A numerical study of acoustic emission characteristics of sandstone specimen containing a hole-like flaw under uniaxial compression. (1st February 2021)

• Record Type: Journal Article
• Authors: Zhang, Qi; Zhang, Xiao-Ping; Yang, Sheng-Qi
• Is Part Of: Engineering fracture mechanics. Volume 242(2021)
• Publication Date: 2021-02-01
• Subjects: Brittle rock -- Failure nature -- Bonded-particle model -- Acoustic emission -- Moment tensor inversion; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2020.107430
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: The AE characteristics of specimens containing hole-like flaw are reproduced by the BPM. The fracture evolution and failure mode of these specimens with hole-like flaw of different shapes are revealed. The failure mechanism of fractures initiating from around the hole-like flaw is discussed. Abstract: For a better understanding of acoustic emission (AE) characteristics and failure mechanism of specimens containing hole-like flaw, a series of uniaxial compression tests are carried out by using the bonded-particle model (BPM). In the BPM, the AE simulation combined with moment tensor inversion is adopted. The results indicate that the stress drop in the stress–strain curve corresponds to a sudden increase of AE counts, which results from the propagation and coalescence of micro-cracks. The shape of hole-like flaw does not have a significant influence on the magnitude distribution of AE event. The b-value of three models is similar, i.e. 1.68, 1.83, and 1.75 corresponding to circular, square, and horseshoe flaw respectively. The forces concentration at upper and bottom of the hole-like flaw is dominated by tensile, and the fracture path only contains micro-tensile cracks. While the forces acting on lateral sides of the hole-like flaw are dominated by compressive. The fracture path contains both micro-tensile and micro-shear cracks and the failure nature is shear and compaction, although the number of micro-tensile crack is predominant.