At IRDL, Corentin Guellec has developed an advanced method for sizing transmission shafts in naval fatigue.
Corentin Guellec, chercheur·e au sein de IRDL (Institut National Polytechnique de Bretagne).
Thèse soutenue en 2023 à l'école doctorale École doctorale Sciences pour l'ingénieur et le numérique.
Référencée dans le réseau ABES/STAR, cette thèse répond aux critères de rigueur de l'enseignement supérieur français.
Research on material fatigue, particularly in the naval sector, is of paramount importance. Indeed, the transmission shafts, which are essential elements in power transmission aboard ships, are subjected to complex cyclic loads that can vary depending on sea conditions, maneuvers performed, and the specific characteristics of each vessel. This requires a rigorous and tailored approach to ensure their durability and, consequently, the safety of maritime operations. Corentin Guellec, within the Research and Development Institute in Languedoc (IRDL), has developed an innovative parametric method that overcomes the limitations of traditional sizing techniques. By integrating self-heating measurements and probabilistic modeling, this thesis paves the way for a better understanding of failure mechanisms, which is crucial for the naval sector where safety is paramount.
Classic fatigue sizing methods, often based on simplistic models, generally do not take into account the complexity of multiaxial loads to which transmission shafts are subjected. This can lead to inaccurate assessments of component durability, thereby jeopardizing the safety of naval systems. For example, a poorly sized transmission shaft could fail under unforeseen stresses, leading to catastrophic failures. Guellec's research proposes an experimental approach that allows for the classification of loads into two categories of cycles, thus facilitating the analysis of fatigue effects. This classification is essential for better understanding the different types of stresses experienced by materials.
The establishment of a database for multiaxial loads represents a significant advancement in this field. It not only allows for a better understanding of the average stresses to which materials are subjected but also integrates specific fatigue criteria into sizing methods. For example, this database could include information on the performance of materials used in different types of vessels, ranging from tankers to warships, including ferries. The strategic recommendations arising from this research are clear: it is imperative to evolve towards sizing methods that are more suited to operational realities, taking into account the specificities of each type of application.
The implications of this research go far beyond the simple academic framework. They directly impact the reliability and safety of naval systems, ensuring that transmission shafts can withstand complex operational conditions. For example, in the context of military naval operations, where missions may involve high-intensity maneuvers, the ability to predict component failure becomes crucial. In summary, this thesis constitutes a major contribution to the understanding of fatigue phenomena in materials used in the naval sector, while proposing concrete solutions to improve the sizing and durability assessment of critical components.
Moreover, this research could also have repercussions in other industrial sectors, particularly those related to energy, where similar components are subjected to extreme operating conditions. By integrating more robust sizing methods, it would be possible to optimize the lifespan of equipment, thereby reducing maintenance costs and improving operational efficiency. In conclusion, Corentin Guellec's innovative approach represents a significant step forward in the field of materials mechanics, with practical implications that could transform the way we design and size critical systems in the naval sector and beyond.
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Sources et accès
Corentin Guellec. Caractérisation en fatigue à grand nombre de cycles par mesures d’auto-échauffement des aciers d’arbres de transmission pour application navale sous chargements cycliques complexes. Matériaux et structures en mécanique [physics.class-ph]. École Nationale Supérieure de Techniques Avancées Bretagne, 2023. Français. ⟨NNT : 2023ENTA0001⟩. ⟨tel-04400737⟩