With transportation's rapid growth, ship-bridge collisions occur frequently, causing substantial losses. Ship-bridge anticollision facilities should not only protect the structural integrity of bridges but also minimise ship damage. This paper designs a novel ship-bridge anti-collision device based on a trapezoidal foam-filled composite sandwich structure. Using the finite element software LS-DYNA, a ship-anti-collision device-bridge collision model was established, taking into account pile-water-soil coupling. The study investigates the selection of box materials, filling materials and wall thickness for the novel anti-collision device. By analysing the damage characteristics of the ship, anti-collision device and pier under typical collision loads, the optimal material properties were determined. The impact resistance of the optimised device was evaluated under different ship speeds and collision angles, demonstrating that the novel anti-collision device exhibits excellent buffering and energy absorption, effectively reducing the peak collision force, extending the collision duration and reducing damage to the ship's bow structure.

There has been an urgent need to develop and analyse multi -layered composite structures with varying material properties to withstand projectile impact. The proposed study focuses on the optimization of the multilayer composite to achieve maximum resistance/energy dissipation. This study investigates the mechanical performance of the proposed multi -layered composite configuration under high strain rate loading through a computational approach. The proposed multi -layered structure incorporates layers of reinforced concrete, boulders, an elastomer layer, an ultra -high-performance concrete panel, and a layer of steel plate. A mesoscalebased approach has been developed for the layer comprising boulders and mortar. A total of six different configurations have been considered to arrive at the most efficient one against projectile impact. Optimization of the proposed configurations has been done by utilizing the concepts of specific energy absorption and shock impedance. Additionally, the fracture and damage characteristics of each configuration are also studied. Ductile hole enlargement in the sandy soil layer, fragmentation failure in the boulders, petaling failure in the steel plate, and spalling failure in the concrete layer have been observed. Based on the specific energy absorption and shock impedance approaches, the optimum laying sequence for the ballistic impact of each material is suggested.