A Ship Collision Analysis Program Based on Upper Bound Solutions and Coupled with a Large Rotational Ship Movement Analysis Tool

Abstract

This paper presents a user-friendly rapid prediction tool of damage to struck and striking vessels in a ship collision event. To do this, the so-called upper bound theorem is applied to calculate internal forces and energies of any substructure involved in the ships crushing process. At each increment of indentation, the total crushing force is transmitted to the external dynamics MCOL program, which calculates the global ship motion correction by solving the hydrodynamic force equilibrium equations. As a first step, the paper gives a brief description of the upper bound method originally developed for perpendicular collisions and recently enhanced for oblique ones. Then, the theory developed in MCOL program for large rotational ship movements is detailed. By comparing results obtained with and without MCOL, the importance of hydrodynamic effects is highlighted. Some simulation results are compared with results provided by classical nonlinear finite element calculations. Finally, by using the developed analytical tool, which mixes internal and external dynamics, different crushing scenarios including oblique collisions are investigated and the influence of some collision parameters like longitudinal and vertical impact location, impact angle, and struck ship velocity is studied.

Simplified analytical methods for the crashworthiness and the seismic design of lock gates

“…More recently, Le Sourne et al [98] also focused on this topic by applying the super-elements approach. Regarding the analytical techniques to evaluate the impact resistance of lock gates, the initial work realized by Le Sourne et al [99] has been completed and extended by Buldgen et al to plane [22] and mitre [24] lock gates.…”

“…These ones were developed for ship-ship collisions, as the rigidities of the two vessels may be quite similar in this case. A general presentation of the methodology is done by Le Sourne [97] and many other details can be found in references [8], [94], [98], [103], [104] and [130].…”

Fast strength assessment of mitre gates to ship impact

“…Through a similar procedure than the one detailed in [2][3][4][5][6][7][8][9][10][11][12][13], it is possible to evaluate the contribution of the four regions to the total power associated with SE1. So, for super-element n • i, we haveĖ i =Ė I +Ė II +Ė III +Ė IV , with the following expressions: Equations (3)- (6) provide a relation betweenĖ i and δ, which was precisely the law sought for evaluating the local resistance offered by SE1.…”

“…However, this topic is rarely reported in the literature. On the other hand, many analytical results are available to deal with ship-ship collisions, especially for evaluating the local crushing of the various components constituting the structure of a struck vessel (see for example, references [7][8][9][10][11][12][13]). All these developments may be used as a starting point for our analytical approach, but they are not sufficient, because the behaviour of an impacted gate may not directly be assimilated to the one of an impacted vessel.…”

Implementation of Linear Potential-Flow Theory in the 6DOF Coupled Simulation of Ship Collision and Grounding Accidents

“…Tabri et al (2010) assumed homogeneity of ship stiffness and represented the collision forces by integrating the normal and tangential tractions over the contact surface between the colliding bodies. The superelement method uses collision resistances based on simplified analytical solutions (Le Sourne, 2007, Lützen et al, 2000. In such cases, emphasis is placed on the global ship motions, but the structural damage cannot be well predicted.…”