Nano-scale mechanisms of bone toughening
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Authors
Wang, Zehai
Issue Date
2018-12
Type
Electronic thesis
Thesis
Thesis
Language
ENG
Keywords
Mechanical engineering
Alternative Title
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
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY