不同矿井煤样变形破裂过程中的电荷感应实验研究

采用单轴压缩煤电荷感应信号测试系统,研究了不同矿井煤在不同加载速度下变形破裂过程中的电荷感应规律。研究结果表明,煤样在加载初期即有电荷感应信号,随着应力水平的增加,不断有电荷感应信号产生,且信号幅值不断增加,在应力峰值前后电荷感应信号最强,信号也最为丰富,煤样主破裂发生后仍有明显的电荷信号,但信号幅值较小;在煤样应力发生突变时有较强的电荷感应信号产生;抗压强度越高、冲击倾向性越强的煤样,电荷感应信号也越强,信号越丰富,持续时间越长;加载速度越大,所产生的电荷感应信号越强。电荷感应信号与煤的变形破裂和煤样类型有一定关系,可以用电荷感应信号反映煤的破坏程度。

Experimental Study of Charge Induction in Process of Coal Deformation and Fracture in Different Mines

By the experimental system for collecting the charge-induced signal of the coal,the law of charge induction of coal in the different mine in process of the coal deformation and fracture is studied under different loading rates in laboratory.The experimental results show that the charge-induced signal is generated in the initial load of coal.With the increase of the loading stress level,the charge-induced signal is generated constantly,and the signal amplitude increases.Before and after the peak stress of coal,the strongest charge-induced signal is generated,and the signal is also the most abundant.After the main rupture of coal,the evident charge-induced signal is still generated,but the signal amplitude is smaller.The stronger signal of charge induction produces during coal stress mutation.The higher compressive strength of the coal and the stronger bump-prone of the coal are,the stronger the charge-induced signal is and the longer the signal duration is.The greater the loading rate is,the stronger the charge-induced signal is.Our result suggests that the charge production is relation to the deformation and fracture of coal and coal type,the coal damage degree under load may be determined from the charge-induced signal.