This study examines the feasibility of the full-field ultrasonic characterization of fractures in rock. To this end, a slab-like specimen of granite is subjected to in-plane, O(104 Hz) excitation while monitoring the induced 2D wavefield by a Scanning Laser Doppler Vibrometer (SLDV) with sub-centimeter spatial resolution. Upon suitable filtering and interpolation, the observed wavefield is verified to conform with the plane-stress approximation and used to: (i) compute the maps of elastic modulus in the specimen (before and after fracturing) via a rudimentary application of the principle of elastography; (ii) reconstruct the fracture geometry; (iii) expose the fracture's primal (traction-displacement jump) contact behavior, and (iv) identify its profiles of shear and normal specific stiffness. Through the use of full-field ultrasonic data, the approach provides an unobscured, high-resolution insight into the fracture's contact behavior, foreshadowing in-depth laboratory exploration of interdependencies between the fracture geometry, aperture, interphase properties, and its seismic characteristics.
|Original language||English (US)|
|Number of pages||10|
|Journal||International Journal of Rock Mechanics and Mining Sciences|
|State||Published - Jun 2018|
Bibliographical noteFunding Information:
The corresponding author kindly acknowledges the support provided by the National Science Foundation (Grant CMMI-1536110 ) and the University of Minnesota's Supercomputing Institute . The data supporting the analysis and conclusions can be accessed by contacting the lead author.
- Full-field ultrasonic sensing
- Heterogeneous specific stiffness
- Seismic behavior of fractures