Stochastic response of jack-up platform by the method of statistical quadratization

Abstract

The use of jack-up platforms in deeper water leads to their response statistics becoming more sensitive to nonlinear drag loading from waves and current and to them deviating from Gaussian assumptions. To study the significance of these effects, the method of statistical quadratization is developed in this paper. The solution is based on the Volterra series approach and computation is done in the frequency domain. An efficient scheme was implemented for the Volterra series solution. As an extension to previous studies, the response kurtosis is also estimated using the statistical quadratization method. The results (i.e. response mean, variance, skewness and kurtosis) are compared with those obtained by both the equivalent linearization method and simulation. It is shown that the statistical quadratization method provides a notable improvement over the statistical linearization method. © 1994.