Local waiting time fluctuations along a randomly pinned crack front -: art. no. 045501
Local waiting time fluctuations along a randomly pinned crack front -: art. no. 045501
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DOI：
10.1103/physrevlett.96.045501
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发表时间：
2006-02-03
影响因子：
8.6
通讯作者：
Toussaint, R
中科院分区：
文献类型：
--
作者：
Måloy, KJ;Santucci, S;Toussaint, R
使用高分辨率快速相机跟踪界面裂纹沿着透明有机玻璃块的异质弱平面的传播。我们表明，裂缝前缘动力学是由具有非常大的尺寸和速度波动的局部和不规则的雪崩控制的。我们通过测量裂纹前沿在其传播过程中的局部等待时间波动来表征观察到的间歇动态，即裂纹前沿的局部钉扎和脱钉。推导出的局部前线速度分布表现出幂律行为，P(v) 与 v(-eta) 成比例，且 eta = 2.55 +/- 0.15，速度 v 大于平均前线速度 < v >。突发大小分布也是幂律分布，P(S) 与 S-gamma 成正比，gamma = 1.7 +/- 0.1。在类似于 15 μm 的无序 L-d 特征长度尺度以上，雪崩簇变得各向异性，提供了裂纹前沿线粗糙度指数的估计，H = 0.66。
The propagation of an interfacial crack along a heterogeneous weak plane of a transparent Plexiglas block is followed using a high resolution fast camera. We show that the fracture front dynamics is governed by local and irregular avalanches with very large size and velocity fluctuations. We characterize the intermittent dynamics observed, i.e., the local pinnings and depinnings of the crack front by measuring the local waiting time fluctuations along the crack front during its propagation. The deduced local front line velocity distribution exhibits a power law behavior, P(v) proportional to v(-eta) with eta = 2.55 +/- 0.15, for velocities v larger than the average front speed < v >. The burst size distribution is also a power law, P(S) proportional to S-gamma with gamma = 1.7 +/- 0.1. Above a characteristic length scale of disorder L-d similar to 15 mu m, the avalanche clusters become anisotropic providing an estimate of the roughness exponent of the crack front line, H = 0.66.