These elementary fatigue damage patterns are investigated at the microscopic scale by distinguishing crack initiation and crack growth.
They divide the process in three main steps: image enhancement using median filtering to remove noise, image segmentation using a histogram modification technique, and Canny edge detection to finally distinguish crack edges from the rest of the image.
For very tough polymers, such as pipe grade polyethylenes, the R curve is very steep and it is difficult to distinguish crack growth from blunting and a definition of initiation becomes problematic.
Correspondingly, experimental data for the four samples plot in different areas in diagrams designed to distinguish oil cracking gas from kerogen cracking gas, such as ln(C2/C3) vs. δ13C2 δ13C3 and δ13C1 vs. δ13C2 δ13C3, indicating compositional variability of crude oil could assert an important influence in these diagrams.
"Reminiscences of Wangchuan" seems to be an active recalling of a dream; the land forms, distinguished by cracks, underscore this notion as they seem to be emerging or breaking out of the composition.
Neither could Dr. Russell of Kettering University, who said his laboratory instruments still could not reliably distinguish a crack from a thunk, even though his ears could.
The results indicated that the recognition CNN is able to distinguish concealed cracks from other types of damages in 6482 GPR images with zero errors.
Using AE tests of unreinforced UHPC and tests of individual fiber pullout, the network was trained to distinguish matrix cracking and fiber pullout.
Distinguishing micro-crack pixels from the background (i.e., the multicrystalline grains) is a very challenging procedure because the gray scale values of these two areas are not significantly different.
The recognition CNN was designed to distinguish concealed cracks from other types of damage in a GPR image, the location CNN determined the location and length measurement of concealed crack images based on the results provided by the recognition CNN, and crack feature points were extracted by the feature extraction CNN to establish the 3D reconstruction models of the concealed cracks.
