Dynamics of ship collisions

Abstract This paper described a procedure for simulation of the outer dynamics in ship collisions. The simulation procedure is derived using the transient equations for the horizontal motion of a ship. The hydrodynamic forces acting on the ships' hull during the collision are calculated by a strip method, where the forces acting on each section are described by means of unit response functions. These functions are determined by cosine transformation of the sectional dampings. The sectional added masses and dampings, and thereby also the sectional unit response functions, are calculated by an approximate method. The deformations of the slip structures during the collisions are modelled as non-linear springs. The resulting system of non-linear equations is solved using a numerical time-integration procedure. A number of different collision situations are simulated by means of the procedure.