Document Type : Original Research Paper


1 Department of Mechanical engineering, University of Tehran, Tehran, Iran

2 Isfahan University of Technology,Esfehan,Iran


Determining the stress intensity coefficient is the main parameter in reservoir design, and what in the linear failure mechanism controls the crack behavior is the value of the stress intensity coefficient. There are different ways to estimate this value. The weight function method is widely used as one of the stress intensity estimation methods. In this paper, the weight function based on estimating the crack displacement function is obtained using modeling in software in a specific geometry of the ball tube. Then, using the weight function, the stress intensity coefficient and the fatigue life of the ball tube in the case of autophagy, using the actual behavior of the material, are obtained and compared with the available results. The method presented in this paper is a general method that can be applied to any geometry of the tank with any number of internal or external cracks and any relative length of cracks.


Main Subjects

[1] Kendall, D. P., A Simple Fracture Mechanics Based Method for Fatigue Life              Prediction in Thick-Walled Cylinders. Transactions of ASME, Vol. 108, NOVEMBER, pp. 490-494, 1986.
[2] Ma, C.C., Huange, J. I. and Tsai, C.H., weight function and stress intensity for axial crack in hollow cylinders, ASTM J. Pressure Vessel Technology, Vol. 116, NOVEMBER, pp 423-430, 1994.
[3] Glinka, G., Shen, G., Universal features of weight functions for cracks in mode I. Engineering Fracture Mechanics ,Volume 40, Pages 1135-1146, 1991.
[4] Parker, A. P., Tan, C. L, Stress Intensity Factor for Internal Straight and Curve-Fronted Cracks in Thick Cylinders, Gun Tube Conference, Cranfield Univ, 2005.
[5] Petroski HJ, Achenbach JD Computation of the weight function from a stress intensity     factor. Engng Fract Mech; 10:257–266, 1978.
[6] Banks-Sills, L., and Eliasi, R. Fatigue life analysis of a cannon barrel. Eng. Failure Analysis 6, pp 371-385, 1999.
[7] Levy, C., Perl, M., and Ma, Q., The Influence of Multiple Axial Erosions on the Fatigue Life of Autofrettaged Pressurized Cylinders. ASTM J. Pressure Vessel Technology, AUGUST, pp 293-297, Vol. 123, 2001.
[8] Jahed, H., Farshi, B., Hosseini, H., Lifle Prediction Of Autofrettaged Tube Using Actualmaterial Behavior, ASTM J. Pressure Vessel Technology.