Experimental and Numerical Study on Crack-Arrest Behaviours of Rock-Like SCDC Specimens
- PDF / 3,131,266 Bytes
- 13 Pages / 547.087 x 737.008 pts Page_size
- 37 Downloads / 204 Views
(0123456789().,-volV) ( 01234567 89().,-volV)
ORIGINAL PAPER
Experimental and Numerical Study on Crack-Arrest Behaviours of Rock-Like SCDC Specimens Yao Song
Received: 3 January 2020 / Accepted: 11 July 2020 Ó Springer Nature Switzerland AG 2020
Abstract Studying rock crack-arrest toughness, which determines the arrest behaviours in rock materials with cracks, is important to prevent further damage to rock mass. To investigate the crack-arrest behaviours both qualitatively and quantitatively, dynamic impact experiments (using caustics and photoelastic methods) were performed on rock-like (epoxy resin) single cleavage drilled compression (SCDC) specimens to study the crack-arrest behaviours and the microscopic fracture characteristics. The crack-arrest toughness of the SCDC specimen was obtained and the extended finite element method (XFEM) in ABAQUS software was used to validate the experimental results. The results show that under the interaction between reflected compression and tensile waves, the running crack experiences two crack-arrest periods before the final arrest, and the crack-arrest toughness stabilizes at a value of 0.669 MPa m1/2. Moreover, the peak propagation velocity in each crack initiation process gradually decreases with the development of the crack path. Additionally, the observations by scanning electron microscopy (SEM) and photoelastic methods show that the roughness of the fracture surface is influenced by the crack-arrest behaviours, causing the spalling
Y. Song (&) School of Traffic and Transportation Engineering, Dalian Jiaotong University, Dalian 116028, China e-mail: [email protected]
fragments as well as wing micro-cracks in the fracture surface. Keywords Rock dynamic fracture Crack-arrest toughness The dynamic caustic method Numerical simulation Scanning electron microscopy
1 Introduction Rock fracture toughness is one of the most important mechanical parameters for rock material and can directly determine the fracture behaviours in rock mass (Zhang and Zhao 2014). Some serious disasters, such as earthquakes, landslides, and rock bursts, are mainly related to the initiation and development of micro-cracks in rock mass. Thus, the corresponding study of rock dynamic fracture behaviours is of great significance for practical engineering applications. In 2012, the International Society for Rock Mechanics (ISRM) Commission published the suggested method for the determination of the mode I fracture toughness for rock materials (Zhou et al. 2012). Various methods have been proposed for the determination of the fracture toughness of rock materials in recent years, including the use of cracked chevron notched Brazilian disc (CCNBD) (Fowell et al. 1995; Amrollahi et al. 2011; Wang et al. 2013; Dai et al. 2016; Wei et al. 2016a, b, 2017, 2018; Xu et al. 2016), cracked straight
123
Geotech Geol Eng
through Brazilian disc (CSTBD) (Atkinson et al. 1982; Fowell and Xu 1994; Azar et al. 2015; Wang et al. 2016), notched semi-circular bend (NSCB) (Chen et al. 2009, 2016; Yin et al.
Data Loading...
