滑移脉冲驱动不同材料的摩擦运动
近日，以色列耶路撒冷希伯来大学拉卡物理研究所的Jay Fineberg及其研究团队取得一项新进展。经过不懈努力，他们对滑移脉冲驱动不同材料的摩擦运动的普遍性、动力学和演化进行了研究。相关研究成果已于2024年11月7日在国际知名学术期刊《美国科学院院刊》上发表。
本研究中，研究人员从实验探究了七种不同双材料界面中的滑移脉冲动力学、演化及结构特征。研究发现，滑移脉冲是双材料界面中摩擦运动的主要载体，它们存在于明确界定的速度范围内，并经历着与理论预测相符的不稳定增长，这一现象被称为“亚当斯不稳定性”。在适当的比例尺下，滑移脉冲展现出普遍的空间结构和增长动力学。
尽管不同界面中的滑移脉冲幅度差异显著，但令人惊讶的是，这种差异并不高度依赖于接触材料弹性性质的对比。相反，滑移脉冲幅度与界面的老化特性密切相关，进而与界面处的材料塑性紧密相关。由于双材料界面具有普遍性，这些结果对于摩擦动力学以及广泛自然断层中地震的动力学，都具有根本性的重要意义。
据悉，具有不同弹性或几何特性（即双材料界面）的物体之间的摩擦滑动，会产生一种独特的断裂形式，即双材料“滑移脉冲”。这些滑移脉冲沿着分隔弹性不同接触物体的界面传播，并表现出高度局部化的滑动，同时伴随着局部正应力的减小。这些脉冲的产生并非源于“摩擦定律”的特性，而是由于接触物体之间的弹性失配所形成的。
附：英文原文
Title: Slip-pulses drive frictional motion of dissimilar materials: Universality, dynamics, and evolution
Author: Poles, Yonatan, Shi, Songlin, Fineberg, Jay
Issue&Volume: 2024-11-7
Abstract: Frictional slip between bodies having different elastic or geometrical properties (bimaterial interfaces) creates a unique type of rupture, bimaterial “slip pulses.” These slip pulses propagate along the interfaces separating elastically different contacting bodies. They exhibit highly localized slip with accompanying local normal stress reduction. These pulses do not result from properties of “friction laws” but, instead, are formed via the elastic mismatch of the contacting bodies. Here, we experimentally study slip pulse dynamics, evolution, and structure in seven different bimaterial interfaces. We find that slip pulses are a major vehicle for frictional motion in bimaterial interfaces, they exist in well-defined velocity windows and undergo unstable growth consistent with theoretical predictions coined the “Adams instability.” When scaled properly, slip pulses exhibit both universal spatial structure and growth dynamics. While slip pulse amplitudes vary considerably within different interfaces, this variation is, surprisingly, not highly dependent on the contrast of the elastic properties of the contacting materials. Instead, slip pulse amplitudes are closely related to the interfaces’ aging properties and, hence, to material plasticity at the interface. As bimaterial interfaces are generic, these results are fundamentally important to both frictional dynamics and the dynamics of earthquakes within a wide class of natural faults.
DOI: 10.1073/pnas.2411959121
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2411959121
