Fatigue crack propagation simulation of vertical centrifugal pump runner using the extended finite element method

Abstract

The performance evaluation of fatigue crack propagation is essential for the safe and stable operation of power plants. In this study, the Walker equation is employed, considering the loading ratio effect. The parameters in the Walker equation for AISI 304 L are fitted by a normal probability distribution based on the experimental information . A numerical simulation of the fatigue crack growth is carried out using the extended finite element method with the Walker equation embended in, and verified on a round compact tension model with the loading ratios of R = 0.1, 0.5, and 0.85. Finally, a fatigue crack growth simulation of a vertical centrifugal pump-turbine runner under turbine conditions is conducted with two crack positions. The crack morphology can be captured together with the corresponding fatigue life by using the developed fatigue crack propagation simulation method based on the extended finite element method. The numerical results can be used as guidance for improving the maintenance plan of pump plants.