近日，美国哈佛大学的D. A. Weitz及其研究小组与中国石油大学的L. Xiao等人合作并取得一项新进展。经过不懈努力，他们揭示通过裂纹前缘变形快速横向扩展和局部成核的延伸破裂传播过程。相关研究成果已于2024年1月29日在国际知名学术期刊《自然—物理学》上发表。

该研究团队发现，在初始破裂过程中，破裂前锋会正向传播，并在某些局部位置成核。随后，它会以高达瑞利波速的速度进行非常迅速的横向扩展。为了实现不间断的延伸破裂前峰，研究人员研究了一个圆形几何形状的断裂，并使用流体来控制决定前向跳跃振幅的加载条件。

研究人员发现，这个振幅与横向速度密切相关。通过动态破裂模拟，他们只捕捉到了高横向速度下的观察结果。这些结果表明，横向动力学在扩展裂缝前向传播中起到了重要的作用。

据悉，破裂是一种常见现象，可能导致材料的灾难性失效。虽然二维平面上的破裂已经得到了很好的理解，但裂缝在三维空间中的延伸和传播行为更为复杂。

附：英文原文

Title: Propagation of extended fractures by local nucleation and rapid transverse expansion of crack-front distortion

Author: Cochard, T., Svetlizky, I., Albertini, G., Viesca, R. C., Rubinstein, S. M., Spaepen, F., Yuan, C., Denolle, M., Song, Y-Q., Xiao, L., Weitz, D. A.

Issue&Volume: 2024-01-29

Abstract: Fractures are ubiquitous and can lead to the catastrophic material failure of materials. Although fracturing in a two-dimensional plane is well understood, all fractures are extended in and propagate through three-dimensional space. Moreover, their behaviour is complex. Here we show that the forward propagation of a fracture front occurs through an initial rupture, nucleated at some localized position, followed by a very rapid transverse expansion at velocities as high as the Rayleigh-wave speed. We study fracturing in a circular geometry that achieves an uninterrupted extended fracture front and use a fluid to control the loading conditions that determine the amplitude of the forward jump. We find that this amplitude correlates with the transverse velocity. Dynamic rupture simulations capture the observations for only a high transverse velocity. These results highlight the importance of transverse dynamics in the forward propagation of an extended fracture.

DOI: 10.1038/s41567-023-02365-0

Source: https://www.nature.com/articles/s41567-023-02365-0