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1

Research on integrated scheduling of equipment predictive maintenance and production decision based on physical modeling approach

Zhang Qinglei, Yang Lei, Duan Jianguo, Qin Jiyun, Zhou Ying

Eksploatacja i Niezawodność

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2024

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Vol. 26, no. 1

art. no. 175409

EN

Equipment performance deteriorates continuously during the production process, which makes it difficult to achieve the expected effect of production decisions made in advance. Predictive maintenance and production decisions integrated scheduling aim to rationalise maintenance activities. It has been extensively researched. However, past studies have assumed that faults obey a specific probability distribution based on historical data. It is difficult to analyse equipment that is brand new into service or has poor historical failure data. Thus, in this paper, we construct a twin model of a device based on a physical modelling approach and tune it to ensure high fidelity of the model. Degradation curves were created based on equipment characteristics and developed maintenance activities.Develop an integrated scheduling model for predictive maintenance and production decisions with the goal of minimising maximum processing time. An improved genetic algorithm is used to solve the problem optimally. Finally, apply a practical scenario to verify the effectiveness of the proposed method.

2

Simulation of infeasible instruments in a sound synthesizer - implementation and control

Pluta Marek

Vibrations in Physical Systems

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2022

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Vol. 33, nr 2

art. no. 2022206

EN

Sound synthesis using mathematical modelling of musical instruments is a method particularly well suited for live performance using a physical controller. Depending on model complexity, it may be able to reproduce various subtle phenomena related to excitation and real time control of an instrument, providing an intuitive tool for a musician. A variant of physical modelling synthesis, referred to as the simulation of infeasible instruments, uses a model of an object that does not have a physical counterpart. Such model has some properties of a real object, which makes it still intuitive for a musician. However, other features, such as geometry, or material properties, are intentionally altered in such manner, that it could not function in reality. These infeasible features introduce new properties to the sound it produces. The study presents a few such models with a discussion regarding their implementation and control issues in a real-time sound synthesizer.

3

The challenges associated with laboratory scale physical modelling of high-plasticity spoil materials

Garala Thejesh Kumar, Cui Ge, Kantesaria Naman, Heron Charles M., Marshall Alec M.

Górnictwo Odkrywkowe

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2022

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R. 63, nr 3

10--15

EN

Characterisation of spoil (surface mine overburden) material is essential when investigating geotechnical issues associated with the spoil, e.g., for investigating the stability of pit lakes formed with spoil or spoil-structure interaction for any structures built on the spoil as part of sustainable developments. A significant proportion of spoils found across European countries are classified predominantly as silty clay with significant plasticity index and low permeability. In this paper, the difficulties associated with laboratory testing of highly plastic spoil materials obtained from different post-mining sites within Europe are discussed. The issues associated with small-scale laboratory testing of field spoil samples, development of an equivalent spoil for performing physical modelling tests, and the difficulties of centrifuge tests with spoil models are discussed in detail.

PL

Charakterystyka odpadów pogórniczych (nadkładu kopalni odkrywkowych) jest niezbędna przy badaniu zagadnień geotechnicznych związanych ze zwałowiskami, np. w celu zbadania stabilności pokopalnianych zbiorników wodnych utworzonych ze zwałowanych materiałów lub interakcji zwałowisko-konstrukcja budowlana dla wszelkich konstrukcji zbudowanych na zwałowisku w ramach zasady zrównoważonego rozwoju. Znaczna część materiału zwałowego występującego w krajach europejskich jest klasyfikowana głównie jako ił pylasty o znacznym wskaźniku plastyczności i niskiej przepuszczalności. W niniejszej pracy omówiono trudności związane z badaniami laboratoryjnymi wysoce plastycznych materiałów pogórniczych uzyskanych z różnych terenów pokopalnianych w Europie. Szczegółowo omówiono zagadnienia związane z badaniami laboratoryjnymi w małej skali próbek materiału pobranego w terenie, opracowaniem materiału równoważnego do przeprowadzenia modelowania fizycznego oraz trudności związane z badaniami w wirówce geotechnicznej modeli materiałów zwałowych.

