Investigation into non-linear bending of elastic bars with application to design of bend stiffeners

The objective of this paper is to examine non-linear bending of a flexible elastic bar near fixed termination and to develop analytical solutions that can be used in the design of bend stiffeners. The non-linear bending of prismatic bars of finite and se-infinite lengths is solved analytically, and results are employed to re-visit the problem of the “ideal” bend stiffener, which provides a constant curvature over its entire length. A complete solution is derived for all properties of the ideal bend stiffener, which is not limited by any assumptions on the system geometry and provides an improvement over known formulations. Other features of the non-linear bending of elastic bars are examined and examples are given to demonstrate application of the present theory to sizing bend stiffeners for flexible risers.

► Analytical solution for bending of a cantilevered elastic bar by force and moment.
► Analytical solution for bending of a semi-infinite elastic bar by tension force.
► Complete non-linear solution for “ideal” bend stiffener.
► Allowable tension–angle curve for the elastic flexible pipe.
► A method for modelling finite bending stiffness near fixed termination in global riser analysis.