煤冲击破坏力学特性试验研究

    Experimental Study on Mechanics Properties of Coal Impact Damage

    • 摘要: 为了探究煤在冲击破坏过程中表现出的力学特性,利用分离式霍普金森压杆(SHPB)装置对平煤十矿1/3焦煤试样进行了不同冲击速度下冲击破坏压缩试验。结果表明:煤样在冲击速度为3.287 ~12.399 m/s,试验测得的最大应变率变化范围为85.25~168 s-1,应力极限值变化范围为15.84~ 47.33 MPa;随着冲击速度的增加,煤试件材料出现了应变硬化和应变软化现象;随着冲击速度的增加,煤试样的平均应变率值先快速增加,然后增加趋于缓慢,采用二次多项式拟合相关性较好,最大应变率值先快速增加,达到一定值后增加趋于缓慢,并呈现出稍微下降趋势,采用三次多项式拟合相关性较好。

       

      Abstract: In order to research mechanical characteristics in the process of coal impact failure, SHPB (Split Hopkinson Pressure Bar) device is used to conduct impact damage compression test with different impact speed for 1/3 coking coal samples from Pingmei No.10 Coal Mine. The results show that the range of maximum strain rate of the coal samples is from 85.25 to 168 s-1 with the impact velocity speed from 3.287 to 12.399 m/s, and the range of limit stress is from 15.84 to 47.33 MPa; with the increase of impact velocity, coal specimen material appears the strain hardening and strain softening phenomenon; with the increase of impact velocity, the average strain rates rapidly increase, then add slowly, and the quadratic polynomial fitting correlation is better, the maximum strain rates also rapidly increase, then increase slowly while reaches a certain value, and present the trend of decreasing slightly, and the cubic polynomial fitting correlation is better.

       

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