Journal of Applied Mathematics
Volume 2012 (2012), Article ID 985349, 18 pages
Research Article

Strength Analysis Modelling of Flexible Umbilical Members for Marine Structures

1Division of Structural Engineering, MARINTEK, P.O. Box 4125 Valentinlyst, 7450 Trondheim, Norway
2Department of Marine Technology, NTNU, 7491 Trondheim, Norway

Received 10 February 2012; Accepted 30 April 2012

Academic Editor: Carl M. Larsen

Copyright © 2012 S. Sævik and J. K. Ø. Gjøsteen. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This paper presents a 3-dimensional finite element formulation for predicting the behaviour of complex umbilical cross-sections exposed to loading from tension, torque, internal and external pressure including bending. Helically wound armours and tubes are treated as thin and slender beams formulated within the framework of small strains but large displacements, applying the principle of virtual displacements to obtain finite element equations. Interaction between structural elements is handled by 2- and 3-noded contact elements based on a penalty parameter formulation. The model takes into account a number of features, such as material nonlinearity, gap and friction between individual bodies, and contact with external structures and with a full 3-dimensional description. Numerical studies are presented to validate the model against another model as well as test data.