Non-linear inertial loading and the onset of structural ringing

With an increasing trend towards deep water production, the susceptibility of offshore structures to dynamic response has become an important issue. Indeed, this has been bough to the forefront by a new response phenomenon, commonly referred to as ‘ringing’, which is thought to be associated with steep near-braking waves. At present, neither the occurrence of ‘ringing’ or the mechanisms which produce this high frequency transient response are fully understood. In particular, current design solutions, which employ linear-based predictions, are unable to account for the observed behaviour.