Simulation of the Kitagawa-Takahashi diagram using a probabilistic approach for cast Al-Si alloys under different multiaxial loads
Article dans une revue avec comité de lecture
This article describes a microstructural-based high cycle fatigue strength modelling approach applied to different cast Al-Si alloys used in an automotive context. Thank to different casting processes (gravity die casting and lost foam casting), associated with several heat treatment (T7 and Hot Isostatic Pressing-HIP), three alloys with very different microstructures have been obtained. In a vast experimental campaign undertaken to investigate the fatigue damage mechanisms governing these alloys under different multiaxial loading conditions, it was shown that the principal crack initiation mechanisms for the porosity-free alloy are either the formation of persistent slip bands (PSB) or the rupture and/or debonding of eutectic particles. For the porosity-containing alloys, the fatigue damage is always controlled by crack growth from pores. In order to take into account these fatigue damage mechanisms, a probabilistic model using a combination of the Dang Van and a modified LEFM criteria is proposed. The modified LEFM criterion is able to take into account the influence of the grain size on the threshold of the stress intensity factor. It is shown that for the porosity-free alloy, the predictions are good for combined tension-torsion loads with R = - 1. However, because the crack initiation mechanisms are not the same depending on the hydrostatic stress, the predictions are non-conservative for the uniaxial and equibiaxial tension oads with R = 0,1. For the porosity-containing alloys, the predictions are very good for the uniaxial, combined tension-torsion and equibiaxial tension loads with both R = - 1and R = 0,1. As observed experimentally, the proposed model can also predict a more pronounced effect of casting porosity for the uniaxial and combined tension-torsion loads, when compared to pure torsion loads.
Files in this item
Showing items related by title, author, creator and subject.
A flexible modelling framework leading to a pobabilistic multiaxial Kitagawa-Takahashi diagram : applied to cast Al-Si alloys Communication avec acteLE, Viet-Duc; BELLETT, Daniel; MOREL, Franck; SAINTIER, Nicolas; PALIN-LUC, Thierry; PESSARD, Etienne; OSMOND, Pierre (MATEC Web of Conferences, 2014)The aim of this work is to propose simple analytical tools to predict the fatigue strength of cast aluminium components as a function of the casting process and post-cast treatment. The proposed methodology is based on the ...
Investigation of the effect of porosity on the high cycle fatigue behaviour of cast Al-Si alloy by X-ray micro-tomography Article dans une revue avec comité de lecturePorosity generated by the casting process has a detrimental effect on the high cycle fatigue strength of cast aluminium alloys. The current study presents an investigation using the non-destructive X-ray micro-tomography ...
Multiaxial high cycle fatigue damage mechanisms associated with the different microstructural heterogeneities of cast aluminium alloys Article dans une revue avec comité de lectureThis article is dedicated to the high cycle fatigue (HCF) behaviour of cast Al-Si alloys. In particular, three similar alloys with different microstructural characteristics are investigated. The result of an experimental ...
Experimental investigation of the size effect in high cycle fatigue: Role of the defect population in cast aluminium alloys Article dans une revue avec comité de lectureEL KHOUKHI, Driss; SAINTIER, Nicolas; BELLETT, Daniel; OSMOND, Pierre; LE, Viet Duc; ADRIEN, Jérôme; MOREL, Franck (Elsevier, 2019)Cast Al-Si alloys have been widely used in automotive applications with regard to their low density and excellent thermal conductivity. Many components made of these alloys are subjected to cyclic loads which can lead to ...
Communication avec acteLE, Viet Duc; BELLETT, Daniel; PESSARD, Etienne; SAINTIER, Nicolas; OSMOND, Pierre; MOREL, Franck (Elsevier, 2015)This paper describes a microstructural-based high cycle fatigue behaviour model applied to cast Al-Si alloys used in an automobile context. These materials are characterized by the presence of different microstructural ...