Experimental study on torsion springing and whipping of a large container ship

Abstract

As the size of container ships increases, springing and whipping phenomena have been one of important design considerations due to its significant effect on wave loads and fatigue analysis. Therefore needs of reliable model test data is increasing for validation of state of the art analysis tools for springing and whipping. In the present study, a model system for measurement of torsion springing and whipping which is composed of a backbone and segmented container ship model in which natural frequencies of bending and torsion are matched using an open section beam. A series of model tests have been carried out for selected cases of springing and whipping in regular and irregular waves. Discussions are focused on physics of torsion springing and whipping observed in model tests, and technical difficulties associated with interpreting torsion moment from measured strains from backbone model. Copyright ？ 2011 by the International Society of Offshore and Polar Engineers (ISOPE).