Development of a transient large strain contact method for biological heart valve simulations

Abstract

A new 2D method to implement transient contact using Comsol Multiphysics (finite element analysis software that enables multiphysics simulations) is described, which is based on Hertzian contact. This method is compared to the existing (default) contact method that does not enable real transient simulations, but instead performs steady-state solutions where time is a constant. The two types of contact modelling have been applied to simple 2D biological heart valve models, undergoing strains in the region of 10% under 20 kPa pressure (applied over 0.3 s). Both the methods predicted comparable stress patterns, locations of peak stresses, deformations and directions of principal stress. The default contact method predicted slightly greater contact stresses, but spreads over a shorter surface length than the new contact method. The default contact method is useful for contact systems with little transient dependency, due to ease of use. However, where transient conditions are important the new contact method is preferred.

Keywords:

• contact modelling
• finite element analysis
• heart valve
• Hertzian contact
• large strain

Acknowledgements

The authors thank the British Heart Foundation for a Junior Fellowship (FS/05/32) awarded to DME during the initial stages of this investigation. DME is currently supported by a Marie Curie Intra-European Fellowship within the 7th European Community Framework Programme (Programme number: FP7/2007-2013; under grant agreement no. 252278).