By conducting uniaxial compressional acoustic emission tests on limestone, the characteristics of the acoustic emission b-value throughout the process of rock fracture and the analysis of b-value calculation errors were investigated. The results show that a threshold of 50 dB and a step length of 7 dB resulted in the smallest error in the b value, where b = 1.07 and the fit R2 = 0.946. When the step length is 1dB, the b-value error is minimised at a starting amplitude of 50dB, where b=1.13, R2=0.886. Both have relatively small errors and b values close to 1, the b value for rock damage. In the dynamic b-value graph over time, the b-value tends to increase in the early stages and is accompanied by a low energy signal from the micro-rupture. In the later stages of compression, an acoustic emission signal with extremely high energy values appears, accompanied by a sharp decrease in the b-value. This indicates that large-scale cracking is beginning to occur within the limestone, producing high energy and amplitude values, which is reflected in the trend of decreasing b-values. At the peak of energy and stress, the b-value drops to close to about 1, at which point the limestone is destroyed. This provides a reference for the study of rock damage using acoustic emission b-values.

Lizhu Wang, Jiale Zhang, Jiahao Guo. Error Analysis of Limestone Acoustic Emission B-Value under Uniaxial Compression. Academic Journal of Engineering and Technology Science (2022) Vol. 5, Issue 8: 17-21. https://doi.org/10.25236/AJETS.2022.050804.

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