1976 · 15 citations · 0 references
EngineeringMarine EngineeringOcean EngineeringOffshore EngineeringOffshore StructuresVibrationIntegrity MonitoringStructural VibrationVibration AnalysisVibration MeasurementVibration MonitoringWind-induced VibrationIntegrity Monitoring SystemsOffshore Structure InspectionPrimary InspectionStructural Analysis Of Offshore PlatformsStructural InspectionVibration Signature AnalysisVibration-based InspectionVibration-based Monitoring
Offshore structures vibrate under the action of the sea, wind and on board machinery. The response is most marked at the natural frequencies of these structures which are dependent on the geometry, stiffness and mass of the structure and are independent of the excitation. Measurements of the responses of three platforms in the North Sea have been made over a period of nine months. Each platform has produced a unique signature which has remained constant within prescribed limits. Failure of any structural member in the platform will produce a change in the signature and changes of greater than 15% have been measured when minor modifications were made to one of the test platforms. This vibration analysis technique for the monitoring of offshore structures as a primary inspection aid is both technically feasible and practically possible.