Crack evolution law and failure mode of red sandstone under fatigue–creep interaction

Abstract

To explore the fracture characteristics of rock under the interaction of fatigue load and creep load, fatigue–creep interactive loading experiments were performed on red sandstone with prefabricated cracks. The crack evolution process and failure mode were analyzed using acoustic emission technology and digital image correlation. The results showed that crack growth mainly occurred in the fatigue loading stage; the crack evolution of the sample could be divided into three stages: nucleation and initiation ( SI), stable expansion ( SII), and unstable fracture ( SIII). There were distinct differences in the crack propagation modes of the rock samples with different prefabricated crack angles. The relationship between the crack initiation angle and prefabricated crack angle was analyzed based on the maximum circumferential stress theory. Moreover, with an increase in the prefabricated crack angle, the rock sample gradually changed from compression–shear failure to tension–shear failure.

Effect of the upper limit stress on the fatigue properties and crack propagation processes of sandstones containing pre‐existing crack under fatigue‐creep interaction

“…The failure modes of the rock mass under the interaction of fatigue-creep are all tensile-shear composite failures. At the same time, as the CSL increases, the surface of the sample can produce greater deformation before failure, the brittleness at failure is weakened, and the failure mode gradually changes from brittleness to ductility, which is consistent with the experimental phenomenon of Shi et al 30 and Wang et al 32…”

“…In terms of fatigue-creep interaction, affected by the heterogeneity and anisotropy of rocks, the existing research mainly focuses on isotropic materials such as metals and asphalt, and there are few related studies on brittle materials such as rocks. 31,32 However, in practical engineering applications, deep engineering rock masses are often under fatigue-creep interaction. Therefore, a series of fatigue-creep tests with different cyclic stress levels (CSL) were carried out on jointed sandstone samples.…”

Study on mechanical behavior and failure mechanism of specimens with single joint subjected to dynamic cyclical loading

“…To sum up, comparing the failure mode of specimens under high and low stress, it is found that the failure mode is continuously changed from single failure to mixed failure 50 . This indicates that the input of high cyclic stress energy moves particles to become disordered and the specimen is more likely to be destroyed macroscopically.…”

“…To sum up, comparing the failure mode of specimens under high and low stress, it is found that the failure mode is continuously changed from single failure to mixed failure. 50 This indicates that the input of high cyclic stress energy moves particles to become disordered and the specimen is more likely to be destroyed macroscopically. From the change of failure mode with different dip angles, the change of failure mode becomes smaller with the increase of cyclic stress limit with the increase of joint inclination angle.…”

A Study of Strength Parameter Evolution and a Statistical Damage Constitutive Model of Cemented Sand and Gravel

“…Under the action of external force, there exists the acoustic emission (AE) phenomenon because of the rapid release of local energy and the material’s emissions of transient elastic waves from the inside [ 52 ]. To implement AE monitoring during the particle flow loading process, Zhou Y et al [ 53 , 54 ] and Cai et al [ 55 ] compiled an AE moment tensor operation function into FISH language.…”