A novel bond-based peridynamic method is proposed to investigate the initiation, propagation, and coalescence of cracks in brittle rock materials subjected compressive loads. To simulate failure under loads, tangent bonds are introduced into theory. By comparing strain energy with energy, micro-peridynamic parameters can be expressed by macromechanical rocks. The model solve problem that normal theory limited constitutive models a Poisson's ratio 1/4 for three-dimensional problems. program...

Cracking behaviors of rocks significantly affect the safety and stability explorations underground space deep resources. To understand deeply microscopic cracking process mechanical property rocks, X-ray micro-computed tomography (X-μCT) is applied to capture rock microstructures. The digital color difference UNet (DCD-UNet)-based learning algorithm with 3D reconstruction proposed reconstruct multiphase heterogeneity microstructure models rocks. properties are studied based on...

High-energy gas fracturing of shale is a novel, high efficacy and eco-friendly mining technique, which typical dynamic perturbing behavior. To effectively extract gas, it important to understand the mechanical properties shale. Dynamic experiments on subjected true triaxial compression at different strain rates are first conducted in this research. The stress–strain curves, peak strain, stress failure modes investigated. results study indicate that intermediate principal minor have...

Abstract A novel coupled thermo‐mechanical nonordinary state‐based peridynamics is proposed to study thermally induced damage in rocks. The thermal expansion characteristics of solid material are introduced into the thermomechanical model consider influence temperature. deformation gradient tensor obtained by temperature fields, which solved peridynamic heat conduction theory. By introducing force state function peridynamics, coupling and mechanical realized. failure criterion developed...

This work discussed the results from tests conducted to study desorption and outburst characteristics of soft hard coal under different gas conditions. The research found that type has a greater influence on coal. Triaxial compression failure can improve rate specimens, is more affected by triaxial failure. In experiments, test pressure, crush degree specimen, proportion small-sized powder (<0.1 mm) increases but gradually stabilizes. Moreover, acoustic emission (AE) signals during process...

It is assumed that a deep spherical cavity subjected to in situ stress at infinity, and the excavation process of treated like decrease pressure applied on its internal boundary. Trigonometric functions hyperbolic cosine sine are used scalar curvature. A non-Euclidean dynamic kinematic equation based strain incompatibility condition derived. Laplace transformation residue theory deduce fields. The strength criterion rock masses determine number magnitude fractured zones nonfractured...

It is assumed that rocks contain three-dimensional (3D) penny-shaped microcracks. The Mode II and III dynamic stress-intensity factors at the tips of 3D microcracks are determined. orientation angle microfailure in rock materials obtained to describe failure rocks. relationship between stress components derived from fracture criterion. Failure-characteristic parameters under triaxial compressive condition defined; these an invariant. A nonlinear strength criterion established using...

Brittle rock contains an important plastic deformation, which causes microcracks when coupled with stress-induced damage. A new elastoplastic damage model is established in order to discuss the behaviors found brittle rock, based on theoretical analysis and experiments. Micromechanic considerations determine effective elastic properties of anisotropic damaged geomaterials. An energy-based criterion used deduce initiation evolution law rocks. Moreover, non-linear unified strength modified. It...

With the increasing excavation depth of underground engineering, engineering problems such as large deformation and rock burst caused by high geo-stress brings new challenges to reinforcement surrounding in deep engineering. The traditional bolt is prone brittle fracture under due its low elongation. Therefore, this work aims develop a novel energy-absorbing with constant resistance displacement reinforce risk or rockburst. refereed rolling extrusion (RE bolt) mainly consists sleeve tube...