Department of Theoretical Physics, University of Debrecen, P.O. Box 5, H-4010 Debrecen, Hungary.
School of Geosciences, University of Edinburgh, EH9 3JW Edinburgh, United Kingdom and Institute for Geophysics and Meteorology, University of Cologne, Cologne, Germany.
Phys Rev Lett. 2014 Feb 14;112(6):065501. doi: 10.1103/PhysRevLett.112.065501.
We investigate the scaling properties of the sources of crackling noise in a fully dynamic numerical model of sedimentary rocks subject to uniaxial compression. The model is initiated by filling a cylindrical container with randomly sized spherical particles that are then connected by breakable beams. Loading at a constant strain rate the cohesive elements fail, and the resulting stress transfer produces sudden bursts of correlated failures, directly analogous to the sources of acoustic emissions in real experiments. The source size, energy, and duration can all be quantified for an individual event, and the population can be analyzed for its scaling properties, including the distribution of waiting times between consecutive events. Despite the nonstationary loading, the results are all characterized by power-law distributions over a broad range of scales in agreement with experiments. As failure is approached, temporal correlation of events emerges accompanied by spatial clustering.
我们研究了在单轴压缩下沉积岩全动态数值模型中噼啪声源的标度性质。该模型通过用具有不同尺寸的球形颗粒填充圆柱形容器来启动，然后通过可破坏的梁将这些颗粒连接起来。以恒定应变速率加载时，黏合元素会失效，由此产生的应力传递会产生突发的相关失效，这与实际实验中声发射的源直接类似。可以为单个事件量化源的大小、能量和持续时间，并且可以对其进行分析以获得其标度性质，包括连续事件之间的等待时间分布。尽管加载是非平稳的，但结果都表现出幂律分布，跨越了广泛的尺度范围，与实验结果一致。随着失效的临近，事件的时间相关性出现，同时空间也出现聚集。
