Parametrically excited vibrations of marine riser under random wave forces and earthquake

Abstract

This article presents theoretical studies for parametrically excited vibrations of marine riser of the floating production, drilling, storage, and offloading system under random wave forces and earthquake excitation. The equation of motion of the riser is obtained by a mathematical method utilizing Euler beam theory and Galerkin method. The trigonometric series method is used to formulate random wave force and earthquake excitation in time domain. The dynamic analysis, spectral response analysis, and key parameters’ sensitivity analysis are conducted for the riser system. Parameter studies are conducted for the effects of wave and earthquake parameters and structural parameters on dynamics response of the riser system. The results from this study can provide valuable recommendations for the design and construction of the parametrically excited marine riser system under random wave forces and earthquake excitation and can promote widely practical application of the deep water riser in complicated environmental conditions.