Acoustic emission in the frequency domain
Abstract
A means for quickly and easily determining the broadband frequency content of acoustic bursts as short as 20 microsec in duration has been developed using a video tape recorder and a standard spectrum analyzer. It is shown by examples from several tests on laboratory specimens and on large structures that the frequency content of an acoustic burst is related to the mechanism which produced it and is not affected substantially by the specimen size or by mode conversion due to multiple reflections in the structure. The frequency content of the burst can be changed in two ways, however: by the frequency-dependent attenuation of the propagation medium and in the cases where the medium is dispersive. Results of measurements on the effect of these factors in a variety of structures are given.
- Publication:
-
In: Monitoring structural integrity by acoustic emission; Proceedings of the Symposium
- Pub Date:
- 1975
- Bibcode:
- 1975astm.proc...11G
- Keywords:
-
- Acoustic Attenuation;
- Acoustic Propagation;
- Emission Spectra;
- Frequency Response;
- Spectrum Analysis;
- Bursts;
- Crack Propagation;
- Mode Transformers;
- Piezoelectric Transducers;
- Plastic Deformation;
- Recording Instruments;
- Sound Waves;
- Tape Recorders;
- Transmission Loss;
- Ultrasonic Radiation;
- Wave Dispersion;
- Acoustics