Non-linear ultrasonic time-reversal mirrors in NDT

0388400 - ÚT 2013 IT eng A - Abstrakt
Převorovský, Zdeněk
Non-linear ultrasonic time-reversal mirrors in NDT.
Lectio Materia. -, č. 4 (2012), s. 4-4
[World Conference on Nondestructive Testing /18./. 16.4.2012-20.4.2012, Durban]
Grant CEP: GA MPO(CZ) FR-TI1/274; GA MPO(CZ) FR-T1/198; GA ČR(CZ) GAP104/10/1430
Výzkumný záměr: CEZ:AV0Z2076919
Klíčová slova: non-linear ime reversal mirror * ultrasonic techniques * ESAM
Kód oboru RIV: BI - Akustika a kmity
http://www.academia-ndt.org/Downloads/AcademiaNews4.pdf

Various NDT techniques based on non-linear time-reversal mirrors (NL TRM) were developed during the last few years and have already been utilised in practice. Different modifications involve, for example, pulse inversion, frequency intermodulation, harmonic filtration, time shifting, decomposition of time reversal (TR) operator (DORT), excitation with symmetry analysis (ESAM) or chirp coding. Piezoelectric transducers are mostly used as both wave transmitters and receivers, and multiplexers switch between modes. Also, the non-contact receiving is realised using laser interferometers or air-coupled transducers. In that case, the reciprocity principle is applied – an array of transmitters is used as a source of both forward and TR waves. Ultrasonic NL TRM techniques are today under intensive development and are becoming very promising in the NDT and structural health monitoring fields.
Trvalý link: http://hdl.handle.net/11104/0217439