Determination of arrival times for acoustic emission source location in composites

Conference · Wed Mar 26 04:00:00 EST 1986

OSTI ID:5566901

Hamstad, M A

The determination of the arrival time of an AE event has been studied using simulated acoustic emission (AE) signals on a Kevlar/epoxy composite. Transient recorder records were used to study the AE waveforms as well as the background electronic noise. Parameters studied include the bandpass and the relative position of the sensor with respect to the source position. The rise of the AE signal out of the background electronic noise was studied in detail by measuring the amplitude of each ''half-cycle'' of the analog signal both before the arrival of the AE event and for the first part of the AE signal. A relatively large amplitude difference was observed between the amplitude of the first half-cycle of the AE event and the peak amplitude of the AE event. Implications of the results obtained in these experiments are discussed relative to the commercial AE instrumentation approach of using penetration of the threshold to determine the arrival time of an AE event. In particular, it is shown that accurate source location in the composite depends on having a significantly large amplitude difference between the threshold and the peak amplitude for each channel in the AE source location array. Finally, an alternative approach is examined for potential use to determine the arrival time of an AE event.

• Research Organization: Denver Univ., CO (USA). Dept. of Engineering
• DOE Contract Number: AC05-84OS21400
• OSTI ID: 5566901
• Report Number(s): Y/Sub-86-19Y27448/1; CONF-860750-1; ON: DE86012964
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420500* -- Engineering-- Materials Testing
ACOUSTIC EMISSION TESTING
ACOUSTIC TESTING
COMPOSITE MATERIALS
MATERIALS
MATERIALS TESTING
NONDESTRUCTIVE TESTING
STRESSES
TESTING
WAVE FORMS