Flexible Riser Fatigue Analysis: Studying Conservatism in Flexible Riser Fatigue Analysis and Development of an Engineering Model to Study Influencing Parameters of Local Wire Stress

Flexible Riser Fatigue Analysis: Studying Conservatism in Flexible Riser Fatigue Analysis and Development of an Engineering Model to Study Influencing Parameters of Local Wire Stress

Nugteren, F.A.

Kaminski, M.L. (mentor)

Mechanical, Maritime and Materials Engineering

Ship & Offshore Structures

Offshore Engineering

2015-05-12

First, the focus of a literature review was on industry visions and fatigue life assessments. Hence fatigue analysis methodology —with a special focus on local modelling— was thoroughly investigated because this is the Shell and industry accepted method to define and assess fatigue life. Secondly, a new strategy was developed to stretch the fatigue life after identifying a significant in-field changed condition. This guideline incorporates in-house analysis activities to enhance the collaboration with specialist consultants. Changed environmental and operational conditions should be incorporated in the fatigue analysis within the limits of fixed geometry parameters. A local model captivates the direct influence on stress levels in the fatigue-critical tensile armour wires as a result of these new conditions. For the purpose of doing a pre-analysis independently, a new in-house analytical model was developed: ABC Fatigue. Finally, a benchmark case-study illustrates the purpose, methodology and conclusions of such preanalysis by analysing a typical flexible riser designed for North-Sea environmental conditions.

fatigue analysis
flexible risers
local analysis
wire stress

http://resolver.tudelft.nl/uuid:80488024-c2be-4601-832f-050811e5736a

Student theses

master thesis

(c) 2015 Nugteren, F.A.