Vortex Induced Vibration (VIV) analysis of risers using time domain Finite Element Analysis (FEA) captures nonlinearity in the system. Such non-linearity may be in the form of boundary conditions or the imposed loadings. Riser VIV analysis using a frequency domain code has to linearize the system, such as imposing linearized boundary conditions.
Non-linear boundary conditions for steel catenary riser (SCR) could be in the SCR-soil interaction and in the hang-off system. An SCR is often supported by a flex joint that has non-linear rotational stiffness. The effect of these non-linear boundary conditions in SCR VIV response is investigated in this paper.
In addition, the effect of the directions of current profiles with respect to the riser on the SCR VIV response is also investigated. Comparison to standard industry practice, that is applying currents either in the plane or normal to the plane of the SCR, is presented.
Time domain VIV code SimVIV coupled with FEA code ABAQUS was used in the analysis.