scholarly journals Recent advances on the measurement and calculation of the elastic moduli of cortical and trabecular bone: A review

2011 ◽  
Vol 38 (3) ◽  
pp. 209-297 ◽  
Author(s):  
Ekaterina Novitskaya ◽  
Po-Yu Chen ◽  
Elham Hamed ◽  
Li Jun ◽  
Vlado Lubarda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Trabecular Bone ◽  
Elastic Properties ◽  
Elastic Moduli ◽  
The Body ◽  
Multifunctional Material ◽  
Recent Advances ◽  
Wide Range ◽  
Experimental Approaches ◽  
Open Issues

In this review, recent advances on the measurement and modeling of elastic properties of cortical and trabecular bone are presented. Bone is a multifunctional material which among its other functions serves as a support for other tissues in the body. As a structural material it is stiff, strong, tough, lightweight and is adaptable. Its excellent mechanical properties are due to its complex, composite and hierarchical structure. In this paper, we outline the experimental approaches that have been used to characterize bone?s structure, composition and elastic properties at several different length scales. Then, we discuss different modeling approaches that have been employed to compute bone?s elastic moduli. We conclude by discussing the challenges and open issues in this area. Analysis of bone is of importance in orthopedics. Also, gained knowledge on bone can be used by engineers to design new bioinspired composite materials for a wide range of engineering applications.

scholarly journals Poly(Propylene Fumarate)–Hydroxyapatite Nanocomposite Can Be a Suitable Candidate for Cervical Cages

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Yong Teng ◽  
Hugo Giambini ◽  
Asghar Rezaei ◽  
Xifeng Liu ◽  
A. Lee Miller ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Moduli ◽  
Failure Load ◽  
Polymeric Composite ◽  
Materials Testing ◽  
Bulk Materials ◽  
Suitable Candidate ◽  
Salt Leaching ◽  
Wide Range ◽  
Poly Propylene

A wide range of materials have been used for the development of intervertebral cages. Poly(propylene fumarate) (PPF) has been shown to be an excellent biomaterial with characteristics similar to trabecular bone. Hydroxyapatite (HA) has been shown to enhance biocompatibility and mechanical properties of PPF. The purpose of this study was to characterize the effect of PPF augmented with HA (PPF:HA) and evaluate the feasibility of this material for the development of cervical cages. PPF was synthesized and combined with HA at PPF:HA wt:wt ratios of 100:0, 80:20, 70:30, and 60:40. Molds were fabricated for testing PPF:HA bulk materials in compression, bending, tension, and hardness according to ASTM standards, and also for cage preparation. The cages were fabricated with and without holes and with porosity created by salt leaching. The samples as well as the cages were mechanically tested using a materials testing frame. All elastic moduli as well as the hardness increased significantly by adding HA to PPF (p < 0.0001). The 20 wt % HA increased the moduli significantly compared to pure PPF (p < 0.0001). Compressive stiffness of all cages also increased with the addition of HA. HA increased the failure load of the porous cages significantly (p = 0.0018) compared with nonporous cages. PPF:HA wt:wt ratio of 80:20 proved to be significantly stiffer and stronger than pure PPF. The current results suggest that this polymeric composite can be a suitable candidate material for intervertebral body cages.

Bioresorbable Composites and Implant

2019 ◽  
pp. 57-76
Author(s):  
Divya Zindani
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Degradation Rate ◽  
Clinical Applications ◽  
The Body ◽  
Metal Alloys ◽  
Medical Sciences ◽  
Intended Function ◽  
Wide Range ◽  
Modification Rate

Different biomaterials in the form of ceramics, metal alloys, composites, glasses, polymers, etc. have gained wide-range acceptance in the realm of medical sciences. Bioimplants from such biomaterials have been constructed and used widely for different clinical applications. With the continual progress, biomaterials that may be resorbed inside the body have been developed. These have done away with the major challenge of removal of an implant after it has served its intended function. Important factors are taken into consideration in design and development of implants from such biomaterials are mechanical properties, degradation rate, surface modification, rate of corrosion, biocompatibility, and non-toxicity. Given the importance of such materials in clinical applications, the chapter presents an overview of the bioresorable composites and their implants. The related properties and the functions served have been outlined briefly. Further, the challenges associated and the remedies to overcome them have also been delineated.

