Full‐Field Experimental Analysis of the Influence of Microstructural Parameters on the Mechanical Properties of Humeral Head Trabecular Bone

This study investigates micro-structural and mechanical properties of trabecular bone in human femoral head with and without osteoporosis using a micro-CT and a finite element model. 15 cored trabecular bone specimens with 20 of diameter were obtained from femoral heads with osteoporosis resected for total hip arthroplasty, and 5 specimens were removed from femoral head of cadavers, which has no history of musculoskeletal diseases. A high-resolution micro-CT system was used to scan each specimen to obtain histomorphometry indexes. Based on the micro-images, a FE-model was created to determine mechanical property indexes. While the non-osteoporosis group had increases the trabecular thickness, the bone volume, the bone volume fraction, the degree of anisotropy and the trabecular number compared with those of osteoporotic group, the non-osteoporotic group showed decreases in trabecular separation and structure model index. Regarding the mechanical property indexes, the reaction force and the Young's modulus were lower in the osteoporotic group than in non-osteoporotic group. Our data shows salient deteriorations in trabecular micro-structural and mechanical properties in human femoral head with osteoporosis.

Download Full-text

Relationships between Microstructure and Mechanical Properties of Polycristalline Alumina

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.625.192 ◽

2014 ◽

Vol 625 ◽

pp. 192-195

Author(s):

Lillia Haddour ◽

Mourad Keddam ◽

Nadir Mesrati

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Alumina Ceramics ◽

Intergranular Phase ◽

Microstructural Parameters ◽

Mechanical And Electrical Properties ◽

Resistance Breakdown ◽

Dielectrical Properties ◽

Scaning Electron Microscopy ◽

Fundamental Mechanism

Some low purity alumina ceramics with an alumina content ranging from 86% to 93% were investigated, in order to explore the effects of microstructural parameters (grain size, intergranular phase) on mechanical (wear) and dielectrical parameters. The microstructure and worn surfaces were analysed using scaning electron microscopy. The correlation between microstructural, dielectrical properties and wear is discussed. It has been proposed that mechanical and electrical properties are two aspects of the same fundamental mechanism. Key words: Al2O3, Microstructure final, Wear resistance, Breakdown.

Download Full-text

Effect of Defect on Elastic/Plastic and Creep Behavior of Bone: A Finite Element Study

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-175843 ◽

2007 ◽

Author(s):

A. Ajdari ◽

P. K. Canavan ◽

H. Nayeb-Hashemi ◽

G. Warner

Keyword(s):

Mechanical Properties ◽

Finite Element ◽

Trabecular Bone ◽

Fatigue Loading ◽

Dimensional Structure ◽

Plastic Behavior ◽

Element Analysis ◽

Elastic Plastic ◽

Local Bone ◽

Osteoporotic Vertebral Fractures

Three-dimensional structure of trabecular bone can be modeled by 2D or 3D Voronoi structure. The effect of missing cell walls on the mechanical properties of 2D honeycombs is a first step towards understanding the effect of local bone resorption due to osteoporosis. In patients with osteoporosis, bone mass is lost first by thinning and then by resorption of the trabeculae [1]. Furthermore, creep response is important to analyze in cellular solids when the temperature is high relative to the melting temperature. For trabecular bone, as body temperature (38 °C) is close to the denaturation temperature of collagen (52 °C), trabecular bone creeps [1]. Over the half of the osteoporotic vertebral fractures that occur in the elderly, are the result of the creep and fatigue loading associated with the activities of daily living [2]. The objective of this work is to understand the effect of missing walls and filled cells on elastic-plastic behavior of both regular hexagonal and non-periodic Voronoi structures using finite element analysis. The results show that the missing walls have a significant effect on overall elastic properties of the cellular structure. For both regular hexagonal and Voronoi materials, the yield strength of the structure decreased by more than 60% by introducing 10% missing walls. In contrast, the results indicate that filled cells have much less effect on the mechanical properties of both regular hexagonal and Voronoi materials.

