Hydrodynamic impact loads on advanced marine vehicles and offshore structures
Over the past three decades there has been increased military and commercial interest in lightweight high-speed ships, mainly due to their ability to provide fast sea transportation and relatively high payload capacity. Australia is an acknowledged world leader in the innovative design and construction of large high-speed aluminium catamarans, such as the vessels developed by Incat Tasmania and Austal.
A major challenge in designing high-speed marine vessels is to increase the ratio of deadweight to lightship weight, whilst ensuring safe structural design and maintaining high operational speeds. Structural optimisation relies on the accurate prediction of the wave loads, which for high-speed ships are generally dominated by slamming, one of the principal mechanisms for wave induced loads on ships. Slamming phenomenon is a significant design issue, for both monohull and catamaran vessels, since it can cause major structural damage and injuries.
To eliminate the prospect of structural damage and to secure insurance cover in case of damage, high-speed ships are designed to high-speed craft rule-based design loads. Several large high-speed vessels have suffered damage due to slamming, although these vessels were designed to classification society rules. Currently classification societies provide designers with a range of empirical formulae that are based on quasi-static pressure predictions due to impact on high-speed vessels, which in-reality may over or underestimate the actual impact pressure distributions.
Thus, there is a need to provide designers and classification societies with an accurate means to predict impact load magnitudes and a validated numerical tool to optimise hull geometries, based on reliable experimental work and CFD simulations.