Influence of Corrosion on the Fatigue Behaviour of 5083 Lap- Welded Joints

Abstract

The design and durability of welded aluminium structures, commonly used in the marine, aerospace, and automotive industries, require a thorough understanding of their mechanical performance under cyclic loading and various environmental conditions, including corrosion. Aluminium–magnesium alloys (such as 5083) are widely used in marine applications due to their favourable strength-to-weight ratio and inherent corrosion resistance. However, prolonged exposure to harsh environments inevitably leads to corrosion-induced damage, which negatively affects the fatigue strength of welded joints. This study investigates the influence of corrosion on the fatigue behaviour of lap-welded 5083 aluminium joints through a controlled experimental programme. Fatigue tests were conducted on two groups of specimens: one with corrosion damage and the other uncorroded. Comparative analysis of the fatigue life data indicates a reduction in fatigue strength attributable to corrosion.
Specifically, the fatigue strength at 2·10⁶ cycles is reduced by approximately 50% or 38%, depending on whether the nominal stress approach or the notch stress approach is used for fatigue assessment.