4

Foundation systems for sustainable revitalisation of spoil dump areas

Kantesaria Naman, Cui Ge, Garala Thejesh Kumar, Doan Nhat-Phi, Halder Koushik, Heron Charles M., Marshall Alec M.

Górnictwo Odkrywkowe

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2022

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R. 63, nr 4

10--15

EN

The design of foundations systems is well established in the literature and codes of practice. However, these are generally applicable to well characterised, homogenous ground conditions. Spoil materials represent a significant challenge when implementing these design procedures due to their time-dependent characteristics, their spatial variability , and the likelihood that they will consist of low strength/stiffness materials. As such, careful consideration is required when designing foundation systems on spoil materials, especially for sensitive structures such as wind turbines. Physical modelling experiments using a geotechnical centrifuge were conducted to study the spoil-foundation system interaction. In these tests, an equivalent spoil was used that provided satisfactory reproduction of key physical and mechanical characteristics of a real spoil material. Three types of foundation systems were considered in the centrifuge tests: (1) raft foundation, (2) pile-group foundation, and (3) pile-raft foundation. The long-term cyclic loading of 87kN, 171kN and 460kN maximum cyclic load were used for the raft foundation. A higher cyclic load of 501kN was applied to the pile-group and pile-raft foundations. To evaluate the effect of climatic condition variations on spoil-foundation interactions, the centrifuge tests were carried out at different water table levels within the spoil material. The experimental results were analysed in terms of foundation rotation and foundation vertical settlement. The raft foundation rotated around 0.1-0.2 degrees and vertically displaced by 5-10 mm, whereas the pile-group rotated about 0.6-0.8 degrees and vertically displaced by 20-30 mm due to long-term cyclic loading. The pile-raft foundation displayed better response as compared to pile-group foundation.

PL

Projektowanie systemów fundamentowych jest dobrze ugruntowane w literaturze i w praktyce. Systemy te mają jednak zastosowanie do dobrze scharakteryzowanych, jednorodnych warunków gruntowych. Materiały zwałowe stanowią poważne wyzwanie przy wdrażaniu procedur projektowych ze względu na ich charakterystykę zależną od czasu, ich zmienność przestrzenną oraz duże prawdopodobieństwo, że będą się składać z materiałów o niskiej wytrzymałości/sztywności. W związku z tym, projektowanie systemów fundamentowych na zwałowiskach, szczególnie w przypadku wrażliwych konstrukcji, takich jak turbiny wiatrowe, wymaga starannego podejścia. W celu zbadania interakcji pomiędzy materiałem zwałowym a systemem fundamentowym przeprowadzono eksperymenty modelowania fizycznego z wykorzystaniem wirówki geotechnicznej. W badaniach tych zastosowano materiał równoważny, który zapewniał zadowalające odzwierciedlenie kluczowych cech fizycznych i mechanicznych rzeczywistego materiału. W badaniach wirówkowych rozpatrywano trzy rodzaje systemów fundamentowych: (1) fundamenty płytowe, (2) fundamenty wielopalowe oraz (3) fundamenty palowo-płytowe. Dla fundamentów płytowych zastosowano długotrwałe obciążenie cykliczne o maksymalnej wartości 87kN, 171kN i 460kN. Dla fundamentów wielopalowych i palowo-płytowych zastosowano większe obciążenie cykliczne - 501kN. W celu oceny wpływu zmienności warunków klimatycznych na interakcje zwałowisko-fundamenty, przeprowadzono badania wirówkowe przy różnych poziomach zwierciadła wody w obrębie zwałowiska. Wyniki eksperymentów analizowano pod kątem rotacji fundamentu i jego osiadania pionowego. W wyniku długotrwałego obciążenia cyklicznego fundament płytowy obrócił się o około 0,1-0,2 stopnia i przesunął w pionie o 5-10 mm, natomiast fundament wielopalowy obrócił się o około 0,6-0,8 stopnia i przesunął w pionie o 20-30 mm. Fundamenty palowo-płytowe odznaczały się lepszą reakcją w porównaniu do fundamentu wielopalowego.

