A numerical study on slow-drift motion and wave-in-deck impact event of a tension leg platform in extreme waves

Abstract

Wave-in-deck impacts in extreme waves can cause a serious damage on both fixed and floating offshore structures. In particular, tension leg platform (TLP) can be exposed to frequent wave-in-deck impact events due to good vertical motion performances as well as wave amplifications inside columns. In this study, the wave-in-deck impact event as well as slow-drift motion response of a tension leg platform are numerically investigated. First, the experimental observations of the wave-in-deck events are suggested based on the model tests of a TLP, where the extreme waves of 100-year and 1, 000 year return periods were tested. Both weak and strong wave-in-deck events are described in detail. Then, time-domain simulations were carried out to predict the motion responses of the TLP and wave-in-deck events. Appropriate numerical modeling is suggested to simulate the TLP motion responses. The numerical prediction results are directly compared with the model test data. Discussion is made on the appropriate numerical modeling for the prediction of the wave-in-deck impact event. ？ Copyright 2017 ASME.