| Budget Amount *help |
¥13,520,000 (Direct Cost: ¥10,400,000、Indirect Cost: ¥3,120,000)
Fiscal Year 2017: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2016: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2015: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
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| Outline of Final Research Achievements |
Two power laws are ubiquitously observed for the statistics of materials failure and earthquakes: the Gutenberg-Richter (GR) law and the Omori law. Interestingly, some parameters in these power laws may reflect the physical state of specimens or earthquake faults such as the stress level. Here we investigated the b-value in the GR law and the c-value in the Omori law focusing on their stress dependence in two distinct systems: granular matter and the bundle of fibers. In sheared granular matter, both the b-value and the c-value exhibit negative stress dependences. Particularly, we found the exponential dependence of the c-value on stress. In the fiber bundle model, we confirmed the Omori law and the inverse Omori law. An analytical solution is obtained for a mean-field model, which reveals slow down due to the saddle-node bifurcation. The c-value here depends on the degree of heterogeneity in the system rather than the stress.
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