论文标题
准脆性材料和亚avalanches（余震）簇中的非对称损坏雪崩形状
Asymmetric damage avalanche shape in quasi-brittle materials and sub-avalanches (aftershocks) clusters
论文作者
论文摘要
裂纹动力学的特征是通过间歇性雪崩释放传入能量。形状，即这些雪崩的内部时间结构，提供了有关所涉及的物理过程的有见地的信息。最近通过实验表明，在考虑微裂纹雪崩的全局特征之间的缩放关系时，可以将逐渐造成准脆性材料的逐渐损害映射到界面的通用类别中。在这里，我们显示了三种混凝土材料以及微裂纹事件产生的声学发射波形的详细分析，这些损害的形状雪崩的形状是强烈不对称的，其特征是非常缓慢的衰变。在这些准脆性材料中，这种显着的不对称性与平均场默认预测的矛盾，可以通过在损害avalanche产生的断裂过程区内增强的粘弹性过程引起的延迟效应来解释。它与主要雪崩中的亚avalanches或余震群有关。
Crackling dynamics is characterized by a release of incoming energy through intermittent avalanches. The shape, i.e. the internal temporal structure of these avalanches, gives insightful information about the physical processes involved. It was experimentally shown recently that progressive damage towards compressive failure of quasi-brittle materials can be mapped onto the universality class of interface depinning when considering scaling relationships between the global characteristics of the microcracking avalanches. Here we show, for three concrete materials and from a detailed analysis of the acoustic emission waveforms generated by microcracking events, that the shape of these damage avalanches is strongly asymmetric, characterized by a very slow decay. This remarkable asymmetry, at odds with mean-field depinning predictions, could be explained, in these quasi-brittle materials, by retardation effects induced by enhanced viscoelastic processes within a fracture process zone generated by the damage avalanche as it progresses. It is associated with clusters of sub-avalanches, or aftershocks, within the main avalanche.
