scholarly journals Anisotropic elastic properties of human femoral cortical bone and relationships with composition and microstructure in elderly

2019 ◽  
Vol 90 ◽  
pp. 254-266 ◽  
Author(s):  
Xiran Cai ◽  
Hélène Follet ◽  
Laura Peralta ◽  
Marc Gardegaront ◽  
Delphine Farlay ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Elastic Properties ◽  
Anisotropic Elastic

Specimen Specific Multiscale Model for the Anisotropic Elastic Properties of Human Cortical Bone Tissue

2007 ◽  
Author(s):  
Justin M. Deuerling ◽  
Weimin Yue ◽  
Alejandro A. Espinoza ◽  
Ryan K. Roeder
Keyword(s):  
Cortical Bone ◽  
Elastic Properties ◽  
Structural Information ◽  
Transversely Isotropic ◽  
Longitudinal Axis ◽  
Orientation Distribution ◽  
Tissue Properties ◽  
Apatite Crystals ◽  
Micromechanical Models ◽  
Anisotropic Elastic

The elastic constants of cortical bone are orthotropic or transversely isotropic depending on the anatomic origin of the tissue. Micromechanical models have been developed to predict anisotropic elastic properties from structural information. Many have utilized microstructural features such as osteons, cement lines and Haversian canals to model the tissue properties [1]. Others have utilized nanoscale features to model the mineralized collagen fibril [2]. Quantitative texture analysis using x-ray diffraction techniques has shown that elongated apatite crystals exhibit a preferred orientation in the longitudinal axis of the bone [3]. The orientation distribution of apatite crystals provides fundamental information influencing the anisotropy of the extracellular matrix (ECM) but has not been utilized in existing micromechanical models.

Elastic Properties of Human Osteon and Osteonal Lamella Computed by a Bidirectional Micromechanical Model and Validated by Nanoindentation

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Radim Korsa ◽  
Jaroslav Lukes ◽  
Josef Sepitka ◽  
Tomas Mares
Keyword(s):  
Cortical Bone ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Micromechanical Model ◽  
Degenerative Diseases ◽  
Coordinate Systems ◽  
Inverse Homogenization ◽  
Curvilinear Coordinate ◽  
Anisotropic Elastic ◽  
Good Agreement

Knowledge of the anisotropic elastic properties of osteon and osteonal lamellae provides a better understanding of various pathophysiological conditions, such as aging, osteoporosis, osteoarthritis, and other degenerative diseases. For this reason, it is important to investigate and understand the elasticity of cortical bone. We created a bidirectional micromechanical model based on inverse homogenization for predicting the elastic properties of osteon and osteonal lamellae of cortical bone. The shape, the dimensions, and the curvature of osteon and osteonal lamellae are described by appropriately chosen curvilinear coordinate systems, so that the model operates close to the real morphology of these bone components. The model was used to calculate nine orthotropic elastic constants of osteonal lamellae. The input values have the elastic properties of a single osteon. We also expressed the dependence of the elastic properties of the lamellae on the angle of orientation. To validate the model, we performed nanoindentation tests on several osteonal lamellae. We compared the experimental results with the calculated results, and there was good agreement between them. The inverted model was used to calculate the elastic properties of a single osteon, where the input values are the elastic constants of osteonal lamellae. These calculations reveal that the model can be used in both directions of homogenization, i.e., direct homogenization and also inverse homogenization. The model described here can provide either the unknown elastic properties of a single lamella from the known elastic properties at the level of a single osteon, or the unknown elastic properties of a single osteon from the known elastic properties at the level of a single lamella.

