L. Edwards, M.E. Fitzpatrick, P.E. Irving, I. Sinclair, X. Zhan, D. Yapp

This paper presents results from an integrated research programme on effects of residual stress on the fatigue and damage tolerance performance of welded aircraft structures. Nondestructive measurements of the residual stress field were made for the full range of specimens used to provide damage tolerant design data for welded aircraft structures. Crack initiation from interdendritic pores in the weld HAZ were studied, and models for the growth and linkage of the micro cracks, including the role of residual stress, have been developed and fatigue initiation behaviour has been accurately predicted from knowledge of intrinsic crack growth rates and HAZ characteristics. Factors controlling macroscopic fatigue crack growth rates have been investigated using constant L1K tests. The changes in growth rate as the cracks cross the weld have been determined and related to the changes in the residual stress field. In the final stage of the work, large scale welded skin stringer panels were tested under both constant and variable amplitude load spectra derived from aircraft lower wing skins. The data obtained were used to validate approaches to prediction of fatigue crack growth in welded wing structures, including the influence of weld residual stress, and to explore fail-safe design options for welded integral stringer panels.

23rd ICAF Symposium of the international Committee on Aeronautical Fatique, 2005, Hamburg

Conference Paper

englisch

A5, 18 Seiten

DGLR-Bericht, 2005, 2005-03, 23rd ICAF Symposium of the international Committee on Aeronautical Fatique - Proceedings; S.265-282; 2005; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

damage tolerance, welding, crack growth, fatigue

Bestellbar

2005