Browsing by Subject "simulations"

Now showing 1 - 11 of 11

Access status: Open Access ,
3D Microstructure Reconstruction of Tetragonal Zirconia Polycrystalline
(AGH University Press, 2025) Grabowski, Grzegorz
The microstructure of a material is fundamental to its properties and behavior under mechanical and thermal loads. Understanding the internal structure of a material and controlling the microstructure at the stage of ceramic materials synthesis are essential for designing materials with desired properties. This study focuses on the three-dimensional reconstruction of the microstructure of yttria-stabilized tetragonal zirconia polycrystalline (TZP). The goal was to create accurate digital models of the microstructure which could be used for further material analysis. The study utilized images obtained through scanning electron microscopy (SEM), on the basis of which the fundamental stereological parameters were determined. The microstructure reconstruction was performed using the Laguerre tessellation method, allowing for the generation of three-dimensional digital models of the microstructure that represent the material’s internal structure. The results confirm that, based on the basic stereological parameters obtained from two-dimensional cross-sections, three-dimensional reconstruction of the microstructure of polycrystalline zirconia is possible. This work, therefore, represents a step towards the effective design of ceramic materials with high performance parameters, through the control and optimization of their microstructure.
Access status: Restricted ,
Analiza adaptacyjnego sterowania predykcyjnego niestacjonarnym procesem przemysłowym z opóźnieniem
(Data obrony: 2017-09-29) Mazur, Nikodem
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej
Access status: Restricted ,
Badanie wpływu dynamiki pojazdów w ruchu na dokładność ważenia w systemach Weigh-in-Motion
(Data obrony: 2018-10-22) Kita, Szymon
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej
Access status: Open Access ,
Computer modelling of the ablation casting process and prediction of the strength properties of AC-42000 castings
(Wydawnictwa AGH, 2022) Małysza, Marcin; Puzio, Sabina; Major-Gabryś, Katarzyna; Głowacki, Mirosław; Wilk-Kołodziejczyk, Dorota; Kamińska, Jadwiga
The demand for castings with superior properties has compelled the development and optimization of manufacturing technologies. By further developing already known techniques, we are able to contribute to the introduction of new research possibilities. The article presents the methodology of conducting simulation tests of the gravity casting process into sand moulds with the use of ablation. The ablation technique consists in spraying water through evenly spaced nozzles onto a mould into which the liquid casting alloy has been poured. The conducted research focuses on an alloy from the group of Al-Si alloys. In order to compare the effects of different techniques, additional tests were carried out for gravity casting into sand and metal die moulds. At the same time, virtual experiments were conducted to develop a simulation methodology for ablation casting technology, taking into account mould degradation. Additionally, the possibility of predicting the final mechanical properties of various manufacturing technologies was tested. Destructive tests were carried out to determine the mechanical properties in the cast samples, as well as microstructure tests and secondary dendrite spacing. The results of the mechanical tests are compared with the predicted simulation properties.
Access status: Open Access ,
Desynchronization of simulation and optimization algorithms in HPC environment
(Wydawnictwa AGH, 2020) Starzec, Mateusz; Starzec, Grażyna; Paciorek, Mateusz
The need for the scalability of an algorithm is essential when one wants to utilize an HPC infrastructure in an efficient and reasonable way. In such infrastructures, synchronization affects the efficiency of the parallel algorithms. However, one can consider introducing certain means of desynchronization in order to increase the scalability. Allowing certain messages to be omitted or delayed can be easily accepted in the case of metaheuristics. Furthermore, some simulations can also follow this pattern and thereby handle bigger environments. The paper presents a short survey on the desynchronization idea, pointing out already obtained results, or sketching out future work focused on scaling the parallel and distributed computing or simulation algorithms.
Access status: Restricted ,
Hardware and control design with simulation analysis of an inverted pendulum with electromagnetic actuators
(Data obrony: 2017-09-29) Francuz, Tomasz
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej
Access status: Open Access ,
Modelling of two phase filtration in fractures of hydraulic fracturing
(2010) Beisembetov, Iskander Kalybekovič; Assilbekov, B. K.; Žapbasbaev, Uzak K.; Kenzhaliev, B. K.
Aim of this work is to demonstrate a simulation of two-phase filtration in ruptures of breakdown which stated by mechanical conception of interpenetrating continuums. The worked out computing method forecasts degree of drowning, an amount of stocked up oil extraction and oil extraction ratio. Design data is in satisfactory fit with hydraulic fracturing coefficients got in industrial acceptance of oil fields. KEYWORDS: two-phase filtration, simulations.
