Tension leg platforms (TLP's) are highly nonlinear due to large structural displacements and fluid motionstructure
interaction. Therefore, the nonlinear dynamic response of TLP’s under hydrodynamic wave loading is necessary
to determine their deformations and dynamic characteristics. In this paper, a numerical study using modified Morison
Equation was carried out in the time domain to investigate the influence of nonlinearities due to hydrodynamic forces and
the coupling effect between all degrees of freedom on the dynamic behavior of a TLP. The stiffness of the TLP was
derived from a combination of hydrostatic restoring forces and restoring forces due to cables and the nonlinear equations of
motion were solved utilizing Newmark’s beta integration scheme. The effect of wave characteristics was considered.