Research On The Impact Force In Ship-bridge Collision Experiments And Numerical Simulations

The possibility of ship-bridge collision is on the rise with a large number of the across seabridges being built and the increasing speed of ships. The losses of lives and property are striking,as well as the destruction to the environment. In order to avoid or reduce the catastrophic losses inthe accidents，it is important to study the mechanism of ship-bridge collision, especially theanti-collision device. It is of very importance of theoretical and realistic significance.A new type of flexible protection device has been put to use in ship bridge protection. Due tothe need of theory and reality, the Mechanics and Material Research Center in Ningbo Universityhas carried out an experiment using a ship with weight of400tones to impact a bridge-pier whichis protected by the flexible anti-collision device. The protective performance of the flexibleanti-collision device was comprehensively tested in the experiment. Basing on this foundation, thispaper investigated on the impact force of the ship and the pier in this collision test. The finiteelement software LS/DYNA was used to simulate the test. Results of the simulation have beencompared to the measured data in the experiment, which is of significance to evaluate theprotective performance and the design of this new type of flexible protection devicesThe results of the study are concluded:1. The maximum impact force of ship and pier in the real collision experiment wasinvestigated and compared with the result deduced from empirical formula. It showed that therewas an error between the measured data and the calculated result from empirical formula. A newformula for calculating the impact force is revised in this paper.2. In the experiment, only one crash happened between ship and the protection devices; at thebeginning of the collision, flexible protection device gave full play to reduce the impact force andenergy dissipation.3. The simulation results obtained by LS/DYNA are used to compare with the measured datain the collision experiments. It proved that the new flexible protection device can largely reduce theimpact peak force of ship colliding to pier, and vastly improve the capacity of anti-collision ofbridge. It not only protects the bridges, but also greatly reduces the damage of ship.4. Under repeatedly crashes, the protection device still works effectively. It indicated that thedevice was much more economical and effective.