A variational constitutive model for soft biological tissues
In this paper, a fully variational constitutive model of soft biological tissues is formulated in the finite strain regime. The model includes Ogden-type hyperelasticity, finite viscosity, deviatoric and volumetric plasticity, rate and microinertia effects. Variational updates are obtained via time discretization and pre-minimization of a suitable objective function with respect to internal variables. Genetic algorithms are used for model parameter identification due to their suitability for non-convex, high dimensional optimization problems. The material behavior predicted by the model is compared to available tests on swine and human brain tissue. The ability of the model to predict a wide range of experimentally observed behavior, including hysteresis, cyclic softening, rate effects, and plastic deformation is demonstrated.
© 2008 Elsevier. Accepted 18 February 2008, Available online 17 April 2008. The authors would like to thank Professor Francesschini and Professor Bigoni for their indispensable collaboration. Also, F.F. greatly acknowledges the support of the Italian Fulbright Commission and the Council for International Exchange of Scholars. There are no conflicts of interest of any kind in the work presented in the manuscript.
Supplemental Material - 1-s2.0-S0021929008000778-mmc1.pdf