Life factor for bending stress

Symbol	Y_NT10
Unit	-
Attribute-ID	stress_cycle_factor_bending_strength_y_nt10_agma_2003
Numeric ID	10135
Value Type	PMDouble

The life factor Y_NT10 determines the slope of the bending fatigue life curve, and thus the decrease to the allowable bending strength number between the load cycle numbers N_L = 3·10⁶ and N_L = 10¹⁰. It can be specified for the calculation of the life factor Y_NT according to AGMA 2003.

For N_L = 3·10⁶, Y_NT = 1.0 applies.

If the permissible contact stress number should not decrease in this range, Y_NT10 = 1.0 must be entered.

The branch of the bending fatigue life curve can be specified as an alternative to the life factor Y_NT10.

If neither the life factor Y_NT10 nor the branch of the bending fatigue life curve is specified, the calculation is performed using the lower branch of the life curve: Y_NT10 = 0.8 (for critical applications).

Stress cycle factor for bending strength Y_NT for carburized case-hardened steel bevel gears according to AGMA 2003

1	Upper branch with Y_NT10 = 0.9 for general applications
2	Lower branch with Y_NT10 = 0.8 for critical applications

The life factor Y_NT10or the branch of the bending fatigue life curve is only used for the S-N curve calculation. If a component S-N curve is specified in the material of the respective gear, it is used for the load capacity and load spectrum calculations.