Natural frequencies and mode shapes of statically deformed inclined risers

Feras Alfosail, Ali H. Nayfeh, Mohammad I. Younis

Research output: Chapter in Book/Report/Conference proceedingConference contribution


In this work, we investigate numerically the linear vibrations of inclined risers using the Galerkin approach. The riser is modeled as an Euler-Bernoulli beam accounting for the nonlinear mid-plane stretching and self-weight. After solving for the initial deflection of the riser due to self-weight, a Galerkin expansion of fifteen axially loaded beam mode shapes are used to solve the eigenvalue problem of the riser around the static equilibrium configuration. This yields the riser natural frequencies and exact mode shapes for various values of inclination angles and applied tension. The obtained results are validated against a boundary-layer analytical solution and are found in good agreement. This constructs a basis to study the nonlinear forced vibrations of inclined risers.
Original languageEnglish (US)
Title of host publicationASME 2016 International Mechanical Engineering Congress and Exposition, IMECE 2016
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Print)9780791850541
StatePublished - Feb 8 2017


Dive into the research topics of 'Natural frequencies and mode shapes of statically deformed inclined risers'. Together they form a unique fingerprint.

Cite this