不同冲击倾向性煤样变形场演化特征

煤样破坏前出现的变形局部化现象,对研究其失稳破坏前兆有重要的意义。选取了冲击和非冲击倾向性煤样进行单轴压缩破坏实验;基于CT扫描,可以预测样品裂隙演化趋势;通过实验发现,冲击与非冲击煤样劈裂破坏前变形局部化带内相对拉伸和相对滑动分量都是从增大到急剧增大、并最终导致样品失稳破坏;冲击煤样的变形局部化出现较突然、更接近破坏的时刻;冲击煤样的变形局部化带内相对拉伸和相对滑动分量均较非冲击煤样变化小数倍;非冲击煤样在微破裂稳定发展阶段的变形局部化带内相对滑动表现较冲击样品复杂。

Evolution of the deformation fields of different outburst proneness coal specimens

Deformation localization which occurs before the destruction of coal specimens is of significance for the instability failure precursor of coal specimens.Outburst proneness and non-outburst proneness coal specimens were selected for uniaxial compression experiment.Based on the computed tomography(CT) scans，the fractured trends of specimens could be predicted.The experimental results reveal that the deformation localization of both outburst and non-outburst proneness coal specimens occurs before the splitting failure，and the relative tension and the relative sliding components inside deformation localization show from increase to increase rapidly，until the instability failure of the sample.The deformation localization of outburst specimens shows more suddenly and closer to the destruction moment than non-outburst ones.Both the relative tension and sliding components of the outburst specimens are several times smaller than non-impact ones.During the stable development stage of micro-fractures，the relative sliding components of non-outburst exhibit a more complex feature.