Nonlinear Free Vibration of a Steel Catenary Riser Available to Purchase

This paper presents a finite element method for nonlinear free vibration analysis of a steel catenary marine riser. The energy method based on the Hamilton's principle is used to derive the nonlinear equation of motion. The work-energy functional is composed of the strain energies due to axial deformation and bending and also the works done by inertia forces of riser and transporting fluid motions. The nonlinear stiffness matrix, the mass matrix, and the gyroscopic matrix of the riser system are developed by using the finite element technique. Consequently, the nonlinear natural frequencies and their corresponding mode shapes are determined by solving the eigenvalue problem incorporating with the direct iteration technique. The examples of large amplitude free vibration of the steel catenary riser with various horizontal offsets and top tensions are also presented in this paper.