Experimental Mechanics

, Volume 15, Issue 2, pp 73–80 | Cite as

Application of photoelasticity to a weld-penetration problem

Photoelastic tests on models of typical weld-penetration defects in butt welds predict that the largest acceptable length of such defects should be around 0.2 times the plate thickness
  • C. P. Burger
  • L. W. Zachary
  • W. F. Riley
Article

Abstract

The need for more information on the “initiation period” in fatigue tests of weld specimens with penetration defects is discussed and the literature which relates the elasticity stress-concentration factor and Irwin's stress-intensity factor is reviewed.

A series of photoelasticity tests on two-dimensional plane-stress models of typical penetration defects is described. In particular a method for casting “ready to use” very narrow defects is explained.

The results are presented in a graph of stress-concentration factor against defect length. This graph has a “knee” at defect length-to-plate thickness ratios around 0.2. Below the “knee”, the stress-concentration factor changes very little with changes in defect length but, for lengths beyond the knee, i.e., ratios larger than 0.2, the stress concentrations increase linearly with defect length. It is concluded that such a critical defect length should have a strong effect on fatigue life of defective welds and that it may constitute a first approach to the specification of an “acceptable” level of penetration defects for production processes.

Keywords

Fatigue Mechanical Engineer Fluid Dynamics Production Process Stress Concentration 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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References

  1. 1.
    Munse, W. H. andWilson, W. M., “Welded Structural Joints,” ASME Handbook—Metals Engineering Design, McGraw-Hill Book Company, New York (1965).Google Scholar
  2. 2.
    Sparagen, W. andRosenthal, D., “Fatigue Strength of Welded Joints—A Review of Literature,”Welding J.,21 (7),297s-348s (1942).Google Scholar
  3. 3.
    Harris, L. A., Nordmark, G. E. andNewmark, N. M., “Fatigue Strength of Butt Welds in Structural Steels,”Welding J.,34 (2),83s-96s (1955).Google Scholar
  4. 4.
    Newman, R. P. and Gurney, T. R., Brit. Welding Research Inst. Report, D2/3/58.Google Scholar
  5. 5.
    Welding Handbook, AWS, Sec. 1, 6th Ed. (1968).Google Scholar
  6. 6.
    Harrison, J. D., “The Analysis of Fatigue Test Results for Butt Welds with Lack of Penetration Defects Using a Fracture Mechanics Approach,”Fracture 1969: Proc. 2nd Int. Conf. on Fracture, Brighton, Chapman and Hall, London (1969).Google Scholar
  7. 7.
    Lawrence, F. V. andMunse, W. H., “Fatigue Crack Propagation in Butt Welds Containing Joint Penetration Defects,”Welding J.,52 (5),221s-225s (1973).Google Scholar
  8. 8.
    Newman, R. P. andDawes, M. G., “Exploratory Fatigue Tests on Transverse Butt Welds Containing Lack of Penetration,”Brit. Welding J.,12 (3),117–120 (1964).Google Scholar
  9. 9.
    Wells, A. A., “The Specification of Permissible Defect Sizes in Welded Metal Structures,”Fracture 1969: Proc. 2nd Int. Conf. on Fracture, Brighton, Chapman & Hall, London (1969).Google Scholar
  10. 10.
    Paris, P. C., “The Fracture Mechanics Approach to Fatigue,” Fatigue—An Interdisciplinary Approach, Proc. 10th Sagamore Army Materials Research Conf., Syracuse Univ. Press (1963).Google Scholar
  11. 11.
    Tetelman, A. S. andMcEvily, A. J., “Fracture of Structural Materials,”John Wiley & Sons, New York (1967).Google Scholar
  12. 12.
    Homma, H. andNakazawa, H., “Effect of Mean Stress on Fatigue Crack Initiation and Propagation,”Bull. of the Japan Soc. of Mech. Engrs.,16 (191),1–11 (1973).Google Scholar
  13. 13.
    McEvily, A. J. and Illg, W., “The Rate of Crack Propagation in Two Aluminum Alloys,” NACA Tech. Note 4394 (Sept. 1958).Google Scholar
  14. 14.
    Tada, H., Paris, P. andIrwin, G., The Stress Analysis of Cracks Handbook, Del Research Corp. Hellertown, PA (1973).Google Scholar
  15. 15.
    Rice, J. R., “Mathematical Analysis in the Mechanics of Fracture,”Fracture, An Advanced Treatise,II,Academic Press, Inc.,New York (1968).Google Scholar
  16. 16.
    Paris, P. C. andErodgan, F., “A Critical Analysis of Crack Propagation Laws,”J. Basic Engr., Trans. ASME,85 (4),528–534 (1963).Google Scholar
  17. 17.
    Hardrath, H. F. and McEvily, A. J., “Engineering Aspects of Fatigue Crack Propagation,” Crack Propagation Symp., Cranfield, England (1961).Google Scholar
  18. 18.
    Savin, G. N., “Stress Concentration Around Holes,”Pergamon Press, New York (1961).Google Scholar
  19. 19.
    Wahl, A. M. andBeeuwkes, R., “Stress Concentration Produced by Holes and Notches,”Product Engineering,5,92–94 (1934).Google Scholar
  20. 20.
    Sternberg, E. andSadowsky, M., “Three Dimensional Solution for the Stress Concentration Around a Circular Hole in a Plate of Arbitrary Thickness,”Trans. ASME,71,27–38 (1949).MathSciNetGoogle Scholar
  21. 21.
    Durelli, A. J. andSciammarella, C. A., “Elastoplastic Stress and Strain Distribution in a Finite Plate with a Circular Hole Subjected to Uni-dimensional Load,”Trans. ASME 85E (J. Appl. Mech.) 1,115–121 (1963).Google Scholar
  22. 22.
    Marloff, R. H., Leven, M. M., Ringler, T. N. andJohnson, R. L., “Photoelastic Determination of Stress-intensity Factors,”Experimental Mechanics,11 (12),529–539 (1971).CrossRefGoogle Scholar

Copyright information

© Society for Experimental Mechanics, Inc. 1975

Authors and Affiliations

  • C. P. Burger
    • 1
  • L. W. Zachary
    • 1
  • W. F. Riley
    • 1
  1. 1.Department of Engineering Science and Mechanics and Engineering Research InstituteIowa State UniversityAmes

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