Evaluation Method of Absorbed Energy in Collision of Ships with Anti-Collision Structure

To verify the effectiveness of Minorsky's formula that is used in the current regulation of ships with collision resistant structure, a simplified analysis method based on rigid-plastic analysis is developed. The collision of the test ship with a T2 tanker and a Suezmax class tanker is analyzed, and it was shown that Minorsky's formula, which assumes the same collapse length for the striking and the struck ship, gives an incorrect estimation of the energy balance when the strength of the ship bow and side have a big difference. Also, the results are compared with those by dynamic FEM analysis, and good agreement is observed. It was shown that the simplified analysis method is an effective tool in the early design stage, and in developing regulations.