TY  - CONF
AU  - Saenger, Erik H.
AU  - Werner, Claudia
AU  - Nguyen, Luan T.
AU  - Kocur, Georg K.
AU  - Ahrens, Benedikt
TI  - Numerical Simulations of Wave Propagation: Time Reverse Imaging and Defect Mapping in Pipes
VL  - 50
CY  - Jülich
PB  - Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
M1  - FZJ-2020-01427
T2  - Publication Series of the John von Neumann Institute for Computing (NIC) NIC Series
SP  - 231 - 241
PY  - 2020
AB  - Time reverse imaging (TRI) is evolving into a standard technique for locating and characterising seismic events. In recent years, TRI has been employed for a wide range of applications from the lab scale, to the field scale and up to the global scale. No identification of events or their onset times is necessary when locating events with TRI; therefore, it is especially suited for locating quasi-simultaneous events and events with a low signal-to-noise ratio. However, in contrast to more regularly applied localisation methods, the prerequisites for applying TRI are not sufficiently known. To investigate the significance of station distributions, complex velocity models and signal-to-noise ratios with respect to location accuracy, numerous simulations were performed using a finite difference code to propagate elastic waves through three-dimensional models. Moreover, we present a reverse-time imaging technique by cross-correlating the forward wavefield with the reverse wavefield for the detection, localisation, and sizing of defects in pipelines. The presented technique allows to capture the wavefield reflectivity at the places of ultrasonic wave scattering and reflections. Thus, the method is suitable for detecting pipe defects of either point-like or finite-size types using data from a pulse-echo setup. By using synthetic data generated by 3D spectral element pipe models, we show that the 3D wavefield cross-correlation imaging is capable in the case of cylindrical guided ultrasonic waves. With a ring setup of transducers, we analyse the imaging results obtained from the synthetic single-transducer and all-transducer firings. The presented pipe flaw imaging method is straightforward to carry out using a suitable wave equation solver.
T2  - NIC Symposium 2020
CY  - 27 Feb 2020 - 28 Feb 2020, Jülich (Germany)
Y2  - 27 Feb 2020 - 28 Feb 2020
M2  - Jülich, Germany
LB  - PUB:(DE-HGF)8 ; PUB:(DE-HGF)7
UR  - https://juser.fz-juelich.de/record/874417
ER  -