Cremonesi, M.

Meduri, S.

Perego, U.

S. Meduri

M. Cremonesi

U. Perego

Archivio istituzionale della ricerca - Politecnico di Milano

13th World Congress on Computational Mechanics (WCCM XIII)2nd Pan American Congress on Computational Mechanics (PANACM II)July 22-27, 2018, New York, NY, USAFully Explicit Three-Dimensional Lagrangian Simulation ofFluid-Structure-Interaction ProblemsSimone Meduri*, Umberto Perego**, Massimiliano Cremonesi****Politecnico di Milano (Italy), **Politecnico di Milano (Italy), ***Politecnico di Milano (Italy)ABSTRACTA partitioned fully Lagrangian and fully explicit approach for the simulation of FSI problems is presented. Partitionedapproaches are particularly interesting for the application to real engineering problems because of the possibility tomake use of existing software. Moreover, explicit methods can be advantageous in many large scale applicationscharacterized by fast dynamics and/or a high degree of nonlinearity. In this work, we propose an explicit version ofthe Particle Finite Element Method (PFEM) [1] for the weakly compressible fluid domain, coupled with thecommercial software Abaqus/Explicit for the structural one. The Gravouil and Combescure approach [2] has beenchosen to enforce a strong coupling together with a global system of fully decoupled (explicit) equations [3].Nonconforming meshes and time increments in the fluid and solid subdomains can be used to optimize thediscretization for the overall efficiency of the coupled solver. The use of a commercial software as structural solverallows including in the model its advanced functionalities, such as the libraries of material constitutive models andfinite elements and other advanced features. Furthermore, the fully Lagrangian framework of the coupledPFEM-FEM approach makes this method particularly suitable for applications with free-surface fluid flows and largedisplacements of the solid partition. In 3D problems, a frequent remeshing of the fluid domain is required by thePFEM. The resulting new mesh is often of a bad quality, with many slivers (tetrahedra with almost zero volume),leading to a vanishing critical time step size. A novel efficient mesh smoothing technique has been developed toproduce a regular mesh, with a reasonably large stable time increment for the explicit solver. This smoothingalgorithm is fully explicit and parallelizable, because it exploits the same architecture of the fluid solver thanks to anelastic analogy. Several three-dimensional examples have been considered to validate the approach againstavailable analytical, experimental and numerical solutions, confirming the robustness and effectiveness of theproposed method. [1] E. Onate, S. Idelsohn, “The particle finite element method: an overview.” Int J Comput Meth,2004;2:267-307. [2] A. Gravouil , A. Combescure, “Multi-time-step explicit-implicit method for non-linear structuraldynamics.” Int J Numer Meth Engng. 2001;50:199-225. [3] S. Meduri et al. “A partitioned fully explicit Lagrangianfinite element method for highly nonlinear fluid-structure interaction problems.” Int J Numer Meth Engng.2018;113:43–64.

Fully Explicit Three-Dimensional Lagrangian Simulation of Fluid-Structure-Interaction Problems

https://re.public.polimi.it/bitstream/11311/1079811/1/2018_Meduri_Cremonesi_Perego_WCCM-NY.pdf

Fully Explicit Three-Dimensional Lagrangian Simulation of Fluid-Structure-Interaction Problems

Abstract

Similar works

Full text

Available Versions

Archivio istituzionale della ricerca - Politecnico di Milano