scholarly journals Influence of osteoporosis on the compressive properties of femoral cancellous bone and its dependence on various density parameters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
F. Metzner ◽  
C. Neupetsch ◽  
J.-P. Fischer ◽  
W.-G. Drossel ◽  
C.-E. Heyde ◽  
...  
Keyword(s):  
Material Testing ◽  
Compressive Modulus ◽  
Osteoporotic Bone ◽  
Review Of The Literature ◽  
Compressive Properties ◽  
Testing Methods ◽  
Fe Modelling ◽  
Plateau Stress ◽  
Cylindrical Samples ◽  
Compressive Tests

AbstractData collection of mechanical parameters from compressive tests play a fundamental role in FE modelling of bone tissues or the developing and designing of bone implants, especially referring to osteoporosis or other forms of bone loss. A total of 43 cylindrical samples (Ø8 × 16 mm) were taken from 43 freshly frozen proximal femora using a tenon cutter. All femora underwent BMD measurement and additionally apparent- and relative- and bulk density (ρapp, ρr, ρb) were determined using samples bordering the compressive specimen on the proximal and distal regions. All samples were classified as "normal", "osteopenia" and "osteoporosis" based on the DEXA measurements. Distal apparent density was most suitable for predicting bone strength and BMD. One novel aspect is the examination of the plateau stress as it describes the stress at which the failure of spongious bone progresses. No significant differences in mechanical properties (compressive modulus E; compressive stress σmax and plateau stress σp) were found between osteopenic and osteoporotic bone. The results suggest that already in the case of a known osteopenia, actions should be taken as they are applied in the case of osteoporosis A review of the literature regarding extraction and testing methods illustrates the urgent need for standardized biomechanical compressive material testing.

Compressive Properties of Hot-Rolled Mg-Zr-Ca Alloys for Biomedical Applications

2011 ◽  
Vol 197-198 ◽  
pp. 56-59 ◽  
Author(s):  
Ying Long Zhou ◽  
Dong Mei Luo ◽  
Wang Yu Hu ◽  
Yun Cang Li ◽  
Peter D. Hodgson ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Biomedical Applications ◽  
Compressive Modulus ◽  
Human Bone ◽  
Compressive Yield Strength ◽  
X Ray Diffraction ◽  
Compressive Properties ◽  
X Ray ◽  
Hot Rolled ◽  
Compressive Tests

This paper investigated the microstructures and compressive properties of hot-rolled Mg-Zr-Ca alloys for biomedical applications. The microstructures of the Mg-Zr-Ca alloys were examined by X-ray diffraction analysis and optical microscopy, and the compressive properties were determined from compressive tests. The experimental results indicate that the hot-rolled Mg-Zr-Ca alloys with 1% Ca are composed of one single a phase and those alloys with 2% Ca consist of both Mg2Ca and a phase. The hot-rolled Mg-Zr-Ca alloys exhibit typical elongated microstructures with obvious fibrous stripe, and have much higher compressive strength and lower compressive modulus than pure Mg. All the studied alloys have much higher compressive yield strength than the human bone (90~140 MPa) and comparable modulus with the human bone, suggesting that they have a great potential to be good candidates for biomedical applications.

Effect of micro in-plane fiber waviness on compressive properties of unidirectional fabric composites

2017 ◽  
Vol 52 (15) ◽  
pp. 2065-2074 ◽  
Author(s):  
Bo Wang ◽  
Nobuhide Uda ◽  
Kousei Ono ◽  
Hiroto Nagai
Keyword(s):  
Compressive Strength ◽  
Numerical Model ◽  
Tensile Stress ◽  
Compressive Modulus ◽  
Two Dimensional ◽  
Compressive Properties ◽  
Fiber Waviness ◽  
Experimental Part ◽  
Fabric Composites ◽  
Vartm Process

In this paper, a combination of experimentation and analysis is used to study the effect of micro in-plane fiber waviness on the compressive properties of unidirectional fabric composites. The experimental part includes a measurement of the micro in-plane fiber waviness in two types of unidirectional fabrics, manufacturing composites with each unidirectional fabric via VaRTM process and tests for establishing the compressive modulus and strengths of the composites. The compressive strengths were confirmed to be affected by the micro in-plane fiber waviness, but the compressive modulus was not. Furthermore, a two-dimensional numerical model is proposed to explain our experimental results. The numerical results indicate that the tensile stress (owing to the micro in-plane fiber waviness) and compressive stress along the weft and warp directions, respectively, of the composite lead to reductions in the compressive strength.

