Title of article :
Cross-Flow Vortex Induced Vibration Fatigue Analysis of Persian South Gas Field Subsea Pipelines Due to Multi-Spanning
Author/Authors :
shabani, Mahdi M.Sc. student of Petroleum University of technology - department of offshore engineering , taheri, Abdolrahim Assistant- Prof. of civil Petroleum University of technology - department of offshore engineering
Abstract :
Free-span in subsea pipelines occur at manmade supports, uneven seabed or
pipeline crossing. Free spanning may induce pipeline vibration due to vortex
shedding which makes pipeline susceptible to some failures such as fatigue,
fracture, etc. Free spanning analysis is an important subject because fatigue is
the most effective factor in reducing the pipeline design life. Free spanning
analysis includes static analysis and dynamic analysis.
DNV-RP-F105 suggests a methodology of dynamic analysis for long pipeline
with multi-mode responses, but the fatigue analysis method for multi-modes is
not detailed. In addition, the fatigue analysis of multi-spanning pipeline is not
clear. Based on the methodology of DNV-RP-F105 fatigue life relates to
natural frequencies of pipeline, the method of determination of effective
natural frequencies still is not clear.
In this paper, a fatigue analysis for multi-spanning pipeline in Persian south
gas field is performed based on VIV analysis. ABAQUS FE model is
developed to obtain the stress distribution and the natural frequency of each
vibration mode for spanning pipeline on seabed with three multi-spans, then
the fatigue analysis of VIV is carried out for the spanning pipeline based on
DNV-RP-F105.
Keywords :
subsea pipelines , fatigue analysis , natural frequency , multi spanning , vortex shedding
Journal title :
Astroparticle Physics
