Finite element implementation of the aortic double-dispersion fibre model and development of a predictive damage model

Abstract

With the development of next-generation cardiovascular prosthesis, the requirement for more advanced simulations for predicting the mechanical response of biological tissue has arisen. Finite-element analysis represents a powerful tool capable of simulating complex behaviours within this framework. The present work proposes the computational implementation of an advanced constitutive model for the fibre-reinforced tissue making up the aortic wall. The formulation available in literature is numerically implemented within the FE software Abaqus© through specific user subroutines, and model predictions are compared with the already available single-dispersion-model results. The influence of each dispersion parameter on the macroscopic behaviour is analysed and discussed. Finally, the model is extended by a damage regime based on strain invariants, which is capable of considering the influence of patient ageing on the mechanical response failure strain. The user subroutines are here provided in the Appendix for applications.