基于整体海洋平台模型的下落物体撞击数值仿真

Simulation of impact load based on finite element model of offshore platform

针对海洋平台受落物撞击后的性能进行研究,采用非线性有限元数值仿真方法,探讨了落物撞击模型的建模技术和参数选取,建立了整体海洋平台模型,对落物与平台的撞击进行了数值仿真,并分析了撞击全过程,得出下落物体撞击海洋平台过程中关于碰撞力、结构损伤变形及能量转换等的一般性规律。主要结论如下:海洋平台结构的碰撞损伤变形主要表现为弹性变形,绝大部分塑性变形发生在撞击区域;海洋平台整体具有较好的弹性变形性能,能够降低下落物体撞击引起的结构损伤;建模时必须建立整个海洋平台模型,以充分体现平台结构的整体性能。

According to the behavior of offshore platform under impact load, nonlinear finite element method was adopted. The techniques of establishing model and the selecton of parameters in the model of dropped object-offshore platform impact were discussed. The whole offshore platform was established with the process discussed. The characteristics and conclusions of impact force, structural damage and energy transformation of fallen objects were investigated. The results show that the main deformation of the platform is elastic, that most of the plastic deformation concentrates at the impacted area of the platform and that the offshore platform has better flexibility which can reduce the damage of impact. Therefore, the platform should be built up completely so as to reflect the whole performance.