Cement lines and interlamellar areas in compact bone as strain amplifiers – Contributors to elasticity, fracture toughness and mechanotransduction

2014 ◽  
Vol 29 ◽  
pp. 235-251 ◽  
Author(s):  
Sabah Nobakhti ◽  
Georges Limbert ◽  
Philipp J. Thurner
Keyword(s):  
Fracture Toughness ◽  
Compact Bone ◽  
Cement Lines

Finite Element Modeling of Microcrack Growth in Cortical Bone

2011 ◽  
Vol 78 (4) ◽  
Author(s):  
Susan Mischinski ◽  
Ani Ural
Keyword(s):  
Fracture Toughness ◽  
Finite Element ◽  
Elastic Modulus ◽  
Crack Growth ◽  
Line Strength ◽  
Crack Deflection ◽  
Cement Line ◽  
Fracture Properties ◽  
Cement Lines ◽  
Microcrack Growth

Bone is similar to fiber-reinforced composite materials made up of distinct phases such as osteons (fiber), interstitial bone (matrix), and cement lines (matrix-fiber interface). Microstructural features including osteons and cement lines are considered to play an important role in determining the crack growth behavior in cortical bone. The aim of this study is to elucidate possible mechanisms that affect crack penetration into osteons or deflection into cement lines using fracture mechanics-based finite element modeling. Cohesive finite element simulations were performed on two-dimensional models of a single osteon surrounded by a cement line interface and interstitial bone to determine whether the crack propagated into osteons or deflected into cement lines. The simulations investigated the effect of (i) crack orientation with respect to the loading, (ii) fracture toughness and strength of the cement line, (iii) crack length, and (iv) elastic modulus and fracture properties of the osteon with respect to the interstitial bone. The results of the finite element simulations showed that low cement line strength facilitated crack deflection irrespective of the fracture toughness of the cement line. However, low cement line fracture toughness did not guarantee crack deflection if the cement line had high strength. Long cracks required lower cement line strength and fracture toughness to be deflected into cement lines compared with short cracks. The orientation of the crack affected the crack growth trajectory. Changing the fracture properties of the osteon influenced the crack propagation path whereas varying the elastic modulus of the osteon had almost no effect on crack trajectory. The findings of this study present a computational mechanics approach for evaluating microscale fracture mechanisms in bone and provide additional insight into the role of bone microstructure in controlling the microcrack growth trajectory.

scholarly journals Fracture Toughness Properties of Various Parts of Bovine and Swine Compact Bone

2005 ◽  
Vol 71 (703) ◽  
pp. 486-493 ◽  
Author(s):  
Jong-heon KIM ◽  
Mitsuo NIINOMI ◽  
Toshikazu AKAHORI
Keyword(s):  
Fracture Toughness ◽  
Compact Bone

Fracture toughness of compact bone

1976 ◽  
Vol 9 (3) ◽  
pp. 131-134 ◽  
Author(s):  
W. Bonfield ◽  
P.K. Datta
Keyword(s):  
Fracture Toughness ◽  
Compact Bone

Change of Fracture Toughness of Compact Bone by Storage Method

2001 ◽  
Vol 2001.13 (0) ◽  
pp. 108-109
Author(s):  
Hisao KIKUGAWA ◽  
Yoshiaki YASUI ◽  
Ryo IMAMURA ◽  
Hiroaki FUKUDA
Keyword(s):  
Fracture Toughness ◽  
Compact Bone ◽  
Storage Method

Fracture Toughness and Quantitative Computed Tomography Number of Human Tibia Cortical Bone

1998 ◽  
Vol 02 (02) ◽  
pp. 151-165
Author(s):  
Gladius Lewis
Keyword(s):  
Computed Tomography ◽  
Fracture Toughness ◽  
Quantitative Computed Tomography ◽  
Compact Bone ◽  
Positive Influence ◽  
Ct Number ◽  
Linear Elastic ◽  
Key Variables ◽  
Elastic Fracture ◽  
Point Bend

