Analysis of wave slam induced hull vibrations using continuous wavelet transforms

Large high-speed wave-piercing catamarans are subject to continuous wave induced hull vibrations during their lifetime of operation. In severe sea conditions, the vessel experiences high load impacts, known as slamming, accompanied by high frequency structural response giving rise to fatigue effects. Classical vibration analysis techniques such as the Fourier Transform fail to identify the exact response frequencies of slamming events due to the transformation to the frequency domain and the loss of temporal information about these transient events which is of great importance to fatigue analysis. The work presented in this paper introduces, describes, applies and recommends the continuous wavelet transform as an effective means to investigate the wave induced hull vibrations in both the time and frequency domains simultaneously.

► Continuous wavelet transform (CWT) is used to investigate transient slamming events. ► CWT can investigate slamming events in time and frequency domain simultaneously. ► CWT is capable of interpreting complex events that involve more than one impact. ► CWT has flexibility to focus on temporal and frequency analysis individually.