Stochastic response of tension leg platform to wave and current forces

Abstract

The linear analysis in the frequency domain is presented for the surge motion of a tension leg platform (TLP) in the case of random waves only and random waves with constant current. A single-degree-of-freedom model of a TLP is employed for response, A simulation technique for determining the exact response statistics of nonlinear structural systems is developed in the time history. The superposition method, one of the simulation techniques, is applied to random sea wave with current, and the response analysis of TLP in time is developed with wave velocity and wave acceleration simulations.

Wave force is calculated using the modified Morison equation. The relative velocity due to the wave particle movement and the TLP movement is considered in both analyses. Current velocity that has a horizontal profile is applied for the model. The effect of wave-current interactions on the response analysis of TLP is examined.

Computational methods for both analyses are developed, and the results of stochastic, dynamic response of the TLP, with and without the presence of current, are discussed.