In spite of its importance, the fracture toughness of human bone has been the subject of only a few studies. The objective of the first part of the present work was, thus, to expand this database. For this purpose, linear elastic fracture mechanics (LEFM) principles and single-edge-notched three-point bend specimens were used to determine the fracture toughness of compact bone cut from the tibiae of embalmed cadavers (donor ages between 36 and 94 years). The overall mean and standard deviations of the fracture toughness were 3.12 and 1.21 MP/m, respectively. The case for using LEFM principles, various aspects of four key variables, and the present results are all fully discussed. In the second part of the study, the computed tomography (CT) number of all the specimens were measured. Correlational analysis of all the results demonstrated that CT number exerts a moderately positive influence on fracture toughness for this bone. The clinical significance of this finding is discussed.

scholarly journals Preparation of Nano-Hydroxyapatite Coated Carbon Nanotube Reinforced Hydroxyapatite Composites

Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 357 ◽  
Author(s):  
Xueni Zhao ◽  
Xueyan Chen ◽  
Li Zhang ◽  
Qingyao Liu ◽  
Yao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Compact Bone ◽  
Preparation Process ◽  
Artificial Bone ◽  
Mixed Acid ◽  
Nucleation Sites ◽  
Practical Guidance ◽  
Coated Carbon

Uniform and dense nano-hydroxyapatite (nHA) coating with nanorod-shaped structure was fabricated on carbon nanotubes (CNTs) by combining electrodeposition with biomineralization. The CNTs with nHA coating (nHA–CNTs) were used as reinforcement to improve the mechanical properties of HA. Firstly, a mixed acid solution of nitric acid and sulfuric acid was used to treat CNTs (NS–CNTs). The dispersion of NS–CNTs was obviously improved, and O-containing functional groups were grafted on the surfaces of NS–CNTs by treatment. Then, calcium phosphate (CaP) was deposited on NS–CNTs by electrodeposition, and NS–CNTs were provided with numerous active nucleation sites for the next coating preparation process. Then nanorod-shaped HA crystals were obtained on the surfaces of NS–CNTs by biomineralization. Using the CNTs with nHA coating (nHA–CNTs) as reinforcement, HA-based composites reinforced with CNTs and nHA–CNTs (nHA–CNTs/HA) were fabricated by pressure-less process. Bending strength and fracture toughness of 1.0 wt % nHA–CNTs reinforced HA composites (HAnC1) reaches a maximum (30.77 MPa and 2.59 MPa), which increased by 26.94% and 7.02% compared with 1.0 wt % CNTs reinforced HA composites, respectively. Importantly, the fracture toughness of HAnC1 is within the range of that to compact bone. This work provides theoretical and practical guidance for preparing nHA coating on nanomaterials. It also contributes to the potential application of nHA–CNTs/HA composites for artificial bone implants.

Effect of Bone Composition on the Fracture Toughness of Cortical Bone

2015 ◽  
Vol 1088 ◽  
pp. 514-518
Author(s):  
Chuan Shao Wu ◽  
Fu Tsai Chiang ◽  
Jui Pin Hung
Keyword(s):  
Fracture Toughness ◽  
Cortical Bone ◽  
Bone Mineral ◽  
Volume Fraction ◽  
Bone Structure ◽  
Compact Bone ◽  
Mean Value ◽  
Mineral Fraction ◽  
Bone Properties ◽  
The Relationship

This study was aimed at investigating the effect of the bone compositions on the fracture toughness of bovine cortical bone. A series of the SENB bovine cortical bone specimens were tested to assess the fracture toughness. Dual energy X-ray absorptiometry (DEXA) was applied to determine the mineral content of each bovine cortical specimen and hence the porosity and bone mineral fraction were measured. Current results indicate that the mean value fracture toughness is 9.37 MNm3/2. Moreover, the fracture toughness was found to be significantly correlated with the apparent wet bone density and porosity of bone structure. No apparent correlations are found among clinical BMD and mechanical properties, implying that the BMD is an invalid indicator of the bone properties. Additionally, the tested data were fitted to the relationship, based on power law model, that the fracture toughness increase as a power (1.526) of increasing volume fraction and as a power of increasing bone mineral fraction (0.8195). These data indicate that small changes in the amount or density of compact bone tissue exert a more pronounced influence on fracture property.

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