Wyniki wyszukiwania - BazTech

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Issues in Designing of Mechanical Parts Models in CAD Programs

Grygorcewicz Paweł, Raczko Konrad

Transactions on Aerospace Research

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2023

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Nr 2 (271)

33--44

EN

The article describes methods of creating mechanical parts in 3D programs, together with presenting very significant issues that emerge during the designing process employed in this creation, the main goal being to show the most important factors playing a role in the design process. Resultantly, it is ascertained that the most important factors needing to be considered by a designer are, inter alia, mass of the parts, strength, and kind of material. The article indicates the different types of parts used in different load cases, the objective being to explain various aspects relevant to design. The parts were different in particular in their nature of work and purpose. The article also presents illustrations after finite element method (FEM) analysis. It was important and interesting to observe how the stress in the tested parts was distributed under load and how the structure changed when the used material changed. The stress had a very large influence for the design of every airplane part; a case in point would be the illustration available from the lever example. The main role of this article is to describe different designing factors that could help a specialist create new designs in the future.

2

Technology for complex parts machining in multiproduct manufacturing

Ivanov Vitalii, Dehtiarov Ivan, Pavlenko Ivan, Kosov Illia, Kosov Mykyta

Management and Production Engineering Review

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2019

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Vol. 10, No. 2

25–-36

EN

At present, the speed of production and its complexity increases with each passing year due to the shorter product life cycle and competition in the global market. This trend is also observed in the machine-building industry, therefore, in order to ensure the competitiveness of enterprises and reduce the cost of production, it is necessary to intensify production. This is especially true in the machining of complex parts that require a great number of setups, and technological equipment. The problem-oriented analysis of complex parts was carried out, the parts classification was structured and developed according to the design and technological features. This made it possible to offer advanced manufacturing processes for complex parts like levers, forks, and connecting rods. The flexible fixtures for specified complex parts were developed. The effectiveness of the proposed manufacturing processes, as compared with the typical ones, provides significant improvement in the production.

3

Comparison of muscle activity during hand rim and lever wheelchair propulsion over flat terrain

Błażkiewicz Michalina, Wiszomirska Ida, Fiok Krzysztof, Mróz Anna, Kosmol Andrzej, Mikicin Mirosław, Molik Bartosz, Marszałek Jolanta

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 3

67--74

EN

The aim of this study was to compare the activity of upper limb muscles during hand rim wheelchair propulsion and lever wheelchair propulsion at two different velocity levels. Methods: Twenty male volunteers with physical impairments participated in this study. Their task was to push a lever wheelchair and a hand rim wheelchair on a mechanical wheelchair treadmill for 4 minutes at a speed of 3.5 km/h and 4.5 km/h in a flat race setting (conditions of moving over flat terrain). During these trials, activity of eight muscles of upper limbs were examined using surface electromyography. Results: The range of motion in the elbow joint was significantly higher in lever wheelchair propulsion (59.8 ± 2.43°) than in hand rim wheelchair propulsion (43.9 ± 0.26°). Such values of kinematics resulted in a different activity of muscles. All the muscles were more active during lever wheelchair propulsion at both velocity levels. The only exceptions were extensor and flexor carpi muscles which were more active during hand rim wheelchair propulsion due to the specificity of a grip. In turn, the examined change in the velocity (by 1 km/h) while moving over flat terrain also caused a different EMG timing of muscle activation depending on the type of propulsion. Conclusions: Lever wheelchair propulsion seems to be a good alternative to hand rim wheelchair propulsion owing to a different movement technique and a different EMG timing of muscle activity. Therefore, we believe that lever wheelchair propulsion should serve as supplement to traditional propulsion.

4

Intact stability of a bulk carrier

Kałkowska E.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2017

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nr 49 (121)

65--68

EN

Due to the accelerating demand for transporting raw materials around the world over the last century, bulk carriers are being constantly developed in order to maximise their capacity and efficiency whilst maintaining safety and durability of the vessels. With regards to safety, the International Maritime Organisation (IMO) and the International Association of Classification Societies (IACS) recurrently issue regulations and technical standards for the design and construction of ships, in order to safeguard the crew and other people on board. In light of these regulations, three issues concerning the properties of a bulk carrier are investigated. Firstly, the floodability of a bulk carrier is researched, to determine the largest possible volumes of compartments which can be flooded without causing the bulk carrier to capsize. Results were determined both manually and by means of marine design software, Maxsurf Enterprise; results generated by the two methods are compared. Additionally, a series of loadcases, each consisting of a different cargo and ballast configuration, are sought to reveal their effect on both the still water bending moment and the intact stability of the vessel. The results are analysed in relation to the IMO’s criteria.

