PSI - Issue 42

Nina Selyutina et al. / Procedia Structural Integrity 42 (2022) 420–424 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 1. Water-saturation effect of sandstone on theoretical and experimental fracture toughness rate dependencies based of proposed model (3) and data (Zhou et al. 2019).

Fig. 2. Water-saturation effect of sandstone on theoretical and experimental fracture energy rate dependencies based of proposed model (3) and data (Zhou et al. 2019). 5. Conclusions The energy and force limiting criteria, determined by the structural-temporal approach, were used to predict the rate dependences of the dynamic stress intensity factor and fracture work, respectively. A comparison of sandstone incubation times estimated from the rate dependencies of fracture toughness and fracture work showed that the resulting incubation time of 0.155 ms for dry sandstone and 0.196 ms for saturated sandstone, calculated from the energy limiting condition, differed from the incubation time of 0.615 ms for dry sandstone and 0.717 ms for saturated sandstone, estimated from the force limiting condition for fracture toughness. The results obtained according to the formulated limiting power and energy criteria are carried out on different time scales, since the incubation time obtained according to the energy limiting criterion is longer than according to the power one.