The Fatigue Scatter Factors and Reduction Factors in the Design of Aircraft and Helicopter's Structural Lives

This paper considers that fatigue scatter factors can be devided into the scatter factors for fatigue testing and those for theoretical computation. Both kinds can also be devided into the scatter factors for crack initiation lives and those for crack growth lives.

This paper also studies the values of different kinds of scatter factors, and gives out suitable ones. Meanwhile, it makes comments on the calculation formulas and different values of scatter factors used by other countries.

Through the study of the definitions and their parameter distributions of scatter factors and reductions factors, the author considers that it is possible to calculate them by a unified formula.