Mechanical properties and microscopic damage characteristics of coal series limestone under coupling effects of high temperature and impact

作者：Peng Wu, Lianying Zhang, Bing Li, Yadong Zheng, Ming Li, Fuqiang Zhu · 发表于：Scientific Reports · 年份：2024 · DOI：10.1038/s41598-024-83599-7 · 被引用次数：7 · 研究领域：Rock Mechanics and Modeling、Geotechnical and Geomechanical Engineering、Landslides and related hazards

To ensure the safe extraction of deep mineral resources, it is imperative to address the mechanical properties and damage mechanism of coal and rock media under the real-time coupling effect of high temperature and impact. In this study, the impact tests (impact velocities of 6.0-10.0 m/s) on coal-series limestone under real-time high-temperature conditions (25 °C-800 °C) were conducted by the real-time high-temperature split Hopkinson pressure bar (HT-SHPB) testing system, and the microscopic changes in mineral composition under the coupling effect of real-time high-temperature and high strain rate action were investigated by X-ray diffraction (XRD), electron scanning microscopy (SEM), energy dispersive spectroscopy (EDS). The results showed that the dynamic stress-strain curve of coal-series limestone under the real-time coupling effect of high temperature and impact during the compaction stage was not significant; As the impact velocity increases and the temperature increases, the plastic characteristics of the dynamic stress-strain curve become more notable, and the brittle failure of the sample is gradually changed into brittle-ductile failure. Additionally, the dynamic peak stress and dynamic elastic modulus exhibit distinct quadratic variations with the increased temperature, and the dynamic peak stress approximately increases linearly with the impact velocity. The main substances in coal-series limestone are calcite, dolomite, and muscovite. The microscopic morphology...