Experimental and numerical study on fracture characteristics and constitutive model of sandstone under freeze-thaw-fatigue

• Published in: International journal of fatigue 2023-01, Vol.166, p.107236, Article 107236
• Main Authors: Shi, Zhanming, Li, Jiangteng, Wang, Ju, Chen, Jinci, Lin, Hang, Cao, Ping
• Format: Article
• Language: English
• Subjects: Constitutive model; Discrete-element method; Drucker-Prager; Fracture characteristics; Freeze-thaw-fatigue
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/j.ijfatigue.2022.107236

•Sandstone is tested under coupling action of freeze-thaw cycles and fatigue load.•Rock mass's fracture characteristics are analyzed by DEM and AE techniques.•Coupling damage is determined based on Lemaitre strain equivalence hypothesis.•The constitutive model of the specimen is established based on the D-P criterion. The present paper proposes a whole-process constitutive model of rock mass under freeze-thaw-fatigue based on the Drucker-Prager criterion and the Lemaitre strain equivalence hypothesis and by using a Weibull distribution. The fracture characteristics of rock mass under freeze-thaw-fatigue are studied from a macro and mesoscopic perspective, by using the discrete element method and acoustic emission technology. The results show that as the number of freeze-thaw treatments increases, the b value fluctuation amplitude of the rock mass at fatigue failure decreases, the shear crack increases, the anisotropy of the mesoscopic force field enhances, and the required energy decreases, and the rock burst tendency weakens.