Fatigue Assessment of Flare Foundations on FPSO Structure

Ozgur Ozguc

Abstract

This paper addresses the fatigue analysis results of the new-built FPSO’s flare tower foundations and associated the hull which is supporting the four cylindrical legs of the flare. Flare foundation is checked for fatigue resistance both in “towing” and “on site” conditions. The fatigue design of the flare supporting structure is to take into account the inertia loads due to wave motions in towing and on site, but also the effect of wind loads. Wind load calculations are based on wind site scatter diagram and dynamic wind spectrum. Calculated fatigue damages, i.e., wave load-induced and wind load-induced damages are combined together considering average frequency of each load component to give final fatigue damage. Calculated fatigue damages including the wind-induced damage for each loading condition are also summarized. Conclusively, it is confirmed that the foundations of flare tower have enough fatigue strength against wave and wind induced loads. Keywords: Fatigue design, flare tower foundation, FPSO, hotspot stress S-N curve Cite this Article Ozguc Ozgur. Fatigue assessment of flare foundations on FPSO structure. Journal of Offshore Structure and Technology. 2015; 2(2): 1–18p.