Department of Theoretical Physics, University of Debrecen, P.O. Box 5, H-4010 Debrecen, Hungary.
Phys Rev Lett. 2013 Aug 23;111(8):084302. doi: 10.1103/PhysRevLett.111.084302. Epub 2013 Aug 21.
We investigate the temporal and spacial evolution of single bursts and their statistics emerging in heterogeneous materials under a constant external load. Based on a fiber bundle model we demonstrate that when the load redistribution is localized along a propagating crack front, the average temporal shape of pulses has a right-handed asymmetry; however, for long range interaction a symmetric shape with parabolic functional form is obtained. The pulse shape and spatial evolution of bursts proved to be correlated, which can be exploited in materials' testing. The probability distribution of the size and duration of bursts have power law behavior with a crossover to higher exponents as the load is lowered. The crossover emerges due to the competition of the slow and fast modes of local breaking being dominant at low and high loads, respectively.
我们研究了在恒定外部载荷下异质材料中单脉冲及其在时空演化中的统计特性。基于纤维束模型，我们证明了当载荷重新分配沿着传播的裂纹前缘局部化时，脉冲的平均时间形状具有右不对称性；然而，对于长程相互作用，得到的是具有抛物线函数形式的对称形状。脉冲形状和爆发的空间演化被证明是相关的，这可以在材料测试中加以利用。爆发的大小和持续时间的概率分布具有幂律行为，随着载荷的降低，指数会升高。这种交叉现象是由于在低载荷和高载荷下，局部破坏的慢模式和快模式分别占主导地位，从而产生了竞争。
