At IRDL, Leandro Mauricio da Silva explored appearance defects on aluminum roofs in the automotive industry.
Leandro Mauricio da Silva, chercheur·e au sein de IRDL (Institut National Polytechnique de Bretagne).
Thèse soutenue en 2025 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.
The research conducted by Leandro Mauricio da Silva at the National Polytechnic Institute of Brittany addresses a crucial issue for the automotive industry: surface defects on aluminum alloy roofs. These defects, often caused by thermal buckling, can compromise not only the aesthetics of vehicles but also their structural integrity. In a context where CO₂ emission regulations are becoming increasingly strict, the need to explore lightweight materials is more pressing than ever. The thesis proposes concrete solutions to anticipate and prevent these defects, relying on an innovative numerical methodology.
The results of this research are revealing and deserve close examination. Tests conducted showed that the EN AW 6016-T4 alloy roof exhibited 1.5 mm waves after a heating cycle, while the EN AW 6056-T4 alloy roof displayed maximum waves of 0.5 mm after cooling. These data underscore the crucial importance of material selection and design in preventing surface defects. Indeed, the difference in behavior between these two alloys highlights the necessity of a rigorous approach when choosing materials for specific applications. In response to these observations, strategic recommendations have been formulated, such as modifying the roof design to induce local deformations, thereby creating stiffer areas in the form of ribs. This could not only improve resistance to deformation but also optimize the distribution of thermal stresses.
The impact of this research goes well beyond mere improvements in manufacturing processes. By adopting the developed simulation methodology, the automotive industry could significantly reduce costs and time associated with large-scale testing. This represents an opportunity not only to improve the quality of automotive components but also to enhance the competitiveness of companies in the face of increasingly demanding regulations. Indeed, the ability to simulate and anticipate material behaviors under real conditions could allow manufacturers to save valuable time in the development of new models.
It is also essential to consider the implications of this research within a broader framework. As the automotive industry evolves towards more sustainable practices, understanding thermomechanical interactions in aluminum alloy structures becomes a strategic asset. Companies that can integrate this knowledge into their design and manufacturing processes will be better positioned to meet future challenges. For example, in the West African context, where climatic conditions can vary significantly, such understanding could enable the adaptation of vehicles to local requirements, thereby increasing their durability and performance.
Furthermore, this research could also have repercussions throughout the supply chain. By improving material quality and reducing defects, manufacturers could decrease product return rates, which is a major issue for customer satisfaction and profitability. In a market where customer loyalty is essential, offering high-quality products can make all the difference.
In summary, Leandro Mauricio da Silva's thesis offers promising perspectives for the automotive industry by proposing pragmatic solutions based on concrete data. Industry stakeholders must be aware of these advancements and consider their integration into their practices to remain competitive in the market. By incorporating these innovations, the automotive industry will not only be able to meet regulatory requirements but also anticipate future consumer needs while contributing to sustainable and responsible development.
Données clés
- 1,5 mm : ondulations observées sur le toit en alliage EN AW 6016-T4 après chauffage
- 0,5 mm : ondulations maximales sur le toit en alliage EN AW 6056-T4 après refroidissement
Accéder à l'étude complète
Sources et accès
Leandro Mauricio da Silva. Control of appearance defects generated by differential thermal expansion on an aluminum alloy roof assembled in a multi material body-in-white. Mechanics [physics.med-ph]. École Nationale Supérieure de Techniques Avancées, 2025. English. ⟨NNT : 2025ESTA0017⟩. ⟨tel-05601231⟩