A COMPUTER-CONTROLLED VIBRATORY FATIGUE TEST RIG WITH PROGRAMMED LOADING FOR BLADING

In order to improve the accuracy in experimental prediction of service life of axial-flow compressor blade,it is necessary to simulate random field loads in the laboratory. Based on recorded flight spectrum loading, a microcomputer system for data processing and counting was successfully utilized to derive a mathematical model for a steppedload spectrum and software programming. For simulation by programmed step loading, a computer-controlled closed cycle servo-electrical test righas been newly devised. This paper describes briefly its design and technical features. On this rig, a fatigue life distribution of certain compressor blading was automatically tested under its simulated flight block load spectrum. This advanced technique for inspection of the fatigue life and quality in blade production may be employed by blade manufacturing factory to enhance the flight reliability.