Computational Time reversal: localization of cracks

0518663 - ÚT 2020 RIV CZ eng A - Abstract
Mračko, Michal - Kolman, Radek - Kober, Jan - Převorovský, Zdeněk - Plešek, Jiří
Computational Time reversal: localization of cracks.
Modelling 2019. Ostrava: Institute of Geonics of the Czech Academy of Sciences, 2019 - (Blaheta, R.; Starý, J.; Sysala, S.). s. 143-143. ISBN 978-80-86407-79-1.
[Modelling 2019: International conference on mathematical modelling and computational methods in applied sciences and engineering. 16.09.2019-20.09.2019, Olomouc]
R&D Projects: GA MŠMT(CZ) EF15_003/0000493; GA ČR(CZ) GA17-22615S
Institutional support: RVO:61388998
Keywords : time reversal * refocusing * elastic wave propagation
OECD category: Mechanical engineering

There are several fields where Time reversal (TR) method has found its application. Our object of interest is the application in ultrasonic non-destructive testing (NDT). In NDT, this method can be used for tracing the source of vibrations in solid bodies, the source being a crack or some other defect, using a backward wave propagation for refocusing of the original source. The computational TR process consists of two steps. In the first step - the Frontal task, a model is loaded at the given place with the defined loading signal and an output is recorded at some location. In the second step
- the Reverse task, this responding signal is reversed in time and loaded back into the model so as to locate the original source (e.g. crack). Here we focus on localization of an initializing and a propagating crack in the prestressed finite element (FE) model. Besides other things, we also study how the length of the computation (number of reections of the elastic waves) in uences the
probability of localization of the crack. For numerical solution, we use the linear FE method, explicit integration in time.
Permanent Link: http://hdl.handle.net/11104/0304502