Bioresorbable Composites and Implant

2021 ◽  
pp. 443-456
Author(s):  
Divya Zindani
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Degradation Rate ◽  
Clinical Applications ◽  
The Body ◽  
Metal Alloys ◽  
Medical Sciences ◽  
Intended Function ◽  
Wide Range ◽  
Modification Rate

Different biomaterials in the form of ceramics, metal alloys, composites, glasses, polymers, etc. have gained wide-range acceptance in the realm of medical sciences. Bioimplants from such biomaterials have been constructed and used widely for different clinical applications. With the continual progress, biomaterials that may be resorbed inside the body have been developed. These have done away with the major challenge of removal of an implant after it has served its intended function. Important factors are taken into consideration in design and development of implants from such biomaterials are mechanical properties, degradation rate, surface modification, rate of corrosion, biocompatibility, and non-toxicity. Given the importance of such materials in clinical applications, the chapter presents an overview of the bioresorable composites and their implants. The related properties and the functions served have been outlined briefly. Further, the challenges associated and the remedies to overcome them have also been delineated.

Elastic Properties of Artificially Layered Thin Films

1987 ◽  
Vol 103 ◽  
Author(s):  
Robert C. Cammarata
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Composite Materials ◽  
Elastic Properties ◽  
Elastic Moduli ◽  
Metallic Thin Films ◽  
Theoretical Understanding ◽  
Composition Modulation

ABSTRACTEnhancements in the elastic moduli by factors of two or more in compositionally modulated metallic thin films have been observed for a certain range of composition modulation wavelengths. The experimental and theoretical understanding of this phenomenon, known as the supermodulus effect, is reviewed. Also, the mechanical properties of other artificially layered and composite materials are discussed and compared with the behavior of metallic superlattice thin films.

scholarly journals Exploring the Role of Nanoparticles in Enhancing Mechanical Properties of Hydrogel Nanocomposites

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 882 ◽  
Author(s):  
Josergio Zaragoza ◽  
Scott Fukuoka ◽  
Marcus Kraus ◽  
James Thomin ◽  
Prashanth Asuri
Keyword(s):  
Mechanical Properties ◽  
Elastic Moduli ◽  
Maximum Modulus ◽  
Polymer Particle ◽  
Particle Interactions ◽  
Polyacrylamide Hydrogels ◽  
The Past ◽  
Wide Range ◽  
Hydrogel Nanocomposites

Over the past few decades, research studies have established that the mechanical properties of hydrogels can be largely impacted by the addition of nanoparticles. However, the exact mechanisms behind such enhancements are not yet fully understood. To further explore the role of nanoparticles on the enhanced mechanical properties of hydrogel nanocomposites, we used chemically crosslinked polyacrylamide hydrogels incorporating silica nanoparticles as the model system. Rheological measurements indicate that nanoparticle-mediated increases in hydrogel elastic modulus can exceed the maximum modulus that can be obtained through purely chemical crosslinking. Moreover, the data reveal that nanoparticle, monomer, and chemical crosslinker concentrations can all play an important role on the nanoparticle mediated-enhancements in mechanical properties. These results also demonstrate a strong role for pseudo crosslinking facilitated by polymer–particle interactions on the observed enhancements in elastic moduli. Taken together, our work delves into the role of nanoparticles on enhancing hydrogel properties, which is vital to the development of hydrogel nanocomposites with a wide range of specific mechanical properties.

Novel approach for simulating the elastic properties of porous rocks including the critical porosity phenomena

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. L37-L44 ◽  
Author(s):  
Mikhail Markov ◽  
Elena Kazatchenko ◽  
Aleksandr Mousatov ◽  
Evgeny Pervago
Keyword(s):  
Elastic Properties ◽  
Elastic Moduli ◽  
Phase 1 ◽  
Elastic Solid ◽  
Critical Value ◽  
Porous Rocks ◽  
Rock Falls ◽  
Critical Porosity ◽  
Type Phase ◽  
Wide Range

We tested an approach for calculating the effective elastic properties of rocks taking into account their critical porosity (the percolation threshold). The concept of critical porosity considers that when the porosity of a rock exceeds the critical value, the shear modulus of the rock tends to zero, making it lose its rigidity and the rock falls apart. The classical homogenization schemes do not describe the mechanical properties of a rock near the critical porosity. The approach proposed here is based on the generalized differential effective medium (GDEM) method. We introduce a model of porous elastic media composed of an elastic solid host containing ellipsoidal inclusions of two types. Inclusions of the first type (phase 1) represent pores, and inclusions of the second type (phase 2) contain elastic solid material described by the same elastic properties as the host (phase 0). In this model, with an increase in porosity, the concentration of the host decreased, and it tended to zero near the critical porosity. The model was used for simulation of rock elastic moduli. We compared the modeling results for elastic moduli and acoustic velocities with the experimental data and empirical petrophysical equations. The comparison showed that the GDEM model describes the elastic properties behavior in a wide range of porosity up to the critical value.

