Discrete element modelling (DEM) of a face-centred cubic assembly of spherical particles has been used to study the influence of anisotropic stress states on the shear wave velocity of a granular material. The shear waves were generated and detected in a way equivalent to the use of bender elements in laboratory testing. Comparisons are presented between the discrete element simulations and ana...

The authors have recently demonstrated the shear wave interference patterns created by two coherent vibration sources imaged with the vibration sonoelastography technique. If the two sources vibrate at slightly different frequencies omega and omega+deltaomega, respectively, the interference patterns move at an apparent velocity of (deltaomega/2omega)upsilon(shear), where upsilon(shear) is the s...

it is very important to study and simulate s-wave structure for near surface (alluvium parts, in particular) owing to its direct relationship to urban facilities in geotechnical and earthquake engineering studies. so, in seismic microzonation, the first step is to study and identify s-wave pattern in alluvium in order to categorize different parts of cites according to s-wave velocity. current ...

Special features of surface gravity waves in deep fluid flow with constant vertical shear of velocity is studied. It is found that the mean flow velocity shear leads to non-trivial modification of surface gravity wave modes dispersive characteristics. Moreover, the shear induces generation of surface gravity waves by internal vortex mode perturbations. The performed analytical and numerical stu...

Plane wave imaging in Shear Wave Elastography (SWE) captures shear wave propagation in real-time at ultrafast frame rates. To assess the capability of this technique in accurately visualizing the underlying shear wave mechanics, this work presents a multiphysics modeling approach providing access to the true biomechanical wave propagation behind the virtual image. This methodology was applied t...

Non-invasive methods for liver stiffness assessment have been introduced over recent years. Of these, two main methods for estimating liver fibrosis using ultrasound elastography have become established in clinical practice: shear wave elastography and quasi-static or strain elastography. Shear waves are waves with a motion perpendicular (lateral) to the direction of the generating force. Shear...

GABRIELS, P., SNIEDER, . and NOLET, G. 1987, In Situ Measurement of Shear-Wave Velocity in Sediments with Higher-Mode Rayleigh Waves, 35,187-196. A seismic survey was carried out on a tidal flat in the SW-Netherlands in order to determine shear-wave velocities in sediments by means of higher-mode Rayleigh waves. The dispersion properties of these Rayleigh waves were measured in the 2-D amplitud...

Five parameters are needed to describe VTI anisotropy in 2-D elastic media. With conventional streamer data and considering that we have a kinematically accurate NMO velocity (vnmo) and η (or horizontal velocity, vh) obtained from tomographic methods, we first show that a parameterization given by vh, η and allows us to focus the inversion to update vh (for traveltime and amplitude fitting) and...

OBJECTIVE The purpose of this study is to determine if crawling wave elastography, a novel sonoelastography technique, can be used to provide quantitative measurements of thyroid tissue shear velocity (a measure of tissue stiffness) and distinguish between benign and malignant thyroid nodules. STUDY DESIGN Diagnostic test assessment. SETTING Academic university. SUBJECTS AND METHODS Fresh...

refractor ambiguities are big problem in seismic refraction method especially in seismic engineering. there can be hidden subsurface geological phenomena such as hidden faults and shear zones which are not simply predicted by the travel-time graph or some geophysical methods. head wave amplitudes are used to show the resolution of refractor ambiguities and the existence of anisotropy in complex...