Numerical simulation for thermo-mechanical analysis within alternative design

There is an increased tendency towards the use of novel lightweight materials, particularly fibre-reinforced plastic composites, in shipbuilding. Composites offer the advantage of reduced structural weight and increased moulding freedom unattainable for traditional materials such as steel. The use of composites for building ships, however, is limited by the current regulations due to their challenging fire behaviour. Recent development of numerical simulation techniques has enabled the study of the thermo-mechanical behaviour of fire-exposed polymer composites, including scenarios relevant for the maritime industries. Even though advanced numerical methods are already used in the design and approval process, there is much potential for their wider application. For instance for design optimisation with reduced need for experiments and testing, thus providing a basis for a more computerised design process including the analysis of fire resistance. During the EU FP7 project Fire-Resist (2011-2015), a multi-field simulation concept was developed based on the interoperability of computational fluid dynamics fire simulation and finite element analysis. This simulation concept enables the comparative analysis of thermal and mechanical behaviour of fire-exposed structures, for instance in the context of the SOLAS Alternative Design process, with respect to load-bearing capacity during and after a fire. The capabilities of the simulation concept are demonstrated by a thermo-mechanical analysis of a typical ship structural element, focusing on a comparative analysis between a SOLAS compliant steel structure and a novel design employing FRP composite material.