AN EXPERIMENTAL STUDY OF THE ELASTIC PROPERTIES OF ROCKS

Geophysics ◽  
1936 ◽  
Vol 1 (3) ◽  
pp. 347-352 ◽  
Author(s):  
J. M. Ide

Laboratory determinations of Young’s modulus, rigidity, and compressibility were made on a set of representative rock samples. These measurements are compared with the theoretical relations between the elastic constants of an isotropic medium. Computed longitudinal and transverse wave velocities are compared with direct field measurements by Leet in granite and norite. Agreement is within 5 per cent for norite, and 20 per cent for granite.

Author(s):  
Jana Simeonovová ◽  
Jaroslav Buchar

The problem of the identification of the elastic properties of eggshell, i.e. the evaluation of the Young's modulus and Poisson's ratio is solved. The eggshell is considered as a rotational shell. The experiments on the egg compression under quasistatic loading have been conducted. During these experiments a strain on the eggshell surface has been recorded. By the mutual comparison between experimental and theoretical values of strains the influence of the elastic constants has been demonstrated.


2021 ◽  
Author(s):  
ahmed wattan ◽  
Mohammed AL‑Jawad

Abstract Shear and compressional wave velocities are useful for drilling operations, the exploration of reservoirs, stimulation processes, and hydraulic fracturing. An ultrasonic device will be used in this investigation to anticipate and analyze the elastic characteristics of carbonate rocks. At the summit of the field, the well WQ1-20 obtained samples of the Mishrif formation from a variety of various depths. The number of samples taken from the well is nine from different units whereas the number of samples taken from the main unit (MB2) was five. The relations between the elastic properties for the carbonate rocks with P-and S-waves were defined. The relations between Vp and Vs with elastic properties were defined by applied Regression analysis. The results showed that a linear relationship between P-and S-wave velocities with the elastic properties of the carbonate rocks. It is found that the relationship between Vp and Young's modulus (E) is R2 equal to 0.979 while the relationship between Vs and Young's modulus (E) is R2 equal to 0.925. The relationship between shear modulus and Vs is good in comparison with Vp where the values of R2 were 0.985 and 0.94 respectively. R2 values for the Bulk modulus and Lame's constant of Vp are 0.925 and 0.6, respectively, while the values for Vs are 0.925 and 0.6 for the latter. The relation between Vp/Vs ratio with Poisson’s ratio showed a good R2 with a value of 0.97. When it comes to predicting the dynamic elastic characteristics of a material, the ultrasonic approach may be regarded as a cost-effective, easy, and non-destructive method.


1947 ◽  
Vol 25a (2) ◽  
pp. 88-95 ◽  
Author(s):  
T. D. Northwood

By measuring the velocity of various types of elastic waves in a solid it is possible to deduce Young's modulus and Poisson's ratio. Longitudinal, extensional, and Rayleigh wave velocities were measured in ice, the first by resonance in a rod and the other two by a pulsing technique. The value obtained for Young's modulus was 9.8 × 1010 dynes per cm.2 and for Poisson's ratio was 0.33.


2001 ◽  
Vol 695 ◽  
Author(s):  
Matthew Bamber ◽  
Adrian Mann ◽  
Brian Derby

ABSTRACTNanoindentation has been successfully used as a mechanical properties microprobe to characterise the elastic properties of materials. However, in an isotropic material it is not possible to measure the two independent elastic constants by nanoindentation. Normally, a value of Young's modulus is determined using an assumed value for Poisson's ratio. It is also possible to use the acoustic microscope in its z-contrast mode to measure the elastic constants of a surface. This too produces a composite measurement of the elastic properties, which can be represented in terms of Young's modulus and Poisson's ratio. By using both techniques on the same sample area, it is possible to make two independent measurements of the elastic properties and thus determine both Young's modulus and Poisson's ratio. This method has been used on well-characterised bulk materials, e.g. silica glass, to demonstrate that it produces consistent results. It has also been uused to characterise thin films of TiN/NbN multilayers. These results show that, although for thin films there is a need to improve the analysis of the mechanics, the combination of nanoindentation and acoustic microscopy shows promise.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3010
Author(s):  
Raphael Lamprecht ◽  
Florian Scheible ◽  
Marion Semmler ◽  
Alexander Sutor

