Theoretical and experimental studies of the axisymmetric behaviour of complex umbilical cross-sections

This paper presents a finite element formulation for predicting the behaviour of complex umbilical cross-sections exposed to loading from tension, torque, internal and external pressure and external contact bodies. Helically wound armours and tubulars are formulated by a combination of curved beam kinematics, thin shell theory and the principle of virtual displacements to obtain finite element equations. Interaction between structural elements is handled by a penalty parameter contact formulation. The model takes into account a number of features, such as material non-linearity, gap between individual bodies, hoop response of tubulars due to contact effects and it may be applied to both cross-section design and verification. Experimental studies are presented to validate the axisymmetric performance of the model.