The detection of wave slamming from vibration measurements on a polar supply and research vessel

Abstract

The SA Agulhas II is a polar supply and research vessel, which operates in the stormy Southern ocean and icy Antarctic waters. She is predisposed to problematic stern slamming. Twelve accelerometer channels from a full-scale vibration measurement system were used to capture measurements of wave incidence on the main deck close to the water line. An automated slamming detection and classification algorithm is proposed to extract slamming incidents from expansive full-scale data. This method is based on image processing of scalograms which are produced by continuous transforms, using the Morlet wavelet. Slams are classified based on the time of incidence. It is shown that high crest factor stern slamming occurs as often as twice per minute.