Development of a fluid-structure interaction numerical algorithm for random wave action on a cantilevered column
Description
To enhance the numerical calculation approach for offshore columns subjected to random wave action, a numerical algorithm for column random wave action based on the boundary element method is developed. Building upon this, a fluid-structure interaction numerical model for random wave effects on a column in three-dimensional unbounded domains is established through iterative coupling between boundary element method and finite element method calculations. The entire solution domain is divided into two parts: the fluid domain and the structural domain. Specifically, the boundary element algorithm is used for calculating the flow field in the fluid domain, while the finite element method is employed for structural calculations in the structural domain. Fluid and structural computations iterate within a time sequence to simulate the coupled effects between fluid pressure and structural deformation. To verify the proposed method, numerical simulations of random wave action on a cylindrical column are conducted using the developed boundary element method algorithm; comparative analysis of numerical and theoretical results confirms the correctness of the algorithm model. Subsequently, for the proposed fluid-structure interaction algorithm model for random wave action on a column, numerical simulations of conventional random wave action are conducted using a rounded-end column as an example. By comparing numerical results under coupled and uncoupled conditions, the fluid-structure interaction effects of random wave action on a column are analyzed. The proposed method is based on potential flow theory, neglects fluid viscosity and radiation effects induced by structural motion, and is applicable to inertia-dominated wave loading scenarios, i.e., scenarios with low Keulegan-Carpenter (KC) numbers.