Abstract
Design rules for very large seagoing vessels are undergoing changes owing to the hydroelasticity of the ship. The hydroelasticity of the ship is in the form of wave-induced vibrations such as springing and whipping, which are known to aggravate fatigue and extreme loads. The present study deals with a method for the estimation of extreme loads. The method consists of a preliminary analysis of linear responses of motions and loads, and a sequential analysis of the nonlinear extreme load. First, a full-time series of the linear response is obtained using response amplitude operators and wave spectra. Next, the candidate waves of extreme event are extracted from the full-time series based on the linear response. The linear response may be a motion or a load depending on the target value of the sequential analysis. Finally, the sequential analysis is conducted using a fully coupled model of the three-dimensional Rankine panel method, three-dimensional finite-element method, and two-dimensional generalized Wagner model with the candidate waves. The method is validated for a nonlinear hogging moment in a short-term sea state and applied for a long-term prediction of an extreme hogging moment on an ultra-large containership. The extreme values of linear and nonlinear loads are compared in terms of the most probable value and probabilistic distribution.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call