不同含水率煤岩声发射特性试验研究

Experimental Study on Acoustic Emission Characteristics of Coal with Different Moisture Content

以含水煤样为研究对象,在压缩变形过程中进行声发射检测试验,研究了不同含水率煤样声发射特性。结果表明,含水软化了型煤试件,且随着含水率的增加,峰值应力和弹性模量减小,变形特征有向岩性转化的趋势;煤样AE计数率变化与应力变化趋势几乎一致,随着含水率的递增,屈服应力及AE计数呈现减小趋势,同时声发射计数率集中区域由大幅值变为小幅值;含水煤样的声发射累积振铃计数比干燥煤样少很多且滞后,但干燥煤样与含水煤样所得曲线在形状上相像。

Taking coal samples containing water as the research objects, the acoustic emission test was carried out during the compression deformation process, where the acoustic emission characteristics of coal samples with different moisture content were studied. The results show that the presence of water makes moulded coal softened, the peak stress and elastic modulus decrease with the increase of the water content, the characteristics of deformation transfer from brittle to ductile. Coal AE count rate is almost the same with stress change trend, with the increasing of water content, yield stress and AE count decreased, while the concentration of acoustic emission count signal trend transfers from a large amplitude to a small one; when the moisture content is higher, the acoustic emission cumulative ring count of water-bearing coal samples is much less than that of dry coal and lags behind, but, obtained curves of the dry coal samples and wet coal samples are similar in shape.