5

Konstrukcja i montaż obróbkowych uchwytów modułowych

Barylski A.

TTS Technika Transportu Szynowego

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2017

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R. 24, nr 12

238--241, CD

PL

W artykule przedstawiono konstrukcję i montaż zaprojektowanych uchwytów modułowych. Wyznaczono również wariantowo koszty uchwytów, dla tego samego typu obrabianego elementu.

EN

The article presents of construction and the assembly of designed modular handles. The work appoints too, in variant mode, costs of handles of the elements for the same type subjected to machining.

6

Analiza numeryczna procesu kucia matrycowego elementu typu dźwignia

Czarnecki M., Filip B., Szala M.

Journal of Technology and Exploitation in Mechanical Engineering

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2015

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Vol. 1, nr 1-2

150--165

PL

Kucie matrycowe jest jedną z najstarszych metod obróbki plastycznej odkuwek. Technologia ta jest jednym z podstawowych sposobów kształtowania części maszyn i jest wykorzystywana w niemal każdej gałęzi przemysłu maszynowego, lotniczego, zbrojeniowego, motoryzacyjnego, rolniczego czy budowlanego. Z odkuwek wykonuje się najbardziej odpowiedzialne części maszyn. Jest to spowodowane licznymi zaletami tego procesu, do których należą: wysoka dokładność, możliwość odkuwania przedmiotów o skomplikowanych kształtach czy możliwość stosowania mniejszych naddatków technologicznych. W produkcji światowej najwięcej wytwarza się odkuwek stalowych, jednakże wzrasta ilość odkuwek wykonywanych ze stopów metali nieżelaznych, takich jak stopy magnezu, tytanu i aluminium. W artykule przedstawiono analizę teoretyczną oraz numeryczną procesu kucia matrycowego na przykładzie kształtowania odkuwki dźwigni. W pierwszej części opisano proces kucia matrycowego oraz przykłady jego szerokiego zastosowania w przemyśle. W kolejnej wykonano rysunki wsadu, matryc dolnej i górnej oraz odkuwki, wykorzystując oprogramowanie Solid Egde. Do wykonania elementu odkuwanego użyto łatwej w obróbce stali niestopowej jakościowej C45. Obliczenia przeprowadzono w oparciu o metodę elementów skończonych (MES), przy użyciu oprogramowania DEFORM 3D. Zastosowano siłę nacisku prasy wynoszącą 10000 kN oraz współczynnik tarcia równy 0,1. Następnie zaprezentowano wyniki symulacji przeprowadzonej w warunkach przestrzennego stanu odkształcenia, które umożliwiły wyznaczenie rozkładów intensywności odkształceń, naprężeń, temperatury oraz zniszczeń. Na ich podstawie stwierdzono poprawny dobór parametrów geometrycznych modelu oraz właściwy przebieg procesu, w którym nie zaobserwowano żadnych niewłaściwych deformacji lub pęknięć materiału.

EN

Die forging is one of the oldest methods of forming forgings. This technology is one of the basic ways of shaping machine parts and is used in almost every branch of mechanical engineering, aerospace, defense, automotive and construction industries. The most responsible parts of machines are made from forgings. It is caused by many advantages of this process, which include: high accuracy, ability to forge objects with complex shapes and the possibility of using fewer technological allowances. Steel forgings are the most popular produced elements in the world production, but the number of forgings made from non-ferrous alloys such as magnesium, titanium and aluminum alloys increase. In this paper, theoretical and numerical analysis of die forging was presented on example of forming of lever forging. In first part die forging procces and examples of their wide use in industry was described. In the next part drawings of the charge, the upper and lower dies and forgings were made, using Solid Edge . Material used to make forging element was carbon quality steel C45. Calculations were based on the finite element method (FEM) using DEFORM 3D. Press force of 10,000 kN and the coefficient of friction equal 0.1 were applied. Then, results of simulations, made in conditions of three dimensional state of strain were presented, allowed for determining distributions of strain intensity, stress, temperature and damage. On the basis of them, it was found that selection of parameters and course of process was appropriate, which influenced by many factors, including the selection of the respective radii of rounding the forging, which prevented the appearance of cracks in the first steps of the process.

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Przesuwanie budynków

Katzer J.

Warstwy, Dachy i Ściany

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2004

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nr 1

36-37