A simple method of determining stress intensity factor K_I from isochromatic fringe loops

Abstract

A new photoelastic method of obtaining mode I stress intensity factor (SIF) is presented. The method considers the influence of far field stress, σ_ox, on the value of SIF. The only information needed for K_I calculation is the area between isochromatic fringe loops. The method is examined by two kinds of specimen in different load cases. Experimental results show that it is quite simple and of high precision.

Keywords

stress intensity factor / mode I fracture / photoelastic method

References

[1] IoakimidisN I, TheocarisP S. A simple method for the photoelastic determination of mode I SIF. Engrg Fract Mech, 1978, 10(3): 677-684

[2] ChenFeng. A high precision photoelastic procedure for determination of mode I stress intensity factor K₁. Int J of Fracture, 1996, 80: R55-R58

[3] ChenFeng, SunZongqi, XuJ C. An easy method for calculation of mode I stress intensity factor using isochromatic fringe patterns. Int J of fracture, 1997, 87(2): L51-L55

[4] TheocarisP S, GdoutosE F. A photoelastic determination of K₁ stress intensity factors. Engrg Fract Mech, 1975, 7(2): 423-430

[5] SanfordR J. Application of the least-square method to photoelastic analysis. Experimental Mechanics, 1980, 20(6): 192-197

[6] RossmanithH P. A hybrid technique for improved K determination from photoelastic data. Int Experimental Mech, 1983, 6: 152-157