Multiscale modeling of fiber recruitment and damage with a discrete fiber dispersion method

Kewei Li, Gerhard Holzapfel*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Recently, we introduced a discrete fiber dispersion model based on triangular discretization of a unit sphere with a finite number of elementary areas. Over each elementary area, we define a representative fiber direction and an elementary fiber density based on the fiber dispersion. The strain energy of fibers distributed in each elementary area is then approximated by the deformation of the representative fiber direction weighted by the corresponding elementary fiber density. A summation of fiber contributions of all elementary areas yields the resultant fiber strain energy. However, in that study we did not consider fiber recruitment, softening and damage. The goal of this study is to incorporate these important properties of collagen fibers into the constitutive model. We first define a fiber recruitment stretch at which the fiber becomes straightened. Then, we adopt the continuum damage mechanics method for modeling fiber softening and damage. We implemented the proposed model in a finite element program and verified it with three representative examples including a uniaxial extension test of a dog-bone shaped specimen up to failure. The computational solution agrees well with the experimental result. In conclusion, the proposed model is able to capture fiber recruitment, softening, and damage. Future studies with more complex boundary conditions are necessary to verify this approach.
Original languageEnglish
Pages (from-to)226-244
JournalJournal of the Mechanics and Physics of Solids
Publication statusPublished - 2019

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