Numerical Analysis of Ship Hull Structure under Bulbous Bow Collision: Influence of Bow Shape and Impact Velocity on Structural Integrity

Resumen

This paper presents a comprehensive finite element analysis (FEA) of a ship's side shell structure under the influence of a bulbous bow collision. The geometry of the forwardmost portion of the bulbous bow of the striking ship is simplified into four different shapes- spherical, cylindrical with hemispherical end, trapezoidal prism and wedge shape to investigate the structural damage and determine the effective bulbous bow shape in case of structural integrity of the side shell under the impact of bulbous bow during collision. Several collision scenarios are simulated varying the collision velocities and bulbous bow shapes and validated with analytical results using two different analytical methods. The analysis yields critical information regarding reaction forces, penetrations and energy absorptions. The numerical results show good agreement to the analytical findings particularly till the crack initiation into the hull structure.  The spherical shape is found more effective bulbous bow shape determined by the maximum energy absorbed and reaction forces exerted of the side shell against the impact of the bow during penetration until fracture into the hull structure.