Determination of mechanical stiffness of bone by pQCT measurements: correlation with non-destructive mechanical four-point bending test data

2004 ◽  
Vol 37 (8) ◽  
pp. 1289-1293 ◽  
Author(s):  
Daniel E Martin ◽  
Anne E Severns ◽  
J.Michael Kabo
Keyword(s):  
Test Data ◽  
Bending Test ◽  
Mechanical Stiffness ◽  
Four Point Bending ◽  
Four Point Bending Test ◽  
Non Destructive

scholarly journals Assessment of Bending Properties of Sawn and Glulam Blackwood in Portugal

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 418 ◽  
Author(s):  
Carlos Martins ◽  
Sandra Monteiro ◽  
Sofia Knapic ◽  
Alfredo Dias
Keyword(s):  
Bending Strength ◽  
Longitudinal Vibration ◽  
Raw Material ◽  
Bending Test ◽  
Mean Values ◽  
Four Point Bending ◽  
Structural Applications ◽  
Four Point Bending Test ◽  
The University ◽  
Non Destructive

Portuguese forests have changed in recent years. These changes were mainly boosted by the wildfires that affected a significant percentage of the softwood area. Data from 2015, conveyed by the Portuguese Institute for Nature Conservation and Forests, indicates that hardwoods occupy 70% of the Portuguese forest area. This paper presents the Blackwood (Acacia melanoxylon R. Br.) species potential, focusing on construction applications, based on recent studies performed at the University of Coimbra and SerQ—Forest Innovation and Competences Center. The valuation of Blackwood for structural applications has been considered through the non-destructive and destructive assessment of their mechanical properties as sawn wood. Their potential was also assessed for a more technologically engineered wood product, the glulam. The dynamic modulus of elasticity (MOE) was estimated through the Longitudinal Vibration Method (LVM) and the Transformed Section Method (TSM); the static MOE and bending strength were assessed through a four-point bending test. Agreement was obtained between both approaches. Sawn Portuguese Blackwood showed a density of 647 kg/m3, 13,900 MPa of MOE and a bending strength of 65 MPa (mean values). The glulam beams fabricated with this raw material had improved properties relative to sawn wood, most obviously concerning the bending strength, with an improvement of 29%. This proves the significant ability and potential of these species to be used in construction products with structural purposes like sawn wood and glulam.

Bending and Contact Strength of Monolithic Ceramic Materials

2011 ◽  
Vol 21 (2) ◽  
pp. 293-305 ◽  
Author(s):  
Lucia Hegedűsová ◽  
Ladislav Ceniga ◽  
Ján Dusza
Keyword(s):  
Mechanical Loading ◽  
Ceramic Materials ◽  
Mechanical Tests ◽  
Bending Test ◽  
Weibull Analysis ◽  
Single Cycle ◽  
Contact Test ◽  
Four Point Bending ◽  
Four Point Bending Test

The article deals with the determination of strength of monolithic ceramic materials by mechanical tests, in bending and contact modes, simulated by a four-point bending test and single-cycle contact test using rollers or spheres, respectively. In general, the determination of strength of ceramic materials results from statistical methods, usually represented by the Weibull analysis comprising of the determination of the characteristic strength σ0 and the Weibull modulus m. Accordingly, the characteristic strength σ0,bend and σ0,cont as well as the Weibull moduli mbend and mcont, related to the four-point bending test and the single-cycle contact test using rollers, are determined, respectively. Additionally, the comparison of numerical results of σ0,bend/ σ0,cont, mbend/ mcont confirms the validity of the Fett's theory. Along with this verification and the Weibull analysis for mechanical loading by spheres, a microstructural analysis of strength-degrading defects as fraction origins is performed for the bending and contact modes which induce different types of crack. Finally, the determination of mechanical loading causing material failure and an analysis of parameters of the cracks is also presented. The mechanical tests were applied to monolithic Si3N4 and SiC ceramic materials.

Contact Strength and Cracking of Laminar Ceramics

2012 ◽  
Vol 31 (2) ◽  
Author(s):  
Lucia Hegedűsov’a ◽  
Ladislav Ceniga
Keyword(s):  
Statistical Methods ◽  
Ceramic Materials ◽  
Mechanical Tests ◽  
Bending Test ◽  
Contact Strength ◽  
Weibull Analysis ◽  
Single Cycle ◽  
Four Point Bending ◽  
Four Point Bending Test

AbstractThe paper deals with the determination of strength of laminar ceramics by mechanical tests in bending and contact modes. The bending and contact modes are simulated by the four-point bending test, and by single-cycle contact test using rollers or spheres, respectively. In general, the determination of strength of ceramic materials results from statistical methods which are usually represented by the Weibull analysis. The Weibull analysis comprises the determination of the characteristic strength

Testing of Concrete and Fibre Reinforced Concrete in Uniaxial Tension

2015 ◽  
Vol 1106 ◽  
pp. 49-52
Author(s):  
Martin Tipka ◽  
Jitka Vašková
Keyword(s):  
Reinforced Concrete ◽  
Uniaxial Tension ◽  
Direct Analysis ◽  
Bending Test ◽  
Strain Diagram ◽  
Fibre Reinforced Concrete ◽  
Four Point Bending ◽  
Deformation Parameters ◽  
Four Point Bending Test

The paper deals with an investigation of tensile properties of concrete and fibre reinforced concrete using the test in uniaxial tension. This arrangement is technically more difficult compared to the commonly used bending test, but allows easier determination of strength-deformation parameters of material. The advantage of the test is the possibility of direct analysis of the post-peak part of the stress-strain diagram in tension. The article describes the recommended test arrangement and analyzes methodology of loading. Attention is focused on the critical phase of the loading process and subsequent evaluation of results. In the experimental research was compared strength and corresponding strain of specific fibre reinforced concrete, obtained in three-point and four-point bending test, and the uniaxial tension test. The results of this comparative study are presented in the conclusion.

Bending and Contact Strength of a Ceramic Nanocomposite

2009 ◽  
Vol 417-418 ◽  
pp. 761-764
Author(s):  
Ján Dusza ◽  
Lucia Hegedűsová ◽  
Monika Kašiarová ◽  
Erika Csehová
Keyword(s):  
Microstructural Analysis ◽  
Bending Test ◽  
Material Failure ◽  
Contact Loading ◽  
Four Point Bending ◽  
Different Dimensions ◽  
Processing Defects ◽  
Four Point Bending Test ◽  
Stable Growth

The paper deals with the determination of the characteristic strength and as well as the Weibull moduli and of the Si3N4+SiC micro/nanocomposite determined by the four-point bending test and the contact test using opposite spheres both applied to specimens of different size, respectively. Material failure in the bending and contact modes is caused by the presence of processing defects as fracture origins, and by the formation of cone cracks, respectively, where a stable growth of the cone cracks initiated during contact loading is assumed to be a reason of , . A microstructural analysis of the processing flaws, and a mathematical analysis of the propagation of the cone cracks regarding different dimensions of a specimen are also presented.

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