采矿与岩层控制工程学报2024，Vol.6Issue(2)：1-11,11.
循环应力损伤对煤体Ⅰ型动态断裂特性的影响
Effect of cyclic stress damage on the mode Ⅰ dynamic fracture characteristics of coal
张传玖 1李果 2任建慧 1姚士茂 1李宣良1
作者信息
- 1. 国能神东煤炭集团有限责任公司 布尔台煤矿, 内蒙古 鄂尔多斯 017209
- 2. 国能神东煤炭集团有限责任公司 神东煤炭技术研究院, 陕西 榆林 719315
- 折叠
摘要
Abstract
To investigate the impact of cyclic stress damage on the dynamic fracture characteristics of coal mass-es,static and dynamic fracture tests were conducted on type Ⅰ single-sided notched beam specimens of coal both prior to and following cyclic stress damage.The test results revealed that the average dynamic mode Ⅰ fracture toughness(KIC)of the coal mass stands at 0.344 MPa·m1/2,with an average mode Ⅰ fracture energy(GC)of 66.99 N/m.These figures are respectively 1.38 and 1.26 times higher than those measured for the static fracture parameters of the coal specimens.After expore to cyclic stress damage,the average static KIC value of the coal specimen was reduced to 0.219 MPa·m1/2,and the average static GC to 44.26 N/m,marking decreases of 12.05％and 16.74％relative to the original specimens.Additionally,the average dynamic KIC and GC values decreased to be 0.279 MPa·m1/2 and 52.72 N/m,respectively,representing reductions of 20.90％and 21.30％compared with the impact fracture test results of the untreated coal specimens.These findings suggest that cyclic stress detrimen-tally affects both the dynamic and static fracture mechanical parameters of coal masses,with dynamic fracture parameters exhibiting a greater degree of degradation.This highlights the enhanced sensitivity of coal mass dy-namic fracture behavior to cyclic stress damage.Furthermore,fractal analysis of the dynamic fracture damage yielded dimensions of 1.32 for untreated specimens and 1.21 for those subjected to cyclic stress damage,indicat-ing a more complex fracture and fragmentation process under impact loading for the former.Numerical calcula-tions based on the cohesive crack model for type Ⅰ dynamic fracture of coal masses align well with experimental results,underscoring the model's effectiveness in capturing the dynamic fracture process of coal masses.These insights provide a reference for coal masses with similar characteristics.关键词
冲击载荷/断裂韧度/分形维数/黏聚裂纹模型Key words
impulse load/fracture toughness/fractal dimension/cohesive crack model分类
建筑与水利引用本文复制引用
张传玖,李果,任建慧,姚士茂,李宣良..循环应力损伤对煤体Ⅰ型动态断裂特性的影响[J].采矿与岩层控制工程学报,2024,6(2):1-11,11.
