Prediction on high cycle life of blades using probability method

High cycle fatigue (HCF) of blades caused by forced vibration is an problem for turbo engines. To solve HCF problems, it is effective to introduce probability method to obtain high cycle life of blades. The probability cumulative damage model according to blades was erected. Based on vibration stress, the numerical method to get probability cumulative damage and to obtain operational reliability was given. The randomicities were taken into account adequately including mode randomicity and load randomicity. Finally certain engineering sample was discussed to illustrate the method, and certain secondary stator used in a missile engine was given as an example. The probability cumulative damages altering with operation time were calculated, and the operational reliabilities were obtained according to each operation time.