Rupture Analysis of Oil Tankers in a Side Collision: Theory of Bow Cutting through Decks

A closed form solution to the problem of initiation and steady state wedge cutting through a ductile metal plate is presented. The considered problemis an idealization of the cutting process of a sharp raked bow of a ship into a deck of a stricken ship.A new kinematic model is proposed for the strain and displacement fields and it is demonstrated that the analysis is greatly simplified if the strain field is assumed to be dominated by plastic shear strains and moving hinge lines. Also, it is shown that the present shear model offers the basis for a convenient extension of the presented plate model to include more structural members as for example the stiffeners attached to deck. The fracture process is discussed and the model is formulated partly on the basis of the material fracture toughness. Th effect of friction and the reaction force perpendicular to the direction of motion is derived theoretically in a new consistent manner. The derived expressions arediscussed and compared to previously published experimental results and formulas.