Ultrasound elastography is a constantly developing imaging technique which is capable of displaying the elastic properties of tissue. The measured characteristics could help to refine physiological tissue models, but also indicate pathological changes. Therefore, elastography data give valuable insights into tissue properties. This paper presents an algorithm that measures the spatially resolved Young’s modulus of inhomogeneous gelatin phantoms using a CINE sequence of a quasi-static compression and a load cell measuring the compressing force. An optical flow algorithm evaluates the resulting images, the stresses and strains are computed, and, conclusively, the Young’s modulus and the Poisson’s ratio are calculated. The whole algorithm and its results are evaluated by a performance descriptor, which determines the subsequent calculation and gives the user a trustability index of the modulus estimation. The algorithm shows a good match between the mechanically measured modulus and the elastography result—more precisely, the relative error of the Young’s modulus estimation with a maximum error 35%. Therefore, this study presents a new algorithm that is capable of measuring the elastic properties of gelatin specimens in a quantitative way using only the image data. Further, the computation is monitored and evaluated by a performance descriptor, which measures the trustability of the results.


2018 ◽  
Vol 233 ◽  
pp. 00025
Author(s):  
P.V. Polydoropoulou ◽  
K.I. Tserpes ◽  
Sp.G. Pantelakis ◽  
Ch.V. Katsiropoulos

In this work a multi-scale model simulating the effect of the dispersion, the waviness as well as the agglomerations of MWCNTs on the Young’s modulus of a polymer enhanced with 0.4% MWCNTs (v/v) has been developed. Representative Unit Cells (RUCs) have been employed for the determination of the homogenized elastic properties of the MWCNT/polymer. The elastic properties computed by the RUCs were assigned to the Finite Element (FE) model of a tension specimen which was used to predict the Young’s modulus of the enhanced material. Furthermore, a comparison with experimental results obtained by tensile testing according to ASTM 638 has been made. The results show a remarkable decrease of the Young’s modulus for the polymer enhanced with aligned MWCNTs due to the increase of the CNT agglomerations. On the other hand, slight differences on the Young’s modulus have been observed for the material enhanced with randomly-oriented MWCNTs by the increase of the MWCNTs agglomerations, which might be attributed to the low concentration of the MWCNTs into the polymer. Moreover, the increase of the MWCNTs waviness led to a significant decrease of the Young’s modulus of the polymer enhanced with aligned MWCNTs. The experimental results in terms of the Young’s modulus are predicted well by assuming a random dispersion of MWCNTs into the polymer.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 968
Author(s):  
Fumitada Iguchi ◽  
Keisuke Hinata

The elastic properties of 0, 10, 15, and 20 mol% yttrium-doped barium zirconate (BZY0, BZY10, BZY15, and BZY20) at the operating temperatures of protonic ceramic fuel cells were evaluated. The proposed measurement method for low sinterability materials could accurately determine the sonic velocities of small-pellet-type samples, and the elastic properties were determined based on these velocities. The Young’s modulus of BZY10, BZY15, and BZY20 was 224, 218, and 209 GPa at 20 °C, respectively, and the values decreased as the yttrium concentration increased. At high temperatures (>20 °C), as the temperature increased, the Young’s and shear moduli decreased, whereas the bulk modulus and Poisson’s ratio increased. The Young’s and shear moduli varied nonlinearly with the temperature: The values decreased rapidly from 100 to 300 °C and gradually at temperatures beyond 400 °C. The Young’s modulus of BZY10, BZY15, and BZY20 was 137, 159, and 122 GPa at 500 °C, respectively, 30–40% smaller than the values at 20 °C. The influence of the temperature was larger than that of the change in the yttrium concentration.


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