A Basic Study of Characteristics Between Stress and Deflection on Strength Test of Bio-Ceramics

Author(s):  
Mitsuyuki Nakayama ◽  
Hideto Suzuki

Comparing the mechanical characteristics of bio-ceramics with the elaborate bone, there are two important conditions required for it. First, the strength must be three times larger than that of the elaborate bone. Second, Young’s modulus must be two or three times larger than that. However, the biomaterial which satisfies these conditions hasn’t developed. So, it is the main purpose of this research to clarify the relation between stress and deflection on strength test of bio-ceramics, and to get the fundamental data for improvement. In this paper, it is discussed how such quantity as deflection, stress and stress increasing rate are related. As the result, the following characteristics were found. First, deflection and the breaking stress increase as an average grain diameter of bio-ceramics becomes small. Second, the behavior of the stress increasing rate to deflection can be classified into two types. These are the fluctuation type and the stable type. Third, the experimental equations are obtained against the maximum deflection. One is for the breaking stress, and the other is for the maximum stress increasing rate. From the discussion, it was found that the characteristics of stress and deflection depended on such material properties of bio-ceramics as Young’s modulus, an average grain diameter, and micro-structure of the biomaterials.

Author(s):  
Mitsuyuki Nakayama

Comparing the mechanical characteristics of bio-ceramics with a elaborate bone, there are two important conditions required for biomaterial. First, the strength must be three times larger than that of a elaborate bone. Second, Young’s modulus must be two or three times larger than that. However, still the biomaterial hasn’t developed which satisfies these conditions. The purpose of this research is to improve the strength of bio-ceramics. It was discussed how the duration time and mean frequency of acoustic emission (AE) parameters depend on time. These parameters are calculated with AE wave on breaking test of a bio-ceramics. The following main results were obtained. First, AE generating pattern is changed by the property of the materials. Second, in tetragonal zirconia polycrystals (TZP), the phase transformation has affected AE parameters. Consequently, it was shown that AE parameters had the material dependability.


2016 ◽  
Vol 18 (31) ◽  
pp. 21508-21517 ◽  
Author(s):  
Xiao-Ye Zhou ◽  
Bao-Ling Huang ◽  
Tong-Yi Zhang

Surfaces of nanomaterials play an essential role in size-dependent material properties.


1954 ◽  
Vol 11 (1) ◽  
pp. 66-70 ◽  
Author(s):  
J. A. GILLESPIE

SUMMARY 1. Paralysis, produced in young male rats by avulsion of peripheral nerves, resulted in a highly significant reduction in the total weight, ash weight, ash percentage, X-ray density and bending moment at the breaking point, of the bones of the affected limb. The breaking stress was significantly reduced, but Young's modulus of elasticity was unaltered. 2. Certain of these changes were modified by treatment with sex hormones. Both oestradiol and testosterone significantly reduced the difference between the bones of the normal and paralysed limbs in respect of total weight, ash weight and bending moment at the breaking point. 3. Treatment with oestradiol significantly increased both the ash percentage and Young's modulus of elasticity, the increase affecting equally the bones of the normal and paralysed limbs. Testosterone treatment did not significantly affect either of these properties, and neither hormone affected the breaking stress.


1986 ◽  
Vol 108 (2) ◽  
pp. 141-148 ◽  
Author(s):  
H. C. Park ◽  
Y. K. Liu ◽  
R. S. Lakes

The elastic Young’s modulus and shear modulus of bone-particle impregnated polymethylmethacrylate (PMMA) has been measured experimentally at room temperature as a function of bone particle concentration. It was found that the moduli increased with increasing bone particle content. This increase was less than the stiffness increase predicted by higher-order composite theory [1, 2] under the assumption of perfect bonding between particles and matrix. It was concluded that a bond existed but that it was not a perfect bond.


2021 ◽  
Vol 64 (6) ◽  
pp. 2025-2034
Author(s):  
Matthew W Schramm ◽  
Mehari Z. Tekeste ◽  
Brian L Steward

HighlightsSimulation of uniaxial compression was performed with flexible fibers modeled in DEM.Bond-specific DEM parameters were found to be sensitive in uniaxial compression.A calibration technique that is not plunger-dependent is shown and validated.Abstract. To accurately simulate a discrete element method (DEM) model, the material properties must be calibrated to reproduce bulk material behavior. In this study, a method was developed to calibrate DEM parameters for bulk fibrous materials using uniaxial compression. Wheat straw was cut to 100.2 mm lengths. A 227 mm diameter cylindrical container was loosely filled with the cut straw. The material was pre-compressed to 1 kPa. A plunger (50, 150, or 225 mm diameter) was then lowered onto the compressed straw at a rate of 15 mm s-1. This experimental procedure was simulated using a DEM model for different material properties to generate a simulated design of experiment (DOE). The simulated plunger had a travel rate of 40 mm s-1. The contact Young’s modulus, bond Young’s modulus, and particle-to-particle friction DEM parameters were found to be statistically significant in the prediction of normal forces on the plunger in the uniaxial compression test. The DEM calibration procedure was used to approximate the mean laboratory results of wheat straw compression with root mean square (RMS) percent errors of 3.77%, 3.02%, and 13.90% for the 50, 150, and 225 mm plungers, respectively. Keywords: Calibration, DEM, DOE, Flexible DEM particle, Uniaxial compression, Wheat straw.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Brent D. Opell ◽  
Sarah D. Stellwagen

