| Abstract: | An experimental procedure has been developed for the investigation of fatigue and crack growth resistance of materials and real compressor blades. Methods for the determination of stress intensity factors in specimens and in blades with cracks have been justified. Investigations have been performed on the influence of manufacturing residual stresses and surface defects in the form of simulators of dents, corrosion pits, and nonmetallic inclusions on the fatigue strength of steels and a titanium alloy. The characteristics of the material crack growth resistance have been studied taking into account the effect of the medium (sea water), stress ratio in a cycle, and programmed mode of loading. The authors also consider fatigue strength of newly-manufactured blades and those in operation, as well as specific features of fatigue crack propagation in blades. They have substantiated a method for predicting the life of blades with cracks. Institute for Problems of Strength, National Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Problemy Prochnosti, No. 1, pp. 28–40, January–February, 1999. |
