Scholarlink

<p>To elucidate the influence of pre-existing damage on the dynamic tensile behavior and energy dissipation mechanisms of sandstone, cyclic loading–unloading followed by dynamic Brazilian splitting tests were conducted using a split Hopkinson pressure bar (SHPB) system. X-ray computed tomography (CT) was utilized to quantify the internal microstructural evolution under varying degrees of initial damage. The results reveal a clear intrinsic coupling relationship among initial damage, dynamic tension, and energy evolution: First, cyclic loading exacerbates internal fracture coalescence, significantly increasing the pre-existing damage degree. Second, this initial damage fundamentally deteriorates the rock’s dynamic tensile properties; the dynamic tensile strength decreases markedly as damage intensifies, with highly damaged samples retaining only 54% of the intact strength. Under impact, crack propagation in pre-damaged sandstone remains predominantly tensile, while macroscopic deformations (shear strain and vertical displacement) are significantly amplified. Finally, from an energy perspective, pre-existing internal cracks act as localized energy absorption zones. Consequently, an increase in initial damage drives a higher damage-dissipated energy density and a corresponding reduction in transmitted energy during dynamic failure. This study highlights the failure mechanisms of damaged rock driven by energy dissipation, providing essential theoretical support for the stability evaluation and dynamic disaster early-warning of surrounding rock in deep mining engineering.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Dynamic tensile mechanical properties and energy dissipation characteristics of sandstone with varying degrees of initial damage

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年6月16日

查看全文
  • Wenbao Shi,
  • Haoran Shi,
  • Chuanming Li,
  • Chao Qi,
  • Jucai Chang,
  • Aoyun Yan,
  • Feiyang Ren

摘要

To elucidate the influence of pre-existing damage on the dynamic tensile behavior and energy dissipation mechanisms of sandstone, cyclic loading–unloading followed by dynamic Brazilian splitting tests were conducted using a split Hopkinson pressure bar (SHPB) system. X-ray computed tomography (CT) was utilized to quantify the internal microstructural evolution under varying degrees of initial damage. The results reveal a clear intrinsic coupling relationship among initial damage, dynamic tension, and energy evolution: First, cyclic loading exacerbates internal fracture coalescence, significantly increasing the pre-existing damage degree. Second, this initial damage fundamentally deteriorates the rock’s dynamic tensile properties; the dynamic tensile strength decreases markedly as damage intensifies, with highly damaged samples retaining only 54% of the intact strength. Under impact, crack propagation in pre-damaged sandstone remains predominantly tensile, while macroscopic deformations (shear strain and vertical displacement) are significantly amplified. Finally, from an energy perspective, pre-existing internal cracks act as localized energy absorption zones. Consequently, an increase in initial damage drives a higher damage-dissipated energy density and a corresponding reduction in transmitted energy during dynamic failure. This study highlights the failure mechanisms of damaged rock driven by energy dissipation, providing essential theoretical support for the stability evaluation and dynamic disaster early-warning of surrounding rock in deep mining engineering.