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Deformation and failure characteristics of sandstone subjected to true‐triaxial unloading: An experimental and numerical study
Author(s) -
Xiao Fan,
Jiang DeYi,
Wu Fei,
Chen Jie,
Zhang JianZhi,
Liu Wei
Publication year - 2021
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/ffe.13470
Subject(s) - principal stress , geotechnical engineering , shear (geology) , materials science , ultimate tensile strength , failure mode and effects analysis , deformation (meteorology) , geology , triaxial shear test , composite material
In this research, we conducted both laboratory experiments and discrete element simulations to investigate the influence of maximum principal stress level on true‐triaxial unloading behaviors of sandstone samples. The results show that as the level of σ 1 at the unloading point increases, the ultimate bearing capacity of sandstone sample is increasingly strengthened, while the sample collapses more easily during the unloading process, and the failure mode of sample changes from mixed tensile‐shear failure to shear failure. With the increase in the level of σ 1 , the accumulative micro‐cracks at the unloading point and micro‐crack generation rate during the unloading phase exhibit increasing trends, while the ratio between the number of tensile micro‐cracks and shear micro‐cracks generally shows a downward trend. The formation of macro fracture in sandstone sample is closely related to the material inhomogeneity and true‐triaxial stress state.