Contributions of Trabecular Rods of Various Orientations in Determining the Elastic Properties of Human Vertebral Trabecular Bone

2007 ◽  
Author(s):  
Xiaowei S. Liu ◽  
X. Henry Zhang ◽  
Paul Sajda ◽  
Punam K. Saha ◽  
Felix W. Wehrli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Trabecular Bone ◽  
Elastic Properties ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Human Trabecular Bone ◽  
Vertebral Trabecular Bone ◽  
Age Related

Osteoporosis is an age-related disease characterized by low bone mass and architectural deterioration. Other than bone volume fraction (BV/TV), microarchitecture of trabecular bone, such as trabecular type (rods or plates), connectivity, and orientation of the trabecular network is also believed to be important in governing the mechanical properties of trabecular bone. A recent study [1] showed that the microarchitecture alone affects elastic moduli of trabecular bone and, further, that trabecular plates make a far greater contribution than rods. In human vertebral trabecular bone, the roles of transverse vs. vertical rods in conferring mechanical properties of trabecular bone have been debated [2, 3]. It has been suggested that the role of transverse trabecular rod is critical in determining elastic modulus of vertebral trabecular bone. However, without explicit classifications of trabecular type, or orientation assessment at an individual trabecula level, it is not possible yet to test this hypothesis in human trabecular bone samples despite the development of three-dimensional (3D) micro computed tomography (μCT) and μCT based finite element (FE) models of human trabecular bone. With the newly developed technique of complete volumetric decomposition and individual trabecula based orientation analyses [4], now it is possible to quantitatively examine the contributions of trabecular rods of various orientations in the elastic properties of vertebral trabecular bone.

Anatomy and mechanical properties of woods used in electric guitars

IAWA Journal ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 106-S6 ◽  
Author(s):  
Patrik Ahvenainen
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Wood Species ◽  
Principal Component ◽  
High Density ◽  
The Body ◽  
Electric Guitar ◽  
Wide Range ◽  
Acoustic Instruments ◽  
Electric Guitars

ABSTRACT Many endangered tropical hardwoods are commonly used in electric guitars. In order to find alternative woods, the current electric guitar woods need to be studied and classified as most research in this field has focused on acoustic instruments. Classification was done based on luthier literature, woods used in commercially available electric guitars, commercially available tonewoods and by interviewing Finnish luthiers. Here, the electric guitar woods are divided into three distinct classes based on how they are used in the guitar: low-density wood used in the body only (alder, poplar, basswood, ash), medium-density wood used in the body and neck (maple and mahogany), and high-density wood used in the fretboard only (rosewood and ebony). Together, these three classes span a wide range of anatomical and mechanical properties, but each class itself is limited to a relatively narrow parameter space. Statistically significant differences between these classes and the average hardwoods exist in the wood anatomy (size and organization of vessels, fibres, rays and axial parenchyma), in the mechanical properties (density, elastic modulus, Janka hardness, etc.) and in the average price per volume. In order to find substitute woods for a certain guitar wood class, density and elastic modulus can already be used to rule out most wood species. Based on principal component analysis of the elastomechanical and anatomical properties of commercially available hardwoods, few species are similar to the low- and high-density class woods. However, for all of the three electric guitar wood classes, non-endangered wood species are already commercially available from tonewood retailers that match the class characteristics presented here.

scholarly journals I. A mathematical discussion on the structure of wood in relation to its elastic properties

1929 ◽  
Vol 228 (659-669) ◽  
pp. 1-62 ◽  
Keyword(s):  
Mechanical Properties ◽  
Internal Structure ◽  
Elastic Properties ◽  
Elastic Moduli ◽  
Elastic Anisotropy ◽  
Complete Theory ◽  
Organic Structure ◽  
Simple Compression ◽  
Distribution Of Stress ◽  
Correct Estimate

1. Introduction .—In estimating the mechanical properties of any material, two sets of quantities have to be measured, the elastic moduli and the strength values. Many materials can be regarded as isotropic and homogeneous, and the theory of the testing of such materials is relatively simple. Wood, however, possesses an organic structure which renders it both anisotropic and heterogeneous, and the usual simple theory will only apply to a few cases, such as simple compression, a more complete theory being necessary for the consideration of more complex deformations. In particular, wood is very definitely anisotropic as regards its elastic properties, and the investigation of such problems as the bending and twisting of wooden members requires a theory as to the nature of this elastic anisotropy, not only for finding the elastic deformation, but also, by showing the distribution of stress in such cases, to enable a correct estimate of the strength of the member to be obtained. The mechanical properties (and, in particular, the elastic properties) of wood depend upon its internal structure, and some definite knowledge of the nature of this dependence would appear to form a useful step towards a more complete theory of wood-testing than at present exists.

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