Multiaxial fatigue and defect assessment of truck stabilisers

Automotive stabilisers can be considered safety components and it is, therefore, important to assess their fatigue behaviour in terms of real load conditions as well as material strength. For the second point, a detrimental effect in the fatigue limit of high strength steels is given by the presence of defects in the component. For this reason, in this paper, starting from FEM analysis in order to obtain the stresses in the component, a multiaxial fatigue assessment taking into account defects is carried out considering round and planar surface defects in terms of their SIFs. Results are then analysed by comparing maximum SIF against the threshold for short cracks, which was obtained experimentally for a quenched and tempered microalloyed steel, which represents a standard option for this kind of component. Critical areas are then identified, in agreement with fatigue full scale tests and some applications of the method for design optimisation are presented.