Impact—Response Behavior of Offshore Pipelines

A method for analyzing the dynamic behavior of marine pipelines subjected to impact loads or sudden forced movements is outlined. Inertia forces (also from hydrodynamic mass), hydrodynamic drag forces as well as friction and lift effects for a pipe at the sea bottom are accounted for. An extensive nonlinear formulation is used for the pipe itself; it includes large displacements and elasto-plastic material behavior. Aspects of the numerical formulation of the problem and the solution of the nonlinear dynamic equations are discussed. The examples show computed dynamic response for pipelines lying on the sea floor and for a pipe section freely submerged in water when subjected to various force and displacement histories.