Accession Number : ADA302552

Title :   Critical Joints in Large Composite Aircraft Structure.

Descriptive Note : Contract rept. Nov 81-Jan 83,

Corporate Author : MCDONNELL DOUGLAS CORP LONG BEACH CA DOUGLAS AIRCRAFT DIV

Personal Author(s) : Nelson, Willard D. ; Bunin, Bruce L. ; Hart-Smith, Leonard J.

PDF Url : ADA302552

Report Date : AUG 1983

Pagination or Media Count : 41

Abstract : A program was conducted at Douglas Aircraft Company under NASA-Langley Contract NAS1-16857 to develop the technology for critical structural joints of composite wing structure that meets design requirements for a 1990 commercial transport aircraft. The prime objective of the program was to demonstrate the ability to reliably predict the strength of large bolted composite joints. Ancillary testing of 180 specimens generated data on strength and load-deflection characteristics which provided input to the joint analysis. Load-sharing between fasteners in multi-row bolted joints was computed by the nonlinear analysis program A4EJ. This program was used to predict strengths of 20 additional large subcomponents representing strips from a wing root chordwise splice. In most cases, the predictions were accurate to within a few percent of the test results. In some cases, the observed mode of failure was different than anticipated. The highlight of the subcomponent testing was the consistent ability to achieve gross-section failure strains close to 0.005. That represents a considerable improvement over the state of the art.

Descriptors :   *COMPOSITE MATERIALS, *COMPOSITE STRUCTURES, *BOLTED JOINTS, TEST AND EVALUATION, AIRCRAFT INDUSTRY, FAILURE, CONSISTENCY, PARTS, WINGS, FASTENINGS, JOINTS, COMPOSITE AIRCRAFT, COMPOSITE WINGS.

Subject Categories : Transport Aircraft
      Flight Control and Instrumentation
      Couplers, Fasteners, and Joints

Distribution Statement : APPROVED FOR PUBLIC RELEASE