Identification of crack initiation and damage thresholds in sandstone using 3D digital image correlation

Zhu, Xing; Fan, Jia; He, Chunlei; Tang, Yao

doi:10.1016/j.tafmec.2022.103653

Cited by 12 publications

(1 citation statement)

References 34 publications

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“…When coupled with high-magnification microscopy, this approach can meet the demand for micron-level precision measurements. In recent years, DIC measurement technology has gradually been applied to experiments such as compression [21], tension [22], crack propagation [23], explosion [24], dynamic fracture [25], and penetration [26] of rock-like materials. Ding et al [27] investigated the effect of stress wave superposition between two neighboring boreholes using a digital image correlation system and concluded that these stress enhancements are not sufficient to cause crack initiation in the stress wave superposition region among the boreholes.…”

Section: Introductionmentioning

confidence: 99%

Evolution Characteristics of Strain and Displacement Fields in Double-Hole Short-Delay Blasting Based on DIC

Zhou,

Ma,

Wang

et al. 2024

Processes

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In the process of porous blasting excavation in engineering projects such as mining, hydropower stations, and tunnels, the delay time between adjacent blast holes significantly influences the characteristics of rock fracture and fragmentation. In order to visually explore the changing characteristics of strain and displacement between adjacent blast holes under different delay times, polymethyl methacrylate (PMMA) plates were used to simulate rock materials, and 2D digital image correlation (2D-DIC) testing methods were employed to measure the explosive strain field with different delay times (0 µs, 5 µs, 15 µs, 40 µs, 70 µs) for dual holes. Full-field principal strain cloud maps and displacement fields of PMMA boards in two-dimensional spatial coordinates were obtained, and the representative monitoring points were analyzed. The experimental results show that the maximum values of the first compressive principal strain peak and the first tensile principal strain peak at the connecting center of the two holes exist at a delay time of 0~40 µs under blasting conditions with the same hole distance and single hole charge. At the center point of the connection between the two holes, the interval time between the two principal strain peaks decreases with the increase in delay time. The maximum principal strain on the central vertical line of the connection line decreases exponentially with the increase in hole distance, and the attenuation trend increases first and then decreases with the delay time between 0 and 40 µs. At the peak of strain, the maximum average displacement of the connecting center of the two holes exists in the delay time between 0 and 40 µs. With the increase in delay time, the displacement trend between the two explosion holes gradually changes from shear to tension, and the vulnerable damage area increases, which makes the communication between the two explosion holes easier. This study can provide a basis for the precise selection of delay times between blasting holes in engineering.

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