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Nonlinear analysis of reinforced concrete walls
Jurášek, Lubomír ; Vymlátil,, Petr (referee) ; Hradil, Petr (advisor)
Master thesis is based on a doctor thesis dealing with the behavior of reinforced concrete elements stressed shear by the author Ing. Stanislav Martinec, Ph.D. Author master thesis has the task create a spatial finally element model loading testing construction and researched the wall element. Defined finally elements model is mainly to provide proper interaction test device steel frame with the test wall element. Need for sufficiently detailed numerical analysis is necessary to define the non-linear concrete material model, that is researched element, using the extensions multiPlas for calculation software Ansys. The key output parameters, for comparison with the results of load tests, are total bevel and maximum level of applied force on the wall element. The goal is assess the effect of a steel frame, contained in finally element model, to output parameters for by non-linear numerical analysis.
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Nonlinear analysis of reinforced concrete walls
Jurášek, Lubomír ; Vymlátil,, Petr (referee) ; Hradil, Petr (advisor)
Master thesis is based on a doctor thesis dealing with the behavior of reinforced concrete elements stressed shear by the author Ing. Stanislav Martinec, Ph.D. Author master thesis has the task create a spatial finally element model loading testing construction and researched the wall element. Defined finally elements model is mainly to provide proper interaction test device steel frame with the test wall element. Need for sufficiently detailed numerical analysis is necessary to define the non-linear concrete material model, that is researched element, using the extensions multiPlas for calculation software Ansys. The key output parameters, for comparison with the results of load tests, are total bevel and maximum level of applied force on the wall element. The goal is assess the effect of a steel frame, contained in finally element model, to output parameters for by non-linear numerical analysis.
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Bezpečná recyklace elektrošrotu
BAMBAS-Elektrošrot, Skalice nad Svitavou ; Charita, Opava ; Vysoká škola báňská - Technická univerzita Ostrava ; Českomoravská elektrotechnická asociace, Praha ; České centrum čistší produkce, Praha ; APUSO plus, a.s., Praha ; Novotný, Pavel ; Bureš, Jiří ; Jurášek, Leon ; Krištofová, Dana ; Uskokovičová, Lenka
Svazek tvoří přílohy k návrhové části. Příloha 1: Příručka pro výrobce EEZ. Ekodesign a jeho využití pro EEZ, nebezpečné látky v EEZ a normy. Příloha 2: Příručka pro zpracovatele OEEZ. Definice elektrošrotu, pojmy, požadavky na množství OEEZ na hlavu a rok, zpětný odběr zařízení, sběr OEEZ, kritéria pro demontáž, požadavky na druhotnou surovinu z pohledu materiálové recyklace, skupiny EEZ, nebezpečné látky v malých domácích spotřebičích, součástky obsahující nebezpečné látky. Příloha 3: Možnosti energetického využití zůstatků OEEZ. Současný stav, problematika zbytkových odpadů po demontáži, obecnější pohled na problematiku alternativních paliv, hlášení o úpravě (zpracování), využívání a odstraňování elektroodpadů. Příloha 4: Finanční toky ve státech EU. Příloha 5: Podklady pro vypracování prováděcího právního předpisu k "elektrošrotové" novele zákona o odpadech.
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Evaluation of KQ toughness and Kefc fracture toughness of hypoeutectoid steel R7T
Holzmann, Miloslav ; Jurášek, L.
Interpretation of the characteristic KQ using linear-elastic fracture mechanics coupled with Irwin´s concept of the effective crack length. The effective yield stress Ref as a basic parameter controlling the level of KQ and its scatter. The use of Irwin´s concept of effective crack length for determining fracture toughness Kefc. Validity of Irwin´s concept up to certain ratio of Fmax/FGY. The scatter of the fracture toughness Kefc, i. e. probability distribution of fracture toughness Kefc diagram. This diagram can be used in the case of application of probabilistic fracture mechanics for determining cumulative fracture probability of the given crack.
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Použití lokálního přístupu při řešení transferability lomově mechanických parametrů
Dlouhý, Ivo ; Hadraba, Hynek ; Jurášek, L.
In some applications the pre-cracked Charpy specimens (PC) can be, after meeting the validity conditions applied for specification of fracture toughness characteristics corresponding to standard specimens. Typically this is the case of pearlitic steel R7T (used for railway wheelset production) with Lüders’ flow and higher strength properties. It has been found that there is a gap in fracture toughness data of PC specimens between the 60 and 90 MPam1/2 due to plastic hinge in net section of PC specimens. The distribution of maximum principal stress ahead of the crack tip in PC specimen loaded into fully plastic regime was found to be identical with that of reference stress-strain field in plane-strain SSY condition. 3D FEM simulations also shown that there is no constraint loss in PC specimens.
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Evaluation of Strain Rate Effects on Transition Behaviour Applying the Master Curve Methodology
Dlouhý, Ivo ; Kohout, J. ; Jurášek, Ladislav ; Holzmann, Miloslav
Master curve methodology has been used for an evaluation of strain rate effects on transition behaviour of wrought CrMo and cast ferritic C Mn steel.The physical aspects of strain rate effect on reference temperature has been analysed as a base for the prediction of this dependence.Statistical aspects of the strain rate effects on the master curve have been discussed showing capability of the method for the prediction of strain rate susceptibility of steel fracture behaviour. It has been experimentally proved that the master curve shape does not depend on the loading rate.The relationship between reference temperature T0 (or the shift of T0 with respect to quasi-static loading rate)and loading rate can be described with linear dependence if logarithmic scale of temporal change of stress intensity factor is considered.For experimental establishing of the dependence of reference temperature on loading rates only two T0 values as determined at different loading rates are sufficient.However,it is useful to achieve the comparable accuracy of both T0 determinations that may demand larger number of specimens for the measurement of T0 at the higher loading rate.Standard quasistatic fracture toughness has been predicted from small pre-cracked Charpy type specimens tested dynamically applying the reference temperature shift obtained experimentally.The predicted fracture toughness temperature diagram has been proved experimentally.
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