Accession Number:

ADB107745

Title:

Design, Fabrication, Testing and Analysis of Bolted Structural Elements

Descriptive Note:

Final rept. 1 Jan 1984-31 Dec 1985

Corporate Author:

NORTHROP CORP HAWTHORNE CA AIRCRAFT DIV

Personal Author(s):

• Ramkumar, R. L.
• Saether, E. S.
• Tossavainen, E.

Report Date:

1986-07-01

Pagination or Media Count:

66.0

Abstract:

This report presents design and fabrication details for a bolted structural element concept that was studied as a potential alternative to the existing vertical tail-to-fuselage attachment in the FA-18A aircraft. Two elements were fabricated, based on an approximate and conservative preliminary design, and were subjected to two lifetimes of representative tension-dominated FA-18A vertical tail spectrum loading. Both elements survived the fatigue loads with no indication of failure. Their residual tensile failure loads were approximately 30 larger than the design ultimate load value the elements were also analyzed using the SAMCJ computer code developed in this NorthropAFWAL program. Analytically predicted element strength was within 7 of the measured value. Analytically predicted failure location also coincided with experimental observations. However, the observed failure mode could not be predicted by the developed analysis. Nevertheless, this task established the adequacy of the SAMCJ computer code for predicting the strength of bolted joints in composite structures.

Descriptors:

• *COMPOSITE STRUCTURES
• *AERONAUTICAL ENGINEERING
• *BOLTED JOINTS
• TENSILE STRENGTH
• TAIL ASSEMBLIES
• FAILURE
• FABRICATION
• STRENGTH(MECHANICS)
• STRENGTH(GENERAL)
• FAILURE(MECHANICS)
• STRESS CONCENTRATION
• POSITION(LOCATION)
• FIGHTER AIRCRAFT
• TEST AND EVALUATION
• COMPUTER PROGRAMS

Subject Categories:

• Attack and Fighter Aircraft
• Couplers, Fasteners and Joints

Distribution Statement:

APPROVED FOR PUBLIC RELEASE