TANK TEST OF FLEXIBLE ACRYLIC SHIP MODEL IN WAVES FOR EXTREME RESPONSE PREDICTION

In this study, the Most Probable Wave Episodes (MPWEs) for given target Vertical Bending Moments (VBMs) are estimated considering the nonlinearities in the wave and VBM, and the tank tests using a flexible acrylic ship model in the MPWEs are carried out to discuss the effect of body nonlinearity in VBMs on the MPWEs. Although whipping was not considered in this study, this is the first study on MPWEs that considers the body nonlinearity in VBMs in addition to wave nonlinearity. The nonlinearity in waves is considered by using the Higher Order Spectral Method (HOSM), while the body nonlinearity including slamming forces in the VBM is considered by a simplified model incorporating nonlinear correction factors together with the transfer function (TF) of VBM. The MPWEs are estimated by using the HOSM and First Order Reliability Method (FORM), in combination with the simplified VBM model. The VBM nonlinear effects on the HOSM+FORM results are discussed by using the tank test results in MPWEs.