5

The Influence of Optimization Parameters on the Efficiency of Aluminium Melt Refining by using Physical Modelling

Walek Josef, Michalek Karel, Tkadlečková Markéta

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 3

60--66

EN

The article describes the influence of optimization parameters on the efficiency of aluminium melt refining by using physical modelling. The blowing of refining gas, through a rotating impeller into the ladle is a widely used operating technology to reduce the content of impurities in molten aluminium, e.g. hydrogen. The efficiency of this refining process depends on the creation of fine bubbles with a high interphase surface, wide-spread distribution, the residence time of its effect in the melt, and mostly on the wide-spread dispersion of bubbles in the whole volume of the refining ladle and with the long period of their effect in the melt. For physical modelling, a plexiglass model on a scale of 1:1 is used for the operating ladle. Part of the physical model is a hollow shaft used for gas supply equipped with an impeller and also two baffles. The basis of physical modelling consists in the targeted utilization of the similarities of the processes that take place within the actual device and its model. The degassing process of aluminium melt by blowing inert gas is simulated in physical modelling by a decrease of dissolved oxygen in the model liquid (water).

6

Two-step inversion of airborne geophysical data: a stable downward continuation approach for physical modelling

Azadi Majid, Abedi Maysam, Norouzi Gholam-Hossain

Acta Geophysica

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2022

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Vol. 70, no 1

121--139

EN

Airborne potential field geophysical survey is employed for a variety of purposes to cover in a cost-effective manner large prospect areas. Despite the many advantages of airborne data measurements, due to the height from the ground, the received response is weakened (signal attenuation) and causes inadequacies in data representation. Accordingly, it is expected that the inversion results are far from reality and there are shortcomings in the retrieved model. This study investigates the impact of airborne survey on small-sized magmatic units, where directly inverting airborne data suffer from signal attenuation and lead to the loss of the causative model. In this study we improved the airborne data inversion by mixing a two-step cooperative approach which enhances the potential field data by a stable downward continuation to the ground surface in the spectral domain, and subsequently running a physical property modelling. The efficiency of the method over one-step airborne data inversion is examined for a synthetic multi-source case (magnetic and gravity) and then is used to find out the close spatial link between magnetometry signatures and iron–phosphate sources in the Esfordi district in Iran. The results showed that the proposed method performed better than direct inversion of airborne data and could satisfactorily identify the sources of the anomaly.

7

Deformation and failure mechanism of deep cement mixing walls: experimental study using physical model tests

Waichita Siriwan, Jongpradist Pornkasem, Patawanit Pongpeera, Jamsawang Pitthaya, Arangelovski Goran, Likitlersuang Suched

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 3

699--715

EN

This article presents the results of experimental research on the behaviour of deep cement mixing (DCM) walls during excavation up to failure. For this purpose, a novel laminar box equipped with a set of springs and a pneumatic loading system were designed and developed to run a total of nine scaled-down model tests at normal gravity on five different testing programs: (1) the wall thickness variation, (2) wall modulus variation, (3) effect of the reinforcement, (4) the bending stiffness (EI) control, and (5) the wall volume control of varying wall slenderness. The responses of the walls were studied through the wall horizontal displacement profile, tensile strains along with wall depth on the retained side, the distribution of strains using photogrammetric analysis and observation of crack initiation at the wall. The experimental results indicate that the behaviours of DCM walls depend strongly on the wall dimensions, particularly the thickness, and the analysis concepts used for conventional retaining walls cannot be directly utilized. The wall-to-excavation shape factor has been proven to effectively distinguish the behaviour mode and characterize the crack location concerning the wall height.

