Cost and weight of composite ship structures: A parametric study based on Det Norske Veritas rules

Abstract

A wider use of composites in larger, commercial vessels has been limited by initial costs and fire regulations, but both of these obstacles are diminishing. Increasing fuel costs and more stringent emission requirements have heightened the value of lightweight structures. Due to the higher acquisition costs and other entry barriers, composite designs must be as cost efficient as possible in order to compete with traditional steel or aluminium designs. The purpose of this article is to investigate which fibre-reinforced polymer materials and types of structures are most suitable for different parts of a ship design in order to minimize weight or cost. This is done by designing and comparing individual composite panels while varying a wide range of input parameters and strictly following the ‘Det Norske Veritas (DNV) Rules for Classification of High Speed, Light Craft and Naval Surface Craft’. The results are presented as weight and cost comparisons between materials and structures and also degree of utilization for the different design criteria; carbon fibre structures are on the average 20%–30% lighter than glass fibre structures but are consistently more expensive. The results also indicate that sandwich panels in most cases are lighter than single-skin panels, and that for sandwich structures, the mechanical properties of the core material are commonly the critical design criterion. The minimum amount of reinforcement stipulated by the rules is also found to be a critical factor.