Analysis and control of corrosion cracking in airframe structures

The basic characteristics of corrosion cracking of a loading-carrying frame on X-type aircraft were analyzed. The mechanism of corrosion cracking was studied through experimental simulation. The cause of cracking was identified as exfoliation corrosion-induced by contact of the LC4CS aluminum alloy and antiaging coatings of the rubber fuel tank, and the consequent reduction of frame effective thickness to a critical level. Among other things, temperature, humidity and the tightness of contact between frame metal and rubber fuel tank were the most influential factors for the cracking. Based on the main factors of corrosion cracking, a control scheme has been proposed.