Nano-scale mechanisms of bone toughening

Authors
Wang, Zehai
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Other Contributors
Picu, Catalin R.
Vashishth, Deepak
Mills, Kristen L.
Oberai, Assad
Issue Date
2018-12
Keywords
Mechanical engineering
Degree
PhD
Terms of Use
This electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
Full Citation
Abstract
In this dissertation, a new three-dimensional bone ultrastructure finite element model is constructed to investigate the formation of dilatational bands at the nanoscale. The stochastic organization of bone mineral phase at mineralized collagen fibrils scale is considered in this model. Under tensile deformation, the local confinement from the extra-fibrillar mineral structure leads to large hydrostatic stress and stress fluctuation. The tensile hydrostatic stress at organic-inorganic interfaces causes the denaturation of non-collagenous proteins and the corresponding energy dissipation. Therefore, the formation of dilatational bands is claimed as a stress-induced protein denaturation mechanism. Also, the occurrence conditions for such interface protein denaturation process are discussed. The intrinsic toughening effect from this nanoscale energy dissipation mechanism is quantified to be on the order of 20%. Our model provides a new fundamental understanding of the intrinsic toughening mechanism of dilatational bands formation and its contribution to macroscopic bone toughness.
Description
December 2018
School of Engineering
Department
Dept. of Mechanical, Aerospace, and Nuclear Engineering
Publisher
Rensselaer Polytechnic Institute, Troy, NY
Relationships
Rensselaer Theses and Dissertations Online Collection
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