A finite element analysis for unbonded flexible risers under torsion

This paper presents a detailed finite-element analysis of unbonded flexible risers. The numerical results are compared to the analytical solutions for various load cases. In the finite-element model, all layers are modeled separately with contact interfaces between each layer. The finite-element model includes the main features of the riser geometry with very little simplifying assumptions made. The numerical model was solved using a fully explicit time-integration scheme implemented in a parallel environment on a 16-processor cluster. The very good agreement found from numerical and analytical comparisons validates the use of our numerical model to provide benchmark solutions against which further detailed investigation will be made.