Fatigue of aluminium bridge decks

Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, such as aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper discusses the fatigue behaviour of an extruded aluminium deck. To determine the fatigue lifetime, the well-known procedure based on S-N curves was applied. In tests, the S-N curve was determined of a welded detail applied often in aluminium bridge decks. In order to check the procedure based on S-N curves, fatigue tests were carried out on a specimen with geometry and loading conditions that are realistic for bridge decks.