Deformation localization and cracking processes of sandstone containing two flaws of different geometric arrangements

Abstract

AbstractWe present deformation localization and cracking process of sandstone with two flaws of different geometric configurations in uniaxial compression. The full field strain and progressive cracking processes are quantitatively monitored using three‐dimensional digital image correlation and acoustic emission techniques. The results show that peak strength and elastic modulus show a first decrease and then increase trend with regard to ligament angle under the same flaw geometry, achieving the minimum at the ligament angle 60°. The tensile strain develops at low stress level and then increases significantly. However, the shear strain only tends to be obvious while approaching peak stress. With the ligament angle increasing, the crack coalescence mode transfers from indirect to direct coalescence. In addition, the complete cracking processes of sandstone can be divided into six stages, together with six crack coalescence modes.