Inverse vibration technique for structural health monitoring of offshore jacket platforms

Haeri, M. H ; Sharif University of Technology | 2017

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  1. Type of Document: Article
  2. DOI: 10.1016/j.apor.2016.11.010
  3. Publisher: Elsevier Ltd , 2017
  4. Abstract:
  5. In this paper a new approach is introduced for structural health monitoring of offshore jacket platforms. The procedure uses the measured ambient vibration responses and the corresponding readable natural frequencies and mode shapes of the structural system. Since offshore platforms are composed of heavy topsides supported by jacket structures, participation of the first mode is dominant in each direction in the response of the structure under field excitations. Moreover, ambient vibrations such as wave loads and boat impacts only excite the first modes of the structure. Therefore, it is difficult to find higher modes and the pertinent frequencies by use of accelerometers data. The introduced innovative method in this research uses the first few fundamental frequencies and mode shapes of the structure. The algorithm employs the inverse vibration technique to develop a simple two and three dimensional reference model for monitoring health of the structure. To show the efficiency of the proposed procedure, a case study is carried out on the models of a jacket-type platform in the Persian Gulf, namely SPD2. Finally, an uncertainty analysis is performed, due to the existence of noises and uncertainties in input data collected by accelerometers. Results indicate that the proposed method has the ability to detect the induced damages by a high level of accuracy considering probable sources of error. © 2016 Elsevier Ltd
  6. Keywords:
  7. Inverse vibration problem ; Offshore jacket platforms ; Structural health monitoring ; Uncertainty analysis ; Accelerometers ; Drilling platforms ; Inverse problems ; Natural frequencies ; Offshore structures ; Three dimensional computer graphics ; Vibration analysis ; Ambient vibrations ; Dimensional reference ; Fundamental frequencies ; Natural frequencies and modes ; Off shore platforms ; Offshore jackets ; Structural systems ; Health monitoring ; Inverse problem ; Steel jacket platform ; Vibration ; Arabian Sea ; Indian Ocean ; Persian Gulf
  8. Source: Applied Ocean Research ; Volume 62 , 2017 , Pages 181-198 ; 01411187 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/pii/S0141118716301249