Computer simulation study of offshore collisions and analysis of ship-platform impacts

The paper deals with a study of relative probabilities and inherent consequences of impacts on offshore platforms caused by ship collisions. A new approach to the analysis of relative frequency of collision is presented. The method is based on the simulation technique. By introducing a selection of critical failure events affecting the manoeuvrability of ships under various environmental conditions, the ship paths are statistically predicted. The load-deformation characteristics and impact energy absorption in ship structures subject to collisions are of major importance for the proper prediction of impact forces. A simplified theoretical calculation model is outlined based on large plastic deformations of the colliding ships suffering indentations of one of the sides. The impact resistance of concrete as well as steel platforms subject to ship collisions is discussed to some extent. A number of simple tests with pendulum impacts on fendered and unfendered reinforced concrete cylindrical shells are described in this context.