Measurement of shear wave attenuation coefficient using a contact pulse-echo method with consideration of partial reflection effects

2019 ◽  
Vol 30 (11) ◽  
pp. 115601 ◽  
Author(s):  
Guangdong Zhang ◽  
Xiling Liu ◽  
Xiongbing Li ◽  
Yongfeng Song ◽  
Shuzeng Zhang
Keyword(s):  
Shear Wave ◽  
Attenuation Coefficient ◽  
Wave Attenuation ◽  
Partial Reflection ◽  
Pulse Echo ◽  
Pulse Echo Method

An ultrasound method for characterization of viscoelastic properties in frequency domain at small deformations

2021 ◽  
pp. 095440622110057
Author(s):  
A Sakhnevych ◽  
A Genovese ◽  
A Maiorano ◽  
F Timpone ◽  
F Farroni
Keyword(s):  
Attenuation Coefficient ◽  
Viscoelastic Properties ◽  
Loss Factor ◽  
Wave Attenuation ◽  
Acoustic Properties ◽  
Master Curves ◽  
Ultrasound Technique ◽  
Pulse Echo ◽  
Pulse Echo Method

Background The ultrasound technique, usually based on the transmission mode, is capable of providing the viscoelastic properties of polymers. Further techniques involving pulse-echo methods were also described in literature, but they still exhibit inaccuracies in the evaluation of the acoustic properties. Objective The manuscript focuses on an innovative approach for the characterization of the viscoelastic behavior of polymers employing the ultrasound methodology. The proposed procedure is based on the pulse-echo method in order to overcome possible inaccuracies in acoustic properties evaluation and in issues related to transmitter mode applications. Methods Starting from the pulse-echo method adopted for the acquisition, a novel formulation for data processing has been developed and described, allowing to determine the wave attenuation coefficient, in comparison to the commonly employed procedures involving ultrasound in polymers characterization, based on transmitter mode inspections. To carry out the study, a specifically designed ultrasound bench has been set up and three different polymers have been tested in the temperature range of interest. Results According to the proposed methodology, the loss factor towards the temperature is determined starting from the data acquired considering the identified attenuation coefficient and the measured sound velocities. The trustworthiness of the novel procedure has been proved comparing the obtained viscoelastic loss factor quantities to the reference master curves obtained by the standard Dynamic Mechanical Analysis characterizations carried out on the same polymer specimens. Conclusions A novel methodology involving ultrasound technology aiming to evaluate the viscoelasticity of the polymers using non-destructive approach has been developed. The results obtained are agreement with the standard viscoelastic master curves determined through the DMA.

Electromagnetic Acoustic Resonance To Assess Creep Damage In 2.25Cr-lMo Steel

1997 ◽  
Vol 503 ◽  
Author(s):  
M. Hirao ◽  
H. Ogi ◽  
T. Ohtani ◽  
T. Morishita
Keyword(s):  
Shear Wave ◽  
Attenuation Coefficient ◽  
Creep Test ◽  
Creep Deformation ◽  
Wave Attenuation ◽  
Creep Damage ◽  
Acoustic Resonance ◽  
Noncontact Measurement ◽  
Electromagnetic Acoustic Transducers ◽  
Acoustic Transducers

ABSTRACTMethod of electromagnetic acoustic resonance (EMAR) was applied to the noncontact measurement of the shear wave attenuation during the creep test of 2.25Cr-1Mo steels. Two electromagnetic acoustic transducers were manufactured for this purpose, which generate the polarized shear waves through the magnetostriction effect. The attenuation coefficient increased with the creep deformation. The evolution range of the attenuation was beyond 0.1 μs−1 before the failure, which was much larger than the attenuation variation among the samples.

Estimation of shear-wave interval attenuation from mode-converted data

Geophysics ◽  
2011 ◽  
Vol 76 (6) ◽  
pp. D11-D19 ◽  
Author(s):  
Bharath Shekar ◽  
Ilya Tsvankin
Keyword(s):  
Shear Wave ◽  
Attenuation Coefficient ◽  
Reservoir Characterization ◽  
Wave Attenuation ◽  
Pure Shear ◽  
Synthetic Data ◽  
Spectral Ratio ◽  
Ratio Method ◽  
S Wave ◽  
Target Layer

Interval attenuation measurements provide valuable information for reservoir characterization and lithology discrimination. We extend the attenuation layer-stripping method of Behura and Tsvankin to mode-converted (PS) waves with the goal of estimating the S-wave interval attenuation coefficient. By identifying PP and PS events with shared ray segments and applying the [Formula: see text] method, we first perform kinematic construction of pure shear (SS) events in the target layer and overburden. Then, the modified spectral-ratio method is used to compute the effective shear-wave attenuation coefficient for the target reflection. Finally, application of the dynamic version of velocity-independent layer stripping to the constructed SS reflections yields the interval S-wave attenuation coefficient in the target layer. The attenuation coefficient estimated for a range of source-receiver offsets can be inverted for the interval attenuation parameters. The method is tested on multicomponent synthetic data generated with the anisotropic reflectivity method for layered VTI (transversely isotropic with a vertical symmetry axis) and orthorhombic media.

