The Investigation of Crack's Parameters on the V-Notch using Photoelasticity Method

Authors: M. Saravani, M. Azizi,

Abstract:

The V-notches are most possible case for initiation of cracks in parts. The specifications of cracks on the tip of the notch will be influenced via opening angle, tip radius and depth of V-notch. In this study, the effects of V-notch-s opening angle on stress intensity factor and T-stress of crack on the notch has been investigated. The experiment has been done in different opening angles and various crack length in mode (I) loading using Photoelasticity method. The results illustrate that while angle increases in constant crack-s length, SIF and T-stress will decrease. Beside, the effect of V-notch angle in short crack is more than long crack. These V-notch affects are negligible by increasing the length of crack, and the crack-s behavior can be considered as a single-edge crack specimen. Finally, the results have been evaluated with numerical finite element analysis and good agreement was obvious.

Keywords: Photoelasticity, Stress intensity factor, T-stress, V-notch.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1332484

References:

[1] Sherry.A.H, France.C.C "Compendium of T-stress solutions for two and three dimensional cracked geometries", Fatigue Fract.Engng.Mater.Struct Vol.18, No1, pp.141-155, 1995
[2] Jones.R, Peng.D "weight functions,CTOD,and related solutions for cracks at notches", Eng.Failure Analysis Vol.11, pp.79-114, 2004.
[3] Williams.M.L "Stress singularities resulting from various boundary conditions insingular corners of plates inextension" J of Applied Mechanics, Vol.19, No.3, pp.526-528, 1952.
[4] MahinFallah.M and Zackery.L "Photoelastic determination of mixed mode stress intensity factors for sharp reentrant corners", Eng.Fract.Mech, Vol.52, No.4, pp.639-645, 1995.
[5] Kondo.T, Kobayashi.M and Sekine. H, "Strain gage method for determining stress intensities of sharp notched strips," Experimental Mechanics,Vol. 41, No.1, 2001, pp. 1-7.
[6] Leguillon. D, and Yosibash. Z," Crack onset at a V-notch. Influence of the notch tip radius" Int.J of Fract. Vol. 122, pp. 1-21, 2003.
[7] X.F.Yao and H.Y.Yeh," Fracture investigation at V-notch tip using coherent gradient sensing(CGS)" Int.J of solids and structures,Vol. 43, No. 5, pp.1189-1200, 2006
[8] Wang.X, Lewis.T, Bell.R, " Estimations of the T-stress for small cracks at notches." Eng. Fract.Mech Vol. 73, pp. 366-375, 2006.
[9] Smith.D.G "Photoelastic determination of mixed mode stress intensity factors.", Eng. Fract.Mech Vol.4, No.2, pp.357-366, 1972.
[10] Gdoutos.E.e and Theocaris.P.G "Photoelastic determination of mixed mode stress intensity factors." Exp.Mech, Vol.18, No.3, pp.87-97, 1978.
[11] Etheridge.J.M and Dally.J.W " A three parameter method of determining SIF from isochromatic fringe loops." J. Strain Analysis, Vol.13, No.2, pp.91-94, 1978
[12] Dally.J.W and Sanford.R.J " A General method for determining mixed mode stress intensity factors from isochromatic fringe patterns," Eng Fract Mech,11,pp.621-633 , 1979.
[13] Ramesh.K, Gupta.S and Kelkar.A.A ." Evaluation of stress field parameters in fracture mechanics by photoelasticity ." Eng. Fract.Mech Vol.56, No.1 , pp.25-45, 1997
[14] Su.R.K.L and Feng.W.J "Accurate determination of mode I and II leading coefficients of the Williams expansion by finite element analysis", Finite elements in Analysis and Design Vol.41, pp.1175-1186, 2005.
[15] Dally, J.W and Sanford,R.J," Experimental determination of KI for short internal cracks" ASME J. Appl Mech ,68, 937-943 , 2001
[16] Dally, J.W and Riley, W.F , Experimental stress Analysis,3rd Ed., MC Graw-Hill, 1991.
[17] Ramesh,K. Digital Photoelasticity, 2rdEd,springer,2000
[18] Ayatollahi.M.R , Pavier.M.J and Smith.D.J "determination of T-stress from finite element analysis for mode I and mixed mode I/II loading" Int.J of Frac, Vol.91, pp.283-298, 1998.
[19] Anderson.T.L, Fracture Mechanics Fundamental and applications, 2rd Ed.CRC Press, 1995