VIV Assessment of Rigid Jumper Systems- A Comparative Study on Jumper Shapes

摘要

Rigid jumper systems are increasingly being used in subsea fielddevelopments. They provide interface between subsea structures andare required to accommodate significant static and dynamic loads. Theability of the jumper system to handle these loads depends on its length,size, material as well as the geometry (shape) of the system. For a givensize, the shape of the jumper system introduces additional tolerance toend displacement. For example, M shaped jumper systems have higherdisplacement tolerances than a free span and U shaped systems. Eventhough the complex jumper systems (U shaped, M shaped and Z shapedjumper systems) are advantageous with regard to the displacementtolerance, they also bring unique challenges of their own such as intheir VIV fatigue damage assessment. There are limited studies onthese complex jumper systems.This paper presents a comparative study of modal contributions to VIVfatigue damage for jumper systems of various shapes (Free span, Ushaped, M shaped and Z shaped) but with the same length andstructural properties.The study follows a structured approach in understanding the gaps inthe current damage assessment method as applied for complex jumpersystems. Comparison of fatigue damage due to the modal differences isa first step in this direction.