Determination of material parameters for soft tissue frequently involves regressing material parameters for nonlinear, anisotropic constitutive models against experimental data from heterogeneous tests. Here, parameter estimation using results from membrane inflation is considered. A four parameter nonlinear, anisotropic hyperelastic strain energy function is used to model the material, in which the parameters are cast in terms of key response features. The experiment is simulated using finite element analysis in order to predict the experimental measurements of pressure and profile stretch. Material parameter regression is automated using inverse finite element analysis; parameter values are updated using both local and global techniques, and the ability of either of these techniques to efficiently converge to a best case is examined. This approach provides a framework in which additional experimental data, including surface strain measurements or local structural information, may be incorporated in order to quantify heterogeneous nonlinear material properties.
Citation: Computer Methods in Biomechanics and Biomedical Engineering
Pub Type: Journals
Cardiovascular, Inflation, Material optimization, Parameter regression