Here’s an interesting Flexcom simulation which illustrates riser “pigtailing” – these are unusual freespans caused by torsion-induced bending. Flexcom is capable of accurately simulating the structural deformation due to its specialised finite element formulation, which fully accounts for coupling between the bending, torsional and axial degrees of freedom. Based on the Flexcom results, both the minimum bend radius and the maximum torque, were found to be within allowable limits. A subsequent slug load fatigue assessment also demonstrated that the predicted fatigue life is also acceptable.
