Directional Cooling-Induced Fracturing (DCIF) experiments were conducted on three rectangular Westerly granite blocks (width=depth=4.0", height=2.0") which were preheated to 200, 400, and 600 degree C to induce damage (microcracks) with varying degrees. Liquid nitrogen was poured in a small, 1"-diameter copper cup attached to the top of the sample, and the resulting acoustic emissions (AEs) and temperature changes on the surface of the sample were monitored. The experiments were conducted under one selected biaxial stress (5.8MPa). The obtained AEs were used to determine the microcracking source locations and amplitude, and the associated moment tensors. The onset time of the AEs was correlated with the cooling temperature, which was used to show that the temperature at the onset of microcracking is not affected significantly by the preexisting damage, compared to the impact of the stress in the sample. Included in this submission are the animations of the AE locations and graphics displaying the measured temperature-AE activity changes for samples with different degrees of microcrack damage.
- DOCXDCIF Borehole Damage Test for Westerly Granite Task 3-0 Metadata.docx
- datDCFI Acoustic Emission Location Data Block G.dat
- datDCIF Acoustic Emission Location Data Block I .dat
- datDCIF Acoustic Emission Location Data Block H.dat
- TXTDCIF Temperature Data Block G.TXT
- TXTDCIF Temperature Data Block H.txt
- TXTDCIF Temperature Data Block I.txt
- aviDCIF Westerly Granite Block G AE Movie.avi
- aviDCIF Westerly Granite Block H AE Movie.avi
- aviDCIF Westerly Granite Block I AE Movie.avi
- TIFDCIF Biaxial Stress Vs Velocity - All Damaged Samples Average Velocity.TIF
- TIFDCIF Pre-Cracking T vs Onset Copper Cup Temperature.TIF
- tifDCIF Time vs AE Rate and Cumulative Count Summary.tif