13th International Conference on Fracture June 16–21, 2013, Beijing, China -6- corresponding values at the tips of the long cracks. Table 1. Material properties of Al2O3 and Si3N4 Young’s modulus (GPa) Poisson’s ratio CTE (10-6/K) Thermal conduc- tivity (W/m-K) Mass density (g/cm3) Specific heat (J/g-K) Fracture toughness (MPa-m1/2) Al2O3 320 0.25 8.0 20 3.8 0.9 4 Si3N4 320 0.25 3.0 35 3.2 0.7 5 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11 Nondimensional time Normailized TSIF τa = 0.0 τa = 0.02 τa = 0.05 Figure 2a: Normalized TSIF versus nondimensional time at the tips of the long cracks (a1/b = 0.1, a2/a1 = 0.2, h/b = 1.0, p = 0.5) 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11 Nondimensional time Normailized TSIF τa = 0.0 τa = 0.02 τa = 0.05 Figure 2b: Normalized TSIF versus nondimensional time at the tips of the short cracks (a1/b = 0.1, a2/a1 = 0.2, h/b = 1.0, p = 0.5)
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