8

Innowacyjna stal wysokokrzemowa z regulowaną niską zawartością zanieczyszczeń i wtrąceń niemetalicznych o kontrolowanej morfologii oraz odpowiednim poziomie inhibitora AlN z przeznaczeniem na wysokojakościowe blachy transformatorowe

Różański Piotr, Radwański Krzysztof, Niesler Marian, Woźniak Dariusz, Zdonek Bogdan, Mazur Artur, Pidvysots’kyy Valeriy, Kuziak Roman, Maracha Grzegorz, Fraś Wojciech

Journal of Metallic Materials

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2020

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Vol. 72, no. 2

63--82

PL

W artykule przedstawiono przebieg i wyniki badań przemysłowych wykonanych w ramach 1 Etapu projektu, którego końcowym celem jest opracowanie innowacyjnej stali elektrotechnicznej nowej generacji, przeznaczonej na blachy transformatorowe o wysokiej przenikalności magnetycznej (wysokiej indukcji 1,9 T i małej stratności 0,8 W/kg) z ziarnem zorientowanym (typ HGO) wraz z technologią jej wytwarzania w zakresie: wytapiania w konwertorze z obróbką pozapiecową uwzględniającą próżniowe odgazowanie stali w demonstracyjnej instalacji, ciągłego odlewania wlewków płaskich i walcowania ich na gorąco na półwyrób do dalszego przerobu. Pozostałe etapy wytwarzania blach transformatorowych obejmujące walcowanie na zimno, międzyoperacyjną obróbkę cieplną i cieplno-chemiczną oraz obróbkę powierzchniową stanowią tajemnicą przedsiębiorstwa. W ramach 1 Etapu projektu wykonano symulacje numeryczne i fizyczne wytapiania, odlewania i walcowania na gorąco stali o założonych parametrach jakościowych, celem uzyskania materiału do dalszych badań. Określono parametry wytapiania i odlewania zapewniające uzyskanie odpowiedniej jakości stali o maksymalnej zawartość tlenu całkowitego 12 ppm i udziale powierzchniowym wtrąceń niemetalicznych max. 0,05%, oraz wymagania techniczno-technologiczne urządzenia do obróbki ciekłej stali w próżni, stanowiącego instalację demonstracyjną, a także opracowano model reologiczny stali transformatorowej dla procesu walcowania blach na gorąco, z użyciem którego przeprowadzono wstępne symulacje w celu uzyskania rozkładów temperatury, odkształcenia i prędkości odkształcenia w walcowanym paśmie.

EN

The article presents the process and results of industrial tests carried out as part of the 1st Stage of the project, the final goal of which is to develop an innovative new-generation electrical steel designed for the manufacture of transformer plates with high magnetic permeability (high inductance of 1.9 T and low lossiness of 0.8 W/ kg) and with oriented grain (HGO type) together with the technology of its production in the scope of: melting of steel in a converter with ladle treatment taking into account vacuum degassing of steel in a demonstration installation, continuous casting of flat ingots and their hot rolling for further processing. The remaining stages of transformer plate production, including cold rolling, inter-operational heat and thermo-chemical treatment, as well as surface treatment operations, are a trade secret. As part of the 1st Stage of the project, numerical and physical simulations of melting, casting and hot rolling of steel with assumed quality parameters were carried out in order to obtain material for further research. The melting and casting processes parameters were determined to ensure obtaining the appropriate quality of steel with a maximum total oxygen content of 12 ppm and the surface fraction of non-metallic inclusions of max. 0.05%, technical and technological requirements for the device for liquid steel processing in vacuum constituting the demonstration installation were determined, and a rheological model of transformer steel for the sheet hot-rolling process was developed, with the use of which preliminary simulations were carried out to obtain temperature, deformation and strain rates in the rolled strip.

9

Modele fizyczne w projektowaniu obiektów hydrotechnicznych

Robakiewicz Małgorzata

Gospodarka Wodna

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2020

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Nr 12

9--12

PL

Artykuł prezentuje ogólne zasady budowy i prowadzenia badań na modelach fizycznych wykorzystywanych w procesie projektowania obiektów hydrotechnicznych. Przedstawiono ograniczenia wynikające z przyjętej metody skalowania modelu, dostępnych metodach oraz zasadach prowadzenia pomiarów.

EN

This article presents general rules for construction and execution of experiments on physical models applied in design of hydro-engineering constructions. It also presents limitations resulting from the adopted scaling method, the available methods and rules for making measurements.

