Timely spread characteristics of micro- and meso-scale fractures based on SEM experiment
- PDF / 11,750,237 Bytes
- 20 Pages / 595.276 x 790.866 pts Page_size
- 77 Downloads / 155 Views
ORIGINAL ARTICLE
Timely spread characteristics of micro‑ and meso‑scale fractures based on SEM experiment Hu‑dan Tang1,2 · Ming‑li Zhu3 Received: 29 August 2019 / Accepted: 17 September 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Macroscale fracture of rocks is a progressive process consisting of the initiation, propagation and coalescence of numerous microcracks, but the micro- and meso-crack propagation process and the accuracy parameters of multiscale crack evolution timely have not been studied systematically. This study investigates the micro- and meso-damage evolution characteristics based on in-situ scanning electron microscopy (SEM) tests of marble specimens under compression. The propagation and evolution characteristics of microcracks at different locations in marble specimen under load are analyzed in detail. The qualitative analysis of micro- and meso-crack propagation of marble specimen under different loading is performed. The results show that during the compression process of marble from a microscopic point of view, there are mainly three types of microcracks between mineral crystals and mineral crystals: through-grain cracks, transgranular cracks and intragranular cracks. The microcracks that dominate the failure of marble samples are intergranular cracks, and intragranular cracks do not play a significant role. The initiation and evolution of micro-fractures are carried out in zones. Unlike the macro-scale, which is basically a single-wing crack initiation, multiple micro-wing cracks initiate from the end of a prefabricated crack, and some micro-cracks close successively during the loading process, the main wing cracks also undergo a slow or even non-propagating stage. Distribution rules of different micro-parameters are obtained, the transformation from micro-scale to meso-scale is realized. Besides the study provides parameters for the study of a multi-scale theoretical model of rock deformation and failure. Different samples have different characteristics of damage expansion, and the warning before instability is different. This study will provide a warning for possible larger fractures in engineering under different conditions. Keywords Micro- and meso-structural · Digital image analysis program · Multiscale damage mechanism
Introduction Rock is a heterogeneous material containing different patterns of flaws. The mechanical behavior of rock is mainly determined by the properties of the aforementioned flaws, as well as the properties of the rock matrix. Understanding the * Hu‑dan Tang [email protected] * Ming‑li Zhu [email protected] 1
School of Civil Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan, China
2
International Joint Research Laboratory of Henan Province for Underground Space Development and Disaster Prevention, Jiaozuo 454000, Henan, China
3
School of Energy Science and Engineering Institute, Henan Polytechnic University, Jiaozuo 454000, Henan, China
strength failure and process of the crack evolution behavior of a ro
Data Loading...
