Analysis of the Design & Construction Methodologies for Carbon Composite Motor Yacht Superstructures

Abstract

Composite hull and superstructure construction using fibreglass reinforcements has been a part of the motor yacht industry for several decades. However increasing demand for greater structural performance has required that motor yacht designers look for materials and composite layups that provide greater strength for equal or less layup thickness and weight. Carbon fibres provide such a suitable option, however their cost and tendency to fail catastrophically without warning has meant that implementation in motor yacht structures requires surety that the performance of the final layup is as required by the demands placed on the hull or superstructure. This thesis investigates the benefits and drawbacks of carbon in regards to material properties, structural design and the manufacturing process, focusing on sandwich laminate construction. Future trends in material use and production techniques will also be put forward, based on an historical trend of technology flow down from predominately the aerospace industry. The investigation focuses on a comparison between the more standard E – Glass and Carbon fibre, and the advantages gained from using the higher performance reinforcement material with respect to. 1. Increased raw material properties, using simple beam theory 2. Advantages available from using carbon in superstructure design, using finite element analysis 3. Additional performance gains when combining carbon fibres with more refined laminate manufacturing methods. Results show that carbon fibre offers an improvement over E – Glass in terms of reduced structural scantlings (Eg. reduced deck stiffener depth) and a corresponding reduced structural weight whilst offsetting its higher raw material cost to be a viable choice for modern yacht superstructures. The thesis was conducted in conjunction with the development of a carbon fibre superstructure for a new class of motor yacht design with the Azimut Benetti group.