Experimental and Numerical Investigation of Failure of Alumina under Plane Stress
Publication: Journal of Engineering Mechanics
Volume 121, Issue 11
Abstract
Failure modes of polycrystalline alumina in compact-tension specimens were studied using the scanning electron microscope. Microcrack propagation was monitored under large magnification. Starting with a preexisting chevron notch, it was found that cracks propagated in a branching manner along the boundaries, that is, intergranular fracture occurred. Based on these experimental observations, a finite-element method was developed based on continuum damage mechanics. A Voronoi diagram was used to generate realistic grain structure for alumina. Numerical analysis of a specimen under pure tension was conducted to show similar features of crack propagation. The effects of different damaging rates for the bulk and shear moduli on peak stress and softening are given. It is shown that the combination of reduced damage of the shear modulus and the restriction of tortuous cracking along grain boundaries results in a significant enhancement of strength in the composite ceramic over the material strength in the grain boundary.
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References
1.
Ashby, M. F., and Jones, D. R. H. (1986). Engineering materials 2: an introduction to microstructure, processing and design, Pergamon Press, Elmsford, N.Y.
2.
Aurenhammer, F.(1991). “Voronoi diagrams—a survey of a fundamental geometric data structure.”ACM Computing Surveys, 23(3), 345–405.
3.
Carter, C. B., Kohlstedt, D. L., and Sass, S. L. (1980). “Electron diffraction and microscopy studies of the structure of grain boundaries in A 2 O 3,”J. Am. Ceram. Soc., 63(11–12), 623–627.
4.
Davidge, R. W. (1979). Mechanical behavior of ceramics, Cambridge University Press, London, England.
5.
Evans, A. G.(1990). “Perspective on the development of high-toughness ceramics.”J. Am. Ceram. Soc., 73(2), 187–206.
6.
Evans, A. G., and Faber, K. T.(1981). “Toughening of ceramics by circumferential microcracking.”J. Am. Ceram. Soc., 64(7), 394–398.
7.
Faber, K. T., and Evens, E. G.(1983). “Crack deflection process—I. theory.”Acta Metall., 31(4), 565–575.
8.
Gerstle, W. H., and Xie, M.(1992). “FEM modeling of frictitious crack propagation in concrete.”J. Engrg. Mech., ASCE, 118(2), 416–434.
9.
Hoagland, R. G., and Embury, J. D. (1980). “A treatment of inelastic deformation around a crack tip due to microcracking.”J. Am. Ceram. Soc., 63(7–8), 404–410.
10.
Ju, J. W.(1991). “On two-dimensional self-consistent micromechanical damage models for brittle solids.”Int. J. Solid & Struct., 27(2), 227–258.
11.
Krajcinovic, D., Basista, M., and Sumarac, D.(1991). “Micromechanically inspired phenomenological damage model.”J. Appl. Mech., 58(2), 305–310.
12.
Preparata, F. P., and Shamos, M. I. (1985). Computational geometry: an introduction . Springer-Verlag, New York, N.Y.
13.
Reichl, A., and Steinbrech, R. W. (1988). “Determination of crack-bridging forces in alumina.”J. Am. Ceram. Soc., 71(6), C299–301.
14.
Rice, R. W. (1979). “Machining flaws and the strength grain size behavior of ceramics.”The science of ceramic machining and surface finishing II, B. J. Hockey et al., eds., National Bureau of Standards Special Publication 562, Washington, D.C., 429–452.
15.
Rodel, J., Kelly, J. F., and Lawn, B. R.(1990). “In-situ measurements of bridged crack interfaces in scanning electron microscope.”J. Am. Ceram. Soc., 73(11), 3313–3318.
16.
Schreyer, H. L., and Wang, M. L. (1990). “Elementary constitutive relations for quasi-brittle materials based on continuum damage mechanics.”Proc., Symp. on Micromechanics of Failure of Quasi-Brittle Materials, S. P. Shah, S. E. Swartz, and M. L. Wang, eds., Elsevier Applied Science, London, England, 95–104.
17.
Underwood, P. (1983). “Dynamic relaxation.”Computational methods in mechanics for transient analysis, T. Belytschko and T. J. R. Hughes, eds., North-Holland Publishing, Amsterdam, The Netherlands, 245–265.
18.
Yazdani, S., and Schreyer, H. L.(1988). “An anisotropic damage model with dilatation for concrete.”Mech. of Mat., 7(3), 231–244.
Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 121 • Issue 11 • November 1995
Pages: 1218 - 1225
Copyright
Copyright © 1995 American Society of Civil Engineers.
History
Published online: Nov 1, 1995
Published in print: Nov 1995
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