An impact dynamics analysis on a new crashworthy device against ship–bridge collision

In order to avoid increasingly serious accidents caused by ship–bridge collision, a new flexible, energy-dissipating crashworthy device is developed, which essentially consists of hundreds of steel-wire-rope coil (SWRC) connected in parallel and series. Experiments show that the force–displacement behavior of the SWRC is rate-dependent and energy dissipating, which is successfully modeled by the ZWT nonlinear visco-elastic relation in the present paper. By using the dynamic finite-element code incorporated with the force–displacement model of the SWRC, dynamic numerical simulations are performed for several typical cases of ship–bridge collision. The results indicate that the peak of impact force markedly decreases due to high compliance (low wave impedance) and viscous energy dissipation characteristic of SWRCs. Particularly, the new device enables the ship having enough time to turn its navigating direction away and consequently a large percentage of initial kinetic energy of ship is carried by the turning-away ship.