MODELLING FLUID-INDUCED STRUCTURAL VIBRATIONS: REDUCING THE STRUCTURAL RISK FOR STORMY WINDS

摘要

The objective of this work is the modelling of the interaction between fluid flow and solid bodies, either rigid or flexible. The fluid flow is governed by the incompressible Navier-Stokes equations and modelled by using stabilised low order velocity-pressure finite elements. The motion of the fluid domain is accounted for by an arbitrary Lagrangian-Eulerian (ALE) strategy. The flexible structure is represented by means of appropriate standard finite element formulations while the motion of the rigid body is described by rigid body dynamics. For temporal discretisation of both fluid and solid bodies, the discrete implicit generalised-α method is employed. The resulting strongly coupled set of nonlinear equations is solved by means of a novel partitioned solution procedure, which is based on the Newton-Raphson methodology and incorporates full linearisation of the overall incremental problem. The strong coupling is resolved and optimal convergence of the residuals is achieved. Numerical examples are presented to demonstrate the robustness and efficiency of the methodology.