A SIMPLE METHOD FOR PREDICTING THE GROUNDING STRENGTH OF SHIPS

Although the destructive effects of grounding accidents are understood , very few tools are available that can be used by designers to evalua te a ship's strength in grounding accidents. This paper proposes a sim ple method to predict the strength of a ship's bottom during the proce ss of grounding. A ship's hull is characterized by structural members that are periodically arranged along the ship length. As a result, the internal resistance force developed during grounding is in a sense pe riodic in the longitudinal direction. For the main structural members of the ship bottom, the following four primary failure modes are consi dered in this paper: the stretching failure of transverse structures, denting, tearing and concertina tearing failure of bottom plates. The calculation formulas for these identified failure modes are assembled to construct the prediction method for bottom strength. The proposed m ethod is verified by checking the predictions against a series of larg e-scale grounding experiments and an actual grounding accident. The at tractiveness of the method developed is that it makes possible the pre diction of the strength of a ship hull in the event of grounding using hand calculation.