基于ABAQUS串列立管碰撞的有限元分析

Finite element analysis on the collision between serial risers by using ABAQUS software

以两串列立管碰撞为研究对象,运用有限元分析软件ABAQUS,考虑水耦合作用研究串列立管的局部碰撞行为。通过模拟立管碰撞前的静态弯曲和动态碰撞过程,将静态分析的结果导入动态分析步中,从单一因素方面分析碰撞速度、立管夹角、内压对立管碰撞应力的影响,并将考虑水耦合作用和不考虑水耦合作用的应力变化情况进行了对比分析。结果表明:在给定工况下,两立管发生多次碰撞,考虑水耦合作用时,立管碰撞产生的应力较小。在分别考虑和不考虑水耦合时,碰撞速度、夹角、内压对立管应力变化的影响是不同的,初始碰撞产生的应力随碰撞速度的增大而增大,存在某一适当的夹角和内压值,使立管较为安全,可以避免立管遭受撞击而发生破坏,为立管群的排列布置提供参考。

The collision between serial risers was studied using the restart analysis of finite element software ABAQUS to consider the coupling effect between the water and risers. In the study, the results of the static bending analysis were input into the dynamic analysis. The collision behavior between adjacent risers was analyzed under the situations with and without considering the riser-water coupling effect and the influences of single factors, such as the velocity, angle, and internal pressure were discussed. The stress responses in the collision process of adjacent risers were obtained. The results show that multiple times of collisions may happen between two serial risers under the given cases, and the stresses with considering the riser-water coupling are smaller than those without considering the coupling. The effects of impact velocity, angles and internal pressure on the stresses are different under the situations with and without considering the coupling. The stresses induced by the first collision increase with the increase of impact velocity. The results show that risers are safer when they are subjected to a certain internal pressure compared to bare risers. When the impact angle is 45 degree, the maximum stress is lower. Therefore, there are proper values of angle and internal pressure for the riser's safety. The results provide a reference to the arrangement of risers group to avoid collision damage. © 2017, Editorial Office of Journal of Vibration and Shock. All right reserved.