Effects of a deformable striking ship's bow on the structural crashworthiness in ship–ship collisions

Abstract

Ship-ship collision frequently occurs in shipping industry. The risks of economic losses and marine pollution have been increased by to ship-ship collisions especially involved with large oil tankers or liquefied natural gas (LNG)-fueled ships. Various type of methods are available for the purpose of safety studies in association with structural crashworthiness involving crushing and fracture in ship-ship collisions. In the perspectives of multi-physics and multi-criteria involved, however, the nonlinear finite element method is 2 certainly one of the most powerful techniques to model the problems. In a shipship collision accident where the bow of a striking ship is collided with the side of struck ship, the kinetic energy must be absorbed by both striking and struck ship structures in terms of collision damages and corresponding strain energies.As the bow structure of the striking ship is usually much stiffer than the side structure of the struck ship. It does not allow for deformation and damage.Therefore, no contribution of energy absorption is made by the striking structure. As the energy absorption characteristics of the striking ship depends on the structural arrangement of bulbous bow and flare, however, the contribution of striking ship cannot be entirely neglected. The aims of the present study are to examine the effects of a deformable striking ship structure on the structural crashworthiness of ship-ship collisions using LS-DYNA nonlinear finite element method computations. As an illustrative example in the paper, the struck ship is a VLCC class double hull oil tanker, while the struck ships are two types: a VLCC class tanker and a SUEZMAX class tanker.The relationships between collision forces versus penetration together with their energy absorption capabilities are characterized in association with the contributions of the striking ship bow where the deformable striking ship structures are compared with the rigid striking ship structures. Developed Findings and insights from the present study are summarized.

Quantitative collision risk assessment of a fixed-type offshore platform with an offshore supply vessel

“…'Automatic_surface_to_surface' and 'automatic_single_surface' cards of LS-DYNA are used to model external contact between ship and platform and internal contacts among different parts of the ship, respectively [59]. Modelling frictional energy in ship-offshore platform collisions is challenging, as it depends on various factors such as surface characteristics (e.g., grain feature), external conditions (e.g., temperature, moisture, and lubrication), and collision scenarios [60].…”

Computational models for the structural crashworthiness analysis of a fixed-type offshore platform in collisions with an offshore supply vessel

“…This study uses the MCOL program of LS-DYNA [48,49] to couple the interaction of ship motions and velocity between structural and hydrodynamic forces. MCOL has been successfully used for ship-ship collisions, for instance, [33,[50][51][52][53]. Initially, MCOL was applied to ship-submarine collision [54,55].…”

Impact crashworthiness of a floating offshore nuclear power plant hull structure in a terrorist attack with an aircraft strike

“…Furthermore, the striking body must be deformable, and the interacting effect between two colliding bodies is complex in many aspects and it should not be overlooked (Ko et al 2018). The energy absorption characteristics of two colliding Double side bodies will depend on individual structural properties, indicating that both the material and geometric properties for two colliding bodies should be realistic.…”