Experimental Investigation of Springing Responses of an Ultra Large Ore Carrier

摘要

Springing is mainly a 2-node continuous vertical vibration of hull girder for large ships in low sea state. It will result in serious effects to fatigue problem for ship structures. Larger ship scale will cause more serious springing phenomena. This paper investigates the springing phenomena by experimental method for an ultra large ore carrier in full and ballast loaded conditions. Springing happened both in regular and irregular head waves. It is confirmed that springing comes into being in low sea states. However, as we know slamming usually result in whipping vibrations when sea state is high and the damping is low, it is difficult to distinguish springing, whipping or their combination. Comparing with full loaded condition, ballast condition can result in much more springing in the model tests. By the analysis of springing phenomena and its mechanism, good knowledge of characteristics of wave-induced responses of large ships in short waves is learnt. Springing will have an important effect on determining the fatigue design wave loads and the designing of ship structures.