Wyniki wyszukiwania - BazTech

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Model matematyczny przepływu ruchu ulicznego w skali makroskopowej

Abrahamowicz E., Orłowski P.

Pomiary Automatyka Robotyka

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2017

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R. 21, nr 3

5--10

PL

Modele matematyczne, będące uproszczoną reprezentacją zachodzących zjawisk, pozwalają na prognozowanie przyszłych stanów. Jest to szczególnie istotne w odniesieniu do problemu przeciążonej infrastruktury drogowej w obszarach miejskich oraz możliwości poprawy tej sytuacji przez zastosowanie inteligentnych algorytmów sterowania. Zaproponowany autorski, dyskretny, nieliniowy model matematyczny reprezentujący przepływ ruchu ulicznego w skali makroskopowej umożliwia przeprowadzenie testowania nowych rozwiązań sterowania przed ich wdrożeniem do realnego systemu. Badania symulacyjne, przeprowadzone z wykorzystaniem środowiska MATLAB, zostały wykonane w celu weryfikacji poprawności działania modelu. Obejmują one scenariusze wolnego przepływu pojazdów oraz blokowania się drogi. Wskazana została również możliwość rozbudowy modelu o złożone ciągi dróg oraz skrzyżowań.

EN

Mathematical models, which are a simplified representation of the phenomena, allow to predict future states. This is particularly important with regard to the problem of congested road infrastructure in urban areas and the possibility of improving this situation through the use of intelligent control algorithms. The proposed discrete, nonlinear mathematical model representing traffic flow on a macroscopic scale enables the testing of new control solutions prior to implementation to the real system. MATLAB simulations are performed to validate the model. These include scenarios of a free flow of vehicles and road blockages.

2

Macroscopic modelling and simulation of two-phase copper matrix materials subjected to tensile deformation

Kosec B., Kampus Z., Kosec L., Kosel F.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 15, nr 1-2

114--119

EN

Purpose: Phenomena of deformation and fracture of two-phase metal matrix materials are two very interesting problems in the sceintific field of materials science and engineering. The study of these two issues can greatly contribute to better mechanical and technological properties of two-phase metal matrix materials. Design/methodology/approach: This work presents macroscopic models of two-phase metal matrix material, composed of ductile matrix and more rigid and hard inclusions (inserts) of secondary phase, prepared for the tensile deformation. These types of models are enlarged for two to three orders of magnitude comparing to the real copper matrix materials, and they are suitable for numerical as well as experimental modelling and simulation. Findings: The basic aim of the numerical and experimental modelling is in the observation of the matrix material flow, and in analysis of the stress-strain state in the matrix. Research limitations/implications: Deficiencies in FEA of the tensile deformation process of represented models, are suppositions: that in the models a non-stressed initial state were supposed, that the secondary-phase inclusions and particles were simulated as perfect rigid bodies, and that the Coulumb coefficient of friction on the insert-matrix interface was assumed as a constant value. Practical implications: The changes of geometrical parameters of the tensile deformed macroscopic models have been experimentally observed with the hardness measurements, geometry measurements, image analysis, and non-destructive testing methods. Originality/value: The most important results of that macroscopic simulation is in the observation of the material flow, the formation and propagation of cracks, motion of the broken secondary-phase inclusions and particles in the matrix, and the stress-strain analysis.

3

On the isotropic properties of a hexagonal - type rigid conductor

Siedlecka U., Wierzbicki E.

Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej

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2005

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Vol. 4, nr 1

239-245

EN

A new macroscopic model for the non-stationary heat transfer processes in a periodic hexagonal-type anisotropic rigid conductor is formulated. The main aim of this contribution is to show that the macroscopic properties of this conductor are transversally isotropic. The tolerance averaging technique as a tool of macroscopic modelling is taken into account [1].