Fatigue life assessment of the centrifugal compressor impeller with cracks based on the properties of FV520B

• Properties of crack propagation of the impeller are obtained based on the fatigue test and the analysis of FV520B.
• Mechanical parameters are obtained based on the finite element analysis of the impeller models with crack.
• Fatigue lives of the impellers with different sizes of cracks are calculated by the life prediction model.

Since centrifugal compressors have a wide range of applications, the reliability of impellers as the vital components should be ensured. Due to the complicated operating conditions, relevant properties of the impellers under working conditions are hardly monitored while they are indispensable for predicting fatigue lives of the impellers. In this paper, relevant calculating parameters are acquired based on the experimental data and the properties of FV520B. Meanwhile, quantitative relations between local stresses and crack sizes are obtained by finite element analysis of the impeller model with cracks. By the prediction model based on the dislocation theory and the fracture mechanics theory, fatigue lives of the impellers with specific crack can be predicted. Then, the failure criteria of the impeller are determined by the size of the crack.