A meshless Hermite-Cloud method for nonlinear fluid-structure analysis of near-bed submarine pipelines under current

摘要

Through higher-order Hermite construction of the interpolation functions, a novel true meshless numerical technique-the Hermite-Cloud method is developed for the analysis of nonlinear fluid-structure interaction of near-bed submarine pipelines under a current. Following the development of the discrete point collocation technique throughout the computational domains, the present method constructs the approximations of both the unknown functions and their first-order derivatives based on the classical reproducing kernel particle method, except that a fixed reproducing kernel approximation is employed instead. For partial differential equations with boundary conditions, certain auxiliary conditions are required due to the use of the Hermite theorem. After validation of the presently developed Hermite-Cloud method by several two-dimensional elasticity examples, the method is used for the failure analysis of a near-bed submarine pipeline under a horizontal current with consideration of a nonlinear fluid-structure interaction effect. The numerical result indicates that the distance from the pipelines to seabed and the current velocity have remarkable influences "on the deformation behavior of the pipelines. It also shows that various critical current velocities corresponding to different failure patterns exist, and the presently simulated relation of the critical velocities agrees with the results in the previous publications.