Crack propagation and induced vibration characteristics of cracked cantilever plates under resonance state: Experiment and simulation

Cracks in aero-engine blades have caused great economic losses and safety hazards in the past decades. High cycle fatigue, as one of the main causes of blade crack propagation, has been of increasing interest in recent years. In this paper, the cantilever plate specimens are selected as the research object to analyze the real crack propagation path and the change of resonance frequencies under the resonance state. First, a joint simulation analysis method based on FRANC3D and ANSYS software is proposed for the analysis of the crack propagation path. The proposed method is verified through crack propagation experiments. Second, a dynamic model for cantilever plates with a real crack propagation path is proposed based on the shell element theory. Finally, the associations between crack propagation lengths and resonance frequencies are studied. Some interesting phenomena are found: the resonance frequency decreases as the crack propagation length increases and the resonance frequencies show a slow decrease, then a constant decrease, and finally a rapid decrease; the nearer the initial crack location is to the root of the cantilever plate, the greater the curvature of the crack propagation path. This study can provide a better understanding of blade fatigue and the reference for analysis of blade crack propagation paths.

Automated summary

This paper analyzes the real crack propagation path and the change of resonance frequencies in cantilever plate specimens. The study reveals that the resonance frequency decreases as the crack propagation length increases, showing a slow decrease, then a constant decrease, and finally a rapid decrease. These findings provide valuable insights into blade fatigue and the analysis of blade crack propagation paths.