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Calculation of residual fatigue life of railway set
Náhlík, Luboš ; Hutař, Pavel ; Knésl, Zdeněk ; Matušek, P.
The calculation of residual fatigue life of railway set is described in the contribution. The initial defect is modeled as a semicircular crack, which propagates preferentially in normal mode of loading perpendicularly on the axis of the axle. The conservative approach based on linear elastic fracture mechanics was chosen for residual fatigue life prediction. The aim of calculation is to determine number of loading cycles, which permits safe run of the railway axle, i.e. the dependence of crack depth on number of loading cycles for given loading spectrum.
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Reliability assessment of bodies with general singular stress concentrator
Klusák, Jan
The paper presents a method leading to reliability assessment of bodies with general singular stress concentrator. The method uses combination of analytical and numerical procedures to determine fracture-mechanics parameters. The approach is based on comparison of fracture behaviour of body with a crack and a body with a general singular stress concentrator. The goal of the paper is to determine value of applied stress that leads to initiation of failure of construction.
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Experiment CAPEX-U: Současnost a Budoucnost
Frolov, Oleksandr ; Koláček, Karel ; Štraus, Jaroslav ; Schmidt, Jiří ; Boháček, Vladislav ; Prukner, Václav
A new pulse capillary discharge driver with a laser-triggered main spark gap has been developed. The assembled CAPEX-U device consists of a Marx generator, of a pulse forming line, a gas-filled laser-triggered spark gap and a ceramic capillary. Its design was supported by mapping of electrostatic fields in the most exposed regions and by analysis of an equivalent circuit. Operation of the laser-triggered spark gap was tested on a single-channel model. In the paper, the results of the modelling and of the first electrical tests of the whole device (capillary current and voltage at the end of pulse forming line) are presented.
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Influence of the T-stress on Plastic zone shape and size for different form of specimens
Seitl, Stanislav
In framework of two-parameter fracture mechanics the shape and size of the plastic zone at the tip of a crack were studied. Analytical estimate of the size and shape of the plastic zone was made by substituting Mises yield criterion. For three different specimens (namely CCT-center cracked plate tension specimen, CT-compact tension specimen and 3PB-single edge cracked three point bending specimen) the numerical solution is calculated by using ANSYS. Numerical results are presented to show the influences of the T-stress on the plastic zone. Both solutions are compared and the effect of constraint on the plastic zone was discussed
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Numerická simulace a vizualizace vytváření syntetizovaného proudu
Trávníček, Zdeněk ; Vogel, Jiří ; Vít, T.
The paper presents the results of numerical and experimental investigations of a synthetic jet generation. The experiments were performed in air by means of flow visualization and hot-wire anemometry. The subsequent numerical simulation was performed using the commercial code FLUENT. The geometry, boundary conditions, and material properties of the numerical simulation were defined according to the real experimental situation.
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Management of education (focused on pupils health and socially disadvanteged)
Muchová, Zdeňka ; Vrzáček, Petr (advisor) ; Hradcová, Dana (referee)
The diploma thesis is focused on problems teaching of elementary school pupils with physical disadvantaged or socially disadvantaged pupils. The number of these pupils is constantly rising in ordinary schools. The present-day school reform makes it possible for schools, with their new educational programmes, to create the conditions for these pupils to individual integration into a regular classroom. The theoretic part deals with alternation in general - how people perceive it, what are its types, directing people during the change etc. Further it deals the problems of deprived or health disadvantaged pupils and their individual integration into a regular school. The practical part of thesis is attended to research investigation. By using of researching methods it analyses the present state of the integration system in one existing elementary school and it also investigates with posibilities of development and alternation. The overall output of the research is creating suggestion of the Integration developing plan.
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Inovative educational materials in teaching literature at secondary scholl
KLŮSOVÁ, Andrea
This master thesis is focused on education of literature. In theoretical part, it maps spectrum of educational materials for teaching on the second grade of elementary school. In the thesis, the main didactic aspects in 1970s, 1980s and their changes after the year 1989 till the present day are also compared. In these periods, the reading books and used methods are analyzed in detail. The question of obligatory reading is also discussed. In the frame of practical part of the thesis, the set of twenty didactically processes of working sheets for novel education of literature on the second grade of elementary school (for each class five working sheets). These sheets are elaborated in accordance to time-tested, but also innovative methods for work with text. Their aim is to develop the literacy of the readers and communication competence in accordance with educational requirements stated in RVP for elementary education. So, the working sheets offer an inspirational and practically usable source for teachers of literature education. The usability of majority of the working sheets or literature education was also verified in praxis.
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