Marine and Offshore
Design and construction practises for marine and offshore structures have been transformed in the last two decades. Considerable use is now made of CAE allied to prefabrication and the industry now ranks amongst the best in terms of business efficiency. Over the same period new technologies and new materials have been espoused to develop improved hull forms e.g. trimarans, fast ferries, Ro-Ros and cruise ships. At the same time, the life extension of existing vessels and offshore platforms to meet changed operational requirements has generated considerable technical challenges, which to some extent are still on-going. These include the prediction of seaway loading, ultimate hull girder strength, fatigue life of primary structure, deterioration modelling, fracture analysis including critical crack lengths and robust repair techniques recently including use of composite materials.
Further difficulties are arising from developments of new fields in deep water. Associated issues require modelling of a large variety of phenomena, such as behaviour of complex mooring systems, structural behaviour of risers made form composite materials or long term resistance of FPSO moored for many years in harsh environment.
Safety and environmental issues are also contributing to the demand for improved simulation technology particularly in areas as diverse as response to extreme loadings, integrated hydrodynamics/ kinematics/ structural response and design for maintenance and reliability.
In response to these challenges the marine and offshore industries have witnessed increasing use of commercial FE packages, particularly those with non-linear capabilities. Furthermore, the safety concerns in the offshore industry have been a driver in development of the reliability theory and, more recently, its integration with FE codes.
Research activities at the state-of-the-art level include stochastic approach to fatigue problems, stochastic crack-growth modelling and vulnerability assessment of naval ships to above or underwater missile or explosion attack. Future research interests also include automatic meshing and CAD/CAE integration.
The main business driver is cost reduction and environmental issues. Some specific issues include improved fatigue management, improved structural safety and reduced cost of design and fabrication. Barriers are a consequence of the gap between the available and applied technology. They include inability of smaller companies to keep up with the new technology, rules and regulations are predominantly empirical and relatively little repetition of work.