Fatigue is an important consideration for your offshore structures. Our work processes will insure your needed structural integrity during the whole life cycle.
Effective inspection and maintenance
Fatigue estimates are uncertain and the actual fatigue capacities are very sensitive to detail design and fabrication quality. To address this, we take on a probabilistic fracture mechanics approach. This will ensure the effect of your inspection and maintenance. This method also allows treatment of the interaction between design, inspection, maintenance and repair requirements. The fatigue potential is expressed by the probability for a fatigue failure or reliability against a fatigue failure.
Our 12 main work processes
- Collection and loading of the operation history and estimation of the FUI-index.
- Collection and loading of the history of structural analyses.
- Collection and loading of the history of inspection and modifications.
- Establishment of the master identification system – Inspection drawings and hot spot definitions.
- Interpretation of the historical inspection and modification history and loading of hot spot specific data.
- Interpretation of the structural analyses results i.e. detailed review of the FLS analyses, generally review of ULS and ALS and loading of the hot spot specific FLS design analyses results.
- Collection and loading of the hot spot specific As-Is description.
- Re-assessment of the design fatigue life estimate by selection of SCF and SN-curve based on the As-Is description and review of FEM analyses and SCF/stress intensity descriptions given in RP, guidelines and research publications.
- Establish crack dossier and judge the cracks to be fabrication or fatigue cracks.
- Assemble the inspection, modification and repair history for each hot spot.
- Combine the re-assessed fatigue life estimate and the assembled inspection, modification and repair history for each hot spot, to give a recommended inspection scheduling based on the SRA-technique.
- Identify and recommend activities for assessment of improvements and give scheduled program for improvements only requiring documentation, not requiring additional analyses.