Simplified Weight Function for Calculating Stress Intensity Factor in Complicated Stress Distributions


  • Jirapong Kasivitamnuay Chulalongkorn University



Weight function, stress intensity factor, fracture mechanics.


Calculation of a stress intensity factor becomes more difficult when crack are subjected to a complicated stress distribution profile. A standard procedure called influence coefficients is inadequate, because a stress profile may not be accurately represented by a polynomial function. This paper applies a piecewise linear approximation of stress profile and a weight function method to overcome that restriction. However, the typical adopted weight function, i.e. universal weight function, is replaced by a weight function, in which its form coincides with the analytical form. Although a new weight function consists of lesser number of terms, it is proved to be accurate when applies to a cracked-cylinder problem, e.g. internal part-through circumferential crack and internal fully circumferential crack under various complicated weld residual stress profiles. Using this simpler weight function and linearized approximation scheme led to a closed-form stress intensity factor solution, which is convenient for programming.


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Author Biography

Jirapong Kasivitamnuay

Department of Mechanical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand


Published In
Vol 20 No 2, May 18, 2016
How to Cite
J. Kasivitamnuay, “Simplified Weight Function for Calculating Stress Intensity Factor in Complicated Stress Distributions”, Eng. J., vol. 20, no. 2, pp. 49-60, May 2016.