A floating two-stage buffer collision-prevention system (FTBCPS) has been proposed to reduce the impact loads on the bridge pier in this paper. The anti-collision process can be mainly divided into two stages. First, reduce the ship velocity and change the ship initial moving direction with the stretching and fracture of the polyester ropes. Second, consume the ship kinetic energy with the huge damage and deformation of the FTBCPS and the ship. The main feature of the FTBCPS lies in the first stage and most of the ship kinetic energy can be dissipated before the ship directly impacts on the bridge pier. The contact stiffness value between the ship and the FTBCPS can be a significant factor in the first stage and the calculation method of it is the focus of this paper. The contact force, the internal force and the general equation of motion have been given in the first part. The structure model of the ship and the FTBCPS are then established in the ANSYS Workbench. After that, 38 typical load cases of the ship impacting on the FTBCPS are conducted in LS-DYNA. The reduction processes of the ship kinetic energy and the ship velocity in different load cases have been investigated. It can be summarized that the impact angle and the ship initial velocity are the main factors in the energy and velocity dissipation process. Moreover, the local impact force-depth curves have also been studied and the impact angle is found to be the only significant factor on the ship impact process. Next, the impact force-depth curves with different impact angles are fitted and the contact stiffness values are accordingly calculated. Finally, the impact depth range, the validity of the local simulation results and the consistency of the fitted stiffness value are verified respectively, demonstrating that the fitted stiffness values are applicable in the global analysis.

为了减少对桥墩的冲击载荷，提出了一种浮动式两级缓冲防撞系统（FTBCPS）。防撞过程主要可以分为两个阶段。首先，随着聚酯绳的拉伸和断裂，降低船速并改变船的初始移动方向。其次，由于FTBCPS和船舶的巨大破坏和变形，消耗了船舶动能。FTBCPS的主要特征在于第一阶段，在船舶直接撞击桥墩之前，大部分船舶动能都可以消散。船舶与FTBCPS之间的接触刚度值在第一阶段可能是一个重要因素，其计算方法是本文的重点。接触力 在第一部分中已经给出了内力和一般的运动方程。然后在ANSYS Workbench中建立船舶和FTBCPS的结构模型。此后，在LS-DYNA中进行了38例影响FTBCPS的船舶典型载荷工况。研究了不同载荷工况下船舶动能和速度的降低过程。可以总结出，冲击角和船舶初始速度是能量和速度耗散过程中的主要因素。此外，还研究了局部冲击力-深度曲线，并且发现冲击角是影响船舶冲击过程的唯一重要因素。接下来，拟合具有不同冲击角的冲击力-深度曲线，并据此计算接触刚度值。最后，