Simplified contact-based segment expansion (CBSE) method for assessment of crashworthiness of double-hulled ship structure

A commonly assumed ship-to-ship collision scenario is a rigid ship bow hitting the side of a ship perpendicularly. A bulbous bow has a slender shape overall but a rounded end, while a stem has a sharp horizontal edge but a gently sloping body. It was found from numerical simulations that the stem collision induces horizontal shear failure on side shell as soon as the stem contacts with the side shell. Also, progressive deformation was observed only at the lower part of side shell as the contact extended downward. Based on the present research, a simplified method for the stem collision case, named a contact-based segment-expansion (CBSE) method, herein is proposed. This method reflects the progressive collapse of side shell and considers the strain energy absorbed by the boundary girders. The validity of the method was verified from the numerical simulations in terms of energy-absorption capacity of the double-hulled structure.