Development and fatigue assessment of wire arc additively manufactured hollow structures made of AA6063 as a basis for functional integrated sections applied to a motorcycle handlebar

Within the framework of multi-functional and multi-material additive manufacturing, hollow structures made of AA6063 (AlMgSi0,5) were manufactured by wire arc additive manufacturing (WAAM). These form the basis for a motorcycle handlebar, which has to resist 3-dimensional bending fatigue load cases with respect to the mid axis of the handlebar: lifting the motorbike and braking. The latter one was chosen for an experimental and numerical fatigue assessment. For the experimental analysis, axial bending fatigue testing was chosen to derive Wöhler curves for the bending moment using the Maximum Likelihood Estimation. On the basis of 3d scans of the experimentally investigated WAAM hollow structures, finite element models were derived. From the load simulations of these models crack initiation locations were predicted and a fatigue assessment based on Von Mises equivalent stresses was carried out, resulting in a stress concentration factor of 2.