scholarly journals Effect of MWCNT Surface Functionalisation and Distribution on Compressive Properties of Kenaf and Hybrid Kenaf/Glass Fibres Reinforced Polymer Composites

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2522 ◽  
Author(s):  
Napisah Sapiai ◽  
Aidah Jumahat ◽  
Mohammad Jawaid ◽  
Anish Khan
Keyword(s):  
Polymer Composites ◽  
Hybrid Composites ◽  
Testing Machine ◽  
Compressive Modulus ◽  
Filament Winding ◽  
Uniaxial Compression Test ◽  
Compressive Properties ◽  
Multi Wall Carbon Nanotubes ◽  
Resin Impregnation ◽  
Reinforced Polymer

The aim of this study is to evaluate the effect of surface treated multi wall carbon nanotubes (MWCNTs) on compressive properties of the unidirectional (UD) kenaf and hybrid woven glass/UD kenaf fibre reinforced polymer composites. The MWCNTs were first treated using concentrated acid (a mix of H2SO4 and HNO3) and silane (three-aminoprophyltriethoxysilane) in order to improve the dispersion within the epoxy matrix using a high shear roll milling technique. In this study, nanomodified epoxies were prepared using 0.5, 0.75 and 1.0 wt % of pristine MWCNT (PCNT), acid treated MWCNT (ACNT) and silane treated MWCNT (SCNT). These nanomodified epoxies were then used for the fabrication of kenaf and hybrid composites using combination of filament winding and resin impregnation. The uniaxial compression test was conducted using a universal testing machine according to the ASTM D3410 standard. The morphology of fractured samples was observed and analysed using scanning electron microscopy (SEM) in order to evaluate the failure behaviour and mechanisms involved during compression. It was found that the addition of treated MWCNT (ACNT and SCNT) improved the compressive properties of kenaf and hybrid composites as compared to those of untreated-MWCNT (PCNT). The addition of 1.0 wt % of SCNT exhibited good compressive properties in both kenaf and hybrid composite systems. The compressive modulus and strength increased by 73.25% and 20.15%, respectively, for composites made of 1.0 wt % SCNT and Kenaf (1.0SCNT/K). For the hybrid composites, the compressive modulus and strength increased by 21.18% and 7.73% for composites made of 1.0 wt % SCNT filled G/K composites (1.0SCNT/G/K).

Compressive properties at elevated temperatures of porous aluminum processed by the spacer method

2005 ◽  
Vol 20 (12) ◽  
pp. 3385-3390 ◽  
Author(s):  
Masataka Hakamada ◽  
Tatsuho Nomura ◽  
Yasuo Yamada ◽  
Yasumasa Chino ◽  
Hiroyuki Hosokawa ◽  
...  
Keyword(s):  
Activation Energy ◽  
Relative Density ◽  
Stress Exponent ◽  
Elevated Temperatures ◽  
Chemical Compositions ◽  
Compressive Properties ◽  
Homogeneous Microstructure ◽  
Plateau Stress ◽  
Porous Aluminum

Compressive properties at 573–773 K of porous aluminum produced by the spacer method were investigated and compared with those of bulk reference aluminum with the same chemical compositions. The stress exponent and activation energy for deformation at elevated temperatures in the porous aluminum were in agreement with those in the bulk reference aluminum. In addition, the plateau stress of the porous aluminum was comparable to the stress of the bulk reference aluminum upon compensation by the relative density. Therefore, it is conclusively demonstrated that the mechanism of deformation at elevated temperatures in the porous aluminum is the same as that in the bulk reference aluminum. This is likely due to the homogeneous microstructure in the porous aluminum produced by the spacer method.

scholarly journals Compressive Properties of A2024 Alloy Foam Fabricated through a Melt Route and a Semi-Solid Route

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 153 ◽  
Author(s):  
Takashi Kuwahara ◽  
Taro Osaka ◽  
Mizuki Saito ◽  
Shinsuke Suzuki
Keyword(s):  
Grain Size ◽  
Absorption Efficiency ◽  
S Phase ◽  
Compressive Properties ◽  
Alloying Element ◽  
Plateau Stress ◽  
Energy Absorption Efficiency ◽  
Semi Solid ◽  
Primary Crystals ◽  
Solid Temperature

