Abstract

An innovative ultrafast time-resolution method based on a picosecond pulsed laser was employed to investigate the mode-I crack propagation characteristics of fractured rock. Its time resolution is as fast as the degree of 45 picoseconds. Then, a series of three-point compressive loading tests with this method were conducted on tuff semi-circular bend (SCB) specimens. Based on this method, we found that the mode-I fracture process of the tuff specimens were composed of repeated crack initiation, arrest, and re-initiation. In addition, the experimental results showed that the fracture rates of the tuff specimens in the initial 10 μs were 636 m/s, 663.9 m/s, and 578 m/s. In comparison, the fracture rates of the specimens were 11.19 m/s, 19.23 m/s, 26.79 m/s during the whole fracture process. As a typical heterogeneous material with primary defects, rock has different fracture toughness at different locations. Therefore, we proposed a new method for determining rock fracture toughness at multipoint during the crack propagation. This new method emphasizes the effect of fracture toughness on crack propagation, which enables to determine the fracture toughness at multipoint and is closer to the original definition of fracture toughness.

Details

Title
An ultrafast time-resolution method based on picosecond pulsed laser for determining rock fracture toughness at multipoint during the crack propagation
Author
Zhang, Mingyuan 1 ; Li, Dejian 1 ; Liu, Yang 1 ; Chen, Lu 1 ; Shen Muao 1 ; Huo Junhao 1 ; Li, Yingjun 2 

 China University of Mining and Technology, State Key Laboratory for GeoMechanics and Deep Underground Engineering, Beijing, China (GRID:grid.411510.0) (ISNI:0000 0000 9030 231X); Institute for Deep Underground Science and Engineering, Beijing, China (GRID:grid.411510.0); China University of Mining and Technology, School of Mechanics and Civil Engineering, Beijing, China (GRID:grid.411510.0) (ISNI:0000 0000 9030 231X) 
 China University of Mining and Technology, State Key Laboratory for GeoMechanics and Deep Underground Engineering, Beijing, China (GRID:grid.411510.0) (ISNI:0000 0000 9030 231X); Institute for Deep Underground Science and Engineering, Beijing, China (GRID:grid.411510.0); Chinese Academy of Sciences, Institute of Physics, Beijing, China (GRID:grid.9227.e) (ISNI:0000000119573309) 
Publication year
2022
Publication date
2022
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2640597243
Copyright
© The Author(s) 2022. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.