title: Constitutive Modeling of Anisotropic Finite-Deformation Hyperelastic Behaviors of Soft Materials Reinforced by Tortuous Fibers.
abstract: Many biological materials are composites composed of a soft matrix reinforced with stiffer fibers. These stiffer fibers may have a tortuous shape and wind through the soft matrix. At small material deformation, these fibers deform in a bending mode and contribute little to the material stiffness; at large material deformation, these fibers deform in a stretching mode and induce a stiffening effect in the material behavior. The transition from bending mode deformation to stretching mode deformation yields a characteristic J-shape stress-strain curve. In addition, the spatial distribution of these fibers may render the composite an anisotropic behavior. In this paper, we present an anisotropic finite-deformation hyperelastic constitutive model for such materials. Here, the matrix is modeled as an isotropic neo-Hookean material. "The behaviors of single tortuous fiber are represented by a crimped fiber model". The anisotropic behavior is introduced by a structure tensor representing the effective orientation distribution of crimped fibers. Parametric studies show the effect of fiber tortuosity and fiber orientation distribution on the overall stress-strain behaviors of the materials.
authors.affiliation: Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309.
authors.forename: Philip H
authors.initials: PH
authors.lastname: Kao
authors.forename: Steven R
authors.initials: SR
authors.lastname: Lammers
authors.forename: Kendall
authors.initials: K
authors.lastname: Hunter
authors.forename: Kurt R
authors.initials: KR
authors.lastname: Stenmark
authors.forename: Robin
authors.initials: R
authors.lastname: Shandas
authors.forename: H Jerry
authors.initials: HJ
authors.lastname: Qi