Crack Initiation Criteria and Fracture Simulation for Precracked Sandstones

<div>Calculation model diagram of single-crack sample (<i>r</i> = 0): (a) closed crack: crack angle <i>β</i> = 15°, crack thickness <i>d</i> = 0.5 mm; (b) nonclosed crack: crack angle <i>β</i> = 45°, crack thickness <i>d</i> = 2 mm.</div>

Advances in Materials Science and Engineering

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Figure 5

Figure 5: Crack Initiation Criteria and Fracture Simulation for Precracked Sandstones 