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A platform for research: civil engineering, architecture and urbanism
A deeper understanding of acoustic emission wave propagation in reinforced concrete
In this paper the behavior of acoustic wave propagation in a reinforced concrete sample is described. Especially the influence of the duct is studied. Numerical simulations show how the propagating wave field is modified compared to a homogeneous model. Where the direct path is inhibited by the duct, traveltime perturbations of several microseconds are induced. Reinforcement bars have less influence due to their small diameter. Altogether, these perturbations are often exceeded by the usual picking errors in noisy data. Waves that were diffracted around the duct have a smaller amplitude and less impulsive onsets. This makes the picking more difficult and is a source of additional errors. In the AE-measurement of the tension crack, the localization was not very susceptible to errors in the picked arrival times. This depends on the sensor covering of the source area, that was quite good for AE-sources coming from inside that volume. A more serious problem for quantitative analysis methods is the occurrence of cracks. Open cracks represent barriers for the propagation of the ultrasound waves. The signals reach the receivers beyond that crack on a devious path or not at all. Therefore, in the tension experiment no AE-events from beyond the next cracks could be detected.
A deeper understanding of acoustic emission wave propagation in reinforced concrete
In this paper the behavior of acoustic wave propagation in a reinforced concrete sample is described. Especially the influence of the duct is studied. Numerical simulations show how the propagating wave field is modified compared to a homogeneous model. Where the direct path is inhibited by the duct, traveltime perturbations of several microseconds are induced. Reinforcement bars have less influence due to their small diameter. Altogether, these perturbations are often exceeded by the usual picking errors in noisy data. Waves that were diffracted around the duct have a smaller amplitude and less impulsive onsets. This makes the picking more difficult and is a source of additional errors. In the AE-measurement of the tension crack, the localization was not very susceptible to errors in the picked arrival times. This depends on the sensor covering of the source area, that was quite good for AE-sources coming from inside that volume. A more serious problem for quantitative analysis methods is the occurrence of cracks. Open cracks represent barriers for the propagation of the ultrasound waves. The signals reach the receivers beyond that crack on a devious path or not at all. Therefore, in the tension experiment no AE-events from beyond the next cracks could be detected.
A deeper understanding of acoustic emission wave propagation in reinforced concrete
Ein vertieftes Verständnis der Ausbreitung von Schallemissionssignalen in Stahlbeton
Schechinger, B. (author) / Vogel, T. (author)
2003
7 Seiten, 6 Bilder, 1 Tabelle, 6 Quellen
(Nicht paginiert)
Conference paper
Storage medium
English
Monitoring Crack Propagation in Reinforced Concrete Shear Walls by Acoustic Emission
| British Library Online Contents | 2013
Monitoring Crack Propagation in Reinforced Concrete Shear Walls by Acoustic Emission
| Online Contents | 2013
| British Library Online Contents | 1999