title: Damage modeling of small-scale experiments on dental enamel with hierarchical microstructure.
abstract: Dental enamel is a highly anisotropic and heterogeneous material, which exhibits an optimal reliability with respect to the various loads occurring over years. In this work, enamel's microstructure of parallel aligned rods of mineral fibers is modeled and mechanical properties are evaluated in terms of strength and toughness with the help of a multiscale modeling method. The established model is validated by comparing it with the stress-strain curves identified by microcantilever beam experiments extracted from these rods. Moreover, in order to gain further insight in the damage-tolerant behavior of enamel, the size of crystallites below which the structure becomes insensitive to flaws is studied by a microstructural finite element model. The assumption regarding the fiber strength is verified by a numerical study leading to accordance of fiber size and flaw tolerance size, and the debonding strength is estimated by optimizing the failure behavior of the microstructure on the hierarchical level above the individual fibers. Based on these well-grounded properties, the material behavior is predicted well by homogenization of a representative unit cell including damage, taking imperfections (like microcracks in the present case) into account.
authors.affiliation: Institute of Materials Research, Materials Mechanics/ACE-Centre, Helmholtz-Zentrum Geesthacht, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Scheider
authors.affiliation: Institute of Materials Research, Materials Mechanics/ACE-Centre, Helmholtz-Zentrum Geesthacht, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Xiao
authors.affiliation: Institute of Advanced Ceramics, Hamburg University of Technology, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Yilmaz
authors.affiliation: Institute of Advanced Ceramics, Hamburg University of Technology, Germany.
authors.forename: G A
authors.initials: GA
authors.lastname: Schneider
authors.affiliation: Institute of Materials Research, Materials Mechanics/ACE-Centre, Helmholtz-Zentrum Geesthacht, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Huber
authors.affiliation: Institute of Materials Research, Materials Mechanics/ACE-Centre, Helmholtz-Zentrum Geesthacht, Germany; Institute of Continuum Mechanics and Materials Mechanics, Hamburg University of Technology, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Bargmann
mesh_terms: D000818:Animals; D002417:Cattle; D003198:Computer Simulation; D003743:Dental Enamel / Q000473:pathology*; D006801:Humans; D008962:Models, Theoretical; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013718:Tensile Strength
keywords: Dental enamel; Hierarchical material; Homogenization; Mechanical characterization; Micromechanical modeling