Estimation of Mechanical Properties and Mass Density of Al-Malwiya Masonry

Abstract This paper presents the first estimation for the mechanical properties and the mass density of the masonry of Al-Malwiya heritage minaret. Many approaches are investigated in order to estimate the modulus of elasticity, shear modulus, Poisson’s ratio, and the mass density for this historic masonry. The mechanical properties are estimated by using empirical formulas and analytical equations, while the mass density is estimated after carrying out experimental tests for the extracted samples of the historic mortar. The estimated properties showed relatively low values compared with the newly constructed masonries, but they were interpreted as reasonable for such a historic construction.

Download Full-text

Determination of Scale Effects on Mechanical Properties of Berea Sandstone

Geofluids ◽

10.1155/2021/6637371 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Hui Li ◽

Kaoping Song ◽

Mingguang Tang ◽

Ming Qin ◽

Zhenping Liu ◽

...

Keyword(s):

Mechanical Properties ◽

Shear Modulus ◽

Bulk Modulus ◽

Poisson’S Ratio ◽

Failure Modes ◽

Shear Failure ◽

Scale Effects ◽

Poisson's Ratio ◽

Axial Splitting ◽

Rock Mechanical Properties

The key rock mechanical parameters are strength, elastic modulus, Poisson’s ratio, etc., which are important in reservoir development. The accurate determination of reservoir’s mechanical properties is critical to reduce drilling risk and maximize well productivity. Precisely estimating rock mechanical properties is important in drilling and well completion design, as well as crucial for hydraulic fracturing. Rocks are heterogeneous and anisotropic materials. The mechanical properties vary not only with rock types but also with measurement methods, sample geometric dimensions (sample length to diameter ratio and size), and other factors. To investigate sample scale effects on rock mechanical behaviors, unconfined compression tests were conducted on 41 different geometric dimensions of Berea sandstones; unconfined compressive strength (UCS), Young’s modulus ( E ), Poisson’s ratio ( υ ), bulk modulus ( K ), and shear modulus ( G ) were obtained and compared. The results indicate that sample geometry can significantly affect rock mechanical properties: (1) UCS decreases with the increase of length to diameter ratio (LDR), and the UCS standardize factor is between 0.71 and 1.17, which means -30% to +20% variation of UCS with LDR changing from 1 to 6.7. The test results show UCS exhibits positive relationship with sample size. (2) Young’s modulus slightly increases with LDR increases, while Poisson’s ratio decreases with the increase of LDR. For the tested Berea sandstones, Poisson’s ratio standardizing factor is between 0.57 and 1.11. (3) Bulk modulus of Berea sandstone samples decreases with the increase of LDR, while shear modulus increases with LDR increases. Both bulk modulus and shear modulus increase with the increase of sample size. (4) The principal failure modes were analyzed. The failure modes of the tested Berea sandstones are axial splitting and shear failure. Stocky samples ( LDR < 2 ) tend to go axial splitting, while slender samples ( LDR > 2 ) tend to show shear failure.

Download Full-text

Elastic Mechanical Properties of 45S5-Based Bioactive Glass–Ceramic Scaffolds

Materials ◽

10.3390/ma12193244 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3244 ◽

Cited By ~ 4

Author(s):

Francesco Baino ◽

Elisa Fiume

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Elastic Modulus ◽

Shear Modulus ◽

Glass Ceramic ◽

Poisson’S Ratio ◽

Mechanical Performance ◽

Poisson's Ratio ◽

Shear Moduli ◽

Bioactive Scaffolds

Porosity is recognized to play a key role in dictating the functional properties of bioactive scaffolds, especially the mechanical performance of the material. The mechanical suitability of brittle ceramic and glass scaffolds for bone tissue engineering applications is usually evaluated on the basis of the compressive strength alone, which is relatively easy to assess. This work aims to investigate the porosity dependence of the elastic properties of silicate scaffolds based on the 45S5 composition. Highly porous glass–ceramic foams were fabricated by the sponge replica method and their elastic modulus, shear modulus, and Poisson’s ratio were experimentally determined by the impulse excitation technique; furthermore, the failure strength was quantified by compressive tests. As the total fractional porosity increased from 0.52 to 0.86, the elastic and shear moduli decreased from 16.5 to 1.2 GPa and from 6.5 to 0.43 GPa, respectively; the compressive strength was also found to decrease from 3.4 to 0.58 MPa, whereas the Poisson’s ratio increased from 0.2692 to 0.3953. The porosity dependences of elastic modulus, shear modulus and compressive strength obeys power-law models, whereas the relationship between Poisson’s ratio and porosity can be described by a linear approximation. These relations can be useful to optimize the design and fabrication of porous biomaterials as well as to predict the mechanical properties of the scaffolds.

