On the extreme response of heave-excited flexible risers

The focus of this paper is on the development of a high effective practical approach to assess the short-term extreme response statistics of flexible risers excited by the first-order heave motion of a floating unit. The extr eme response statistics is obtained by fitting a probability distribution d irectly to a sample of extreme response values. Each sample is obtained thr ough the analysis of a short-time window of a heave motion realization that encompasses the instant when the extreme response takes place. The locatio n of this window is determined with the help of a time-dependent nonlinear transfer function relating the response to the excitation. The analyses of three different flexible risers configurations illustrate the accuracy and the robustness of this approach to calculate the extreme response statistic s. (C) 2000 Elsevier Science Ltd. All rights reserved.