NDLI: Simplified Model for Evaluation of Fatigue From Vortex Induced Vibrations of Marine Risers

Content Provider	The American Society of Mechanical Engineers (ASME) Digital Collection
Author	Baarholm, Gro Sagli Carl, M. Larsen Lie, Halvor Mo̸rk, Kim Meling, Trond Stokka
Copyright Year	2004
Abstract	This paper presents a novel approach for approximate calculation of the fatigue damage from vortex-induced vibrations (VIV) of marine risers. The method is based on experience from a large number of laboratory tests with models of full-length risers, large-scale tests and also full-scale measurements. The method is intended to provide a conservative result and be used for screening purposes at the early design stage. The model is in particular aimed at predicting fatigue for risers that respond at very high mode orders (above 10), but may as well yield valid results for lower mode numbers. The model will, however, not be adequate for free span pipelines or other structures that normally will respond at first and second mode. The riser will be defined in terms of some key parameters like length, weight, tension, hydrodynamic diameter and stress diameter. A current profile perpendicular to the riser in one plane must be known. The program will apply a simple model for calculation of eigenfrequencies and mode shapes, and these are sorted into in-line (IL) and cross-flow (CF) bins. An effective current velocity and excitation length can be defined from the profile and will be applied to identify the dominating cross-flow response frequency and the total displacement rms value. The dominating in-line response frequency is taken as twice the cross-flow frequency, and inline response rms is taken as a given portion of the cross-flow rms value. A set of contributing modes is defined from an assumed frequency bandwidth that reflects observed bandwidths, but also modal composition for cases with discrete frequency response. A simple mode superposition technique is then used to find the set of modes that gives the identified rms values. Bending stresses will be found directly from the curvature of the mode shapes. Fatigue damage will be found from stress rms values, user defined stress concentration factor and given SN curves. The model has been implemented in a simple computer program and verified by comparing results to measurements. The ambition has not been to obtain an exact match between computed results and observations, but to verify that the model gives reasonable but conservative results in almost all cases. However, an unrealistic over prediction of the fatigue damage is not desired. The results are promising, but the need for more information from measurements and response analyses with programs like VIVANA and SHEAR7 is still obvious.
Sponsorship	Ocean, Offshore, and Arctic Engineering Division
Starting Page	799
Ending Page	806
Page Count	8
File Format	PDF
ISBN	0791837459
DOI	10.1115/OMAE2004-51407
e-ISBN	0791837386
Volume Number	23rd International Conference on Offshore Mechanics and Arctic Engineering, Volume 3
Conference Proceedings	ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering
Language	English
Publisher Date	2004-06-20
Publisher Place	Vancouver, British Columbia, Canada
Access Restriction	Subscribed
Subject Keyword	Stress concentration Bending (stress) Computer software Marine drilling risers Fatigue Stress Displacement Vortex-induced vibration Pipeline risers Mode shapes Design Cross-flow Free spanning pipelines Weight (mass) Frequency response Tension Excitation Risers (casting) Fatigue damage
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

An Empirical Procedure for Fatigue Damage Estimation in Instrumented Risers

Experimental Study on Flexible Bare Pipe Arrays Undergoing Vortex-Induced Vibrations

Effect of Higher Stress Harmonics and Spectral Width on Fatigue Damage of Marine Risers

Calculation of In-Line Vortex Induced Vibrations of Free Spanning Pipelines

Efficient Modal Decomposition and Reconstruction of Riser Response due to VIV

Re-Evaluation of VIV Riser Fatigue Damage

Influence From Helical Strakes on Vortex Induced Vibrations and Static Deflection of Drilling Risers

On Determination of VIV Coefficients Under Shear Flow Condition

Fatigue Analysis of Free Spanning Pipelines Subjected to Vortex Induced Vibrations

Simplified Model for Evaluation of Fatigue From Vortex Induced Vibrations of Marine Risers

Similar Documents

An Empirical Procedure for Fatigue Damage Estimation in Instrumented Risers

Experimental Study on Flexible Bare Pipe Arrays Undergoing Vortex-Induced Vibrations

Effect of Higher Stress Harmonics and Spectral Width on Fatigue Damage of Marine Risers

Calculation of In-Line Vortex Induced Vibrations of Free Spanning Pipelines

Efficient Modal Decomposition and Reconstruction of Riser Response due to VIV

Re-Evaluation of VIV Riser Fatigue Damage

Influence From Helical Strakes on Vortex Induced Vibrations and Static Deflection of Drilling Risers

On Determination of VIV Coefficients Under Shear Flow Condition

Fatigue Analysis of Free Spanning Pipelines Subjected to Vortex Induced Vibrations

Simplified Model for Evaluation of Fatigue From Vortex Induced Vibrations of Marine Risers