For the fracture fault of the high-pressure turbine blade in the miniature short-life turbofan engine during a certain rig test

the blade fractography

the vibration signal and the fault blade dynamics was observed and analyzed.Blades natural characteristics and exciting sources were analyzed in details;the faults mainly stemmed from fatigue for the 1st order

the 2nd order and the coupled mode vibrations due to the instantaneous severe rub impact force.Reasonable control of the clearance and improving the blade root damping can prevent the fault effectively.