A Low-Cycle Fatigue Life Prediction Method of Compressor Disk Grooves Based on Strain Energy Density Gradient

Abstract In engineering components, stress concentration regions such as corners exhibit significant stress gradients and are susceptible to fatigue failure during service. In this study, taking the aero engine disk groove as an example, a low-cycle fatigue life prediction method considering strain energy density gradients is established. First, designating the transition arc region as the groove assessment part, the groove simulation specimen is employed instead of actual disks to evaluate the groove's life. A design criterion for the simulation specimen with consistent strain energy density is proposed, and a groove simulation specimen of the slotted plate type is developed. Then, low-cycle fatigue life results are obtained through fatigue tests conducted on multiple samples. According to the test results, the reliable life of the disk groove is estimated to be 9519 cycles. Furthermore, a life prediction model based on the strain energy density gradients is established and validated through fatigue tests on a different type of specimen, with the experimental results falling within a 1.5-factor dispersion band around the life prediction results. This study provides valuable methods and data support for the life assessment of the stress concentration regions.