Wyniki wyszukiwania - Biblioteka Nauki

1

Surface Green’s function of a soft elastomer with the gravity effect

100%

Liang X. , Liu J. , Xu P. , Li K.

Journal of Theoretical and Applied Mechanics

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2020

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tom Vol. 58 nr 1

35--44

EN

Gravity can play a tremendous effect on deformation of rubberlike materials and biological soft tissues. In this paper, considering the gravity effect, we proposed a surface Green’s function of a soft elastomer based on the neo-Hookean model. The proposed surface Green’s function is applied to analyze the elastic deformation of a soft elastomer subjected to uniform pressure. The surface normal displacement of the soft elastomer is calculated and the results show that gravity has a large impact on the surface deformation of the elastomer. Generally, the surface normal displacement decreases with the increasing gravitational force.

2

The numerical verification of the bending composite model

100%

Kobza W.

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2000

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tom z. 58

79-87

EN

The classical theory of bending neglects the interaction between longitudinal layers and assumes their constant thickness independently of the magnitude of load. The theory is successfully applied for isotropic materials. In this work the model of bending multilayers composites materials filled with soft materiais such as for example honeycomb, porous materials or distance textile is described. The bending layers are compressed in transverse direction and theirs thickness and stiffness of bending decrease. The model of bending is numerically verified using an energetic finite element method.

3

Rapid machining with industrial robot

86%

Kampa A. , Gołda G.

Selected Engineering Problems

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2014

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tom nr 5

57--62

EN

Industrial robots are used for many tasks, mainly for material handling and welding. Robots can be also equipped with other tools and used for machining. Nowadays small numbers of robots are used mainly for machining of soft materials, such as plastic, wood, foam and aluminium. This technique is used mainly for rapid prototyping. In this article an example of computer modelling of robotic cell for machining is shown. Some problems related with robot programming, accuracy, repeatability and calibration are discussed. An example of machining in polystyrene is presented.

4

Analysis of the possibility of assessing the ability to strengthen of the selected materials in the study indentation

72%

Makuch A. , Grygiel D.

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2016

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tom nr 3

39--44

EN

This work undertakes the problem of the possibility of assessing the ability to strengthen of the materials with very different hardness, i.e. copper, ordinary steel, silicon carbide and zirconium oxide. Measurements of parameters of hardness and elasticity by means of the DSI method were conducted under constant conditions of the indentation process of Vickers indenter into the sample material. On the basis of the curves of power P-h (loading/unloading power as the function of depth) the work of elastic, inelastic and total deformation was determined, and then the coefficient k, which is postulated in Oliver Pharr's works as a measure of the ability of materials to strengthen, was determined.

PL

W pracy podjęto problem możliwości oceny zdolności do umocnienia materiałów o bardzo zróżnicowanej twardości, tj. miedzi, stali zwyklej, węglika krzemu i tlenku cyrkonu. Wykonano pomiary parametrów twardości i sprężystości metodą DSI przy stałych warunkach procesu zagłębiania się wgłębnika Vickersa w próbki materiału. Na podstawie krzywych energetycznych P-h (silą obciążania/odciążania w funkcji głębokości) wyznaczono pracę odkształcenia sprężystego, niesprężystego, całkowitego, a następnie wyznaczono wskaźnik k, który jest postulowany w pracach Oliviera-Pharra jako miara zdolności do umocnienia materiałów.

5

Practices of the circular economy in Community Source projects: A preliminary study

58%

Almigheerbi T. S.

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2020

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nr 4 (58)

9-12

EN

Nowadays, the ‘Circular Economy’ (CE) is a modern topic that benefits business, society, and the environment. So far, the application of the CE has been restricted to certain areas that do not include the field of Information System development. From this point of view, the ‘community source’ model can be considered as an area to investigate the practices of the CE in Information System development. The community source model is a new model in software development that is intermediate between two well-known models (closed and open source systems). The practices of the CE found in projects that follow the community source model is then a potential area of scientific interest. A project was launched to comprehensively analyse this phenomenon. This paper presents the results of the preliminary study to initially explore the CE practices in community source projects. During the fieldwork, community source projects in EU countries were surveyed. The preliminary study concluded that practices such as recycling and resource-sharing are those that can arguably be found in these projects. As a term, a new kind of material has emerged, ‘soft material’ along with the typical kinds of material previously identified in the CE, namely biological and technical materials. The paper also briefly discusses the strategy of circular community in dealing with e-waste management

PL

Community Source to nowoczesny temat; który przynosi korzyści biznesowi; społeczeństwu i środowisku. Do tej pory stosowanie CE było ograniczone do pewnych obszarów, które nie obejmują dziedziny rozwoju systemów informatycznych. Z tego punktu widzenia model Community Source można uznać za obszar do badania praktyk CE w rozwoju systemów informatycznych. CE to nowy model w rozwoju oprogramowania, który jest pośrednikiem między dwoma dobrze znanymi modelami (systemy zamknięte i otwarte). Potencjalnym obszarem zainteresowań naukowych są praktyki CE występujące w projektach wykorzystujących model Community Source. Uruchomiono projekt kompleksowej analizy tego zjawiska. W artykule przedstawiono wyniki wstępnych badań, których celem było zbadanie praktyk CE w projektach Community Source. Podczas prac terenowych przebadano projekty wykorzystujące model CE w krajach UE. Wstępne badanie wykazało, że praktyki, takie jak recykling i dzielenie się zasobami, prawdopodobnie można znaleźć w tych projektach. Pojawił się nowy rodzaj materiału – „miękki materiał”, wraz z popularnymi typami materiałów wcześniej zidentyfikowanymi w CE, a mianowicie „biologicznymi” i „technicznymi”. W artykule omówiono również wstępnie strategię Circular Community w zakresie postępowania z e-odpadami.

6

Governing Differential Equations for the Mechanics of Undamageable Materials

51%

Voyiadjis G. Z. , Kattan P. I.

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tom Vol. 62, iss. 3

241–-267

EN

In this work the mathematical foundations of the mechanics of elastic undamageable materials are presented. In particular the governing differential equations are derived for both the scalar and tensorial cases. In the isotropic case it is found that the resulting scalar differential equations are simple and easy to solve. However, in the anisotropic case the tensorial differential equations are complicated and unsolvable at this time. The current work presents the solution in the form of explicit nonlinear stress-strain relations for the simple one-dimensional case. However, the general solution of the three-dimensional case remains unattainable at the present time. Only the governing tensorial differential equations are derived for this latter case. It is to be noted that the term “undamageable” is reflected in the context of the material stiffness and not the property of indestructibility due to various loading conditions. Thus, the undamageable material reflects that no microcracks or microvoids occur as well as no plastic yielding in the material. To illustrate this concept, a last section is added on applications.