characteristic-damage-by-flutter-vibrationsTypical dynamic fatigue fracture surfaces with nopronounced lines of rest indicate short-time, uninterrupted high dynamic stress. Several blades with comparably large dynamic fatigue fractures indicate simultaneous crack initiation under extremelyhigh dynamic loads. The identical location of the dynamicfatigue fractures indicates thatthe vibration type was the same. The crack initiation on the sides nearthe edges indicates a torsionalvibration. Fracture characteristics of compressor rotorblades that failed due to flutter vibrations:Affected rotor stageFlutter vibrations result in damage symptomswith characteristics of short-time, extremelyhigh dynamic loads.Fan blades without clappers.Clappers were introduced asa remedy.