With the need to extend the economic life of Offshore Platforms, the structural integrity of offshore Structures is attracting significant interest. This paper presents information on a study to investigate the effectiveness of Acoustic Emission Continuous Monitoring of critical welds within these structures for crack propagation. Signal interpretation is investigated and noise rejection techniques evaluated as effective. The benefits of using strain gauge data to correlate against Acoustic Emission data is also discussed. Advantages of Continuous Monitoring for Acoustic Emission from crack propagation is compared to conventional periodic inspection regimes.
Data will be presented on a laboratory case study for using Remote Monitoring of Acoustic Emission as a method of extending the safe working life of offshore platforms. Included in this software reporting alarms were functionally tested and evaluated as part of the Acoustic Emission monitoring strategy and suitable Acoustic Emission equipment and associated software were functionality checked and evaluated.
Active corrosion on storage tank floors gives rise to acoustic emission. The acoustic emission may be detected from the outside of the tank wall while the tank is full of product. The data can be interpreted to evaluate the extent of corrosion on the tank floor and this information can assist in the decision to defer entry or to schedule an internal inspection. This study looks at common noise sources commonly present during these surveys and how to identify them. The most common problem with acoustic emission tank floor testing is the unidentified noise in the data contributing to an inaccurate result. EN 15856:2010 ‘General principles of AE testing for detection of corrosion within metallic surrounding filled with liquid’, is applicable to metallic storage tanks but here is very little content about noise sources. A good knowledge of common noise sources can allow testing in noisy environments with accurate results.