Sensitivity of Flexibility Monitoring of Offshore Jacket Platforms

Flexibility monitoring is a vibration-based method for simplifying the detection of major underwater damage on offshore jacket platforms. Ambient vibrations are detected at each of the underwater framing levels relative to abovewater vibration in the fundamental sway and torsional modes. Derived are flexibility parameters which relate to the shear flexibilities of each framing bay and of the foundation. Great promise has been shown by laboratory and field testing. This paper presents a comprehensive sensitivity assessment for severance of diagonal members over a wide range of structural redundancy for generic platform configurations.