https://www.um.edu.mt/library/oar/handle/123456789/930 2026-04-17T14:56:13Z https://www.um.edu.mt/library/oar/handle/123456789/145489 Title: A development on plastic work methods for determining the plastic load for mechanical components and structures Authors: Degiorgio, Kevin; Muscat, Martin; Mollicone, Pierluigi Abstract: This paper revisits and discusses some of the methods found in literature for determining the plastic load for the prevention of excessive deformation of a component under the action of a monotonically increasing load. The literature discussion concentrates on advantages and challenges when using the existing plastic load determination methods. In this paper, the authors present a novel method as a development from literature that suggests that the ratio of plastic work and elastic work induced under the action of a monotonically increasing load can be used to determine the plastic load of a component. The proposed new method is applied to a number of test case examples and the results are compared with those obtained using the methods found from literature. The benefits of adopting the novel method are discussed at the end of the paper. 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145008 Title: Progress in the concept development of the VNS — a beam-driven tokamak for component testing Authors: Bachmann, Chris; Siccinio, Mattia; Aiello, Giorgia; Ambrosino, Roberto; Bajari, J.; Boscary, J.; Carusotti, S.; Claps, V.; Cufar, A.; Elbez-Uzan, J.; Federici, G.; Franke, T.; Giannini, L.; Gliss, C.; Haertl, T.; Hopf, C.; Luongo, C.; Maione, I.; Maisonnier, D.; Marzullo, D.; Maviglia, F.; Marek, P.; Mollicone, Pierluigi; Moscato, I.; Mozzillo, R.; Muscat, Martin; Pagani, I.; Park, J.H.; Pereslavtsev, P.; Quartararo, A.; Renard, S.; Steinbacher, T.; Tarallo, A.; Vallone, E.; Vigano, F.; Wiesen, S.; Wu, C. Abstract: The Volumetric Neutron Source (VNS) is a compact beam-driven tokamak with D–T plasma to generate a high neutron flux that will allow the testing and qualification of fusion nuclear components, in particular the breeding blanket. Recently, EUROfusion concluded a design study that confirmed the feasibility of VNS for construction and operation. Also, aspects were identified that require further development and assessment, and these have been key subjects of the on-going conceptual design phase. This article summarises the progress made in the design of VNS, including the rationale for the small adjustments of major radius and aspect ratio, the configuration and performance of the equilibrium coils, the design of the in-vessel components including their remote handling concepts, (vi) design of the nuclear buildings and layout of the main plant systems including those related to the fuel cycle. 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/143546 Title: Energy-efficient towing of floating offshore wind turbines : challenges and perspectives on platform drag reduction Authors: Scerri, Nathaniel; Zammit, Martina; Micallef, Christopher; Sant, Tonio; Mollicone, Jean-Paul; Fengmei, Jing; Xinru, Wang; Le, Conghuan; Yali, Fan; Yanqi, Zhu Abstract: Floating offshore wind turbines (FOWTs) are essential for expanding renewable energy capacity into deep-water regions. However, the deployment of semi-submersible FOWTs faces significant operational and financial hurdles, primarily driven by the high costs and logistical complexity of towing these structures to site. This perspective paper critiques current transportation processes, noting that existing offshore guidelines typically fail to account for the hydrodynamic drag generated by the unique bluff-body geometries of these hulls. The substantial pressure drag inherent in these structures leads to excessive fuel consumption and elevated carbon emissions during long-distance transit. Consequently, potential drag-reduction strategies must be explored to address these hydrodynamic inefficiencies. Among various technologies, fairings attached to the FOWT structure emerge as a promising solution, with potential drag reductions of around 40%. However, extensive research is required to ensure these designs do not compromise system stability, while also providing a net carbon emission reduction that justifies their production for large-scale deployment. Ultimately, integrating effective drag-reduction technologies is a vital step towards improving both the economic viability and the environmental footprint of the FOWT industry, ensuring its long-term sustainability in the global energy transition. 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/143522 Title: Mechanical properties of mono-fibre and intraply hybrid sisal–flax fibre-reinforced composites : a comparative study Authors: Cavalcanti, Daniel K. K.; Joy, Jobin; Ullah, Tehseen; Camilleri, Duncan; Grech, Brian Ellul; De Marco Muscat-Fenech, Claire; Muscat, Martin; Li, Hongjun Abstract: The growing demand for sustainable alternatives to synthetic composites has increased the interest in natural-fibre-reinforced composites (NFRCs), due to their reduced environmental impact. This study presents a comparative investigation of the mechanical properties of mono-fibre and intraply sisal/flax hybrid composites as cost-effective bio-based solutions. Flax offers high tensile performance but is constrained by higher cost and geographical availability. Sisal, on the other hand, is widely available at lower cost, but exhibits a coarser morphology and reduced processing versatility. Mechanical testing demonstrated that intraply hybrids achieved well-balanced performance, with reduced flax content still delivering competitive tensile strength and stiffness when compared to the higher performing mono-fibre flax composites. However, sisal-rich and hybrid laminates outperformed monofibre flax composites in transverse and shear behaviour, with the 67% sisal/33% flax hybrid composite exhibiting the highest transverse properties and the 33% sisal/67% flax hybrid achieving the highest shear properties. Rule-of-mixtures models predicted longitudinal tensile behaviour effectively, while Halpin–Tsai models successfully estimated shear but not transverse and compressive properties. Compressive strength showed limited variation across configurations. Failure analysis identified intra-yarn fracture in flax, limited resin infiltration in sisal, and compressive failure modes such as brooming and microbuckling. Overall, intraply sisal/flax hybrid mats provide a structurally efficient, sustainable, and economically viable alternative to mono-fibre natural composites. 2026-01-01T00:00:00Z