10

The physical modelling of high speed broaching of the heat-resistant steels for studies surface layer quality

Dvirna Olha

Journal of KONES

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2019

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Vol. 26, No. 3

23--29

EN

The main idea of the work is to create a physical model of high speed broaching heat-resistant materials is used to study the parameters of the surface layer quality. Modelling is a method of mediated cognition, in which the object under study is in some correspondence with the model, and the object-model is capable in some way or another to replace the original at some stages of the cognitive process. Physical modelling is primarily distinguished by the fact that studies are conducted on models with physical similarity, i.e. preserving completely (or at least partially) the nature of the phenomena. The work of the broach can be likened to the work of a number of planning cutter displaced relative to each other by a small amount, which is called lifting (feed per tooth). Therefore, for experimental work, a planning cutter of a special geometric was designed and manufactured – a physical model of a broach, in which geometric, mechanical and dynamic similarity is realized. The article also presents an experimental justification for the use of the created physical model in the study of the surface quality parameters of the, tab grooves of turbine and compressors disks made of heat-resistant materials.

11

Physical modeling of a fire with the use of the Froude number

Zimny Mateusz

Budownictwo i Architektura

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2019

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Vol. 18, nr 1

71--80

PL

Testy pożarowe w małej skali (skali modelowej) od samego początku istnienia dziedziny Inżynierii Bezpieczeństwa Pożarowego były źródłem wielu cennych informacji na temat zjawisk zachodzących podczas spalania. Przez lata wykształciło się kilka metod obliczeniowych pozwalających wyznaczyć kryteria podobieństwa pożarów w rzeczywistej i małej skali geometrycznej. Celem niniejszego artykułu jest przedstawienie metody wykonywania testów pożarowych w skali modelowej z wykorzystaniem liczby Froude’a. Omówione zostały podstawy skalowania, warunki podobieństwa, jakie muszą zostać zachowane, sposoby opisywania zjawisk pożarowych, a także metody przeliczania parametrów pożaru ze skali rzeczywistej i modelowej. Przedstawiono również przykładowe badania fizykalne z wykorzystaniem pomniejszonych modeli badawczych. W sposób szczególny podkreślono, jak ważne są tego typu eksperymenty oraz jaka odpowiedzialność spoczywa na osobach, które je przeprowadzają. Motywacją do przeprowadzenia badań jest bowiem bezpieczeństwo ludzi, którzy przebywają w budynkach z zabezpieczeniami przeciwpożarowymi opartymi na testach w skali modelowej.

EN

Ever since the field of Fire Safety Engineering first came into existence, small-scale (model scale) fire tests were the source of much valuable information about the phenomena occurring during combustion. Over the years, several computational methods to determine the criteria for the similarity of fires on both a real and small geometric scale have been developed. The purpose of this article is to present a method of performing fire tests on a model scale using the Froude number. The basics of scaling, similarity conditions that must be preserved, ways of describing fire phenomena, as well as methods of calculating fire parameters from the real and model scale have been discussed. An example of physical tests with the use of reduced research models is also presented. What is particularly emphasized is how important these types of experiments are and what responsibility rests with the people who carry them ouvol. The motivation to conduct research is the safety of people who reside in buildings with fire protection based on model scale test.

12

The Influence of Parameters of Argon Purging Process Through Ladle on the Phenomena Occuring in the Area of Phase Distributions: Liquid Steal-Slag

Pieprzyca J., Merder T., Saternus M., Gryc K., Socha L.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 2

653--658

EN

Purging the liquid steel with inert gases is a commonly used treatment in secondary metallurgy. The main purposes for which this method is used are: homogenization of liquid steel in the entire volume of the ladle, improvement of mixing conditions, acceleration of the absorption process of alloy additives and refining of liquid steel from non-metallic inclusions. The basic processing parameters of this treatment are: gas flow rate and the level of gas dispersion in liquid steel. The level of gas dispersion depends on the design and location of the porous plug in the ladle. Therefore, these parameters have a significant impact on the phenomena occurring in the contact zone of liquid steel with slag. Their improper selection may cause secondary contamination of the bath with exogenous inclusions from the slag, or air atmosphere due to discontinuity of the slag and exposure of the excessive surface of the liquid steel free surface. The article presents the results of modelling research of the effect of liquid steel purging with inert gases on phenomena occurring in this zone. The research was carried out using the physical (water) model of steel ladle. As a modelling liquid representing slag, paraffin oil was used, taking into account the conditions of similarity with particular reference to the kinematic viscosity. The results of the conducted research were presented in the form of visualization of phenomena occurring on the surface of the model liquid free surface in the form of photographs. The work is a part of a bigger study concerning modelling of ladle processes.

