Fault analysis of aero-engine spacer ring crack

Cracks on the mounting edge of spacer ring were found in the decomposition inspection of a turboshaft engine after test. Through the comprehensive analysis of appearance inspection, fracture analysis, metallographic analysis and simulation calculation of the faulty parts, the crack properties and fault causes were determined. The analysis shows that the relative radial deformation of the spacer ring and the centrifugal blade disc exceeds the design clearance in cold state during operation, and the contact compressive stress and relative displacement of the positioning surface of the installation edge end produce fretting wear. Under the action of working fatigue, the spacer ring appears fretting fatigue, and the expansion crack first appears in the region with the maximum steady-state stress. At the same time, the improvement measures are put forward for the fault part.