Application of two damage detection techniques to an offshore platform

In the petroleum industry one fundamental problem which must be addressed is the condition monitoring of structure of offshore platforms. Maintenance checks of the legs may be performed by under-water inspection but usually this damage detection procedure is expensive and time-consuming. Vibration-based inspection of offshore platforms has been an area of active research for the past 30 years. The techniques deal with natural frequency and dynamic response variation, but usually they are not capable of distinguishing between a change in the operating condition and the onset of structural damage. This paper compares results of the application to simulated data of a typical offshore structure using two recently proposed methods, a novelty detection method and a SVD-based technique both capable of dealing with dynamic behaviour variations induced by changes in the operational condition.