Analysis and Experimental Study of DFR Values for Aircraft Wing-fuselage
Joint Structure
Abstract
Previous studies obtained the static and fatigue strength
characteristics of the wing-fuselage joint structure by finite element
analysis. In this paper, for the wing-fuselage tie rod and its
connecting joint, the stress distribution at the detail design points
and the calculated Detail Fatigue Rating (DFR) values were obtained by
finite element analysis, and the test part design was simplified; the
test life data were obtained by fatigue tests of the wing-fuselage tie
rod and its connecting joint, and the test DFR values were obtained. The
results show that the stress level of the simplified structure differs
little from that of the real structure, so the simplified structure can
be used for the test instead of the real structure; in the test, the
contact area of the wing lug structure is the initial area for fatigue
cracks generation. The DFR values obtained from the test are larger than
those calculated, which indicates that the calculated results are on the
conservative and safe side.