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Virtual laboratories in the teaching of mechanical technology

Major Štěpán, Hubálovská Marie

Chemistry-Didactics-Ecology-Metrology

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2023

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R. 28, NR 1-2

135--155

EN

The aim of this article is to familiarise the reader with the issue of virtual laboratories and to demonstrate their possible use on a concrete example. This example deals with the use of virtual laboratories in the teaching of mechanical engineering in high schools and universities. The Covid-19 pandemic has led to significant changes in the teaching process and its organisation. In this period, teaching usually took place online, which was implemented using resources such as Google Classroom or MS Teams. This article presents a sample task a project on which students of the second and third year of study at a secondary technical school are working. The project has an interdisciplinary character, because during its implementation students apply and further develop skills and knowledge from several subjects, namely physics, mechanics, chemistry and CAD design. The project is dedicated to the design of a pulley casting for a steel rope.

2

Metody oczyszczania ścieków w zakładach mięsnych

Kwiecińska M., Kruszelnicka I., Ginter-Kramarczyk D.

Przemysł Spożywczy

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2017

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T. 71, nr 8

39--43

PL

Przemysł spożywczy zajmuje się wytwarzaniem produktów i półproduktów przeznaczonych do spożycia i jest bardzo prężnie rozwijającym się działem gospodarki. Przedsiębiorstwa te charakteryzują się jednak znacznym rozproszeniem i rozdrobnieniem, co ma istotny wpływ na wielkość emitowanych zanieczyszczeń, m.in. ścieków. W artykule zawarto fragment przeglądu nowoczesnych metod oczyszczania ścieków w przemyśle spożywczym i przedstawiono możliwe rozwiązania wynikające ze zmieniających się i coraz bardziej restrykcyjnych przepisów wodnoprawnych. Przedstawiono też definicję ścieków pochodzących z przemysłu mięsnego i ich charakterystykę oraz omówiono sposoby ich oczyszczania za pomocą metod mechanicznych, chemicznych i biologicznych.

EN

Food industry deals with the manufacture of products and semi-products, intended for consumption; it is very dynamically developing sector of economy. The involved enterprises are, however characterized, by a considerable scattering and disintegration what has a significant effect on the level of emitted contamination, including wastes. The present paper contains a fragment of a review of modern methods for waste water treatment in food industry; the possible solutions, resulting from the changing and more and more restrictive water-legal regulations, have been presented. The definition of the wastes, coming from the meat industry and their characteristics has been also included. The methods for their treatment, using mechanical, chemical and biological methods were discussed.

3

Selected examples of research and knowledge transfer in the area of machine building and exploitation

Gawlik J., Krajewska-Śpiewak J.

Journal of Machine Construction and Maintenance - Problemy Eksploatacji

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2017

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no. 1

19--27

EN

The variety of possible construction solutions of machinery and technological equipment and research related to these solutions require knowledge of materials engineering, mechanics, strength of materials, electronics and mechatronics, the basics of machine construction and machine technology. It is impossible to cover such an extensive range of required information in just one publication. Therefore, the authors of this article concentrated only on selected examples of research, construction solutions, and technological recommendations that have found application in industrial environments. Topics presented in the article include the following: - A research and design solution of a specialized drill for making holes in the diameter range of 4 to mm to a depth of 1600 mm; - Shaping elements by precision machining; - A research workstation for precision machining of microelements with the use of unconventional technologies - laser machining and Electrical Discharge Machining (EDM); and, The influence of machining conditions on the state of residual stresses in the surface layer of the workpiece. The choice of the above examples shows how wide is the area of problems which can be presented in the journal “Journal of Machine Construction and Maintenance”.

PL

Różnorodność rozwiązań konstrukcyjnych urządzeń i wyposażenia technicznego oraz prowadzonych badań w zakresie tych rozwiązań wymaga wiedzy z obszaru inżynierii materiałowej, mechaniki, wytrzymałości materiałów, elektroniki i mechatroniki, podstaw budowy maszyn oraz technologii maszyn. Nie jest możliwe, aby w jednej publikacji objąć tak szeroki zakres merytoryczny, dlatego też, autorzy artykułu skoncentrowali się na wybranych przykładach badań, rozwiązań konstrukcyjnych oraz zaleceniach technologicznych, które realizowano w warunkach przemysłowych. Zaprezentowana w artykule tematyka obejmuje: Badania oraz rozwiązania projektowe specjalizowanego wiertła do wiercenia otworów o średnicy od f4 do φ32 mm do głębokości 160 mm; Kształtowanie elementów w procesie obróbki precyzyjnej; Stanowisko badawcze do obróbki precyzyjnej mikroelementów z wykorzystaniem niekonwencjonalnych technologii - obróbki laserowej i obróbki elektroerozyjnej (EDM); Wpływ warunków obróbki skrawaniem na naprężenia własne w warstwie wierzchniej próbki. Wybór powyższych przykładów pokazuje obszerność problematyki, która może być zaprezentowana w czasopiśmie “Journal of Machine Construction and Maintenance”.

4

Bulk-metal forming processes from computational modelling via sensitivity analysis to tool shape optimization

Antunez H. J.

Prace Instytutu Podstawowych Problemów Techniki PAN

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2001

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nr 1

3-207

EN

Within the proceding framework, the present work is a collection of developments performed at the Institute of Fundamental Technological Research of the Polish Academy of Science. All of them are concerning one specific way of modelling metal forming processes; this is especially suited for hot forming condition, and has conceived for steady-state processes, although it can be applied in transient ones as well. The naturally suited application of this model is extrusion; however, it can be used also in free forging, cutting and rolling (including seamless tube rolling), for which results are shown as well. Stationary and transient processes are separately presented here; not only for the sake of clarity of the exposition and for historical reasons, but to show the analysis problem, sensitivity analysis and shape optimization as successive steps within a logical line of thinking. Essentially this process was followed in the computer simulation of metal forming, feeding into each step all the results obtained in the proceding ones. In this work, the steady state is presented first, starting by the flow approach. Following, the descretization by finite elemtens is given. Here the different features accounted for in the model are explained. One the analysis model is complete, the sensitivity is ready to be introduced. First, parametric sensitivity is discussed, what is incidentally useful to show the available methods for sensitivity analysis. Shape sensitivity is considered next, followed by the optimization algorithm which finds, according to given criteria and design restrictions, the optimum design. Afterwards transient processes are considered. A full transient formulation is concidered and used to obtain an incremental method that makes use of linear elements due to a proper time-step splitting. Attention is focused on the full explicit version. Further, sensitivity analysis within such model and discretization is shown. In addition, the pseudo-concentration method is briefly revisited and used in connection to Fourier series expansion of the problem of seamless tube rolling. Some additional -but significant- topics are discussed in the course of the main presentation. The simulation of almost perfect plasticity poses the problem of uniqueness (or its lack), and this is discussed in the context of cutting simulation. Pressure stabilization is necessary to apply a friction model based on a Coulomb-type law. In this context a bilinear interpolation is introduced, which takes advantages of a method for similar pressure stabilization used in fluid mechanics. Sensitivity analysis suggests that its results can have an additional application in evaluating the effect on the solution of numerical parameters needed in some models. This is the case of the upwind parameters in coupled thermo-mechanical problems and the time step in time integration of transient processes. The introduction of shape sensitivity analysis of fomring processes gives the occasion to consider the extension to large displacements of the two available methods. In the shape optimization part, the problem of shape parameterization requires special attention. Two different techniques of interpolating points in the discretized domain in terms of the design parameters are proposed.