Accession Number:

AD0770217

Title:

The Evaluation of Acoustic Impact Technique for Detection of Incipients Cracks in Aircraft Components.

Descriptive Note:

Final rept. 1 Jul 71-30 Jun 72,

Corporate Author:

BOEING VERTOL CO PHILADELPHIA PA

Personal Author(s):

• Bickford,Russell H.
• Demchak,G. V.
• Sciarra,J. J.

Report Date:

1973-07-01

Pagination or Media Count:

114.0

Abstract:

The need for a reliable method for detection of incipient cracks near or under fasteners in aircraft structures is well known. The objective of this study is to permit or preclude the utilization of an acoustic impact technique AIT as a field inspection tool. The approach in this investigation is directed toward evaluating the reliability and reproducibility of test data on various specimens with specific boundary conditions to determine those variables which effect validity of test data and performance. A SERIES OF PREDEFINED UNCRACKED AND CRACKED SPECIMENS HAVE BEEN TESTED AND EVALUATED. Initial results produced inconsistant data which precluded the possibility of detecting cracks. Modifications were made to the technique, calibration of the impacter was performed, and reproducibility of data was achieved. Investigations were completed which indicated that the AIT system is not a feasible tool for the detection of incipient cracks in aircraft components. Author, modified-PL

Descriptors:

• *Cracks
• *Aircraft equipment
• *Airframes
• *Acoustic waves
• Fatigue(Mechanics)
• Fracture(Mechanics)
• Aluminum
• Titanium

Subject Categories:

• Aircraft
• Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE