Experimental and numerical study of structural behavior of a flexible riser model

Experimental tests and detailed finite element analyses were carried out on a model of flexible riser to evaluate the capability of the finite element method to predict its nonlinear structural response. The riser consists of four layers, which include two cylindrical polycarbonate tubes and two steel helical layers. One helical layer represents the carcass layer in a flexible riser whilst the other represents the riser tendon armour layer. First, bending load experiments on the model are described which provide some insight regarding the fundamental behavior of flexible pipe structures. This is followed by the description of the FE models in which all layer components are individually modelled and a surface-to-surface frictional contact model is used to simulate their interaction. Finally, the FE numerical results were compared with the test data to outline the capacity of the numerical method to predict the response of flexible riser structures.