Numerical Methods for the Calculation of Material Parameter Values for Trilayered Porcine Aortic Valve Leaflets

Porcine aortic valve leaflets are comprised of three layers, each of which has a different composition and consequently, different mechanical properties. Each layer exhibits non-linear stress-strain behaviour and is modelled using a hyperelastic material model. Our objective is to determine the mechanical properties of each layer from experimental force-indentation depth data, ensuring that the material model parameters in each layer are unique and have converged to their correct values. To achieve this objective, material model parameters are calculated using inverse finite element simulations and non-linear optimization methods. To ensure that these parameters converge to their correct values, mathematical models of the indentation problem are used to obtain approximate values of these parameters to be used as initial conditions in the finite element simulations. This paper describes our progress with the development of these mathematical models and numerical simulations, as well as our ongoing work to achieve our defined objective.