Determination of Stress Intensity Factor $K_I$ from Two Fringe Orders by Fringe Multiplication and Sharpening

  • Chen, Lei (Department of Mechanical Engineering, Graduate School, Kunsan National University) ;
  • Baek, Tae-Hyun (School of Mechanical Engineering, Kunsan National University)
  • Published : 2007.12.30

Abstract

Stress intensity factor is one of the most important parameters in fracture mechanics. Both the stress field distribution and the crack propagation are closely related to these parameters. Due to the complexity of actual engineering problems, it is difficult to calculate the stress intensity factor by theoretical formulation, so photoelasticity method is a good choice. In this paper, modified two parameter method is employed to calculate stress intensity factor for opening mode by using data from more than one photoelastic fringe loop. For getting accurate experiment results, the initial fringes are doubled and sharpened by digital image programs from the fringe patterns obtained by a CCD camera. Photoelastic results are compared with those obtained by the use of empirical equation and FEM. Good agreement shows that the methods utilized in experiments are considerably reliable. The photoelastic experiment can be used for bench mark in theoretical study and other experiments.

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References

  1. ABAQUS/Standard, Example Problems Manual, Hibbitt. Karlsson&Sorense. Inc., Pawtucket, RI., USA, http://abaqus.com
  2. Anderson, T. L. (1995) Fracture Mechanics Fundamentals and Applications, Second Edition, CRC Press, Inc., pp. 53-64
  3. Baek, T. H. and Burger, C. P. (1991) Accuracy Improvement Technique for Measuring Stress Intensity Factor m Photoelastic Experiment, KSME International Journal, Vol. 5, No. 1, pp. 22-27 https://doi.org/10.1007/BF02945147
  4. Baek, T. H., Kim, M. S., Rhee, J. and Rowlands, R. E. (2000) Hybrid Stress Analysis of Perforated Tensile Plates Using Multiplied and Sharpened Photoelastic Data and Complex­Variable Techniques, JSME International Journal, Series A: Solid Mechanics and Material Engineering, Vol. 43, No.4, pp. 327-333 https://doi.org/10.1299/jsmea.43.327
  5. Bradley, W. B. and Kobayashi, A. S. (1970) An Investigation of Propagating Cracks by Dynamic Photoelasticity, Exp. Mech., Vol. 10, pp. 106-113 https://doi.org/10.1007/BF02325114
  6. Budynas, R. G. (1999) Advanced Strength and Applied Stress Analysis, McGraw-Hill, Inc., pp. 642-646
  7. Dally, J. W. and Riley, W. F. (1991) Experimental Stress Analysis, 3rd Ed., McGraw-Hill, Inc., New York, USA
  8. Irwin, G. R. (1958) Discussion of Ref. Wells and Post, 1958, Proc., SESA, Vol. XVI, No. 1, pp. 93-96
  9. Liebowitz, H. (1971) Fracture an Advanced Treatise, Vol. 3, Academic Press (London) Inc
  10. Murakami, Y. (1987) Stress Intensity Factors Handbook, Vol. 1 & 2, Pergamon Press, New York, USA
  11. Wells, A. and Post, D. (1958) The Dynamic Stress Distribution Surrounding a Running Crack­A Photo elastic Analysis, Proc., SESA, Vol. XVI, No. 1, pp. 69-92