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Crack propagation in cortical bone is affected by the characteristics of the cement line : a parameter study using an XFEM interface damage model

Gustafsson, Anna LU ; Wallin, Mathias LU ; Khayyeri, Hanifeh LU and Isaksson, Hanna LU (2019) In Biomechanics and Modeling in Mechanobiology 18(4). p.1247-1261
Abstract

Bulk properties of cortical bone have been well characterized experimentally, and potent toughening mechanisms, e.g., crack deflections, have been identified at the microscale. However, it is currently difficult to experimentally measure local damage properties and isolate their effect on the tissue fracture resistance. Instead, computer models can be used to analyze the impact of local characteristics and structures, but material parameters required in computer models are not well established. The aim of this study was therefore to identify the material parameters that are important for crack propagation in cortical bone and to elucidate what parameters need to be better defined experimentally. A comprehensive material parameter study... (More)

Bulk properties of cortical bone have been well characterized experimentally, and potent toughening mechanisms, e.g., crack deflections, have been identified at the microscale. However, it is currently difficult to experimentally measure local damage properties and isolate their effect on the tissue fracture resistance. Instead, computer models can be used to analyze the impact of local characteristics and structures, but material parameters required in computer models are not well established. The aim of this study was therefore to identify the material parameters that are important for crack propagation in cortical bone and to elucidate what parameters need to be better defined experimentally. A comprehensive material parameter study was performed using an XFEM interface damage model in 2D to simulate crack propagation around an osteon at the microscale. The importance of 14 factors (material parameters) on four different outcome criteria (maximum force, fracture energy, crack length and crack trajectory) was evaluated using ANOVA for three different osteon orientations. The results identified factors related to the cement line to influence the crack propagation, where the interface strength was important for the ability to deflect cracks. Crack deflection was also favored by low interface stiffness. However, the cement line properties are not well determined experimentally and need to be better characterized. The matrix and osteon stiffness had no or low impact on the crack pattern. Furthermore, the results illustrated how reduced matrix toughness promoted crack penetration of the cement line. This effect is highly relevant for the understanding of the influence of aging on crack propagation and fracture resistance in cortical bone.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Crack deflection, Fracture toughness, Interface, Microstructure, Osteons
in
Biomechanics and Modeling in Mechanobiology
volume
18
issue
4
pages
1247 - 1261
publisher
Springer
external identifiers
  • scopus:85064213453
ISSN
1617-7959
DOI
10.1007/s10237-019-01142-4
language
English
LU publication?
yes
id
a586461f-676f-4d95-9a30-804fa2e698d7
date added to LUP
2019-04-25 14:37:59
date last changed
2019-08-23 16:21:22
@article{a586461f-676f-4d95-9a30-804fa2e698d7,
  abstract     = {<p>Bulk properties of cortical bone have been well characterized experimentally, and potent toughening mechanisms, e.g., crack deflections, have been identified at the microscale. However, it is currently difficult to experimentally measure local damage properties and isolate their effect on the tissue fracture resistance. Instead, computer models can be used to analyze the impact of local characteristics and structures, but material parameters required in computer models are not well established. The aim of this study was therefore to identify the material parameters that are important for crack propagation in cortical bone and to elucidate what parameters need to be better defined experimentally. A comprehensive material parameter study was performed using an XFEM interface damage model in 2D to simulate crack propagation around an osteon at the microscale. The importance of 14 factors (material parameters) on four different outcome criteria (maximum force, fracture energy, crack length and crack trajectory) was evaluated using ANOVA for three different osteon orientations. The results identified factors related to the cement line to influence the crack propagation, where the interface strength was important for the ability to deflect cracks. Crack deflection was also favored by low interface stiffness. However, the cement line properties are not well determined experimentally and need to be better characterized. The matrix and osteon stiffness had no or low impact on the crack pattern. Furthermore, the results illustrated how reduced matrix toughness promoted crack penetration of the cement line. This effect is highly relevant for the understanding of the influence of aging on crack propagation and fracture resistance in cortical bone.</p>},
  author       = {Gustafsson, Anna and Wallin, Mathias and Khayyeri, Hanifeh and Isaksson, Hanna},
  issn         = {1617-7959},
  keyword      = {Crack deflection,Fracture toughness,Interface,Microstructure,Osteons},
  language     = {eng},
  number       = {4},
  pages        = {1247--1261},
  publisher    = {Springer},
  series       = {Biomechanics and Modeling in Mechanobiology},
  title        = {Crack propagation in cortical bone is affected by the characteristics of the cement line : a parameter study using an XFEM interface damage model},
  url          = {http://dx.doi.org/10.1007/s10237-019-01142-4},
  volume       = {18},
  year         = {2019},
}