Scantling assessment of large yacht rigs using carbon-fiber and aluminum masts. (15th October 2019)

• Record Type: Journal Article
• Authors: Ghelardi, Stefano; Conti, Claudia; Gaiotti, Marco; Rizzo, Cesare Mario; Paci, Matteo
• Is Part Of: Ocean engineering. Volume 190(2019)
• Publication Date: 2019-10-15
• Subjects: Sail system -- Mast -- Rigging -- Structural lightning -- Aluminium alloy -- Composites; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2019.106480
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Weight saving is crucial in naval architecture to reduce costs and improve performances. In sailing ships design, rig's scantling is important also for ship stability, as rig's weight generates heeling actions on the vessel, due to heeled navigation. Therefore, rig's weight saving remarkably reduces ship's heeling, allowing to increase the wind exposed area, consequently improving the sailing performances. However, because of the complexity of the structure and uncertainties in loading conditions, the structural scantling of a rig implies the adoption of high safety factors. Furthermore, the increasing trend to use composite materials represents an additional source of complexity due to their anisotropic non-homogeneous nature and uncertainties on material properties, and generally implies even larger safety factors, besides implying high construction costs. The present work shows a comparison between an existing 76 m carbon mast and an aluminium alloy one. Suitable FEM models of both rigs were built up and used to assess the structural system strength according to applicable class rules. The cross-section stiffness of the aluminium mast was optimized in order to make masts' performances comparable. The optimized aluminium mast, of comparable weight of the carbon one, results to be more cost-effective for such range of sailing vessels. Highlights: Based on actual tuning data, a FE model was built in ADINA software environment and validated. An aluminium mast was compared to the current shipyard solution made out of expensive CRP. The aluminium cross section was optimized, in order to satisfy the requirements provided by DNV-GL. The optimized configuration has slightly less bending stiffness of the carbon mast, being only about 145 kg heavier. The buckling capacity is lower than the carbon mast, but still complies with the rules. The optimized configuration is only slightly heavier than the original CRP mast, but its construction much simpler and cheaper.