A Finite Element Analysis of Flow-Induced Vibration in Nonlinear Elastic Structures
Congress: COBEM
ABSTRACT:
The focus of this study is to evaluate flow-induced vibration in solid structures for large deformations in the elastic regime. For that, the Finite Element Analysis is a powerful numerical method that allows complex problems to be modeled through a discretization of the domain. First, mass and momentum equations are presented for both fluid and solid domains, along with their respective constitutive relations. The semi-Lagrangian (SL) technique, where unconditional stability is successfully achieved for the numerical solution in different geometries, is developed. For the solid domain, a two-dimensional approach was used with a quadratic triangular element mesh in a dynamic simulation, with a linearization of the governing equation to apply the finite element method. As for the fluid domain, a second order special convergence is assured for velocity fields, since a quadratic + linear pair of triangular mesh elements is used, fulfilling the well-known LBB condition. Since the movement of the solid body in the fluid requires an adaptative technique to be employed in the mesh, avoiding greater distorsion, the Arbitrary Lagrangian-Eulerian method, also known as ALE, was used. For code verification, different cases whose references are found in the literature were simulated for both fluid and solid problems. Then, a Fluid-Structure Interaction is shown to investigate vibration effects, such as the Von Mises stress.