Rapid Prediction of Damage to Struck and Striking Vessels in a Collision Event

This paper presents theory and application examples of a mathematical model for rapid prediction of damage to both the side structure of a struck vessel and the bow of a striking vessel in a collision event. The geometry of the bow of the striking ship is idealised such that it can be described by only few parameters, still covering with sufficient accuracy almost all existing ship bows with and without bulbs. The model for the internal mechanics of the struck ship side is based on a set of so-called superelements. Each super-element represents an assembly of structural components and contains solutions for the structural behaviour of this assembly under deep collapse. By summing up the crushing force of each super-element, it is possible to determine the total contact load between the two involved ships. A number of parameter studies are presented where the sensitivity of the damage to the loading conditions and striking positions are illustrated. Furthermore, the difference between longitudinal and transverse bow stiffening has been examined. Transversely stiffened bows are shown to be significantly softer than longitudinally stiffened bows. Thirty collision events with five different striking vessels and six different struck vessels have been examined. The examples illustrate that the usual assumption of a rigid bow only holds true for certain categories of struck and striking vessels.