The worldwide demand for oil and limited onshore deposits have led to increased offshore exploration and production in deep water. One of the problems associated with deep- water production, is the possibility of progressive collapse of pipelines and other tubes subjected to external pressure due to a propagating buckle. The phenomenon is most likely to occur during pipe-laying operations. To contain the damage that can be inflicted on a pipeline by buckle propagation, stiffeners, known as arrestors, are used. In this study, the “integral-ring” arrestor, widely regarded as most efficient, is examined. The analysis uses a three-dimensional finite element model in which the continuum is discretized by three-node isoparametric pipe finite elements developed for the purposes of this study. Geometric nonlinearities are treated using a net of convected coordinates, embedded in the continuum and deforming with it. Elastoplastic material behavior is taken into account by means of the J2-flow theory of plasticity with isotropic hardening. The constant average acceleration scheme is applied for step-by-step integration of the equation of motion. Finally, arc-length techniques are used for advancing along equilibrium paths past critical points. Quasistatic as well as dynamic analyses are carried out towards estimation of the cross-over pressure at which an incident propagating buckle will overcome the integral- ring arrestor.
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