Acoustic emission characteristics of rock under impact loading

Abstract

Acoustic emission tests were performed using a split Hopkinson pressure bar system (SHPB) on 50-mm-diameter bars of granite, limestone, sandstone and skarn. The results show that the amplitude distribution of hits is not well centralized around 50 dB, and that some hits with large amplitudes, usually larger than 70 dB, occur in the early stages of each test, which is different from the findings from static and low-loading-rate tests. Furthermore, the dominant frequency range of the recorded acoustic emission waveforms is between 300 kHz and 500 kHz, and frequency components higher than 500 kHz are not significant. The hit with the largest values of amplitude, counts, signal strength, and absolute energy in each test, displays a waveform with similar frequency characteristics and greater correlation with the waveform obtained from the elastic input bar of the split Hopkinson pressure bar system compared with the waveforms of the other hits. This indicates that the hit with the largest values of amplitude, counts, signal strength, and absolute energy is generated by elastic wave propagation instead of fracture within the rock specimen.

Keywords

rock / acoustic emission (AE) / split Hopkinson pressure bar (SHPB) / hit driven features / frequency characteristics / correlation analysis

References

[1] LiuX-l, LiX-b, LiF-b, ZhaoG-y, QinY-h. 3D cavity detection technique and its application based on cavity auto scanning laser system [J]. Journal of Central South University of Technology, 2008, 15(2): 285-288

[2] LiuX-l, LiX-b, GongF-q, LiD-y. Safety isolation layer thickness and acoustic emission monitoring of cavity under open pit benches [J]. Chinese J Rock Mech Eng, 2012, 31: 3357-3362

[3] GrosseC U, OhtsuMAcoustic emission testing-basics for research and applications in civil engineering [M], 2008BerlinSpringer11-18

[4] KaiserJA study of acoustic phenomena in tensile tests [D], 1950MunichTechnical University of Munich

[5] DrouillardT F, LanerF JAcoustic emission: A bibliography with abstracts [M], 1979New YorkIFI Plenum Data Co.

[6] DrouillardT FAcoustic emission—The first half century [C], 1994SapporoThe Japanese Society for NDI27-38

[7] LavorovA. Kaiser effect observation in brittle rock cyclically loaded with different loading rates [J]. Mech Mater, 2001, 33(1): 669-677

[8] FilimonovY. Acoustic emission in rock salt: Effect of loading rate [J]. Strain, 2002, 38(4): 157-159

[9] BackersT, StanchitsS, DresenG. Tensile fracture propagation and acoustic emission activity in sandstone: The effect of loading rate [J]. Int J Rock Mech Min Sci, 2005, 42: 1094-1101

[10] LiS-l, TangH-y. Acoustic emission characteristics in failure process of rock under different uniaxial compressive loads [J]. Chinese J Geotech Eng, 2010, 32(1): 147-152

[11] ShcherbakovI P, KuksenkoV S, ChmelA E. Acoustic emission accumulation stage in compression and impact rupture of granite [J]. J Min Sci, 2012, 48(4): 656-659

[12] VettegrenV I, KuksenkoV S, MamalimovR I, ShcherbakovI P. Dynamics of fractoluminescence, electromagnetic and acoustic emission upon impact on a granite surface [J]. Phys Solid Earth, 2012, 48(5): 415-420

[13] DouL-m, HeX-q, DrzezlaB. AE method of evaluating the danger of rock burst [J]. J China U Min Technol, 2000, 29(1): 85-88

[14] TanY-l, LiF-c, ZhouH, HanX-j. Analysis on acoustic emission pattern for rock burst [J]. Chinese J Rock Mech and Eng, 2000, 19(4): 425-428

[15] DiederichsaM S, KaiserP K, EberhardtE. Damage initiation and propagation in hard rock during tunneling and the influence of near-face stress rotation [J]. Int J Rock Mech Min Sci, 2004, 41(5): 785-812

[16] TangS-f, TongM-m, HuJ-l, HeX-m. Characteristics of acoustic emission signals indamp cracking coal rocks [J]. Min Sci Technol, 2010, 20(1): 143-147

[17] LiX B, LokT S, ZhaoJ, ZhaoP J. Oscillation elimination in the Hopkinson bar apparatus and resultant complete dynamic stress-strain curves for rocks [J]. Int J Rock Mech Min Sci, 2000, 37: 1055-1060

[18] LiX B, LokT S, ZhaoJ. Dynamic characteristics of granite subjected to intermediate loading rate [J]. Rock Mech Rock Eng, 2005, 38(1): 21-39

[19] LiX B, ZhouZ L, LokT S, HongL, YinT B. Innovative testing technique of rock subjected to coupled static and dynamic loads [J]. Int J Rock Mech Min Sci, 2008, 45: 739-748

[20] ZhaoJ, LiH B. Experimental determination of dynamic tensile properties of a granite [J]. Int J Rock Mech Min Sci, 2000, 37: 861-866

[21] FieldJ E, WalleyS M, ProudW G, GoldreinH T, SiviourC R. Review of experimental technique for high rate deformation and shock studies [J]. Int J Impact Eng, 2004, 30: 725-775

[22] DaiF, XiaK, TangL Z. Rate dependence of the flexural tensile strength of Laurentian granite [J]. Int J Rock Mech Min Sci, 2009, 47: 469-475

[23] XiaK, DaiF, ChenR. Split Hopkinson pressure bar tests of rocks [M]. ZHAO J Advances in rock dynamics and applications, 2011LondonTaylor & Francis Group35-77

[24] XiaKZhaoJ, LiJ C. Review of laboratory measurements of dynamic strength and fracture properties of rock [M]. Rock Dynamics and Applications-State of the Art, 2013LondonTaylor & Francis Group125-136

[25] ZhaoJ, WuW, ZhangQ B, SunLZhaoJ, LiJ C. Some recent developments on rock dynamic experiments and modelling [M]. Rock Dynamics and Applications-State of the Art, 2013LondonTaylor & Francis Group25-40

[26] ZhouY X, XiaK, LiX B, LiH B, MaG W, ZhaoJ, ZhouZ L, DaiF. Suggested methods for determining the dynamic strength parameters and mode-I fracture toughness of rock materials [J]. Int J Rock Mech Min Sci, 2012, 49: 105-112

[27] ZhangQ BZhaoJ, LiJ. Review of dynamic testing methods and results of rock materials in tension [M]. Rock Dynamics and Applications-State of the Art, 2013LondonTaylor & Francis Group275-282

[28] HellierC JHandbook of nondestructive evaluation [M], 2003New YorkMcGraw-Hill10.32

[29] HardyH RDrnevichV P, GrayR E. Applications of acoustic emission techniques to rock and rock structures: A state-of-the-art review [M]. Acoustic Emissions in Geotechnical Engineering Practice, 1981DetroitAmerican Society for Testing and Materials Special Technical Publication4-92