Study on the Accuracy of Structural and FSI Heart Valves Simulations
- 140 Downloads
The performance of heart valves, either native or artificial, can be evaluated by means of finite element analyses, either from a structural or a fluid–structure interaction (FSI) point of view. The latter captures the coupling between the valve leaflets and the blood in a more realistic way. The selection of the appropriate finite elements approach for the model is the first and fundamental step to achieve accurate simulations. The aim of this work is to investigate the influence of the type, formulation, size, and shape of the elements in heart valves simulations.
The effects related to the choice of the finite elements-shell or solid- in structural and FSI simulations were analyzed. In particular, the analysis of grid convergence on both the structure and fluid domains, the influence of the element typology, formulation and damping factor in an idealized three-leaflets valve model loaded with physiological pressure conditions were investigated.
Stress values and valve kinematics results confirmed the importance of performing a proper verification process for selecting the most appropriate elements with the optimal accuracy to computational cost ratio.
In this regard, our results indicate the quadrangular shell with reduced integration and viscous hourglass control to be the best choice to model heart valves. If a solid discretization is required, quadratic hexahedral elements with full integration are also acceptable. Finally, our results show that the damping coefficient needs to be carefully selected in order to smooth out the high frequency modes of the structure without introducing excessive numerical artificial viscosity.
KeywordsFluid–structure interaction (FSI) Verification Finite element analysis Heart valve Cardiovascular mechanics
The authors thank Prof. Ethan Kung and Rithwik Jallepalli for the thoroughly reading of the manuscript and their valuable suggestions.
Conflict of interest
Author Luraghi, Author Migliavacca, and Author Rodriguez Matas declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- 2.American Society of Mechanical Engineers. Guide for Verification and Validation in Computational Solid Mechanics. New York: American Society of Mechanical Engineers, 2006.Google Scholar
- 3.American Society of Mechanical Engineers. Standard for Verification and Validation in Computational Fluid Dynamics and Heat Transfer. New York: American Society of Mechanical Engineers, 2009.Google Scholar
- 4.American Society of Mechanical Engineers. An Illustration of the Concepts of Verification and Validation in Computational Solid Mechanics. New York: American Society of Mechanical Engineers, 2012.Google Scholar
- 9.Bavo, A. M., G. Rocatello, F. Iannaccone, J. Degroote, J. Vierendeels, and P. Segers. Fluid-structure interaction simulation of prosthetic aortic valves: comparison between immersed boundary and arbitrary Lagrangian–Eulerian techniques for the mesh representation. PLoS ONE 11:e0154517, 2016.CrossRefGoogle Scholar
- 30.Knepell, P. L., and D. C. Arangno. SIMULATION VALIDATION : A Confidence Assessment Methodology. New York: Wiley-IEEE Computer Society Press, 1993.Google Scholar
- 53.Roache, P. J. Verification and Validation in Computational Science and Engineering. Albuquerque: Hermosa, 1998.Google Scholar
- 61.Wall, W. A., A. Gerstenberger, P. Gamnitzer, C. Förster, and E. Ramm. Large deformation fluid-structure interaction: advances in ALE methods and new fixed grid approaches. In: Fluid-Structure Interaction, edited by H. J. Bungartz, and M. Schäfer. Berlin: Springer, 2006, pp. 195–232.CrossRefGoogle Scholar