Finite Element Modeling of Flexible Pipes Under Crushing Loads

The launching procedure can be one of the most critical stages of the operational lifetime of a flexible pipe. From the beginning of the pipe unrolling off the reel to the moment of its separation from the launching vessel, the flexible pipe is subjected to severe loads such as crushing and tension. This paper focuses on the crushing load applied to the flexible riser by the shoes of the caterpillars on the launching vessel. The objective is to present an effective methodology to evaluate the stresses at the structural nucleus of a flexible pipe during launching using the Finite Element Method. Firstly, a tridimensional ring model is used to represent the structural nucleus of the flexible pipe. In that model, the geometry of the interlocked carcass and the pressure armor is accurately represented. Then, similar models are constructed including a series of geometry simplifications. Those simplified models are compared to the baseline in order to evaluate the relevancy of an accurate representation of the geometry of the metallic layers. The results of these comparisons are presented and discussed.Copyright © 2013 by ASME