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.
El Sayed
Tamer
T
Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA. tamer@caltech.edu
Mota
Alejandro
A
Fraternali
Fernando
F
Ortiz
Michael
M
D004548:Elasticity; D020342:Finite Element Analysis; D008954:Models, Biological; D013314:Stress, Mechanical; D014783:Viscosity