How surface governs vibration-induced degradation of glass Structure: A view from molecular dynamics

Abstract

Silica glass, renowned for its exceptional thermal stability and mechanical strength, is widely used in optics, manufacturing, and aerospace. However, the mechanisms underlying its structural degradation under external vibrational fields is still rare due to the inherent disordered network. Using molecular dynamics (MD) simulations, we uncover the structural responses and evolution mechanisms of silica glass under external vibration field. Fourier transform of the root-mean-square displacement (RMSD), reduced pair distribution function G(r), and rearrangement of topological rings are applied to elucidate the dynamic behavior of the glass network. Vibration-induced alterations manifest as enhancing high-frequency vibration modes, loosened local structures, and progressive degradation of the network connectivity. Quantitatively, the FWHM of the main G(r) peak increased from 0.077 to 0.193 after repeated vibration, while the average ring size increased from 6.8224 to 6.8495 after three vibration cycles. This study provides molecular-level insights into the structural dynamics of silica glass under external mechanical stress, revealing a novel pathway for understanding the performance degradation of disordered materials.