Download Full-text

Dependence of Microstructures and Mechanical Properties on the Growth Rate and Composition in Directionally Solidified Mg-Gd Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.327.82 ◽

2022 ◽

Vol 327 ◽

pp. 82-97

Author(s):

He Qin ◽

Guang Yu Yang ◽

Shi Feng Luo ◽

Tong Bai ◽

Wan Qi Jie

Keyword(s):

Mechanical Properties ◽

Growth Rate ◽

Tensile Strength ◽

Ultimate Tensile Strength ◽

Dendritic Structure ◽

Directionally Solidified ◽

Dendrite Morphology ◽

Microstructural Parameters ◽

Wide Range ◽

Microstructures And Mechanical Properties

Microstructures and mechanical properties of directionally solidified Mg-xGd (5.21, 7.96 and 9.58 wt.%) alloys were investigated at a wide range of growth rates (V = 10-200 μm/s) under the constant temperature gradient (G = 30 K/mm). The results showed that when the growth rate was 10 μm/s, different interface morphologies were observed in three tested alloys: cellular morphology for Mg-5.21Gd alloy, a mixed morphology of cellular structure and dendritic structure for Mg-7.96Gd alloy and dendrite morphology for Mg-9.58Gd alloy, respectively. Upon further increasing the growth rate, only dendrite morphology was exhibited in all experimental alloys. The microstructural parameters (λ1, λ2) decreased with increasing the growth rate for all the experimental alloy, and the measured λ1 and λ2 values were in good agreement with Trivedi model and Kattamis-Flemings model, respectively. Vickers hardness and the ultimate tensile strength increased with the increase of the growth rate and Gd content, while the elongation decreased gradually. Furthermore, the relationships between the hardness, ultimate tensile strength, the growth rate and the microstructural parameters were discussed and compared with the previous experimental results.

Download Full-text

The mechanical properties of trabecular bone: Dependence on anatomic location and function

Journal of Biomechanics ◽

10.1016/0021-9290(87)90023-6 ◽

1987 ◽

Vol 20 (11-12) ◽

pp. 1055-1061 ◽

Cited By ~ 423

Author(s):

S.A. Goldstein

Keyword(s):

Mechanical Properties ◽

Trabecular Bone ◽

Anatomic Location ◽

And Function

Download Full-text

Mechanical properties of trabecular bone. Dependency on strain rate

Journal of Biomechanics ◽

10.1016/0021-9290(91)90305-7 ◽

1991 ◽

Vol 24 (9) ◽

pp. 803-809 ◽

Cited By ~ 117

Author(s):

Frank Linde ◽

Peter Nørgaard ◽

Ivan Hvid ◽

Anders Odgaard ◽

Kjeld Søballe

Keyword(s):

Mechanical Properties ◽

Strain Rate ◽

Trabecular Bone

Download Full-text

Experimental Analysis of Aluminum Alloy Section Bars and their Mortise and Tenon Joints under Bending Load

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.2338 ◽

2011 ◽

Vol 415-417 ◽

pp. 2338-2344

Author(s):

Xin Shen Huang ◽

Qun Gao ◽

Zhi Jian Zong

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Energy Absorption ◽

Experimental Analysis ◽

Absorption Capacity ◽

Main Section ◽

Bending Properties ◽

Energy Absorption Capacity ◽

Bending Load ◽

Mortise And Tenon

Different laid modes of aluminum alloy section bars and their mortise and tenon joints were bending tested, and their mechanical properties were compared, in order to research on the influence that forming a mortise and tenon joint brought to the original bars. Opening a hole laterally and inserting another shorter bar in the hole changed the bending properties and energy absorption capacity of the original bar. In horizontal laid mode, the mortise and tenon joint was weaker than the original bar when bearing bending load, but it was stronger in vertical laid mode. Weld beads of the mortise and tenon joints were strong enough to maintain the structure integrality before the main section bars were destroyed by load.

Download Full-text