The effect of selected parameters on ship collision results by dynamic FE simulations

Abstract

The purpose of the paper is to study the effect of selected design parameters on crashworthiness of the struck ship. The dynamic collision process is simulated by the ABAQUS/Explicit code, and two problems are analysed: (1) a plate struck by a cone, and (2) a collision of two ships. The first problem, of a plate struck by a rigid cone, has a preliminary character and validates our FE modelling; a similar crushing force is obtained as in Amdahl and Kavlie (DNV-MIT Workshop on Mechanics of Ship Collision and Grounding, DNV H øvik, Oslo, September) and Simonsen (ISESO Report No. I108.02.02.052.004, Department of Naval Architecture and Offshore Engineering, Technical University of Denmark, April), despite the differences in methods of analysis applied. The current computations go further than the cited papers, and assess the dependence of results on the material model of the plate (including failure), the contact within the plate interior, and the mass of the striking cone. The second problem is of practical interest, as it concerns a collision of a double hull crude oil carrier ship and a container vessel with a bulbous bow. The progress of deformation in time is monitored including large plastic strains as well as contact between the ships, which allows to model crushing and tearing. The effect of the following parameters is assessed: the material model of the struck ship, the friction coefficient for the contact between the vessels, the initial velocity of the striking ship, the motion of the struck ship, and the mass scaling option used to accelerate computations. The included results present the deformed struck objects, and also the crushing force and various types of energy vs. penetration of the striking body. Conclusions are formulated regarding the numerical method used, the striking ship velocity data and the material model for the struck ship.