Access status: Open Access ,
Przyczyny powstawania niedolewów w supercienkościennych elementach odlewanych z nadstopów na osnowie niklu
(Data obrony: 2010) Cygan, Rafał
Wydział Odlewnictwa
The research described in this doctoral thesis is a result of a wider project aimed at the description of physical and chemical phenomena occurring at the metal – ceramic mold and ceramic mold – environment boundary during the casting and solidification of investment castings (Research and development project R15 008 03 realized by the AGH in Cracow 2007 – 2010). The physical and chemical phenomena occurring at the metal-ceramic mold interface during the pouring of liquid metal into the mold influence the casting process significantly, and can constitute one of the main reasons for the forming of defects, including misruns and nonfills. In order to efficiently model and, as a result, optimize those technological processes, a series of experiments aimed at the investigation of metal-mold interface phenomena was conducted. The phenomenon of wetting of ceramic materials by liquid metals plays a major role in technological processes involving ceramics and liquid phase. The characteristic used most often to describe the degree of ceramic wetting by a liquid metal is the wetting angle $\theta$. The thermal and physical properties of shelling (molding) materials have a decisive influence on the structure and properties of a casting. That is so because they have the decisive influence on the thermal exchange processes between the casting and the ceramic mold. The exact importance of such properties can be especially appreciated when performing computer simulations of the casting solidification and cooling processes. The solidification process creates the original, primary structure, and the cooling of an already solidified casting creates the final structure of the casting alloy. The course of these processes, which decides about the obtained structure and properties of the casting, is largely dependant on the rate, at which the heat is being removed from the solidifying alloy. Very complicated geometries (super-thin sectioned castings with turbine blade sections measuring at times as little as 0,2 mm), less than perfect casting properties of superalloys and very strict quality standards contribute to the fact, that scrap rates for such castings can be very high. The purpose of a comparison between computer simulations and real-life experiments was to define the preliminary basic physical and chemical parameters, such as the thermal conductivity coefficient between the ceramic mold and insulation or between the ceramic mold and the environment; as well as to perform an initial verification of the ProCast simulation suite ceramic and thermally insulating materials database.
Access status: Open Access ,
Streamlining the car order picking tasks in a warehouse
(AGH University of Science and Technology Press, 2009) Jakubiak, Michał
An attempt to find the best possible way to allocate goods in a warehouse, so as to make the process of completing the order as short as possible, is the subject of this paper. Order picking is the most laborious warehouse process and it contributes to 55%-65% of all the costs of operations performed in a warehouse. In a modern warehouse every manipulation of materials is subjected to detailed verification at the stage of planning. The best possible goods- allocation allows to fully exploit the limited capacity of a given warehouse and to reduce the number of manipulations with a given product. The small shifts of goods on a short distances are starting to play a very important part. On the basis of a practical problem observation in a company, a computer program has been created. This program helps to simulate different goods allocation variants in a way which makes the process of order picking as short as possible.
Access status: Restricted ,
Symulacje rozkładów pola magnetycznego w otoczeniu napowietrznych wysokonapięciowych linii elektroenergetycznych
(Data obrony: 2019-01-29) Wojtyło, Michał
Wydział Elektrotechniki, Automatyki, Informatyki i Inżynierii Biomedycznej
Access status: Restricted ,
Wpływ wody na bezpieczeństwo posadowienia obiektów geotechnicznych w zabudowie miejskiej
(Data obrony: 2018-07-23) Kumorowska, Marta
Wydział Geologii, Geofizyki i Ochrony Środowiska
Osiadanie zapadowe, pęcznienie, skurcz to zjawiska powszechne w czasach prężnie rozwijającego się budownictwa, zwłaszcza w zabudowie miejskiej. W pracy została podjęta próba wizualizacji procesów związanych z działalnością wody w ośrodku gruntowym, skupiono się na gruntach wrażliwych na zmiany wilgotności: lessy, iły oraz grunty organiczne. W modelu fizycznym zostały przeprowadzone symulacje, które były odwzorowaniem rzeczywistych błędów wynikających z niedokładnego rozpoznania ośrodka gruntowo-wodnego lub sytuacji nieszczelnej kanalizacji. Pomiar osiadań w czasie trwania symulacji umożliwiły czujniki odkształceń, a ich przebieg udokumentowano za pomocą nagrań oraz zdjęć. Praca przytacza również przykłady rzeczywistych katastrof budowlanych mających miejsce w ostatnich latach i rozprawia nad ich przyczyną. Ponadto podkreśla konieczność rzetelnego rozpoznania ośrodka gruntowo-wodnego przed przystąpieniem do realizacji przedsięwzięć budowlanych.