13

Physical Simulation of the Mannesmann Effect in the Rolling Process

Wójcik Ł., Pater Z.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 4

1369--1375

EN

The study presents the results of laboratory testing of the phenomenon of cracking in the process of cross rolling. A new method of determining the critical value of the damage function was developed, in which a disc-shaped sample is subjected to rotational compression in a channel. In this method the Mannesmann effect was used. The laboratory tests were conducted for C45, 50HS and R260 grade steel in the temperature range 950°C-1150°C. In order to research various methods of simulating the phenomenon of cracking in the process of cross rolling, physical modelling was also employed. The model material was commercial plasticine, cooled to the temperature 0°C-20°C. Comparing the test results for both the real and model material allowed one to determine the range of the forming temperature for the model material, in which the cracking process is similar to the case of the real material.

14

Numerical and Experimental Modeling of Plastic Deformation the Multi-Layer Ti/Al/Mg Materials

Mróz S., Stefanik A., Szota P., Kwapisz M., Wachowski M., Śnieżek L., Gałka A., Szulc Z.

Archives of Metallurgy and Materials

|

2019

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Vol. 64, iss. 4

1361--1368

EN

The paper has presented the results of theoretical studies and experimental tests of the plastic deformation of multi-layered Ti/Al/Mg specimens. Theoretical studies were carried out using the Forge2011® computer program. Physical modeling, on the other hand, was performed using the Gleeble3800 simulator. Cuboidal specimens were cut off from the plates obtained in the explosive welding method. Based on the obtained investigation results it has been found non uniform deformation of the particular layer as a result their different value of flow stress.

15

Development of an Approximation Model of Selected Properties of Model Materials Used for Simulations of Bulk Metal Plastic Forming Processes Using Induction of Decision Trees

Hawryluk M., Wilk-Kołodziejczyk D., Regulski K., Głowacki M.

Archives of Metallurgy and Materials

|

2019

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Vol. 64, iss. 3

1073--1085

EN

The article discusses the development of an approximation model of selected plastic and mechanical properties obtained from compression tests of model materials used in physical modeling. The use of physical modeling with the use of soft model materials such as a synthetic wax branch with various modifiers is a popular tool used as an alternative or verification of numerical modeling of bulk metal forming processes. In order to develop an algorithm to facilitate the choice of material model to simulate the behavior of real-metallic materials used in industrial production processes the induction of decision trees was used. First of all, the Statistica program was used for data mining, which made it possible to determine / find the relationship between the percentage of particular constituents of the model material (base material and modifiers) and yield strength, critical and maximum strain, and provide the opportunity to indicate the most important variables determining the shape of the stress - strain curve. Next, using the induction of decision trees, an approximation model was developed, which allowed to create an algorithm facilitating the selection of individual modifying components. The last stage of the research was verification of the correctness of the developed algorithm. The obtained research results indicate the possibility of using decision tree induction to approximate selected properties of modeling materials simulating the behavior of real materials, thus eliminating the need for costly and time-consuming experiments carried out on metallic material.

16

Zastosowanie druku 3D w modelowaniu fizycznym procesu walcowania kątownika

Dąbrowski M., Dobromilski R., Bulzak T., Wójcik Ł.

Hutnik, Wiadomości Hutnicze

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2018

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Vol. 85, nr 3

80--83

PL

W artykule przedstawiono wyniki badań porównujących modelowanie fizyczne oraz modelowanie numeryczne. Do realizacji badań wytypowano proces walcowania kątownika równoramiennego. Badania numeryczne przeprowadzono metodą elementów skończonych z użyciem oprogramowania DEFORM-3D, a w modelowaniu fizycznym wykorzystano możliwości druku 3D do wykonania walców. Przeprowadzone badania potwierdzają zgodność pomiędzy przyjętymi metodami modelowania. Ponadto potwierdzono, że materiał modelowy jakim jest kopolimer akrylonitrylo-butadieno-styrenowy (ABS) może być wykorzystany na narzędzia do walcowania ołowiu w gatunku Pb1.

