ULTRASONIC WAVE IS DETERMINED BY FABRIC TENSOR: AN APPLICATION TO CALCANEUS

2015 ◽  
Vol 15 (02) ◽  
pp. 1540030
Author(s):  
YOUNG JUNE YOON
Keyword(s):  
Mechanical Properties ◽  
Ultrasonic Wave ◽  
Wave Velocity ◽  
Cancellous Bone ◽  
Speed Of Sound ◽  
Fast Wave ◽  
Bulk Wave ◽  
Fabric Tensor ◽  
Bone Ultrasound ◽  
Poroelastic Theory

The fabric tensor is a good measure for determining the mechanical properties of cancellous bone. Ultrasound is one method used to measure these mechanical properties. Ultrasound-generated speed of sound (SOS) measures the mechanical properties of cancellous bone. Thus, in this paper, we started with the fact that the fast wave in poroelastic theory is identical to the bulk wave velocity. We then formulate the equation for the fast wave in terms of fabric tensor for the calcaneus. The formulation in this paper is simpler than previously published results and will be easy to use in future experiments.

scholarly journals Experimental Investigation on the Correlation between Dynamic Ultrasonic and Mechanical Properties of Sandstone Subjected to Uniaxial Compression

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Yunjiang Sun ◽  
Jianping Zuo ◽  
Yue Shi ◽  
Zhengdai Li ◽  
Changning Mi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Ultrasonic Wave ◽  
Uniaxial Compression ◽  
Wave Velocity ◽  
Poisson’S Ratio ◽  
P Wave ◽  
Poisson's Ratio ◽  
Ultrasonic Wave Velocity ◽  
P Wave Velocity

Ultrasonic wave velocity is effective to evaluate anisotropy property and predict rock failure. This paper investigates the correlation between dynamic ultrasonic and mechanical properties of sandstones with different buried depths subjected to uniaxial compression tests. The circumferential anisotropy and axial wave velocity of sandstone are obtained by means of ultrasonic wave velocity measurements. The mechanical properties, including Young’s modulus and uniaxial compressive strength, are positively correlated with the axial P wave velocity. The average angles between the sandstone failure plane and the minimum and maximum wave directions are 35.8° and 63.3°, respectively. The axial P wave velocity almost keeps constant, and the axial S wave velocity has a decreasing trend before the failure of rock specimen. In most rock samples under uniaxial compression, shear failure occurs in the middle and splitting appears near both sides. Additionally, the dynamic Young’s modulus and dynamic Poisson’s ratio during loading are obtained, and the negative values of the Poisson’s ratio occur at the initial compression stage. Distortion and rotation of micro/mesorock structures may be responsible for the negative Poisson’s ratio.

Influence of cancellous bone microstructure on two ultrasonic wave propagations in bovine femur: An in vitro study

2010 ◽  
Vol 128 (5) ◽  
pp. 3181-3189 ◽  
Author(s):  
Katsunori Mizuno ◽  
Hiroki Somiya ◽  
Tomohiro Kubo ◽  
Mami Matsukawa ◽  
Takahiko Otani ◽  
...  
Keyword(s):  
Ultrasonic Wave ◽  
Cancellous Bone ◽  
In Vitro Study ◽  
Bone Microstructure ◽  
Vitro Study

Synergetic effect of freeze-drying and gamma irradiation on the mechanical properties of human cancellous bone

2010 ◽  
Vol 12 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Olivier Cornu ◽  
Jérome Boquet ◽  
Olivier Nonclercq ◽  
Pierre-Louis Docquier ◽  
John Van Tomme ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gamma Irradiation ◽  
Cancellous Bone ◽  
Freeze Drying ◽  
Synergetic Effect ◽  
Human Cancellous Bone

scholarly journals The effect of liquid nitrogen cooling on coal cracking and mechanical properties

2018 ◽  
Vol 36 (6) ◽  
pp. 1609-1628 ◽  
Author(s):  
Chengzheng Cai ◽  
Feng Gao ◽  
Yugui Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Acoustic Emission ◽  
Liquid Nitrogen ◽  
Wave Velocity ◽  
Count Rate ◽  
Initial State ◽  
Nitrogen Injection ◽  
Strength Tests ◽  
Liquid Nitrogen Cooling

Liquid nitrogen is a type of super-cryogenic fluid, which can cause the reservoir temperature to decrease significantly and thereby induce formation rock damage and cracking when it is injected into the wellbore as fracturing fluid. An experimental set-up was designed to monitor the acoustic emission signals of coal during its contact with cryogenic liquid nitrogen. Ultrasonic and tensile strength tests were then performed to investigate the effect of liquid nitrogen cooling on coal cracking and the changes in mechanical properties thereof. The results showed that acoustic emission phenomena occurred immediately as the coal sample came into contact with liquid nitrogen. This indicated that evident damage and cracking were induced by liquid nitrogen cooling. During liquid nitrogen injection, the ring-down count rate was high, and the cumulative ring-down counts also increased rapidly. Both the ring-down count rate and the cumulative ring-down counts during liquid nitrogen injection were much greater than those in the post-injection period. Liquid nitrogen cooling caused the micro-fissures inside the coal to expand, leading to a decrease in wave velocity and the deterioration in mechanical strength. The wave velocity, which was measured as soon as the sample was removed from the liquid nitrogen (i.e. the wave velocity was recorded in the cooling state), decreased by 14.46% on average. As the cryogenic samples recovered to room temperature, this value increased to 18.69%. In tensile strength tests, the tensile strengths of samples in cooling and cool-treated states were (on average) 17.39 and 31.43% less than those in initial state. These indicated that both during the cooling and heating processes, damage and cracking were generated within these coal samples, resulting in the acoustic emission phenomenon as well as the decrease in wave velocity and tensile strength.

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