The student Imanol Ruiz De Eguino Aguirre obtained an EXCELLENT CUM LAUDE

The student Imanol Ruiz De Eguino Aguirre obtained an EXCELLENT CUM LAUDE

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• Thesis title: Modelizado multifísico de la pultrusión UV para el desarrollo de perfiles estructurales destinados a la industria naval

Court:

• Presidency: Maria Lluisa Maspoch Rulduá (Universitat Politècnica de Catalunya)
• Vocal:Koldo Gondra Zubieta (Gaiker)
• Vocal: Isabel Harismendy Ramirez de Arellano (Tecnalia)
• Vocal: Alberto Lopez Arraiza (UPV/EHU)
• Secretary:Mariasun Sarrionandia Ariznabarreta (Mondragon Unibertsitatea)

Abstract:

This doctoral thesis aims to establish the foundations for the shipbuilding industrys adoption of UV pultrusion. This novel technology implements photopolymerization in the pultrusion process to cure profiles out of the die, overcoming two intrinsic limitations of conventional pultrusion. The significant reduction of the pulling forces achieved by curing the profile out of the die enables the use of a robotic pulling system, which allows manufacturing not only straight but also complex curvature profiles, according to the applied pulling trajectory. Another benefit of the pulling force reduction is that the in process stresses induced in the profile no longer constrain the definition of its reinforcement configuration, allowing to arrange more fibre reinforcement in non-longitudinal orientations. In this way, the mechanical behaviour of pultruded composites can be tailored to the structural requirements of applications that conventional pultruded composites cannot handle. In conclusion, UV pultrusion has the potential to considerably broaden the range of applications targeted by pultruded profiles, as it solves both the geometrical and mechanical limitations of conventional pultrusion.

However, the lack of maturity of the UV pultrusion technology hinders its industrial adoption, even though it is an automated, flexible, productive and efficient composite transformation process. Without simulation tools that reproduce the interactions between the physicochemical phenomena involved in the process, its fine-tuning has to be performed iteratively, an approach that is not operational for its industrialisation. Therefore, the first block of this doctoral thesis focuses on the identification, adaptation and numerical integration of the models that reproduce each of the physicochemical phenomena involved in UV pultrusion. Thus, the development of a simulation tool capable of optimising the pulling velocity and the intensity emitted by the UV sources has been accomplished. In a second block, the advantages that the implementation of UV pultrusion can transfer to the naval sector have been analysed. To this end, the mechanical performance of multiaxially reinforced pultruded composites was assessed, and a set of structural prototypes were developed to showcase the disruptive benefits provided by the technology in terms of productivity, costs and mechanical response.