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为了探索煤岩在冲击过程中的破坏特征和能量耗散规律,利用Φ75 mm霍普金森压杆(SHPB)实验装置,对煤岩试件进行不同应变率条件下的冲击压缩实验,分析了冲击加载速率对煤岩破碎耗能和块度分布的影响。实验结果表明:在实验应变率范围内,随着子弹速度的提高,应变率和应力波携带的能量均呈线性增长,而煤岩破碎耗散能则呈指数上升。通过对实验碎块进行块度分维,发现随着应变率的提高,试件的耗散能密度快速增大,煤岩碎块的分形维数就越大,块度越细,破坏的程度越剧烈。分形维数与应变率及耗散能密度之间呈对数增长的关系,即分形维数增大的趋势变缓。
In order to explore the damage characteristics and energy dissipation law of coal and rock during the impact process, using the Φ75 mm Hopkinson pressure bar (SHPB) experimental device, the impact compression tests of coal and rock specimens under different strain rates were conducted, and the impact Effect of Loading Rate on Disintegration Energy and Fragment Distribution of Coal and Rock. The experimental results show that both the strain rate and the energy carried by the stress wave increase linearly with the increase of the bullet velocity in the range of experimental strain rate, while the dissipation energy of rock breaking increases exponentially. According to the fractal dimensions of experimental fragments, it is found that with the increase of strain rate, the dissipated energy density of specimens rapidly increases, and the fractal dimension of coal and rock fragments increases, the finer the degree of fracture and the degree of destruction The more intense. The relationship between fractal dimension and strain rate and dissipated energy density shows a logarithmic increase, that is, the trend of increasing fractal dimension becomes slow.