DATA_Multi_stages_loading_and_relaxing_of_double_torsion

Based on linear elastic fracture mechanics, we performed several double torsion tests using shale samples with various initial stress levels under constant loading displacement. The pre-set initial stress levels were selected as 34%, 54%, 72% and 94% of the pre-cracking load. These initial load were applied with a high rate of 2.7 mm/min first and then the natural load relaxation occured. At certain moment, we dripped water into crack tip zone to capture the subcritical crack growth induced by water-rock interaction, exactly referred to clay hydration, which could create damage and accelerate crack growth. Hereafter, water diffused into the external environment, which caused the potential crack healing. Specifically, the crack healing can make the monitored load increase, which is a representive signal for this. The dataset here is a complete recording with a raw data sensing under different loading stages.