A physical interpretation of the scale effect in fatigue of fillet welded aluminium alloys

摘要

The thickness effect in fatigue of fillet welded aluminium alooys was investigated. After a brief review of some criteria widely adopted or recently proposed to account for the scale effect, a new approach proposed by the Authors was presented, which allow for the separation of a global and a local stress concentration effect at the weld toe, where fatigue cracks mostly initiate. This approach was applied to interpret some experimental results taken from literature about fatigue tests of fillet welded joints in 3 mm to 24 mm thich 6061-T6 aluminium alloy. A scale effect correction factor was finally proposed and its predictions, together with those obtained by the design criteria found in literature, were compared with the experimental results.