Abstract:For the unexpected tip failure of hollow fan blade HCF test, the stress distribution test, vibration simulation
and crack analysis were done. The test results indicate that the failure region is not the high stress region, and fracture analysis
indicates that the crack initiates from the welding area of the duct in the blade tip. Validation test on the blades without
the tip welding shows that the failure is induced by the welding defect in the blade tip duct. Based on the fatigue analysis
and test validation, the failure occurs by improper welding method selection and welding process control in the manufacturing
process. Consequently, the improved process is applying the EB welding in manufacturing and CT inspection.