EN

The article presents the results of research comparing physical modelling and numerical modelling. A rolling process of an angle bar was selected for the implementation of the tests. Numerical research was performed using the finite element method with the use of DEFORM-3D software. In physical modelling the possibilities of 3D printing for making rolls were used. The conducted research confirms the compatibility between the adopted modelling methods. Moreover, it was confirmed that the material which is ABS can be used for tools for rolling Pb1 lead.

17

Wpływ temperatury i smarowania na współczynnik pary trącej plastelina handlowa - kopolimer abs

Wójcik Ł., Pater Z.

Hutnik, Wiadomości Hutnicze

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2018

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Vol. 85, nr 10

362--366

PL

W pracy przedstawiono wyniki badań laboratoryjnych na podstawie których określono warunki tarcia pomiędzy materiałem modelowym, a narzędziami wykonanymi z materiału ABS. W badaniach wykorzystano model tarcia Amontonsa - Coulomba. Jako materiał modelowy przyjęto plastelinę handlową na bazie wosku firmy PRIMO, natomiast narzędzia wykonano metodą druku 3D FDM/FFF. Materiałem budulcowym wykorzystanym do wydruku był ABS P430. Badania laboratoryjne przeprowadzono dla pięciu temperatur (0, 5, 10, 15, 20) ˚C w warunkach tarcia suchego i ze smarowaniem (olej PTFE). Do analizy laboratoryjnej wykorzystano próbki materiału modelowego w kształcie krążków w kolorze czarnym oraz białym. Na podstawie zebranych informacji zaobserwowano, że w warunkach tarcia suchego w zakresie badanych temperatur wartości współczynników tarcia dynamicznego dla obu kolorów plasteliny są bardzo wysokie (μ≈1). Po zastosowaniu smarowania olejem teflonowym otrzymano wyniki odpowiednio dla plasteliny białej: 0˚C - 0,454; 5˚C - 0,411; 10˚C - 0,376; 15˚C - 0,319; 20˚C - 0,223, natomiast dla plasteliny czarnej: 0˚C - 0,44; 5˚C - 0,365; 10˚C - 0,362; 15˚C - 0,382; 20˚C - 0,196. Zastosowanie odpowiedniego smarowania podczas modelowania fizycznego pozwala na otrzymanie dokładniejszych wyników symulacji fizycznej procesów obróbki plastycznej.

EN

The paper presents the results of laboratory tests on the basis of which the friction conditions between the model material and tools made of ABS material were determined. The Amontons -Coulomb friction model was used in the research. As a model material, commercial plasticine based on the PRIMO company was adopted, while the tools were made using the 3D FDM / FFF. The building material used for printing is ABS P430. Laboratory tests were carried out for five temperatures (0, 5, 10, 15, 20˚C) ˚C under dry friction and lubrication conditions (PTFE oil). For laboratory analysis, samples of model material in the shape of discs in black and white were used. Based on the collected information, it was observed that in conditions of dry friction in the range of the tested temperatures, the values of dynamic friction coefficients for both colors of plasticine are very high (μ≈1). After applying Teflon oil lubrication results were obtained for white plasticine, respectively: 0˚C - 0.454; 5˚C - 0.411; 10˚C - 0.376; 15˚C - 0.319; 20˚C - 0.223, while for black plasticine: 0˚C - 0.44; 5˚C - 0.365; 10˚C - 0.362; 15˚C - 0.382; 20˚C - 0.196. The use of appropriate lubrication during physical modeling allows to obtain more accurate results of physical simulation of plastic forming processes.

18

Badania warunków tarcia pary trącej ołów - ABS w warunkach modelowania fizycznego

Wójcik Ł., Lis K.