Effect of Bi2O3 on Elastic Properties of Silica Bismuthate Glasses by Pulse-Echo Method

2012 ◽  
Vol 2 (5) ◽  
pp. 546-548
Author(s):  
P. Vasantharani P. Vasantharani ◽  
◽  
I.Sankeeda I.Sankeeda
Keyword(s):  
Elastic Properties ◽  
Pulse Echo ◽  
Pulse Echo Method

scholarly journals Lorentz force induced shear waves for magnetic resonance elastography applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillaume Flé ◽  
Guillaume Gilbert ◽  
Pol Grasland-Mongrain ◽  
Guy Cloutier
Keyword(s):  
Magnetic Resonance ◽  
Shear Wave ◽  
Lorentz Force ◽  
Wave Attenuation ◽  
Shear Waves ◽  
Estimation Method ◽  
Biological Tissues ◽  
Magnetic Resonance Elastography ◽  
Motion Generation ◽  
Wave Source

AbstractQuantitative mechanical properties of biological tissues can be mapped using the shear wave elastography technique. This technology has demonstrated a great potential in various organs but shows a limit due to wave attenuation in biological tissues. An option to overcome the inherent loss in shear wave magnitude along the propagation pathway may be to stimulate tissues closer to regions of interest using alternative motion generation techniques. The present study investigated the feasibility of generating shear waves by applying a Lorentz force directly to tissue mimicking samples for magnetic resonance elastography applications. This was done by combining an electrical current with the strong magnetic field of a clinical MRI scanner. The Local Frequency Estimation method was used to assess the real value of the shear modulus of tested phantoms from Lorentz force induced motion. Finite elements modeling of reported experiments showed a consistent behavior but featured wavelengths larger than measured ones. Results suggest the feasibility of a magnetic resonance elastography technique based on the Lorentz force to produce an shear wave source.

Pulse-echo method of investigating plastic strain

1974 ◽  
Vol 6 (2) ◽  
pp. 248-251
Author(s):  
E. V. Korovkin ◽  
Ya. M. Soifer
Keyword(s):  
Plastic Strain ◽  
Pulse Echo ◽  
Pulse Echo Method

scholarly journals Absolute stress measurement of structural steel members with ultrasonic shear-wave spectral analysis method

2017 ◽  
Vol 18 (1) ◽  
pp. 216-231 ◽  
Author(s):  
Zuohua Li ◽  
Jingbo He ◽  
Jun Teng ◽  
Qin Huang ◽  
Ying Wang
Keyword(s):  
Spectral Analysis ◽  
Structural Steel ◽  
Shear Wave ◽  
Wave Amplitude ◽  
Stress Measurement ◽  
Amplitude Spectrum ◽  
Uniaxial Stress ◽  
Wave Pulse ◽  
Steel Members ◽  
Pulse Echo

Absolute stress in structural steel members is an important parameter for the design, construction, and servicing of steel structures. However, it is difficult to measure via traditional approaches to structural health monitoring. The ultrasonic time-of-flight method has been widely studied for monitoring absolute stress by measuring the change in ultrasonic propagation time induced by stress. The time-of-flight of the two separated shear-wave modes induced by birefringence, which is particular to shear waves, is also affected by stress to different degrees. Their synthesis signal amplitude spectrum exhibits a minimum that varies with stress, which makes it a potential approach to evaluating uniaxial stress using the shear-wave amplitude spectrum. In this study, the effect of steel-member stress on the shear-wave amplitude spectrum from the interference of two shear waves produced by birefringence is investigated, and a method of uniaxial absolute stress measurement using shear-wave spectral analysis is proposed. Specifically, a theoretical expression is derived for the shear-wave pulse-echo amplitude spectrum, leading to a formula for evaluating uniaxial absolute stress. Three steel-member specimens are employed to investigate the influence of uniaxial stress on the shear-wave pulse-echo amplitude spectrum. The testing results indicate that the amplitude spectrum changes with stress and that the inverse of the first characteristic frequency in the amplitude spectrum and its corresponding stress exhibit a near-perfect linear relationship. On this basis, the uniaxial absolute stress of steel members loaded by a test machine is measured by the proposed method. Parametric studies are further performed on three groups of steel members made of 65# steel and Q235 steel to investigate the factors that influence the testing results. The results show that the proposed method can measure and monitor steel-members uniaxial absolute stress on the laboratory scale and has potential to be used in practical engineering with specific calibration.

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