Meso-fracture mechanism of Longmaxi shale with different crack-depth ratios: Experimental and numerical investigations

The mechanical properties and fracture mechanism of shale are vital to the design of hydraulic fracturing schemes. To better understand the formation and evolution of hierarchical crack networks in shales, a scanning electron microscope (SEM) with a loading device was applied to carry out three-point bending experiment on Longmaxi shale with different crack-depth ratios (CDR). The micro-damage and fracture processes of shale were observed in...