terhadap kondisi makroekonomi suatu negara. Selanjutnya, akan dikonstruksikan pula fungsi ongkos yang berhubungan dengan model matematika yang telah diturunkan. Mengingat model matematika tersebut masih dalam bentuk sistem persamaan nonlinear, maka diperlukan proses linearisasi untuk menghasilkan model matematika yang linear sehingga memudahkan untuk dianalisis maupun diaplikasikan. [This paper discusses the mathematical model of the impact of climate change on the macroeconomic conditions of a country. By referring to an endogenous economic growth model in a country, with the output function in the form of a Cobb-Douglas function, a mathematical model will be described that describes the effects of climate change on the macroeconomic conditions of a country. Furthermore, it will also construct cost functions related to mathematical models that have been derived. Considering that the mathematical model is still in the form of a nonlinear equation system, a linearisation process is needed to produce a linear mathematical model that makes it easy to analyze and apply.]

Mathematical Model and Analytical Solution for the Vibration of Inclined Fluid-Transporting Submarine Pipelines

2019 ◽  
Vol 161 (A4) ◽  
Keyword(s):  
Mathematical Model ◽  
Dynamic Response ◽  
Integral Transform ◽  
Internal Flow ◽  
Equation System ◽  
Theoretical Understanding ◽  
Wake Oscillator ◽  
Lock In ◽  
Irregular Topography ◽  
The Mathematical Model

Due to the complexity of submarine environments, the nature of the dynamic response of free-spanning submarine pipelines, particularly inclined pipelines, is unclear. This paper aims to theoretically analyze the vibration behaviors of inclined fluid-transporting free-spanning submarine pipelines in the deepwater area. The mathematical model for the vibration of inclined fluid-transporting pipelines is established considering the influence of gravity on vibration response, and a non-linear wake oscillator is employed to model the vortex shedding behind the pipeline free span. The partial differential equation system is solved through the generalized integral transform technique (GITT), which is an analytical or semi-analytical method. Parametric analysis are carried out to investigate the effects of the inclination on the dynamic response of fluid-transporting pipelines. It is found that the inclination of the free-spanning pipeline will radically alter the natural frequency of the structure, and consequently the VIV lock-in region. In addition, the slope of the seabed will cause a more significant internal flow effect. The thorough theoretical understanding of inclined fluid-transporting pipelines helps increase the design accuracy for pipelines installed on a seabed with a highly irregular topography.

Development of a Numerical Model to Predict Residual Stress Based on Acoustoelastic Effect Using Critically Refracted Ultrasonic Longitudinal (LCR) Waves

2012 ◽  
Author(s):  
Malur N. Srinivasan ◽  
Shrijwal Joshi ◽  
Jiang Zhou
Keyword(s):  
Mathematical Model ◽  
Residual Stress ◽  
Numerical Model ◽  
Longitudinal Wave ◽  
Compressive Stress ◽  
Ultrasonic Wave ◽  
Time Travel ◽  
Acoustoelastic Effect ◽  
The Mathematical Model

The paper contains the development of mathematical model of the ultrasonic wave travelling through the medium which has been critically refracted known as critically refracted longitudinal wave or Creep wave. This wave is very sensitive to the residual stress induced in a medium. The mathematical model uses ultrasonic wave as a compressive stress source, which shows a relation of stress with the time travel. The result shows that when the stress is increased by 400 MPa the time travel jumps from 3187 to 3158 ns.

scholarly journals DEVELOPING EXPANDED POWELL’S ALGORITHM TO IDENTIFY THE MATHEMATICAL MODEL PARAMETERS FOR TRANSESTERIFICATION OF FISH FAT INTO BIODIESEL FUEL

2011 ◽  
Vol 14 (3) ◽  
pp. 34-48
Author(s):  
Hai Xuan Le ◽  
Anh Huynh Tuyet Le
Keyword(s):  
Mathematical Model ◽  
Random Search ◽  
Equation System ◽  
Optimal Operation ◽  
Descent Method ◽  
Steepest Descent Method ◽  
Biodiesel Fuel ◽  
Model Parameters ◽  
Operation Conditions ◽  
The Mathematical Model

By employing the system approach methodology, this research showed the expansion of Powell’s algorithm to solve the identification of kinetic parameters in the differential equation system which describes the transesterification of fish fat into biodiesel fuel. The expanded Powell’s method is developed on the basis of the algorithm that combines Taxi-Cab method with random search method and gradient method (steepest descent method). The obtained results allow us to simulate and optimize the biodiesel fuel production in order to assess the influence of technological factors on the effect of process and to determine the optimal operation conditions. The expanded Powell’s algorithm can also be advantageously applied to simulation or optimizzation in the cases when the mathematical model of the research object contains several parameters which must be identified.

Physical and mathematical models of ballast bed tamping via rotary device

2016 ◽  
pp. 5-16
Author(s):  
Nikita Polyanichko
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Operation Mode ◽  
Practical Importance ◽  
Theoretical Research ◽  
Technological Parameters ◽  
Physical Experiments ◽  
Physical And Mathematical Models ◽  
The Mathematical Model ◽  
Rotary Device

Objective: To develop a mathematical model and program for defining rational technological parameters and operation mode of a rotary device for tamping the ballast bed in the tie space area. Establish the veracity of calculations performed using the mathematical model and program developed via mathematical and physical experiments. Methods: Experimental and theoretical research conducted. Results: Established veracity of the mathematical model and program for calculating the technological parameters and operation mode of the device for tamping the ballastbed in the tie space area. Practical importance: The program developed provides the ability to select rational technological parameters and operation mode for the device. It is recommended that it be used when creating tools for ballast bed solidification in the ballast box area.

scholarly journals FINDING THE LINEAR DEPENDENCE OF THE CROSS-SECTION PROFILE FOR A UNIFORM FEEDING OF BREAD MATERIAL IN THE THRESHING PROCESS

2020 ◽  
Author(s):  
I.R. Antypas ◽  
◽  
T.P. Savostina
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Numerical Model ◽  
Cross Section ◽  
Reliability Optimization ◽  
Profile Line ◽  
Section Profile ◽  
The Cross ◽  
Cross Section Profile ◽  
The Mathematical Model

The use of advanced methods and technologies of threshing and separation allows you to predict and minimize losses. The results of reliability optimization of the cross-section profile of the transporting device and its influence on threshing and separation have not yet been studied. To solve this problem, the article modeled a mathematical numerical model that allows you to describe the function of the cut profile line in a General way. The mathematical model is solved using experimental data.

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