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<p>During deep coal mining, dynamic impact loading critically triggers surrounding rock instability, making comprehensive revelation of coal’s dynamic failure mechanisms essential for controlling mining-induced dynamic hazards. This study investigates coal’s dynamic response and damage evolution under impact loading using split Hopkinson pressure bar (SHPB) tests at five impact velocities, obtaining dynamic mechanical parameters, stress–strain curves, and fragmentation characteristics. An LS-DYNA 3D numerical model with the Holmquist-Johnson–Cook (HJC) constitutive model was established, conducting parameter sensitivity analysis validated by experiment-simulation comparisons to analyze failure processes and damage evolution. Results indicate: dynamic compressive strength, energy dissipation, and dissipation ratio increase significantly with impact velocity; failure modes transition from localized cracking to fragmentation, confirming strain-rate effects; HJC parameters A/B positively correlate with peak stress/transmitted wavelength while N shows negative correlation, with diminishing influence rates; simulation-experiment errors remain below 10% with matched stress–strain curves and failure modes; energy distribution follows incident &gt; reflected &gt; absorbed &gt; transmitted, all increasing monotonically with incident energy; damage evolution exhibits three phases—slow development, rapid acceleration (contributing 92% damage), and stabilization—with damage variable growing exponentially with impact velocity. These findings establish theoretical and experimental foundations for coal’s dynamic behavior under impact loading.</p>

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Dynamic Mechanical Response and Damage Evolution of Coal Subjected to Impact Loading: Experimental Investigation and Numerical Simulation

  • 期刊论文

  • 发表日期：

    2025年9月2日

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  • Changxing Zhu,
  • Duo Li,
  • Dazhi Wu,
  • Jiaxin Huo

摘要

During deep coal mining, dynamic impact loading critically triggers surrounding rock instability, making comprehensive revelation of coal’s dynamic failure mechanisms essential for controlling mining-induced dynamic hazards. This study investigates coal’s dynamic response and damage evolution under impact loading using split Hopkinson pressure bar (SHPB) tests at five impact velocities, obtaining dynamic mechanical parameters, stress–strain curves, and fragmentation characteristics. An LS-DYNA 3D numerical model with the Holmquist-Johnson–Cook (HJC) constitutive model was established, conducting parameter sensitivity analysis validated by experiment-simulation comparisons to analyze failure processes and damage evolution. Results indicate: dynamic compressive strength, energy dissipation, and dissipation ratio increase significantly with impact velocity; failure modes transition from localized cracking to fragmentation, confirming strain-rate effects; HJC parameters A/B positively correlate with peak stress/transmitted wavelength while N shows negative correlation, with diminishing influence rates; simulation-experiment errors remain below 10% with matched stress–strain curves and failure modes; energy distribution follows incident > reflected > absorbed > transmitted, all increasing monotonically with incident energy; damage evolution exhibits three phases—slow development, rapid acceleration (contributing 92% damage), and stabilization—with damage variable growing exponentially with impact velocity. These findings establish theoretical and experimental foundations for coal’s dynamic behavior under impact loading.