This paper focuses on ship impact analysis on lock gate. First, the lock gate structure is
determined by an elastic design and optimization process. Then, a nonlinear numerical analysis
by finite elements is conducted to study the response of the lock gate in case of ship impact. It is
shown that the elastically optimized structure is not able to resist significant impacts, because of
the buckling of its reinforcement elements; the gate is thus reinforced. Finally, several ship
impact analyses are conducted on the reinforced gate and they highlight the influence of the
stiffener dimensions and the impact zone on the structural behavior of the gate. The results of
the numerical analyses underline the importance of the development of a global plastic
mechanism with the purpose of dissipating a large amount of energy