FATIGUE TEST AND CRACK GROWTH ANALYSIS OF RETIRED MILITARY AIRCRAFT WING

摘要

The right wing of a retired military aircraft was tested under measured load spectra, which had serviced for more than twenty years in a coastal airport located at high temperature, high humidity and high salt fog place, and the remainder fatigue life was obtained. The test result showed that the crack in fatigue critical part (the second hole of main beam flange of aircraft wing) initiated earlier and crack growth rate increased greatly than the full-scale fatigue test result of new aircraft, as a result of corrosive environment and service load. Based on comparing crack growth rate da/dN, crack growth coefficient increased 5.9 times, provided that the crack growth exponent was constant. The macro- and micro-fatigue fracture characteristics of main spar were observed by use of scanning electron microscope. And fatigue crack growth life was retro-estimated through fracture quantity analysis; also the test result was analyzed.