Numerical Study on the Underwater Collision Characteristicsof a Double Hull Submarine

To investigate the damage characteristics of submarine structures in collision， a double hull submarine with 2 500 ton displacement is chosen as a research object， and its equally proportional solid model is constructed to realize the collision between the striking bow and shipboard. From the perspectives of energy absorption， collision force and shock environment， the influences of the collision are studied via non-linear code Ls-Dyna， where the major conclusions are as follows： the collision energy is mainly absorbed by the outer shell and intermediate structures， rendering the lower stiffness bow to suffer significant plastic deformation； the stronger shipboard reacts mainly with kinetic energy， and a relatively smaller plastic zone is resulted. Single and double peak of collision force tend to appear when the velocity is around the critical magnitude （15-16 kn）. The shock environment along the longitudinal direction resembles the logarithmic function trend， which suggests that the affected region for crew members， measured with the intermediate damaged degree， is within 0.11 ship length from the bow impingement zone.