Interpolation with restrictions -- role of the boundary conditions and individual restrictions

summary:The contribution deals with the remeshing procedure between two computational finite element meshes. The remeshing represented by the interpolation of an approximate solution onto a new mesh is needed in many applications like e.g. in aeroacoustics, here we are particularly interested in the numerical flow simulation of a gradual channel collapse connected with a~severe deterioration of the computational mesh quality. Since the classical Lagrangian projection from one mesh to another is a dissipative method not respecting conservation laws, a conservative interpolation method introducing constraints is described. The constraints have form of Lagrange multipliers enforcing conservation of desired flow quantities, like e.g. total fluid mass, flow kinetic energy or flow potential energy. Then the interpolation problem turns into an error minimization problem, such that the resulting quantities of proposed interpolation satisfy these physical properties while staying as close as possible to the results of Lagrangian interpolation in the L2 norm. The proposed interpolation scheme does not impose any restrictions on mesh generation process and it has a relatively low computational cost. The implementation details are discussed and test cases are shown

Abrasive wear in three-phase waste-based polymeric particle composites

Eksperiment se zasniva na abraziji s dva i tri tijela u sustavima trofaznih kompozita od otpadnog materijala. Otpornost kompozitnih sustava na abraziju definira se ne samo fizikalno-mehaničkim odnosima pojedinih faza kompozita nego i uzajamnom interakcijom faza te međupovršinom matrica-punilo. Kako bismo opisali otpornost kompozitnog sustava na abraziju primijenili smo abrazivno trošenje "s dva tijela" na abrazivnom platnu i abrazivno trošenje "s tri tijela" na stroju s gumenim diskom uz abraziju pijeskom. Rezultati pokazuju da se ne može pronaći jasna korelacija između abrazija s dva i tri tijela sve dok se radi o smanjenju volumena sustava. U isto vrijeme, nije potvrđen jasan odnos između tvrdoće mjerene prema Brinellu i smanjenja volumena i pojedinačnih vrsta trošenja. Kompozit koji se pokazao najotpornijim na abrazivno trošenje bio je onaj s 30 % punila koji se u odnosu 6:1 sastojao od metalnih strugotina i F80 frakcije otpada korunduma u dvo-komponentnoj epoksi smoli (smanjenje volumena bilo je 0,0395 cm3 kod abrazije s dva tijela i 0,008 cm3 kod abrazije s tri tijela).The experiment centres on two and three body abrasion in three-phase waste-based composite systems. The composite systems abrasion resistance is defined not only by the physical-mechanical relationships of the separate phases of the composite, but also by the mutual interaction of the phases and on the matrix-filler interface. To describe the composite system abrasion resistance, we used a "two-body" abrasive wear on an abrasive cloth and a "three-body" abrasive wear on a machine with a rubber disc using sand abrasion. The results show that we cannot find a clear correlation between the two- and three-body abrasions as far as the systems’ volume decrease is concerned. At the same time, no clear relationship was confirmed between the hardness measured according to Brinell and the volume decreases with individual kinds of wear. The composite that proved the most resistant to abrasive wear was the one with 30 % filler based 6:1 on metallic chips and the F80 fraction waste corundum in two-component epoxy (the volume decrease was 0,0395 cm3 by two body abrasion and 0,008 cm3 by three body abrasion)

characterization of vegetable oil as cutting fluid

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Recycling of corundum particles - two-body abrasive wear of polymeric composites based on waste

Moderno bi društvo trebalo podržavati recikliranje svih materijala. Recikliranje materijala jedan je od najvažnijih načina tretiranja otpada. Jedna od mogućnosti recikliranja materijala je uključivanje otpadnih materijala u primarne matrice. Odgovarajući omjer i kombinacija otpadnih čestica na pozitivan način utječu na mehanička svojstva materijala u kojem su raspršene, a smanjuju mu i cijenu. Primjer recikliranja spomenutog materijala je disperzija čestica otpada korunda u polimernoj matrici. Kombinacija takvih vrsta matrica i punila dovodi do novog kompozita polimernih čestica – stvara kvalitativno sasvim novi materijal. Kao najvažnije značajke kompozita od polimernih čestica često se navode otpornost na abrazivno trošenje, tvrdoća, otpornost na udar i čvrstoća, i zadnje, ali ne manje važno, cijena. Rad se uglavnom bavi otpornošću na abrazivno trošenje između dva tijela i tvrdoćom kompozita od polimernih čestica s otpadnim Al2O3 kao punilom i dvo-komponentnom matricom od epoksidne smole.Recycling of all materials should be supported by modern society. Material recycling is one of the most important ways of dealing with waste. One of material recycling possibilities is an inclusion of waste into primary matrices. A suitable ratio and a combination of waste particles influence in a positive way mechanical properties of the material in which they are dispersed and they decrease its price. An example of the mentioned material recycling is a dispersion of corundum waste particles in the polymeric matrix. The combination of these types of matrix and filler gives birth to new polymeric particles composite - creates a qualitatively brand new material. As most important characteristics of the polymeric particle composites, one often lists resistance to abrasive wear, hardness, impact resistance and strength and, last but not least, their cost. This article deals mostly with the two-body abrasive wear resistance and hardness of polymeric particle composites with the waste Al2O3 as filler and two-component epoxy matrix