AbstractAn orb web’s prey capture thread relies on its glue droplets to retain insects until a spider can subdue them. Each droplet’s viscoelastic glycoprotein adhesive core extends to dissipate the forces of prey struggle as it transfers force to stiffer, support line flagelliform fibers. In large orb webs, switchback capture thread turns are placed at the bottom of the web before a continuous capture spiral progresses from the web’s periphery to its interior. To determine if the properties of capture thread droplets change during web spinning, we characterized droplet and glycoprotein volumes and material properties from the bottom, top, middle, and inner regions of webs. Both droplet and glycoprotein volume decreased during web construction, but there was a progressive increase in the glycoprotein’s Young’s modulus and toughness. Increases in the percentage of droplet aqueous material indicated that these increases in material properties are not due to reduced glycoprotein viscosity resulting from lower droplet hygroscopicity. Instead, they may result from changes in aqueous layer compounds that condition the glycoprotein. A 6-fold difference in glycoprotein toughness and a 70-fold difference in Young’s modulus across a web documents the phenotypic plasticity of this natural adhesive and its potential to inspire new materials.


2017 ◽  
Vol 6 (3) ◽  
pp. 37
Author(s):  
Yoshiharu Mae

The abundance of elements in the universe was plotted on the TC-YM diagram. The most abundant elements show the unique pattern drawing a quadrant. Next, the neutron multiple number, the number of neutron per proton in the nucleus, was introduced. The neutron multiple numbers of elements show the same pattern as the abundance of elements on the diagram. As a result, the abundance of elements shows a good correlation with neutron multiple numbers of elements. With increasing neutron multiple number, the abundance decreases. Besides, the neutron multiple number relates to the materials properties such as the Young’s modulus, thermal conductivity and melting temperature of elements.


2010 ◽  
Vol 160-162 ◽  
pp. 1691-1698 ◽  
Author(s):  
Zhi Xin Huang ◽  
Cai Fu Qian ◽  
Peng Liu ◽  
Xu Liang Deng ◽  
Qing Cai ◽  
...  

This study aimed at investigating the effects of the post material properties on the maximum stress in the root and maximum deformation of the restorative system. Effects of material properties of fiber post on the maximum equivalent stress in the root and the maximum deformation of the restorative system were numerically investigated. Results show that the maximum equivalent stress in the root can be decreased by 8.3% and the maximum deformation of the restorative system decreased by 10% compared with corresponding maximum values if changing Young’s modulus, Shear modulus and Poisson’s ratio in the range studied here. The maximum equivalent stress in the root is more sensitive to Young’s modulus and Poisson’s ratio while the deformation of the restorative system is more seriously affected by the Shear modulus of the post material.


2018 ◽  
Vol 140 (11) ◽  
Author(s):  
A. Delissen ◽  
G. Radaelli ◽  
L. A. Shaw ◽  
J. B. Hopkins ◽  
J. L. Herder

A great deal of engineering effort is focused on changing mechanical material properties by creating microstructural architectures instead of modifying chemical composition. This results in meta-materials, which can exhibit properties not found in natural materials and can be tuned to the needs of the user. To change Poisson's ratio and Young's modulus, many current designs exploit mechanisms and hinges to obtain the desired behavior. However, this can lead to nonlinear material properties and anisotropy, especially for large strains. In this work, we propose a new material design that makes use of curved leaf springs in a planar lattice. First, analytical ideal springs are employed to establish sufficient conditions for linear elasticity, isotropy, and a zero Poisson's ratio. Additionally, Young's modulus is directly related to the spring stiffness. Second, a design method from the literature is employed to obtain a spring, closely matching the desired properties. Next, numerical simulations of larger lattices show that the expectations hold, and a feasible material design is presented with an in-plane Young's modulus error of only 2% and Poisson's ratio of 2.78×10−3. These properties are isotropic and linear up to compressive and tensile strains of 0.12. The manufacturability and validity of the numerical model is shown by a prototype.


2010 ◽  
Vol 654-656 ◽  
pp. 2220-2224 ◽  
Author(s):  
Takuya Ishimoto ◽  
Takayoshi Nakano

To evaluate the material parameters of regenerated bone, it is important to clarify the mechanical performance of the regenerated portion. In general, the shape and size of regenerated bone tissue is heterogeneous. It is often difficult to elucidate material properties by means of conventional mechanical tests such as compressive and/or tensile tests and bending tests. The nanoindentation technique has been utilized to evaluate the material properties of small or microstructured materials because they do not necessarily require a large well-designed specimen. Thus, this technique may be useful for the evaluation of the material properties of regenerated bone tissue. In this study, this technique was applied for the assessment of the Young’s modulus and hardness of regenerated and intact long bones of a rabbit. The regenerated bone exhibited a significantly lower Young’s modulus and hardness than the intact bone. The regenerated long bone also exhibited impaired mechanical properties, which may have been caused by the difference in the nano-organization of its collagen fibers and mineral crystals (the main components of bone tissue), from that of the intact bone.


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