The automotive industry is facing a severe conflict concerning the vehicle weight. If on one hand the target is to obtain a drastic CO2 reduction, on the other hand the tendency is to enhance the safety as the performance characteristic of the vehicle. In this context, the novel high-strength steel (HSS) grades represent a cost efficient method to overcome this conflict. For this reason, the application of HSS in vehicles is increasing and at present it covers almost 50% of the components in some vehicle. This increasing demand on HSS give rises to a series of new topics that needs to be adressed, especially regarding its application to fatigue loads. Automotive stabilisers can be considered safety components and it is, therefore, important to asses 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 components. For this reason, in this paper, starting from FEM analysis in order to obtain the stresses in the component, a multiaxial fatigue assesment 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 components. Critical areas are then identified, in agreement with fatigue full scale tests and some applications of the method for design optimisation are presented. The method here proposed has been applied with succes to stabilisers, but can be extended straightforwardly to other kinds of tubular automotive components subjected to fatigue loads. The proposed approach also gives the designer important information in order to optimise the geometry and weight of the component as well as the final surface treatment on the component.
Multiaxial fatigue and defect assessment of truck stabilisers
Mehrachsige Ermüdungs- und Fehlerbewertung von Lkw-Stabilisatoren
International Journal of Vehicle Design ; 40 , 1-3 ; 212-227
2006
16 Seiten, 12 Bilder, 19 Quellen
Article (Journal)
English
Anwendung im Fahrzeugbau , Fahrzeugsicherheit , Werkstoffwahl , Gewichtseinsparung , Risseinleitung , Risswachstum , Ermüdungsgrenze , Dauerschwingfestigkeit , Bewertung , mikrolegierter Stahl , hochfester Stahl , Finite-Elemente-Methode , Spannungsberechnung , mehrachsige Spannung , Lkw (Lastkraftwagen) , Entwurfstechnik , Schadenanalyse , Schadenursachenforschung
Multiaxial fatigue and defect assessment of truck stabilisers
Online Contents | 2006
|Multiaxial fatigue and defect assessment of truck stabilisers
Automotive engineering | 2006
|Automotive engineering | 1994
|Emerald Group Publishing | 2009