title: Damage mechanisms in uniaxial compression of single enamel rods.
abstract: Enamel possesses a complex hierarchical structure, which bestows this tissue with unique mechanical properties. In this study, the mechanical behavior of single enamel rods was investigated under uniaxial compression. Numerical simulations were also performed using micromechanics models for individual enamel rods to identify the damage mechanisms contributing to the constitutive behavior. Experimental results showed that the single rods exhibited an elastic modulus ranging from 10~31 GPa, and that they undergo post-yield strain-hardening. The primary damage mode consisted of delamination within the assembly of mineral crystals. Results from numerical simulations suggest that strain localization within individual rods is responsible for the observed delamination, which is believed to arise from the non-uniform arrangement of mineral crystals. This mechanism was independent of mineral morphology and properties. The non-uniform crystal arrangement results in friction between crystals with different inclination angles and is believed to be responsible for the post-yield strain hardening behavior.
authors.affiliation: Department of Physics, Shanghai University, Shanghai 200444, PR China; Department of Mechanics, Shanghai University, Shanghai, 200444, PR China.
authors.forename: Bingbing
authors.initials: B
authors.lastname: An
authors.affiliation: The Tenth People׳s Hospital of Tongji University Shanghai, 200072, PR China.
authors.forename: Raorao
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, University of Washington Seattle, WA USA; Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA USA.
authors.forename: Dwayne
authors.initials: D
authors.lastname: Arola
authors.affiliation: Department of Mechanics, Shanghai University, Shanghai, 200444, PR China; Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai, 200072, China. Electronic address: donzhang@staff.shu.edu.cn.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Zhang
mesh_terms: D001696:Biomechanical Phenomena; D019245:Compressive Strength; D003743:Dental Enamel; D055119:Elastic Modulus; D006801:Humans; D008954:Models, Biological; D013314:Stress, Mechanical
keywords: Damage mechanism; Enamel; Non-uniform arrangement; Strain localization