Computational time reversal method based on finite element method: influence of temperature

0491021 - ÚT 2019 RIV CZ eng C - Konferenční příspěvek (zahraniční konf.)
Mračko, Michal - Kolman, Radek - Kober, Jan - Převorovský, Zdeněk - Plešek, Jiří
Computational time reversal method based on finite element method: influence of temperature.
Engineering mechanics 2018. Book of full texts. Prague: Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, 2018 - (Fischer, C.; Náprstek, J.), s. 561-564. ISBN 978-80-86246-88-8. ISSN 1805-8248.
[Engineering mechanics 2018 /24./. Svratka (CZ), 14.05.2018-17.05.2018]
Grant CEP: GA MŠMT(CZ) EF15_003/0000493; GA ČR(CZ) GA17-22615S
Institucionální podpora: RVO:61388998
Klíčová slova: time reversal method * elastic wave propagation * finite element method * temperature sensitivity * refocusing
Obor OECD: Mechanical engineering

Time reversal method is used to focus elastic waves to the location of the original source and reconstruct its source time function. The procedure consists of two steps: Frontal task and Reversal task. In the Frontal task, the medium is excited by an arbitrary source, elastic waves propagate through a body of interest and the dynamic response at few points on boundary is recorded. In the second step (say the Reversal task) the response signal is reversed in time and transmitted back into the medium resulting in focusing in the original source location. It is of practical importance to investigate a case when the medium changes its properties between the frontal and reversal wave propagation steps. An example is a problem of transferring experimentally recorded data to a computational model, where discrepancies in geometry, elastic properties and boundary conditions are expected. Our motivation is to develop a methodology for computation of time reversal problems in commercial finite element software. The results prove that this method is extremely sensitive to the change of temperature and one have to pay special attention to tuning of elastic parameters relevant to the
experiment.
Trvalý link: http://hdl.handle.net/11104/0290051