HiTeAM – High Tech Acoustic Monitoring

Acoustic Emission Condition Monitoring of Higly-loaded Low-speed Bearings

HiTeAM is a multiple-phase Joint Industry Project (JIP) aiming at development and validation of a reliable quantitative method for condition monitoring of highly-loaded low-speed roller bearings. Notable applications of these bearings in offshore structures include (i) sheave blocks of offshore heavy-lifting cranes, (ii) turret mooring systems of Floating Production Storage and Offloading (FPSO) vessels, Floating Storage Regasification Units (FSRU), Floating Liquefied Natural Gas (FLNG) vessels, and (iii) turntables of deep- and shallow-water buoy or tower mooring and offloading systems.

The main objectives of this research program are: (i) early-stage identification and classification of damage, and (ii) maximizing the Probability of Detection (PoD) while preventing troublesome false alarms.

In the prior art, proposing non-intrusive assessment of highly-loaded low-speed bearings, substantial research can be found on vibration monitoring techniques. Despite their promising features such as low-cost and straight-forward application, vibration-based methods still exhibit shortcomings in early-stage and robust identification of damage, partly due to their low-frequency nature.

In order to alleviate the abovementioned issues, recent trends have involved mid- and high-frequency Acoustic Emission (AE), i.e. on-line acquisition and analysis of the elastic stress waves released by development of the defects. To date however, the complexities of the bearing geometry, contact and boundary conditions, loading conditions, and furthermore their insufficiently-understood effects on the AE signals have not allowed a successful implementation of the method. These topics will be methodically investigated and addressed in HiTeAM.