Numerical study on the effect of residual stresses on stress intensity factor and fatigue life for a surface-cracked T-butt welded joint using numerical influence function method

The flaw evaluation procedure in ASME Boiler and Pressure Vessel Code Section XI Appendix A is based on the linear elastic fracture mechanics, where the stress intensity factor for the given flaw geometry and applied stress is used to evaluate fatigue crack growth and unstable brittle fracture. The current original procedure for calculation of stress intensity factor for elliptical subsurface crack was based on a linearization method to have conservative estimation for nonlinear stress fields. To improve this current approach, the stress intensity factor solution for subsurface flaw was discussed to allow for the stress variation at the crack location to be represented by a forth order polynomial function. The use of a forth order polynomial fit to represent the actual stress distribution will greatly improve the accuracy of the method for nonlinear stress fields such as those caused by thermal transient loadings and residual stresses caused by weld. The coefficients of stress intensity factor for elliptical subsurface flaw for polynomial fit were estimated by the influence function method. These coefficients were verified by the comparison of stress intensity factor calculated by other similar solutions.

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Calculation of stress intensity factor for functionally graded cylinders with two radial cracks using the weight function method

Theoretical and Applied Fracture Mechanics ◽

10.1016/j.tafmec.2016.06.004 ◽

2016 ◽

Vol 85 ◽

pp. 447-456 ◽

Cited By ~ 8

Author(s):

Hassan Mirahmadi ◽

Majid Azimi ◽

Seyed Sajad Mirjavadi

Keyword(s):

Stress Intensity Factor ◽

Stress Intensity ◽

Intensity Factor ◽

Weight Function ◽

Function Method ◽

Functionally Graded ◽

Weight Function Method ◽

Radial Cracks

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Slow Crack Growth in Glasses and Ceramics Under Residual and Applied Stresses

Journal of Electronic Packaging ◽

10.1115/1.3226510 ◽

1989 ◽

Vol 111 (1) ◽

pp. 61-67 ◽

Cited By ~ 3

Author(s):

F. Erdogan

Keyword(s):

Stress Intensity Factor ◽

Stress Intensity ◽

Intensity Factor ◽

Residual Stresses ◽

Crack Growth ◽

Slow Crack Growth ◽

Threshold Value ◽

Crack Arrest ◽

Growing Crack ◽

Applied Stresses

The problem of slow crack growth under residual stresses and externally applied loads in plates is considered. Even though the technique developed to treat the problem is quite general, in the solution given it is assumed that the plate contains a surface crack and the residual stresses are compressive near and at the surfaces and tensile in the interior. The crack would start growing subcritically when the stress intensity factor exceeds a threshold value. Initially the crack faces near the plate surface would remain closed. A crack-contact problem would, therefore, have to be solved to calculate the stress intensity factor. Depending on the relative magnitudes of the residual and applied stresses and the threshold and critical stress intensity factors, the subcritically growing crack would either be arrested or become unstable. The problem is solved and examples showing the time to crack arrest or failure are discussed.

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