Investigation on the Structural Damage of a Double-Hull Ship, Part II – Grounding Impact

Abstract

Possibility of marine and offshore structures to experience accidental loads has been seriously considered up to this day. Remarkable casualties on related aspects are rising demand to ensure ship safety which in this subject is observed on marine structure. Ship is an example of marine structure that may be subjected to accidental loads during its operation. The aim of this paper is to investigate damage extent of the target ship under different accidental loads, namely collision and grounding with considerations to failure process and deformation contours. This work is divided into two parts which in the Part I, ship collision is discussed, and the Part II deals with interaction of ship structure with sea bottom in grounding. In Part II - Grounding impact, evaluating tearing damage on the bottom structure is essential in estimating environmental casualties caused by oil leakage. A chemical tanker is modelled to be the target ship in a series of grounding scenarios. Condition of the structural damage and tendency of the internal energy, crushing force and structural acceleration are observed. Prediction of the tearing opening and location of the initial failure in further grounding process are also presented in this paper. Virtual experiment is conducted by nonlinear finite element method in order to calculate the defined grounding scenarios which are built based on the target location on the bottom structure. Based on calculation results, condition of the double-hull structure after grounding is found to be highly influenced by arrangement of the longitudinal members which is evidenced by the fact that these members provide higher resistance than the transverse part. Finally, influence of the indenter's position on structural responses in grounding is summarized.