Finite element modeling of corneal strip extensometry

Abstract

Corneal biomechanical properties are an important element in the study of corneal biomechanics. There are currently two techniques to obtain these properties; an inflation test and the strip extensiometry test. As the inflation test has been numerically modelled in several studies, this study focusses on accurately modelling the strip extensiometry test. Two methods were considered to simulate the experimental conditions namely, a single phase and a two phase method. A finite element model of the corneal strip specimen was developed using an elastic fibre reinforced constitutive model to describe the corneal microstructure. The experimental conditions were simulated by defining prescribed displacements to simulate the required phases for each method. The results indicated that by using the two phase method, which is a more accurate description of the experimental setup that no additional post processing is required to obtain a reaction force response which correlates with experimental data.