Fatigue and corrosion in aircraft pressure cabin lap splices

Aircraft structures are susceptible to fatigue and corrosion damage, notably at joints. There may be interactions between fatigue and corrosion, especially as aircraft age. Longitudinal lap splices from several types of transport aircraft pressure cabins were disassembled and investigated for Multiple Site Damage (MSD) fatigue cracking and corrosion. The results are compared with NASA data for a full-scale fatigue test. Broadly speaking, pressure cabin lap splices have either a fatigue problem or a corrosion problem: MSD fatigue cracking is not initiated by corrosion. The results are discussed with respect to lap splice MSD fatigue modelling, testing and analysis.