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Acoustic Emission at Wedge Indentation Fracture in Quasi-Brittle Materials

Published online by Cambridge University Press:  05 May 2011

L. H. Chen ,
K. C. Huang  and
Y. C. Chen
L. H. Chen*
Affiliation:
Department of Civil Engineering, National Taipei University of Technology, Taipei, Taiwan 10608, R.O.C.
K. C. Huang*
Affiliation:
Department of Construction Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10672, R.O.C.
Y. C. Chen*
Affiliation:
Department of Construction Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10672, R.O.C.
*
*Assistant Professor
**Ph.D., corresponding author
***Professor
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Abstract

To improve the safety and automation of mechanical excavation methods used in tunnels, this present report studied the behavior of rock materials indented by a single cutter, based on the theory of indentation fracture mechanics. The development of microcracks during the indentation process and the correlation between microcracks and macrocracks was investigated using the nondestructive technique of acoustic emission. Microseismic activity of the microcracks received by the acoustic emission (AE) technique was used to interpret and represent the initiation and propagation of macrocracks. As the wedge angle increased, the maximum indentation force increased, but the nominal indentation pressure and the destructive indentation depth decreased. On the other hand, the direction of macrocrack propagation did not significantly change with the various wedge angles. Furthermore, the localization occurred earlier and the dimensionless radius of the elasto-plastic interface decreased with increased wedge angle. In addition, the dimensionless radius of the elasto-plastic interface obtained by the experiment was consistent with closed-form analytical solutions.

Keywords

Acoustic emission (AE)Indentation fractureCavity expansion model (CEM)Wedge angleContact mechanics.
Type
Articles
Information
Journal of Mechanics , Volume 25 , Issue 2 , June 2009 , pp. 213 - 223
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2009

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References

1.Hertz, H. H., Hertz's Miscellaneous papers, Macmillan, London (1896).Google Scholar
2.Boussinesq, J., Applications of Potentials for the Study of Equilibrium and Movement of Elastic Solids, Gautier-Villars, Paris (1885).Google Scholar
3.Timoshenko, S. P. and Goodier, J. N., Theory of Elasticity (3rd Ed.), McGraw-Hill, New York (1969).Google Scholar
4.Marsh, D., “Plastic Flow in Glass,” Philosophical Transactions of the Royal Society of London, Series A, 279, pp. 420–435 (1964).Google Scholar
5.Johnson, K. L., “The Correlation of Indentation Experiments,” Journal of the Mechanics and Physics of Solids, 18, pp. 115–126 (1970).CrossRefGoogle Scholar
6.Johnson, K. L., “Contact Mechanics,” Cambridge University Press (1987).Google Scholar
7.Drescheret, A. and Kang, Y., “Kinematic Approach to Limit Load for Steady Penetration in Rigid-Plastic Soils,” Geotechnique, 37, pp. 233–246 (1987).CrossRefGoogle Scholar
8.Lawn, B. and Swain, M., “Microfracture Beneath the Point Indentation in Brittle Solids,” Journal of Materials Science, 10, pp. 113–122 (1975).CrossRefGoogle Scholar
9.Lawn, B. and Wilshaw, R., “Review Indentation Fracture: Principles and Applications,” Journal of Materials Science, 10, pp. 1049–1081 (1975).CrossRefGoogle Scholar
10.Lawn, B. and Evans, A., “A Model for Crack Initiation in Elastic/Plastic Indentation Field,” Journal of Materials Science, 12, pp. 2195–2199 (1977).CrossRefGoogle Scholar
11.Lawn, B. and Marshall, D., “Hardness, Toughness, and Brittleness: An Indentation Analysis,” Journal of the American Ceramic Society, 62, pp. 347–350 (1979).CrossRefGoogle Scholar
12.Liou, J. L. and Lin, J. F., “Elastic-Plastic Microcontact Analysis of a Sphere and a Flat Plate,” Journal of Mechanics, 23, pp. 341–351 (2007).CrossRefGoogle Scholar
13.Chang, J. C., Liao, J. J. and Pan, Y. W., “Failure Mechanism and Bearing Capacity of Shallow Foundation on Poorly Cemented Sandstone,” Journal of Mechanics, 24, pp. 285–296 (2008).CrossRefGoogle Scholar
14.Detournay, E., Fairhurst, C. and Labuz, J. F., “A Model of Tensile Failure Initiation Under an Indentor,” Proc. 2nd Int. Conf. On Mechanics of Jointed and Faulted Rock (MJFR-S), Ed. by Rossmanith, P., Vienna, Austria (1995).Google Scholar
15.Damjanac, B. and Detournay, E., “Numerical Modeling of Normal Wedge Indentation in Rocks,” Proc. 35th U.S. Rock Mechanics Symposium, Ed. by Daemon, J. J. K. and Schultz, R. A., Balkema, Rotterdam (1995).Google Scholar
16. Chinese National Standards (CNS 1010), “Method of Test for Compressive Strength of Hydraulic Cement Mortars (Using 50mm or 2 in. Cube Specimens),” (1993).Google Scholar
17.Chen, L. H., “Failure of Rock Under Normal Wedge Indentation,” Ph.D. Thesis, University of Minnesota, U.S.A. (2002).Google Scholar
18.Kaiser, J., “Undersuchungen Uber Das Aufrterten Geraucchen Beim Zevgersuch,” Ph.D. Thesis. Technische Hochschule, Munich (1953).Google Scholar
19. American Society for Testing and Materials (ASTM E610-82), “Standard Definitions of Terms Relating to Acoustic Emission,” (1991).Google Scholar
20. American Society for Testing and Materials (ASTM E976-84), “Standard Guide for Determining the Reproducibility of Acoustic Emission Sensor Response,” (2000).Google Scholar
21.Chen, L. H. and Labuz, J. F., “Indentation of Rock by Wedge-Shaped Tools,” International Journal of Rock Mechanics and Mining Sciences, 43, pp. 1023–1033 (2006).CrossRefGoogle Scholar
22.Hu, K. Y., Chen, L. H. and Li, C. Y., “Estimation of Plastic Zone and Intrinsic Flaw on Rock Indentation Fracture by Electric-Optic Interferometry,” The 12th Conf. on Current Researches in Geotechnical Engineering,Sitou, Taiwan, R.O.C. (2007).Google Scholar
23.Alehossein, H., Detournay, E. and Huang, H., “An Analytical Model for the Indentation of Rocks by Blunt Tools,” Rock Mechanics and Rock Engineering, 33, pp. 267–284 (2000).CrossRefGoogle Scholar
24.Huang, H., Damjanac, B. and Detournay, E., “Numerical Modeling of Normal Wedge Indentation in Rocks with Lateral Confinement,” International Journal of Rock Mechanics and Mining Sciences, 34, pp. 613–613 (1997).CrossRefGoogle Scholar
25.Kuang, B. S., “Studies of the Influence of Confining Pressure on the Mechanical Behavior of Hualien Marble,” M.S. Thesis, National Taiwan University, R.O.C. (1992).Google Scholar