Download Full-text

Experimental Study on Dynamic Poisson’s Ratio of Rock-Fill Materials under Cyclic Loadings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.2443 ◽

2011 ◽

Vol 243-249 ◽

pp. 2443-2450

Author(s):

De Gao Zou ◽

Jing Mao Liu ◽

Bin Xu ◽

Xian Jing Kong ◽

Tao Gong

Keyword(s):

Shear Modulus ◽

Shear Strain ◽

Poisson’S Ratio ◽

Dynamic Properties ◽

Dynamic Responses ◽

Poisson's Ratio ◽

Dynamic Shear Modulus ◽

Empirical Formulas ◽

Rock Fill ◽

Fill Materials

Dynamic Poisson’s ratio is a very important parameter for the numerical analysis of dynamic responses in a rock-fill dam. It is generally taken as a constant of which the significance is generally underrated. In order to have a better understanding of the dynamic properties of rock-fill materials, a series of tests were performed to investigate the effects of the shear strain on the dynamic Poisson’s ratio. The experimental results show that dynamic Poisson’s ratio varies with the shear strain, the dynamic shear modulus and the confining pressure. In addition, the empirical formulas to determine the dynamic Poisson’s ratio with the shear strain or normalized shear modulus are given in this paper.

Download Full-text

The Mechanical Properties and Elastic Anisotropies of Cubic Ni3Al from First Principles Calculations

Crystals ◽

10.3390/cryst8080307 ◽

2018 ◽

Vol 8 (8) ◽

pp. 307 ◽

Cited By ~ 12

Author(s):

Xinghe Luan ◽

Hongbo Qin ◽

Fengmei Liu ◽

Zongbei Dai ◽

Yaoyong Yi ◽

...

Keyword(s):

Mechanical Properties ◽

Shear Modulus ◽

Bulk Modulus ◽

Young’S Modulus ◽

First Principles ◽

Poisson’S Ratio ◽

Density Functional ◽

Young's Modulus ◽

Small Deviation ◽

Poisson's Ratio

Ni3Al-based superalloys have excellent mechanical properties which have been widely used in civilian and military fields. In this study, the mechanical properties of the face-centred cubic structure Ni3Al were investigated by a first principles study based on density functional theory (DFT), and the generalized gradient approximation (GGA) was used as the exchange-correlation function. The bulk modulus, Young’s modulus, shear modulus and Poisson’s ratio of Ni3Al polycrystal were calculated by Voigt-Reuss approximation method, which are in good agreement with the existing experimental values. Moreover, directional dependences of bulk modulus, Young’s modulus, shear modulus and Poisson’s ratio of Ni3Al single crystal were explored. In addition, the thermodynamic properties (e.g., Debye temperature) of Ni3Al were investigated based on the calculated elastic constants, indicating an improved accuracy in this study, verified with a small deviation from the previous experimental value.

Download Full-text

Experimental Analysis of the Tensile Properties of Painting Canvas

Autex Research Journal ◽

10.1515/aut-2015-0023 ◽

2016 ◽

Vol 16 (4) ◽

pp. 182-195 ◽

Cited By ~ 2

Author(s):

Željko Penava ◽

Diana Šimić Penava ◽

Marijana Tkalec

Keyword(s):

Mechanical Properties ◽

Modulus Of Elasticity ◽

Poisson’S Ratio ◽

Experimental Testing ◽

Tensile Force ◽

Poisson's Ratio ◽

Basic Material ◽

Breaking Force ◽

Elongation At Break ◽

Relative Extension

Abstract In this paper, the practical application of uniaxial testing of painting canvas for determining its mechanical properties is presented. Painting canvases have a complex composite structure whose mechanical properties are considerably improved in relation with the initial basic material. Painting canvas or coated fabrics are obtained by applying a certain number of coatings to raw fabrics. Experimental testing and determining mechanical properties of painting canvas under tensile force at different angles in relation to the weft direction are discussed in the paper. The fabrics were tested before coating, as well as after one, two and three coatings. The values of tensile force in relation to relative extension of coated textiles were measured, as well as breaking force values, elongation at break, contraction at break, work to rupture. Based on the experimentally obtained values, modulus of elasticity, Poisson’s ratio and the level of anisotropy of the coated textile materials were calculated. The experimental results demonstrate the applicability of theoretical formulae. The number of coated layers on the raw fabric exerts a significant impact on the Poisson’s ratio. The values of breaking force, elongation at break, work to rupture and modulus of elasticity increase with an increase in the number of coated layers, and at the same time coefficient of anisotropy decrease. It has been shown that by increasing the number of coated layers in a coated material, its anisotropic properties decrease, while isotropic properties increase. With an increase in the number of coatings, the differences between experimental and theoretical values of modulus of elasticity decrease.

