FINITE-ELEMENT ANALYSIS OF PROPAGATING BUCKLES

A finite element technique is described for the analysis of propagating buckles in deep-water pipelines, accounting for large deformation, elastoplastic material behaviour and contact between regions of the interior wall of the pipe. Within the framework of a Lagrangian formulation and a convected co-ordinate system, nine-node isoparametric shell finite elements are employed along with contact elements. They are equipped with a so-called pressure node which facilitates the tracing of unstable equilibrium paths during the deformations of the pipe. For the analysis of a pipe surrounded by water, fluid-structure interaction is treated in an approximate manner. Numerical results are presented and comparisons with experimental data are made, demonstrating the excellent performance of the technique.