Abstract:
This paper reviews the understanding in the UK of the effects of kinetic heating on fatigue in aluminium alloy aircraft structure. It describes how heating can affect subsequent fatigue at ambient temperature by softening strain-hardened material and redistributing local stress by creep. It also discusses the effect on structural joints of the relaxation of clamping pressure and interference fit, and the curing of interfay compound. Tests on structural elements are described which show that, under representative load-temperature sequences with a maximum temperature of 100°C, effects on life can range between reduction and improvement by a factor of 2, depending on circumstances.
