To facilitate the modelling of the fatigue life of an offshore structure, a methodology based on the Operational Modal Analysis (OMA) is proposed. The idea is to utilize monitoring results as a means to reduce uncertainties associated with structural responses and to take benefit of this information to optimize assets integrity management. In the present work a scaled model of a structure is considered for which the displacements are measured under random excitation. The strains at any point of the model structure are estimated based on OMA and the accuracy is assessed and verified by comparing the estimates with strain gauge measurements. The obtained strains are used to evaluate the equivalent stress range, which is further used to compute fatigue failure probabilities as well as risk estimates. Obtaining information comes at a cost, which is quantified using value of information analysis. The value of information assessment is illustrated through a principal example.
|Title of host publication||8th IOMAC - International Operational Modal Analysis Conference, Proceedings|
|Editors||Sandro D. R. Amador, Rune Brincker, Evangelos I. Katsanos, Manuel Lopez Aenlle, Pelayo Fernandez|
|Number of pages||8|
|Publisher||International Group of Operational Modal Analysis Conference (IOMAC)|
|Publication status||Published - 2019|
|Event||8th International Operational Modal Analysis Conference, IOMAC 2019 - Copengahen, Denmark|
Duration: 13 May 2019 → 15 May 2019
|Conference||8th International Operational Modal Analysis Conference, IOMAC 2019|
|Period||13/05/2019 → 15/05/2019|
|Sponsor||Bruel and Kjaer, Gfai Tech, Siemens, Structural Vibration Solutions|
Bibliographical noteFunding Information:
The authors would like to thank Anders Skafte for sharing and providing input data from experiments in order to evaluate the results achieved in this paper. The authors acknowledge the funding received from Centre for Oil and Gas – DTU/Danish Hydrocarbon Research and Technology Centre (DHRTC).
The authors would like to thank Anders Skafte for sharing and providing input data from experiments in order to evaluate the results achieved in this paper. The authors acknowledge the funding received from Centre for Oil and Gas - DTU/Danish Hydrocarbon Research and Technology Centre (DHRTC).
© 2019 International Group of Operational Modal Analysis.
- Fatigue stress
- Offshore structure
- Value of information