A2024 alloy foams were fabricated by two methods. In the first method, the melt was thickened by Mg, which acts as an alloying element (melt route). In the second method, the melt was thickened by using primary crystals at a semi-solid temperature with a solid fraction of 20% (semi-solid route). A2024 alloy foams fabricated through the semi-solid route had coarse and uneven pores. This led to slightly brittle fracture of the foams, which resulted in larger energy absorption efficiency than that of the foams fabricated through the melt route. Moreover, A2024 alloy foams fabricated through the semi-solid route had a coarser grain size because of the coarse primary crystals. However, by preventing the decrease in the alloying element Mg, the θ/θ’ phase was suppressed. Additionally, by preventing the precipitation of the S′ phase, the amount of Guinier-Preston-Bagaryatsky (GPB) zone increased. This resulted in a larger plateau stress.

Mechanical Testing of Diffusion Bonded Metallic Hollow Sphere Structure (MHSS)

2008 ◽  
Vol 280-281 ◽  
pp. 85-96 ◽  
Author(s):  
Christoph Veyhl ◽  
Rolf Winkler ◽  
Markus Merkel ◽  
Andreas Öchsner
Keyword(s):  
Mechanical Properties ◽  
Flow Stress ◽  
Mechanical Testing ◽  
Hollow Sphere ◽  
Material Behaviour ◽  
Initial Flow ◽  
Plateau Stress ◽  
Plastic Modulus ◽  
Compressive Testing ◽  
Compressive Tests

The paper investigates the mechanical properties of sintered hollow sphere struc- tures. First of all, the Young's modulus, plastic modulus, initial flow stress, initial flow strain, plateau stress and densifcation strain are derived from compressive tests. In addition, the material behaviour during the compressive testing is described. Furthermore, the influence of different specimen shapes on the results is discussed.

Methods of Material Testing in High-Pressure Hydrogen Environment and Evaluation of Hydrogen Compatibility of Metallic Materials: Current Status in Japan

2018 ◽  
Author(s):  
Hideo Kobayashi ◽  
Hiroshi Kobayashi ◽  
Takeru Sano ◽  
Takashi Maeda ◽  
Hiroaki Tamura ◽  
...  
Keyword(s):  
High Pressure ◽  
Material Testing ◽  
Test Methods ◽  
Current Status ◽  
Metallic Materials ◽  
Testing Methods ◽  
Hydrogen Environment ◽  
The Status ◽  
Compatibility Of Materials ◽  
Pressure Hydrogen

In Japan, with regards to the widespread commercialization of 70 MPa-class hydrogen refueling stations and fuel cell vehicles, two national projects have been promoted on both the infrastructure and the automobile sides. These projects have been promoted to establish the criteria for determining hydrogen compatibility of materials and to expand the usable materials for high-pressure hydrogen environment. For these projects, establishing test methods to evaluate the hydrogen compatibility of materials is one of the most important tasks. This paper describes the status of common standardization of testing methods. Two projects share a common database for the testing results, which is currently put to practical use.

Use of Scanning Vibrating Electrode Technique to Localized Corrosion Evaluation

2015 ◽  
Vol 228 ◽  
pp. 353-368 ◽  
Author(s):  
Bożena Łosiewicz ◽  
Magdalena Popczyk ◽  
Magdalena Szklarska ◽  
Agnieszka Smołka ◽  
Patrycja Osak ◽  
...  
Keyword(s):  
Current Density ◽  
Potential Gradient ◽  
Localized Corrosion ◽  
Review Of The Literature ◽  
Testing Methods ◽  
Electrochemical Testing ◽  
Local Element ◽  
Corrosion Evaluation ◽  
Alloy Steels ◽  
Electrode Technique

This work presents the basic theory and the usability of the scanning vibrating electrode technique (SVET), especially in the field of corrosion. At present, SVET is to be considered as one of the latest electrochemical testing methods. The essence of determining the current density resulting from corrosion is limited to the measurement of the potential gradient between the two points on the surface of the metal and over it, within the electric field of a local element. SVET has been used to study local, galvanic and intercrystalline corrosion. It is particularly useful in studying the corrosion of alloy steels and welding agents. This paper presents a review of the literature on the newest research in this field.

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