自浮式防船撞装置滚动构件性能分析

Performance of Rolling Components in Self-Floating Anti-collision Device

为减少自浮式防船撞装置在水位变化作用下与桥墩的相互磨损,提出一种具有熔断能力的滚动构件,可与防撞浮筒共同形成整体自浮式防撞装置,将防撞装置与桥墩的滑动接触变为滚动接触,同时实现防撞装置在不同撞击强度下的多级耗能。防撞浮筒由钢材及功能材料组成,滚动构件由纵肋板、加劲肋、螺栓剪力销等组成。当螺栓剪力销所受剪力小于设计熔断力时,由浮筒弹性耗能,即一级耗能;螺栓剪力销所受剪力达到设计熔断力时,螺栓剪力销断裂,橡胶护舷与桥墩接触,橡胶护舷压缩变形耗能(二级耗能),进而钢浮筒塑性变形耗能(三级耗能)。通过LS-DYNA软件对原型及刻槽优化后滚动构件进行熔断行为模拟,并进行船舶撞击整体防撞装置动力过程模拟,分析滚动构件的可靠性及在防撞装置中的防撞性能。结果表明:滚动构件可实现熔断行为,刻槽优化后能使螺栓剪力销断裂行为更精准,熔断行为更可控;钢浮筒与滚动构件组合形成的防撞装置能够使整体装置依次进入三级耗能,且在桥梁实际应用中具有可更换、易于维修的特点。

A type of fusible roller that can be used together with the anti-collision pontoon to form an integral self-floating anti-collision device are presented,which transforms the slipping contact between the anti-collision device and pier to rolling contact,reduce the friction between the two under waving water and achieve multi-level energy dissipation of impact forces.The anti-collision pontoon consists of steel and functional materials,and the roller is formed of longitudinal stiffening plate,stiffening rib and shear pin.When the shear force on the pin is smaller than the design fusing force,the impact force is dissipated elastically by the pontoon,namely the first-level energy dissipation.When the shear force on the pin reaches the design fusing force,the pin fractures,the rubber fender contacts the pier,being compressed and deformed to dissipate energy(second-level energy dissipation),subsequently the pontoon is plastically deformed for energy dissipation(third-level energy dissipation).The fusing behaviors of the original roller and the roller grooved for optimization were simulated in LS-DYNA,and the dynamic process of ship and anti-collision device impact was modelled,to analyze the reliability of the roller and the collision protection contribution to the anti-collision device.It is shown that the roller is fusible,after being grooved,the fracture of the pin can occur more accurately as needed,and the fusing performance is quite under control.The anti-collision device consisting of steel pontoon and roller allows the overall device to reach the third-level energy dissipation,which is replaceable and easy to be repaired.