Accession Number:

ADA076421

Title:

Evaluation of the Crack Gage Concept for Monitoring Aircraft Flaw Growth Potential. Volume 1. Technical Discussion.

Descriptive Note:

Final rept. 1 Jul 77-1 Dec 78,

Corporate Author:

BOEING WICHITA CO KS

Personal Author(s):

• Cassatt,Gary G.

Report Date:

1979-06-01

Pagination or Media Count:

113.0

Abstract:

The results of a test program to evaluate the ability of a bonded on precracked coupon to monitor the growth of flaws in the basic structure are included. All testing utilized 7075-T651 aluminum from a single plate. Both constant thickness and stepped crack gages were evaluated. Evaluation of a wide range of sensitivity in crack gage crack growth response was made. Structure flaws of, 1 corner flaw at a hole, 2 through flaws at a hole and 3 center notch flaw were evaluated. The cyclic test loading included constant amplitude of two R ratios and three representative aircraft usage flight profiles. Strain gage instrumentation was used to measure structure stresses and load transferred into the crack gages. Author

Descriptors:

• *CRACKS
• *CRACK PROPAGATION
• *AIRFRAMES
• *GAGES
• STRESSES
• MEASUREMENT
• AIRCRAFT
• ALUMINUM ALLOYS
• DEFECTS(MATERIALS)
• STRAIN GAGES
• MONITORS
• TRANSFER
• FLIGHT LOADS
• CYCLIC TESTS

Subject Categories:

• Aircraft
• Test Facilities, Equipment and Methods
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE