Abstract: The hydropneumatic tensioner used for the connection of deepwater platform and top tension risers (TTRs) was studied based on the hull/mooring/riser coupled analysis program developed in ABAQUS. The present study focused on the challenges for the tensioner numerical simulation, and proposed a nonlinear tensioner model considering the nonlinear stiffness, friction and the connection of platform, tensioner and TTR. The tensioner is simplified as a linear model, and the predicted responses are compared with that of nonlinear model, from which the effect of nonlinearity on the risers and platform is obtained, which would contribute to more accurate predicted ultimate strength and fatigue life.

Key words: full coupled model, hydropneumatic tensioner, strokes, nonlinear stiffness, friction effect