Natural vibration analysis of tensioned risers by segmentation method

Abstract

The natural vibration of deepwater Pensioned uniform risers is analysed. The riser is considered as both a cable and a beam due to the fairly weak flexural stiffness. The exact and asymptotic solutions of the cable differential equation are presented. The beam vibration is determined by modifying the cable solution for each half-wave of the natural mode which are called segments. The simplified analytical procedure is verified by the finite element method. Very valuable conclusions are drawn on riser dynamic behaviour in the lower and higher frequency domain. The main application of the study is the assessment of forced vortex-induced riser vibration. Copyright © 2006, Institut français du pétrole.