Methods for stress based life and its reliability analyses of discs with medium-long and long life

Considering the difficulty in calculating the stress concentration factor of mortise of a disk and the error of life is big by using the traditional stress-life method,an improved stress-life method is proposed to compute the life of disks.It includes the concept of stress correction coefficient,a new method to determine the stress concentration factor of mortise of a disk and a new method for correcting the stress ratio.When once the stress correction coefficient of the bars was computed,the improved Stress-Life method can be used to calculate disk's life with the experimental data of bars without notch,at the same time,the influence of the stress concentration is also considered.Then a new stress-life probabilistic model is built for the purpose of life reliability analysis.Finally,the fatigue life reliability of a fan disk is analyzed by the method given,and the computational results fit well with experimental ones.