Abstract
The chevron notched three-point bend test specimen is often used for measuring the fracture toughness of brittle materials such as ceramics. Specimen sizes are often very restricted when testing advanced materials due to limited volume of material available or high material costs. Since the minimum chevron notch width is limited by the size of the cutting wheels or wire saw used to produce it, as the sample size gets small enough, the notch width becomes large in relation to the sample size. It is shown via finite element analysis that the notch width has an important effect on the stress intensity factors of short cracks. The minimum in the normalized stress intensity factor versus crack length is lost, rendering the usual analysis of the experimental results invalid and contributing greatly to decreased fracture stability of such specimens. Previous analytical and numerical studies do not take into account the width of the chevron notch. Based on the calculations, a guideline to permissible notch widths is introduced.
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References
Bluhm, J.I. (1975). A slice synthesis of a three dimensional work of fracture. Engineering Fracture Mechanics 7, 593–604.
Hartranft, R.J. and Sih, G.C. (1970). An approximate three–dimensional theory of plates with application to crack problems. International Journal of Engineering Sciences 8, 711–729.
He, M.Y. and Evans, A.G. (1990). Three dimensional finite element analysis of chevron–notched, three–point and four–point bend specimens. Fracture Mechanics: Twenty–Second Symposium. Vol I, Atlanta, Georgia, USA, 26–28 June.
Hibitt, Karlsson, and Sorensen Inc. ABAQUS/Standard Example Problems Manual, version 5.5 edition.
Jenkins, M.G., Kobayashi, A.S., White, K.W. and Bradt, R.C. (1987). A 3–d finite element analysis of a chevronnotched, three–point bend fracture specimen for ceramic materials. International Journal of Fracture 34, 281–295.
Joch, J., Zemankova, J. and Kazda, J. (1988). Analysis of a chevron–notch four–point–bend specimens by the three dimensional finite–element method. Journal of American Ceramic Society 71(3), C–154–C–155.
Munz, D., Bubsey, R.T. and Shannon Jr., J.L. (1980). Fracture toughness determination of Al2O3 using four–point–bend specimens with straight–through and chevron notches. Journal of the American Ceramic Society 63(5–6), 300–305.
Newman Jr., J.C. (1984). A review of chevron–notched fracture specimens. Chevron–notched specimens, testing and stress analysis: a symposium (ASTM STP 855), (Edited by W.W. Freiman, J.H. Underwood and F.I. Baratta) 5–31. American Society for Testing and Materials, Philadelphia
Rice, J.R. (1968). Mathematical analysis in the mechanics of fracture. Fracture: An Advanced Treatise, (Edited by H. Liebowitz), volume 2, pages 191–311.
Shih, C.F., Moran, B. and Nakamura, T. (1986). Energy release rate along a three dimensional crack front in a thermally stresses body. International Journal of Fracture 30, 79–102.
Ustundag, E. (1996). Processing, structure, and characterization of in–situ formed metal–ceramic composites obtained by partial reduction reactions. Ph.D. thesis, Cornell University.
Wu, Shang–Xian (1984). Compliance and stress intensity factor of chevron–notched three point–bend specimen. Chevron–notched specimens, testing and stress analysis: a symposium (ASTM STP 855), (Edited by W.W. Freiman, J.H. Underwood and F.I. Baratta), 176–192. American Society for Testing and Materials, Philadelphia.
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Kolhe, R., Hui, CY. & Zehnder, A.T. Effects of finite notch width on the fracture of chevron – notched specimens. International Journal of Fracture 94, 189–198 (1998). https://doi.org/10.1023/A:1007451005263
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DOI: https://doi.org/10.1023/A:1007451005263