On the effective anisotropic elastic properties of porous hydroxyapatite, porous collagen, and cortical bone: A homogenization scheme with percolation threshold concept

2018 ◽  
Vol 24 (4) ◽  
pp. 1091-1102 ◽  
Author(s):  
Mai-Ba Vu ◽  
Tuan Nguyen-Sy
Keyword(s):  
Percolation Threshold ◽  
Cortical Bone ◽  
Elastic Properties ◽  
Organic Content ◽  
Homogenization Theory ◽  
High Porosity ◽  
Porous Hydroxyapatite ◽  
Threshold Concept ◽  
Homogenization Scheme ◽  
Anisotropic Elastic

The objective of this study is to model the effective anisotropic elastic properties of porous hydroxyapatite, wet collagen, and cortical bone by an advanced homogenization scheme with a percolation threshold concept. The theoretical basis of the anisotropic homogenization theory is first presented. A homogenization scheme with a percolation threshold concept is then introduced and validated against experimental data for porous hydroxyapatite as well as bone after decollagenization. It is also validated on a porous collagen that is a result of the demineralization of bone. Even though aligned collagen fibers are considered, similar values of the elastic stiffnesses [Formula: see text] and [Formula: see text] were found for demineralized bone due to its very high porosity. Finally the proposed method is used to model cortical bone as a mixture of hydroxyapatite mineral and soft organic content that is in turn a mixture of collagen fiber and pores filled by water. Good agreement between modeled and measured data is observed. The model presented herein is simpler than existing multi-scale homogenization schemes in the literature, but its results fit very well with the experimented trends.

scholarly journals Prediction of anisotropic elastic properties of snow from its microstructure

2016 ◽  
Vol 125 ◽  
pp. 85-100 ◽  
Author(s):  
Praveen K. Srivastava ◽  
Chaman Chandel ◽  
Puneet Mahajan ◽  
Pankaj Pankaj
Keyword(s):  
Elastic Properties ◽  
Anisotropic Elastic

Tuning the interfacial thermal conductance via the anisotropic elastic properties of graphite

Carbon ◽  
2019 ◽  
Vol 144 ◽  
pp. 109-115 ◽  
Author(s):  
Zhiyong Wei ◽  
Fan Yang ◽  
Kedong Bi ◽  
Juekuan Yang ◽  
Yunfei Chen
Keyword(s):  
Elastic Properties ◽  
Thermal Conductance ◽  
Interfacial Thermal Conductance ◽  
Anisotropic Elastic

scholarly journals Measurement of the Anisotropic Dynamic Elastic Constants of Additive Manufactured and Wrought Ti6Al4V Alloys

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 638
Author(s):  
Ofer Tevet ◽  
David Svetlizky ◽  
David Harel ◽  
Zahava Barkay ◽  
Dolev Geva ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Elastic Constants ◽  
Electron Backscatter Diffraction ◽  
Mechanical Design ◽  
Rolling Direction ◽  
Micro Computed Tomography ◽  
Phase Layer ◽  
Anisotropic Elastic ◽  
Hot Rolled ◽  
Pulse Echo

Additively manufactured (AM) materials and hot rolled materials are typically orthotropic, and exhibit anisotropic elastic properties. This paper elucidates the anisotropic elastic properties (Young’s modulus, shear modulus, and Poisson’s ratio) of Ti6Al4V alloy in four different conditions: three AM (by selective laser melting, SLM, electron beam melting, EBM, and directed energy deposition, DED, processes) and one wrought alloy (for comparison). A specially designed polygon sample allowed measurement of 12 sound wave velocities (SWVs), employing the dynamic pulse-echo ultrasonic technique. In conjunction with the measured density values, these SWVs enabled deriving of the tensor of elastic constants (Cij) and the three-dimensional (3D) Young’s moduli maps. Electron backscatter diffraction (EBSD) and micro-computed tomography (μCT) were employed to characterize the grain size and orientation as well as porosity and other defects which could explain the difference in the measured elastic constants of the four materials. All three types of AM materials showed only minor anisotropy. The wrought (hot rolled) alloy exhibited the highest density, virtually pore-free μCT images, and the highest ultrasonic anisotropy and polarity behavior. EBSD analysis revealed that a thin β-phase layer that formed along the elongated grain boundaries caused the ultrasonic polarity behavior. The finding that the elastic properties depend on the manufacturing process and on the angle relative to either the rolling direction or the AM build direction should be taken into account in the design of products. The data reported herein is valuable for materials selection and finite element analyses in mechanical design. The pulse-echo measurement procedure employed in this study may be further adapted and used for quality control of AM materials and parts.

Sign in / Sign up

Export Citation Format

Share Document