Flexible risers are exposed to complicated loading conditions including internal/external pressure, wave and current loads, as well as floater movements. The combination of these three loads may lead to instability of the tensile armor wire in both longitudinal and transverse directions, which may result in different stress state based on different numerical models in BFLEX software. Simplified models have been implemented to calculate the stress in tensile armor wires with moderate accuracy, with only considering the longitudinal slip of wires.
In order to investigate how the transverse slip will influence the stress state, a full finite element (FullFE) modeling option has been implemented recently to capture the interaction between different layers more precisely thus giving more accurate stress prediction. Different stress components will be compared with already existing simplified approaches. In addition, geodesic and loxodromic slip assumptions will be applied to study the slip behavior of the tensile armor layers.