| The dynamic model of an unburied submarine pipeline is developed to observe the effects of hazardous loadings and end conditions of pipeline on its bottom stability. The model includes the large angle deflections of pipeline in space, longitudinal extensibility, the effect of internal flow and the evaluation of hydrodynamic loads and seabed soil reaction forces. A finite element formulation of this nonlinear, vector-valued, time-dependent and fourth-order problem is derived for the numerical model. Numerical experiments are performed with the latest available experimental data for hydrodynamic coefficients and seabed soil stiffness characteristics. The dynamic stress distribution and bottom motion of pipeline is discussed for various wave and current condition and end condition of pipeline. The choice of weight coating and the possible failure mechanism of pipeline is presented. |
