Fatigue life analysis of aero-engine blades for abrasive belt grinding considering residual stress

Abstract

Abrasive belt grinding technology is widely used in the processing of aero-engine blades. Residual stress is used as an indicator of grinding gauge integrity, which has a significant impact on the fatigue performance of aero-engine blades. In fatigue life research, experiments are mainly used to explore the influence of residual stress on fatigue life. Restricted by factors such as experimental efficiency and cost, it is necessary to simulate the influence of residual stress in the process of fatigue failure. Based on the theory of crack initiation and propagation, this paper proposes a life prediction algorithm considering residual stress; carries out a bending vibration fatigue experiment and simulation fatigue life analysis of aero-engine blade grinding with abrasive belt; compares the results of experiments and simulations and proposes a residual stress equivalent calibration method. Used theory, simulation, and experiment to verify the effectiveness of the method, and uses this equivalent calibration method to analyze the effect of residual stress on the fatigue life of aero-engine blades ground by abrasive belts. The experimental results show that the surface residual compressive stress will optimize the size and distribution of the surface stress during the service process of the aero-engine blade. Under the same external load and surface roughness conditions, a larger surface residual compressive stress will increase the aero-engine blade stiffness, reduce the aero-engine blade’s vibration amplitude, and reduce Surface stress, which in turn, has a beneficial effect on fatigue life. The proposed calibration method considering residual stress can accurately predict the fatigue life of aero-engine blades with a prediction accuracy up to 90%.