BELLETT Daniel
Délégué Régional AMVALOR / Ingénieur de recherche
Ingénieur de Recherche
DIPPE - Durabilité, Ingénierie des Procédés et Physique des Ecoulements
The gears used in aircraft engines are typically made from high-strength steels reinforced by thermochemical treatments (TCT). These treatments increase surface fatigue strength through microstructural modifications, enhancing hardness and adding compressive residual stresses. In some cases, the com…
International Journal of Fatigue. 2026;207:109495.
DOI : 10.1016/j.ijfatigue.2026.109495
Hot-forged wheel bearing hubs are manufactured using a complicated fabrication process chain to obtain the desired microstructure and mechanical properties in different zones that experience varying local stress states. The different process steps modify the surface roughness and the residual stress…
Fatigue and Fracture of Engineering Materials and Structures. 2025;48:3353-3367.
DOI : 10.1111/ffe.14648
This paper focuses on the characterisation of fatigue crack initiation mechanisms under fully reversed torsional loads for the porosity-containing cast AlSi7Mg0.3 aluminium alloy by synchrotron X-ray tomographic imaging and Diffraction Contrast Tomography (DCT). The aim is to analyse the relation be…
International Journal of Fatigue. 2025;193:108762.
DOI : 10.1016/j.ijfatigue.2024.108762
<div><p>This study focuses on the evolution of the fatigue strength of Laser Powder Bed Fusion (L-PBF) produced Ti-6Al-4V as a function of the chemical etching finishing process. The aim is to identify the critical fatigue crack initiation mechanisms and the transitions between them in terms of the …
Fatigue and Fracture of Engineering Materials and Structures. 2024;47:4498-4515.
DOI : 10.1111/ffe.14392
Additive manufacturing is nowadays already used on aeronautical serial parts but very few of them are highly loaded critical components. Titanium alloy Ti-6Al-4V and laser powder bed fusion (L-PBF) manufacturing process are both part of the most studied materials and processes. Many studies have bee…
Procedia Structural Integrity. 2024;57:61-72.
DOI : 10.1016/j.prostr.2024.03.008
The influence of a proof load, or an initial overload, on the fatigue resistance of welded structures is investigated in this study. Arc welded stiffeners made of S355 steel are considered and fatigue-tested in as-welded and proof-loaded conditions. X-ray diffraction analyses are carried out to eval…
International Journal of Fatigue. 2023;172:107604.
DOI : 10.1016/j.ijfatigue.2023.107604
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 fatigue failure. For these materials, the well-known size effect in fatigue, wh…
Procedia Structural Integrity. 2022;38:611-620.
DOI : 10.1016/j.prostr.2022.03.063
Two cast aluminium alloys fabricated by different casting processes (gravity die-casting and lost foam casting) and showing different degrees of porosity were characterized with X-ray Computed tomography. Information concerning the pore distribution inside the investigated materials is obtained in t…
Materials Characterization. 2021;177:111165.
DOI : 10.1016/j.matchar.2021.111165
Weld toes and weld roots of continuously welded structures subjected to cyclic loading are critical zones in terms of the fatigue resistance. The finite element method coupled with a fatigue criterion is commonly used to ensure the correct sizing and fatigue design of welded structures. However, wel…
Engineering Failure Analysis. 2021;124:105280.
DOI : 10.1016/j.engfailanal.2021.105280
In this study, a probabilistic model based on Monte-Carlo theory is applied to predict the fatigue behavior of cast aluminum alloys. The objective of the proposed approach is to investigate the effect of porosity (i.e. the defect size distribution and spatial density) on the fatigue strength and its…
International Journal of Fatigue. 2021;106177.
DOI : 10.1016/j.ijfatigue.2021.106177
Procedia Structural Integrity. 2019;19:719-728.
DOI : 10.1016/j.prostr.2019.12.078
Procedia Structural Integrity. 2019;19:566-574.
DOI : 10.1016/j.prostr.2019.12.061
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 fatigue failure. Furthermore, for these materials the well know size effect in …
International Journal of Fatigue. 2019;129:105222.
Porosity 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 technique of the effect of the size and the population of casting pores on the …
International Journal of Fatigue. 2018;106:24-37.
This article presents a review of selected multiaxial high-cycle fatigue criteria with an emphasis on their ability to take into account the mean stress effect and the effect of a biaxial stress state. It is shown that the predictions of the various criteria are very different for the case of biaxia…
Fatigue and Fracture of Engineering Materials and Structures. 2017..
DOI : 10.1111/ffe.12699
This 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 campaign are presented, in order to characterise the fatigue behaviour, and mor…
Materials Science and Engineering: A. 2016;649:426–440.
DOI : 10.1016/j.msea.2015.10.026
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 heterogeneities at different scales: the aluminium matrix (DAS/SDAS and the preci…
2015;133:562–575.
