Cracks in a rock mass subjected to a uniaxial stress will be preferentially closed depending on the angle between the fracture normal and the direction of the applied stress. If the prestress fracture distribution is isotropic, the effective elastic properties of such a material are then transversely isotropic due to the preferred alignment of the cracks. Velocity measurements in multiple direc...

This article establishes a new model for estimating the peak indentation force of the edge chipping of rocks when using a conical or a pyramidal point-attack pick. The investigation points out that the existing formulation in the literature is based on an inappropriate stress assumption and equilibrium, and hence leads to incorrect cutting force estimations. The new model developed in this stud...

In this paper, three-dimensional modeling of the fatigue crack growth profiles was performed in a simple riveted lap joint. Simulation results showed that mode I was dominated on the one side of the plates and the crack straightly grew on this side, while the other side of the plates was in a mixed-mode condition and the crack propagation path was not straight on this side. Afterward, the fract...

Initial cracks occur in high strength concrete sleepers for various reasons, such as shrinkage and wrong curing and long lifetime of over 50 years of sleepers. These cracks may lead to complete failure of the structure. In order to more accurately design the sleepers, fracture mechanics (not strength of materials) should be incorporated. In order to achieve this purpose, it is important to fore...

The initiation, expansion, and penetration of microscopic cracks in rock is the macroscopic manifestation creep. This paper investigates mechanical creep characteristics fracture evolution processes masses with different angles, lengths, bridge dip angles. Single fractures, dual parallel groups are considered. approach comprises discrete element simulation based on continuum mechanics, utilizin...

This paper studies the application of an inverse methodology for problem solving in fracture mechanics using the finite element analysis. The method was applied to both detection of subsurface cracks and the study of propagating cracks. The procedure for detection of subsurface cracks uses a first order optimization analysis coupled with a penalty function to solve for the unknown geometric par...

Under uniaxial loading, the heterogeneity of rock mass, change mechanical properties joints, and progressive fracture process mass significantly affect size effect anisotropy columnar jointed basalts (CJBs). To reveal features failure mechanisms CJBs influenced by anisotropy, digital image correlation (DIC), meso-damage mechanics, statistical strength theory, continuum mechanics were combined (...

By partitioning the total stresses in a damaged composite into either mechanical and residual stresses or into initial and perturbation stresses, it was possible to derive two exact results for the energy release rate due to crack growth. These general results automatically include the effects of residual stresses, tractionloaded cracks, and imperfect interfaces. These effects are normally not ...