Experimental study on torsion springing and whipping of large container ship

Abstract

As the size of container ships increases, the springing and whipping phenomenon has been among important design considerations due to its significant effect on wave loads and fatigue analysis. Thus the need for reliable model test data is increasing for validation of state-of-the-art analysis tools for the springing and whipping. In the present study, a model system for the measurement of torsion springing and whipping has been described. The model was composed of an elastic backbone and a segmented container ship in which the natural frequencies of bending and torsion were matched to the target values. A series of model tests has been conducted for the selected cases of springing and whipping in regular and irregular waves. Discussions were focused on the physics of torsion springing and whipping observed in the model test, and technical difficulties associated with interpreting the torsional moment from measured strains from the backbone model. ？ The International Society of Offshore and Polar Engineers.