A Magnetic Method for Testing of Homogeneity of Fibre Concrete

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26110%2F11%3APU96235" target="_blank" >RIV/00216305:26110/11:PU96235 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

A Magnetic Method for Testing of Homogeneity of Fibre Concrete

Popis výsledku v původním jazyce

Homogeneity of fibre concrete structures, characterized, from the macroscopic point of view, by (nearly) constant volume fraction of randomly oriented fibre particles, determines their mechanical, thermal, etc. properties, consequently their long-time behaviour, reliability and range of user applications. Destructive validation of homogeneity is available under laboratory conditions, but frequently impossible in situ. A reasonable alternative to the radiographic control method can be based on stationary measurements of magnetic field strength, thanks to the composite structure with ferromagnetic particles, incorporated in the concrete matrix. The permanent magnet generates a (nearly) stationary magnetic field, whose distribution is described by the Laplace equation, supplied by appropriate boundary conditions, containing the effective relative magnetic permeability as just one material parameter; the crucial problem is then to estimate some formally homogenized (with a priori unknown permeability of fibres) as a function of , without the a priori knowledge of permeability of particles. The paper demonstrates that in such case the numerical analysis of solution of the Laplace equation can be avoided, thus is allowed to be evaluated directly, using local measurements of the magnetic field strength from the Hall-effect-based measurement and non-trivial MATLAB-supported computations, based on the least squares optimization, supported by the Newton method for the numerical evaluation of roots of nonlinear equations.

Název v anglickém jazyce

A Magnetic Method for Testing of Homogeneity of Fibre Concrete

Popis výsledku anglicky

Homogeneity of fibre concrete structures, characterized, from the macroscopic point of view, by (nearly) constant volume fraction of randomly oriented fibre particles, determines their mechanical, thermal, etc. properties, consequently their long-time behaviour, reliability and range of user applications. Destructive validation of homogeneity is available under laboratory conditions, but frequently impossible in situ. A reasonable alternative to the radiographic control method can be based on stationary measurements of magnetic field strength, thanks to the composite structure with ferromagnetic particles, incorporated in the concrete matrix. The permanent magnet generates a (nearly) stationary magnetic field, whose distribution is described by the Laplace equation, supplied by appropriate boundary conditions, containing the effective relative magnetic permeability as just one material parameter; the crucial problem is then to estimate some formally homogenized (with a priori unknown permeability of fibres) as a function of , without the a priori knowledge of permeability of particles. The paper demonstrates that in such case the numerical analysis of solution of the Laplace equation can be avoided, thus is allowed to be evaluated directly, using local measurements of the magnetic field strength from the Hall-effect-based measurement and non-trivial MATLAB-supported computations, based on the least squares optimization, supported by the Newton method for the numerical evaluation of roots of nonlinear equations.

Druh

D - Stať ve sborníku

CEP obor

JN - Stavebnictví

OECD FORD obor

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Projekt

<a href="/cs/project/GA103%2F09%2F1073" target="_blank" >GA103/09/1073: Vývoj nedestruktivních metod pro posouzení homogenity ztvrdlého drátkobetonu</a><br>

Návaznosti

Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2011

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

9th International Conference NDT 2011 Nedestruktivní testování v technických oborech

ISBN

978-80-7204-774-1

ISSN

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e-ISSN

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Počet stran výsledku

10

Strana od-do

19-29

Název nakladatele

Neuveden

Místo vydání

Brno

Místo konání akce

brno

Datum konání akce

7. 12. 2011

Typ akce podle státní příslušnosti

EUR - Evropská akce

Kód UT WoS článku

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