Research on time-domain dynamic analysis method for self-elevating drilling units

A self-elevating drilling unit, with its particular structure, shows obvious dynamic characteristics under wind, wave and current. In the traditional dynamic analysis method, the dynamic amplification are often from a single-DOF approach or frequency domain dynamic analysis. In this paper, a dynamic analysis method of a jack-up unit under combinations of wave and current is proposed, the interface technology between MSC/Patran Nastran and the Morison force calculation program is developed to perform the automatic application of wave loads and the dynamic analysis under both regular wave and irregular wave are carried out. Based on the simulation results, further discussion and study is performed on the influence of the wave parameter on the dynamic amplification.