MODELING OF CORROSION PILLOWING IN LAP JOINTS MADE OF LY12CZ

Finite element techniques were used to determine the effect of pillowing stress on lap joints. The stress caused by the internal pressure, the contacts between the fastener and skin, and geometrical nonlinearity were taken into account. The results show that corrosion pillowing can significantly increase the stress in a lap joint for material loss below the detection limit of current nondestructive inspection techniques, thus increasing the risk of premature cracking. In addition, the analyses show that the locations of maximum stress of lap joint will change with the material loss increases. Simulating the effect of corrosion on lap joint only by reducing the panel thickness will result in nonconservative life estimates if corrosion pillowing is ignored.