Investigating stress corrosion-induced rupture behavior using the acoustic emission technique

The rupture behavior of rocks in water environments is influenced by complex rock-water interactions, with stress corrosion recognized as a significant factor. However, the effect of stress corrosion on rock rupture is often masked by concurrent rock-water interaction mechanisms, complicating its isolated analysis. In this study, fused quartz glass samples were used to eliminate extraneous factors, enabling a dedicated investigation of the stress corrosion-induced rupture under controlled fracture modes and water conditions. Semi-circular bending tests in a water-based environment were conducted, with fracture processes monitored using the acoustic emission (AE) technique. Loading curves, rupture paths, and surface morphologies were analyzed to reveal macroscale fracture features. AE parameter analysis, source localization, and moment tensor inversion were employed to investigate spatiotemporal damage evolution at the mesoscale. The stress corrosion-induced failure exhibits interesting softening fracture behavior at both the mesoscale and macroscale. At the macroscale, softening deformation is induced by stress corrosion, with energy release at the crack tip occurring gently. At the mesoscale, meso-crack proliferation can be triggered by stress corrosion, leading to a cross-scale damage evolution process. The damage process exhibits distinct instability characteristics at 50-80 % load levels under mode I fracture, whereas it remains relatively stable under mode II fracture. As peak stress approaches, the proliferation of mesoscale fractures forms an irreversible crack network that alters the local mesostructure, governing failure behavior and facilitating macroscale softening rupture. It is found that the flowing water and tensile fracture mode stimulate corrosion and intensify degradation, which deserves heightened concern in engineering.