Production TTR modeling and dynamic buckling analysis

In the process of a Production TTR design, it was found that its outer casing could be subjected to compression in a worst-case scenario with some extreme metocean and hardware conditions. The present paper shows how FEA models using beam elements and two different software packages (Flexcom and ABAQUS) were constructed to simulate the TTR properly, especially the pipe-in-pipe effects. An ABAQUS model with hybrid elements (beam elements globally shell elements locally) can be used to investigate how the outer casing behaves under compression. It was shown for the specified TTR design, even with its outer casing being under some local compression in the worst-case scenario, dynamic buckling would not occur therefore the TTR design was adequate.