Laboratory Studies on Acoustic Emission Characteristics to Coal Dynamic Response under Variable Accelerative Load

Abstract:

To simulate the fracture of the coal under impact load, uniaxial pressure test of coal which retrieved from KongZhuang coal mine-DaTun coal and electricity Company of China coal group was done in the manner of strain control which rest with a function of uniform variable acceleration. Through researches on the stress-strain relationships and acoustic emission characteristics, the relationship between ring count rate and time series was founded, and the process before failure of coal was divided into four stages: low-level ringing count rate, higher level, highest level and peaceful period. Through the comparison and analysis, it is founded that acoustic emission characteristics in the stage of higher level of ringing count rate can be regarded as a basis for the prediction of coal fracture. According to three obvious rise stages of acoustic emission signal in the process before failure of coal, growth factor of climbing speed is introduced and the values are calculated between 2 to 4, and it is conferred that the value of is proportional to compressive strength of coal and loading rate. It is of great significance for the prediction of coal fracture by acoustic emission characteristics in the stage of new cracks.

• Periodical: Applied Mechanics and Materials (Volumes 580-583)
• Pages: 623-627
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.580-583.623
• Online since: July 2014
• Authors: Xing Hui Liu, Chuan Xiao Liu*, Shuai Zhuang, Long Wang, Shu Seng Lin
• Keywords: Acoustic Emission (AE), Coal Failure, Impact Load, Monitoring and Prediction

References

[1] Jan Vilhelm , Vladimír Rudajev , Tomáš Lokajíček , Roman Živor: Application of autocorrelation analysis for interpreting acoustic emission in rock. International Journal of Rock Mechanics and Mining Sciences, 2007, 45(7): 1068-1081.

DOI: 10.1016/j.ijrmms.2007.11.004

[2] V. Rudajev , J. Vilhelm , T. Lokajı́ček: Laboratory studies of acoustic emission prior to uniaxial Compressive rock failure. International Journal of Rock Mechanics and Mining Sciences, 2000, 37(4): 699-704.

DOI: 10.1016/s1365-1609(99)00126-4

[3] Xinming Peng, Youhong SUN, Anning LI: Application present of the rock acoustic emission technique. World Geology, 2000, 19(3): 303-306.

[4] Yong Chen: Application of acoustic emission techniques to rock mechanics research. Acta Geophysica Sinica, 1997, 20(4): 312-322.

[5] Chun-an Tang: Numerical simulation of AE in rock failure. Chinese Journal of Rock Mechanics and Engineering, 1997, 16(4): 368-374.

[6] Ru Zhang, Heping Xie, Jianfeng Liu, et al: Experimental study on acoustic emission characteristics of rock failure under uniaxial multilevel loadings. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(12): 2584-2588.

[7] Hu Qin, Gun Huang, Weizhong Wang: Laboratory studies on Acoustic Emission characteristics to whole process of compressed coal petrography deformation and failure in different moisture content. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(6): 1116- 1121.