Research on Influence of Loading Speed of Structural Two-component Epoxy Adhesives on Adhesive Bond Strength☆

Abstract Adhesive bonds belong among a prospective technology of materials connecting, they are applied in many industrial branches when single applications use many advantages of these constructional bonds among which also good shear strength can be ranked. Just the shear strength of the adhesive bond belongs among factors determining an applicability of single adhesives. Standards describing the experimental determination of the adhesive bond shear strength specify the time which is needed for reaching the bond failure. For an extension of adhesives specification for given application the definition of the shear strength can be spread also of other speeds. The paper deals just with the determination of the time influence which is necessary for breaking a steel test adherent on the resultant shear strength of structural adhesives. An electron microscopy was used for an evaluation of fracture surfaces. The aim of the performed experiment is to describe the influence of changeable rate of deformation of the adhesive bond on the shear strength. From the result of the constructional carbon steel S235J0 testing the increase of the breaking strength and yield strength at increasing loading speed is obvious. At increasing loading speed the fall of the elongation of the adhesive bonded material occurred. From the results it is obvious that the loading speed of the adhesive bonds has a positive influence on the strength results of tested adhesive bonds. It came to the increase of the adhesive bond strength up of 21-57% at the speed 500 mm·min-1

Hodnocení hluku a vibrací v pracovním prostředí

Import 03/10/2007Prezenční030 - Katedra požární ochrany a ochrany obyvatelstv

Hand-Arm Vibration at Work with Hand Electric Tools

Import 01/09/2009Diplomová práce řeší problematiku vibrací v pracovním prostředí. Autor se zaměřuje převážně na vibrace přenášené na ruce. Diplomová práce obsahuje specifika pro měření a hodnocení vibrací, shrnuje jejich negativní účinky na lidský organismus a vytyčuje legislativní rámec týkající se vibrací. Součástí práce je měření a hodnocení vibrací při práci s ručním elektrickým nářadím pomocí přístroje Human Vibration Analyzer (Typ 4447), jehož měřicí funkce, včetně softwarového příslušenství, jsou v práci detailně popsány. Autor srovnává praktickým měřením míru expozice mezi osobou adaptovanou a neadaptovanou při konkrétním pracovním postupu a z výsledných hodnot vyvozuje patřičné závěry.Thesis solves the problems of vibration in the occupational environment. Author is mainly focusing on hand-arm vibrations. The thesis contains specifics of vibration measurement and evaluation, summarizes their negative effects on human body and sets out legislation framework concerning vibrations. The thesis includes vibration measurement and its evaluation during working with the hand-held electric tool by Human Vibration Analyzer (Type 4447) device, which measuring functions, including software equipment, are described in details. Author compares in a practical way measuring exposition volume between adapted and non adapted person during specific operation sequence and makes appropriate conclusions due to the resultant values.Prezenční040 - Katedra bezpečnostního managementuvýborn

Návrh konstrukce a technologie výroby forem pro tváření plastických hmot

Import 20/04/2006Prezenční výpůjčkaKatedra obrábění a montáže (346) FS VŠB (Ostrava

Innovation of planning process and control of JCL scripts on mainframe system project

Cílem této diplomové práce je vytvořit v prostředí konkrétní firmy inovativní přístup pro stávající proces plánování a kontroly JCL skriptů na systému mainframe. Tyto procesy jsou v současné době neefektivní a je nutné je inovovat. U procesu plánování JCL skriptů bude cílem vytvořit interní aplikaci, která výrazně zvýší efektivitu týmu a ulehčí přípravu zadávacích protokolů. Při této změně bude potřeba nově využívat nadstavbu systému mainframe Control-M od firmy BMC Software, která výrazně zkvalitní proces kontroly JCL skriptů. Přílohou této diplomové práce je funkční aplikace se zdrojovým kódem.The aim of this diploma thesis is to create, for a particular company, an innovative approach for the ongoing process of planning and verification of JCL scripts integrated in the system mainframe. These processes are currently inefficient and must be improved. During the planning process of JCL scripts an internal application will be created that increases team effectiveness and simplifies the preparation of procurement reports. With the internal application the company will also need a system upgrade of the mainframe Control-M from BMC software company, which will significantly improve the process of verifying JCL scripts. This thesis includes a functional application with the source code

Practical use of mainframe system

The mainframe system is not notorious known system, therefore the main purpose of the bachelor thesis is its explanation and introduction on practical examples. These examples will simplify future system users activities and can be used as a useful model. There is necessary a basic knowledge of programming and orientation in this sphere for implementation of examples into practise. Described system and introduced examples are generalized from theoretical and practical experiences of the author. My hope is, that after reading this bachelor thesis, the readers should get an general overview over discussed area