DOI : 10.1016/j.proeng.2015.12.630
Machine d'essai en fatigue disposant d'une éprouvette (10), cette machine comportant un poinçon mobile appliquant une charge axiale cyclique sur une face de l'éprouvette (14) perpendiculaire à l'axe du poinçon, cette éprouvette étant en appui sur une base fixe par une face opposée (12) à la première…
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 Murakami approach to predict the maximum defect size and a flexible modelling…
2014;12(02002):1-3.
DOI : 10.1051/matecconf/20141202002
This article describes a flexible modeling framework which leads to the construction of a probabilistic, multiaxial Kitagawa-Takahashi diagram. This framework has been developed following experimental observations that clearly indicate that two independent fatigue damage mechanisms can be activated,…
2014;891-892:1372-1378.
DOI : 10.4028/www.scientific.net/AMR.891-892.1372
A mechanistic approach to the Kitagawa-Takahashi diagram using a multiaxial probabilistic framework.
The aim of this paper is to propose a flexible multiaxial modelling framework that is capable of combining two fatigue damage mechanisms so as to continuously describe the Kitagawa-Takahashi diagram. It is proposed that this diagram represents two distinct fatigue damage mechanisms: one associated w…
Engineering Fracture Mechanics. 2013;109:89-104.
DOI : 10.1016/j.engfracmech.2013.06.001
In this work, the high cycle fatigue behavior of cast hypo-eutectic Al-Si alloys is investigated. It is observed that two different coexisting fatigue initiation mechanisms can occur in these materials depending on the presence of different microstructural heterogeneities (i.e. micro-shrinkage pores…
2013;1-8.
This article is dedicated to the high cycle fatigue behaviour of cast hypo-eutectic Al-Si alloys. In particular, the AlSi7Cu05Mg03 alloy is investigated. It presents the results of a vast experimental campaign undertaken to investigate the fatigue behaviour, and more specifically the fatigue damage …
International Journal of Fatigue. 2013;47:44-57.
DOI : 10.1016/j.ijfatigue.2012.07.008
This article is dedicated to the high cycle fatigue behaviour of cast hypo-eutectic Al-Si alloys. In particular, the AlSi7Cu05Mg03 alloy is investigated. It presents the results of a vast experimental campaign undertaken to investigate the fatigue behaviour, and more specifically the fatigue damage …
International Journal of Fatigue. 2013;47:44-57.
This article is dedicated to the high cycle fatigue behaviour of cast hypo-eutectic Al-Si alloys and in particular the AlSi7Cu05Mg03 alloy. In a vast experimental campaign undertaken to investigate the fatigue damage mechanisms operating in this alloy, subject to complex loading conditions, it was s…
International Journal of Fatigue. 2013;47:137-147.
DOI : 10.1016/j.ijfatigue.2012.08.004
The objective of this work is to propose an anisotropic fatigue criterion for the sizing of industrial forged components. The results from different experimental campaigns using three different rolled steels are first presented. The effect of inclusions and the microstructure on the fatigue behaviou…
International Journal of Fatigue. 2012;168-178.
DOI : 10.1016/j.ijfatigue.2012.01.005
The aim of this paper is to present a novel un-notched fatigue test specimen in which a biaxial stress state is achieved using a uniaxial loading condition. This allows the problem of multi-axial fatigue to be studied using relatively common one-axis servo-hydraulic testing machines. In addition the…
Strain. 2011;47(3):227-240.
DOI : 10.1111/j.1475-1305.2009.00674.x
Forged components are known to show high cyclic and monotonic mechanical properties. This is mainly due to a better compactness and a finer microstructure introduced by the forming process. However, this good mechanical behaviour is sometimes a source of anisotropy especially when the microstructura…
International Journal of Fatigue. 2011;33(4):568-577.
DOI : 10.1016/j.ijfatigue.2010.10.012
Laser assisted machining (LAM) can improve the machinability of materials by locally heating the material prior to its removal. The work presented here is a study of the laser assisted machining of Inconel 718 (NiCr19FeNb at 46 HRc) with carbide and ceramic insert. The tests have shown a reduction i…
International Journal of Material Forming. 2008;1(1):p. 523-526.
DOI : 10.1007/s12289-008-0213-y
Cette étude concerne l'effet des défauts de fonderie sur la tenue en fatigue de l'alliage d'aluminium AlSi7Mg0,6 dans le domaine de l'endurance limitée. Des essais de fatigue ont été réalisés en traction (R=0,1 et R=-1) et en flexion plane (R=0,1) sur des éprouvettes provenant d'un même carter de tr…
2007..
L'objectif de ce travail est de mieux comprendre l'influence de fortes contraintes hydrostatiques sur le comportement en fatigue multiaxiale à grand nombre de cycles. La démarche est analogue à celle traditionnellement mentionnée dans la littérature : analyse dissociée de l'effet de la contrainte mo…
2007..