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Original title:
Stability of a bar influenced by small and large imperfections
Authors: Náprstek, Jiří ; Fischer, Cyril
Document type: Papers
Conference/Event: Engineering mechanics 2020 /26./, Brno (CZ), 20201124
Year: 2020
Language: eng
Abstract: The geometrical and physical imperfections of systems can drastically reduce their critical loading. These imperfections are usually of stochastic character and, therefore, they act as random parametric perturbations of coefficients of corresponding differential equations. In this paper, the imperfections are introduced as multidimensional statistics on the set of a large number of realizations of the same system. As far as the amount of information is small or the imperfections themselves cannot be considered small, the convex analysis is preferable. The paper compares results obtained by both stochastic and convex analyses for hyperprism and demonstrates when each of them is more convenient to be used. Besides of the hyper-prism, the possibilities and properties of other modifications of convex method are considered, especially those based on the definition of imperfection zone marked as a centric hyper-ellipsoid or as an eccentric hyper-ellipsoid. The analytical background was brought up to the level when only a few configurations of imperfections are sufficient to be evaluated numerically. These configurations are obtained by means of the convex analysis as points of extreme critical loading using the Lagrange method of constrained extremes.
Keywords: convex domain method; hyper-prism and hyper-ellipsoid domains; system stability
Project no.: GA19-21817S (CEP)
Funding provider: GA ČR
Host item entry: Engineering mechanics 2020. 26th International conference. Book of full texts, ISBN 978-80-214-5896-3, ISSN 1805-8248
Note: Související webová stránka: https://doi.org/10.21495/5896-3-374
Institution: Institute of Theoretical and Applied Mechanics AS ČR (web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences.
Original record: http://hdl.handle.net/11104/0317396
Permalink: http://www.nusl.cz/ntk/nusl-432475
The record appears in these collections:
Research > Institutes ASCR > Institute of Theoretical and Applied Mechanics
Conference materials > Papers
Authors: Náprstek, Jiří ; Fischer, Cyril
Document type: Papers
Conference/Event: Engineering mechanics 2020 /26./, Brno (CZ), 20201124
Year: 2020
Language: eng
Abstract: The geometrical and physical imperfections of systems can drastically reduce their critical loading. These imperfections are usually of stochastic character and, therefore, they act as random parametric perturbations of coefficients of corresponding differential equations. In this paper, the imperfections are introduced as multidimensional statistics on the set of a large number of realizations of the same system. As far as the amount of information is small or the imperfections themselves cannot be considered small, the convex analysis is preferable. The paper compares results obtained by both stochastic and convex analyses for hyperprism and demonstrates when each of them is more convenient to be used. Besides of the hyper-prism, the possibilities and properties of other modifications of convex method are considered, especially those based on the definition of imperfection zone marked as a centric hyper-ellipsoid or as an eccentric hyper-ellipsoid. The analytical background was brought up to the level when only a few configurations of imperfections are sufficient to be evaluated numerically. These configurations are obtained by means of the convex analysis as points of extreme critical loading using the Lagrange method of constrained extremes.
Keywords: convex domain method; hyper-prism and hyper-ellipsoid domains; system stability
Project no.: GA19-21817S (CEP)
Funding provider: GA ČR
Host item entry: Engineering mechanics 2020. 26th International conference. Book of full texts, ISBN 978-80-214-5896-3, ISSN 1805-8248
Note: Související webová stránka: https://doi.org/10.21495/5896-3-374
Institution: Institute of Theoretical and Applied Mechanics AS ČR (web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences.
Original record: http://hdl.handle.net/11104/0317396
Permalink: http://www.nusl.cz/ntk/nusl-432475
The record appears in these collections:
Research > Institutes ASCR > Institute of Theoretical and Applied Mechanics
Conference materials > Papers
Record created 2021-02-24, last modified 2021-11-24