Hutnik, Wiadomości Hutnicze

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2018

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Vol. 85, nr 9

327--331

PL

W artykule przedstawiono wyniki badań warunków tarcia ołowiu Pb1 wykorzystywanego do modelowania fizycznego procesów obróbki plastycznej. Do badań laboratoryjnych wykorzystano narzędzia wykonane z ABS (metodą druku 3D). Celem badań było wyznaczenie czynników oraz współczynników tarcia przy różnych warunkach smarowania. W badaniach wykorzystano metodę spęczenia pierścieni. Testy przeprowadzono dla tarcia suchego oraz z zastosowaniem: oleju PTFE i suchego PTFE. Odczytane z wykresu Burgdorfa wartości współczynników oraz czynników tarcia porównano z wynikami symulacji numerycznych. Do analizy FEM wykorzystano program symulacyjny DEFORM 3D. Na podstawie przeprowadzonych badań doświadczalno - numerycznych określono wpływ rodzaju smaru oraz sposobu przygotowania narzędzi (powierzchnia ABS po wydruku oraz powierzchnia po obróbce papierem ściernym o granulacji 240) na wartości współczynnika i czynnika tarcia. Zastosowanie narzędzi oszlifowanych pozwala na zmniejszenie wartości współczynników oraz czynników tarcia tylko w przypadku zastosowaniu smarowania.

EN

The article presents the results of friction conditions for lead Pb1 used for physical modeling of metal forming processes. In the laboratory study used tools made with ABS (using 3D printing).The aim of the research was to determine the factors and coefficients of friction for different lubrication conditions, using a ring upsetting method. The tests were performed for dry friction using: PTFE oil and dry PTFE. The coefficients and factors of friction read from the Burgdorf plot were compared to the numerical simulations’s results. For the FEM analysis, the DEFORM 3D simulation program was used. The influence of the type of lubricant and the method of preparing the tools (ABS surface after printing and surface after processing with abrasive paper of 240 grit) on the values of coefficient and facto rof friction were determined on the basis of experimental and numerical tests. The use of polished tool allows to reduce coefficients and factors of friction only in the case of using lubrication.

19

Physical Modelling of Degassing Process by Blowing of Inert Gas

Michalek K., Tkadlečková M., Socha L., Gryc K., Saternus M., Pieprzyca J., Merder T.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 2

987--992

EN

This paper deals with the possibilities of using physical modelling to study the degassing of metal melt during its treatment in the refining ladle. The method of inert gas blowing, so-called refining gas, presents the most common operational technology for the elimination of impurities from molten metal, e.g. for decreasing or removing the hydrogen content from liquid aluminium. This refining process presents the system of gas-liquid and its efficiency depends on the creation of fine bubbles with a high interphase surface, uniform distribution, long period of its effect in the melt, and mostly on the uniform arrangement of bubbles into the whole volume of the refining ladle. Physical modelling represents the basic method of modelling and it makes it possible to obtain information about the course of refining processes. On the basis of obtained results, it is possible to predict the behaviour of the real system during different changes in the process. The experimental part focuses on the evaluation of methodical laboratory experiments aimed at the proposal and testing of the developed methods of degassing during physical modelling. The results obtained on the basis of laboratory experiments realized on the specific physical model were discussed.

20

Numerical Analysis of the Structure of Liquid Flow in the Tundish with Physical Model Verification

Merder T.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 4

1895--1901

EN

Detailed studies of the movement of liquid steel (hydrodynamics) on a real object are practically impossible. The solution to this problem are physical modelling carried out on water models and numerical modelling using appropriate programs. The method of numerical modelling thanks to the considerable computing power of modern computers gives the possibility of solving very complex problems. The paper presents the results of model tests of liquid flow through tundish. The examined object was model of the twonozzle tundish model. The ANSYS Fluent program was used to describe the behavior of liquid in the working area of the tundish model. Numerical simulations were carried out using two numerical methods of turbulence description: RANS (Reynolds-Averaged Navier-Stokes) – model k-ε and LES (Large Eddy Simulation). The results obtained from CFD calculations were compared with the results obtained using the water model.