Natural vibration analysis of tensioned risers by segmentation method Analyse des vibrations propres des risers tendus par la méthode de segmentation

摘要: The natural vibration of deepwater tensioned 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 halfwave 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 vortexinduced riser vibration.RésuméDans le but de l'évaluation des vibrations des risers induites par vortex (VIV), les vibrations modales d'un riser uniforme tendu en eau profonde sont considérées. Du fait de la faible rigidité des risers, les vibrations du type câble et poutre sont analysées. Les …