船舶与海洋平台撞击的荷载模拟

Simulation of impact load on ship-platform collision

以某导管架结构的X斜撑在导管架安装阶段受到大吨位起重铺管船撞击后的损伤检测结果为依据,对碰撞过程进行了数值模拟,按照构件模型从简单到复杂的模拟思路得到了船舶对海洋平台结构的撞击力。建立了船舶与海洋平台碰撞系统的力学模型,对导管架平台受损构件进行了等效静力强度计算分析。为了考虑在船舶冲撞下的整体平台结构动力效应的影响,在分析时考虑了碰撞过程的水动力效应,桩-土-平台结构的相互作用,采用非线性弹簧来模拟受损构件局部凹陷损伤,在船舶以不同的速度与平台发生碰撞的情况下,模拟出平台受撞击构件的永久凹陷变形与碰撞接触时间的曲线,反演分析计算了船舶对平台结构碰撞的最大撞击力。为确定受到撞击后导管架平台结构构件和管节点的损伤程度,提出合理可行的修理加固方案提供了分析依据。

On basis of scathing inspected results of some offshore jacket platform with X diagonal brace impacted by the large tonnage Derrick & Lay Barge during installation of steel jacket structures, a numerical simulation analysis for collision process is developed, which cover that establish a static and dynamic analysis model for the ship|platform collision system and analyze the static equivalent intensity for the damaged X diagonal brace of platform structure. In the dynamic elastic-plastic analysis process, the added mass coefficients for the seawater dynamic effective and the pile-soil-structure interaction are considered; a nonlinear spring is introduced for the simulation of the force-deflection relationship of the local indentation for the damaged X diagonal brace, and the curves of indentation deformation of the damaged member versus the collision contact time is simulated under different ship velocity. According to the curves, the formula of indentation deformation of the damaged member and different collision contact time is obtained to determine the maximum impact load. This paper provides the analysis qualifications to evaluate the damage extent and choose feasible and reasonable repairing and strengthening schemes.