Download Full-text

Simultaneous determination of Young's modulus, shear modulus, and Poisson's ratio of soft hydrogels

Journal of Materials Research ◽

10.1557/jmr.2010.0067 ◽

2010 ◽

Vol 25 (3) ◽

pp. 545-555 ◽

Cited By ~ 33

Author(s):

Uday Chippada ◽

Bernard Yurke ◽

Noshir A. Langrana

Keyword(s):

Mechanical Properties ◽

Shear Modulus ◽

Young’S Modulus ◽

Poisson’S Ratio ◽

Young's Modulus ◽

Complete Characterization ◽

Poisson's Ratio ◽

Surface Topology ◽

Polyacrylamide Gels ◽

Shear Moduli

Besides biological and chemical cues, cellular behavior has been found to be affected by mechanical cues such as traction forces, surface topology, and in particular the mechanical properties of the substrate. The present study focuses on completely characterizing the bulk linear mechanical properties of such soft substrates, a good example of which are hydrogels. The complete characterization involves the measurement of Young's modulus, shear modulus, and Poisson's ratio of these hydrogels, which is achieved by manipulating nonspherical magnetic microneedles embedded inside them. Translating and rotating these microneedles under the influence of a known force or torque, respectively, allows us to determine the local mechanical properties of the hydrogels. Two specific hydrogels, namely bis-cross-linked polyacrylamide gels and DNA cross-linked polyacrylamide gels were used, and their properties were measured as a function of gel concentration. The bis-cross-linked gels were found to have a Poisson's ratio that varied between 0.38 and 0.49, while for the DNA-cross-linked gels, Poisson's ratio varied between 0.36 and 0.49. The local shear moduli, measured on the 10 μm scale, of these gels were in good agreement with the global shear modulus obtained from a rheology study. Also the local Young's modulus of the hydrogels was compared with the global modulus obtained using bead experiments, and it was observed that the inhomogeneities in the hydrogel increases with increasing cross-linker concentration. This study helps us fully characterize the properties of the substrate, which helps us to better understand the behavior of cells on these substrates.

Download Full-text

Mechanical properties of the most common European woods: a literature review

Frattura ed Integrità Strutturale ◽

10.3221/igf-esis.54.18 ◽

2020 ◽

Vol 14 (54) ◽

pp. 249-274

Author(s):

Beatrice Bartolucci ◽

Andrea De Rosa ◽

Chiara Bertolin ◽

Filippo Berto ◽

Francesco Penta ◽

...

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Modulus Of Elasticity ◽

Poisson’S Ratio ◽

Longitudinal Section ◽

Great Difficulty ◽

Poisson's Ratio ◽

Depth Study ◽

The Subject ◽

Or Modelling

Wood is an orthotropic material used since ancient time. A literature research about the mechanical properties of density, fracture toughness, modulus of elasticity, and Poisson’s ratio has been done to have a broader view on the subject. The publications relating to the topic were found through the two search engines Scopus and Google Scholar that have yielded several papers, including articles and book sections. In general, there is no standardization on the method of analysis carried out on wood, underlining the great difficulty in studying this complex material. The parameter of density has a great variability and needs a deeper investigation; fracture toughness is not always available in literature, not even in the different directions of the wood sample. Interesting is the modulus of elasticity, which provides a correlation with density, especially in longitudinal section but, again, it needs to be studied in detail. The parameter of Poisson’s ratio is provided as single values in three different directions, but mainly for softwood. All the parameters require a more in-depth study for both softwood and hardwood. Furthermore, the type of analysis, whether experimental or modelling, needs to be standardized to have more comparable results.

Download Full-text

Variations in Orthotropic Elastic Constants of Green Chinese Larch from Pith to Sapwood

Forests ◽

10.3390/f10050456 ◽

2019 ◽

Vol 10 (5) ◽

pp. 456 ◽

Cited By ~ 1

Author(s):

Fenglu Liu ◽

Houjiang Zhang ◽

Fang Jiang ◽

Xiping Wang ◽

Cheng Guan

Keyword(s):

Shear Modulus ◽

Elastic Constants ◽

Coefficient Of Variation ◽

Modulus Of Elasticity ◽

Poisson’S Ratio ◽

Poisson's Ratio ◽

Stress Wave Propagation ◽

Sampling Distance ◽

Poisson's Ratios ◽

Poisson’S Ratios

Full sets of elastic constants of green Chinese larch (Larix principis-rupprechtii Mayr) with 95% moisture content at four different cross-section sampling positions (from pith to sapwood) were determined in this work using three-point bending and compression tests. Variations in the material constants of green Chinese larch from pith to sapwood were investigated and analyzed. The results showed that the sensitivity of each elastic constant to the sampling position was different, and the coefficient of variation ranged from 4.3% to 48.7%. The Poisson’s ratios νRT measured at four different sampling positions were similar and the differences between them were not significant. The coefficient of variation for Poisson’s ratio νRT was only 4.3%. The four sampling positions had similar Poisson’s ratios νTL, though the coefficient of variation was 11.7%. The Poisson’s ratio νLT had the greatest variation in all elastic constants with a 48.7% coefficient of variation. A good linear relationship was observed between the longitudinal modulus of elastic EL, shear modulus of elasticity GRT, Poisson’s ratio νRT, and sampling distance. EL, GRT, and νRT all increased with sampling distance R. However, a quadratic relationship existed with the tangential modulus of elasticity ET, radial modulus of elasticity ER, shear modulus of elasticity GLT, and shear modulus of elasticity GLR. A discrete relationship was found in the other five Poisson’s ratios. The results of this study provide the factual changes in the elastic constants of green wood from pith to sapwood for numerical modelling of stress wave propagation in trees or logs.

Download Full-text