This paper presents an innovative procedure for the modelling and optimisation of an advanced materials propeller axis bracket for sailing ships of 24 m length. Currently, the commercial brackets for sailboats are built in bronze, thanks to the good casting specifications of this material. Nevertheless, the high density leads to very high weights and, although this is not a mandatory requirement in marine, a mass reduction can be advantageous. The weight spared in the rear zone of the vessel allows, in equal centering, to increase the weight of the accessories in the stern area, where typically are the living spaces and more furnishings are required. Moreover, some boats are currently built entirely in carbon fibre and the problems caused by the contact of heterogeneous materials are to be avoided. At present, some shipyards have begun to experiment propeller axis brackets made in composite materials, but only with prototypes and testing models: not a commercial product is present “off the shelf” on the market. With this background, the paper describes the activity of modelling and design performed in order to achieve the best compromise between: aesthetic design, bracket structural strength, hydrodynamic drag, and cost. The design optimisation has been carried out by means of a genetic algorithm, evaluating a fitness function representative of project constraints and requirements. The authors believe that the result obtained is valid from the aesthetic, structural and economic points of view: the propeller axis bracket here modelled and optimised has been physically built in several models, and will be inserted on catalogue for the sale to the public in the next future. The final component, although more expensive than the bracket in bronze, presents a much less weight, a pleasant design and an increased structural resistance. Future developments will follow the certification by RINA (Italian civil naval authority) and the extension of the developed methodology to the modelling of other naval items in composite materials.
A. Ceruti, E. Troiani (2008). MODELLING AND OPTIMIZATION OF A PROPELLER SHAFT BRACKET IN CARBON FIBER FOR SAILBOAT. VALENCIA : Universitad Politecnica de Valencia.
MODELLING AND OPTIMIZATION OF A PROPELLER SHAFT BRACKET IN CARBON FIBER FOR SAILBOAT
CERUTI, ALESSANDRO;TROIANI, ENRICO
2008
Abstract
This paper presents an innovative procedure for the modelling and optimisation of an advanced materials propeller axis bracket for sailing ships of 24 m length. Currently, the commercial brackets for sailboats are built in bronze, thanks to the good casting specifications of this material. Nevertheless, the high density leads to very high weights and, although this is not a mandatory requirement in marine, a mass reduction can be advantageous. The weight spared in the rear zone of the vessel allows, in equal centering, to increase the weight of the accessories in the stern area, where typically are the living spaces and more furnishings are required. Moreover, some boats are currently built entirely in carbon fibre and the problems caused by the contact of heterogeneous materials are to be avoided. At present, some shipyards have begun to experiment propeller axis brackets made in composite materials, but only with prototypes and testing models: not a commercial product is present “off the shelf” on the market. With this background, the paper describes the activity of modelling and design performed in order to achieve the best compromise between: aesthetic design, bracket structural strength, hydrodynamic drag, and cost. The design optimisation has been carried out by means of a genetic algorithm, evaluating a fitness function representative of project constraints and requirements. The authors believe that the result obtained is valid from the aesthetic, structural and economic points of view: the propeller axis bracket here modelled and optimised has been physically built in several models, and will be inserted on catalogue for the sale to the public in the next future. The final component, although more expensive than the bracket in bronze, presents a much less weight, a pleasant design and an increased structural resistance. Future developments will follow the certification by RINA (Italian civil naval authority) and the extension of the developed methodology to the modelling of other naval items in composite materials.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
