Modal decomposition and reconstruction (MDR) of marine riser vortex induced vibration (VIV) is a technique where vibration is measured using accelerometers and/or angular rate sensors, the modal displacements are solved for and the stress and fatigue damage is reconstructed along the riser. Recent developments have greatly increased the accuracy and reliability of the method. However the computational burden is onerous due to stress time history reconstruction and rainflow cycle counting at every desired location along the riser. In addition, fully synchronous data are required to reconstruct the stress histories. Dirlik’s method for obtaining rainflow damage for Gaussian random stress using only spectral information (four spectral automoments) has proven to be quite accurate with a significant reduction in computational effort. In this paper two spectral formulations of MDR are introduced. The first method is applicable when all the measured data are synchronous. In this method, spectral cross moments of the modal displacements are solved from the spectral cross moments of the measured data using basis vectors consisting of normal mode shapes. The spectral automoments of stress are obtained from the modal displacement cross moments and analytical stress mode shapes. Dirlik’s method is then applied to obtain rainflow damage. The second method is a generalization of the first, where the measured data cross moments are only partially known. This method is applicable when measured data are partially synchronous or asynchronous. A numerical root-finding technique is employed to solve for the modal response cross moments. The method then proceeds in the same manner as the first. The spectral methods are applied to simulated VIV data of a full-scale deepwater riser and to Norwegian Deepwater Program (NDP) scale-model test data on a 38 m long slender riser. Comparisons of reconstructed fatigue damage versus simulated or measured damage indicate that the method is capable of estimating fatigue damage accurately for Gaussian VIV even when data are not fully synchronous. It is also shown that computational cost is greatly reduced.
Skip Nav Destination
Article navigation
November 2012
Structures and Safety Reliability
Spectral Formulations for Vortex Induced Vibration Modal Decomposition and Reconstruction
S. I. McNeill
S. I. McNeill
Stress Engineering Services, Inc., 13610 Westland East Blvd.,
Houston, TX 77041
Search for other works by this author on:
S. I. McNeill
Stress Engineering Services, Inc., 13610 Westland East Blvd.,
Houston, TX 77041J. Offshore Mech. Arct. Eng. Nov 2012, 134(4): 041601 (8 pages)
Published Online: May 31, 2012
Article history
Received:
February 9, 2011
Revised:
November 8, 2011
Published:
May 30, 2012
Online:
May 31, 2012
Citation
McNeill, S. I. (May 31, 2012). "Spectral Formulations for Vortex Induced Vibration Modal Decomposition and Reconstruction." ASME. J. Offshore Mech. Arct. Eng. November 2012; 134(4): 041601. https://doi.org/10.1115/1.4006147
Download citation file:
54
Views
Get Email Alerts
Cited By
Automatic Clustering of Metocean Conditions on the Brazilian Coast
J. Offshore Mech. Arct. Eng (August 2023)
Assessment of the Hydrodynamic Performance of an Oscillating Water Column Device in Front of a V-Shaped Vertical Wall
J. Offshore Mech. Arct. Eng (October 2023)
ANALYZING EXTREME SEA STATE CONDITIONS BY TIME-SERIES SIMULATION ACCOUNTING FOR SEASONALITY
J. Offshore Mech. Arct. Eng
Mitigation of Wave Impact on Sea Wall by a Floating Elastic Plate and a Porous Structure
J. Offshore Mech. Arct. Eng
Related Articles
An Empirical Procedure for Fatigue Damage Estimation in Instrumented Risers
J. Offshore Mech. Arct. Eng (June,2017)
Characteristic Analysis of VIV-Induced Fatigue Damage of Top Tensioned Risers Based on Simplified Model
J. Offshore Mech. Arct. Eng (May,2011)
Simulating High-Mode Vortex-Induced Vibration of a Riser in Linearly Sheared Current Using an Empirical Time-Domain Model
J. Offshore Mech. Arct. Eng (August,2021)
Prediction of Combined Inline and Crossflow Vortex-Induced Vibrations Response of Deepwater Risers
J. Offshore Mech. Arct. Eng (August,2019)
Related Proceedings Papers
Related Chapters
Production Riser Life Extension – A Class Perspective
Ageing and Life Extension of Offshore Facilities
Transverse Free Vibration Analysis of Hybrid SPR Steel Joints
Proceedings of the 2010 International Conference on Mechanical, Industrial, and Manufacturing Technologies (MIMT 2010)
Case Study 10: Data Reconciliation
Engineering Optimization: Applications, Methods, and Analysis