Life factor root
| Symbol | YN |
|---|---|
| Unit | - |
| Attribute-ID | abs_life_factor_y_n |
| Numeric ID | 5359 |
| Value Type | PMDouble |
The life factor YN for the tooth root explains the higher permissible stress, including static load, permitted for a limited life (number of load cycles lower than fatigue strength) compared to the maximum permissible stress for fatigue strength (NL=3*106).
The following options are available:
- Direct specification
Direct specification, exclusively for calculation acc. to ABS. - acc. to ABS
If not specified, the life factor for limited life time YN is determined by using the table 5 (ABS 2019, 4-3-1A1).
| YN | Life factor for the tooth root |
| NL | Number of load cycles |
| 1 | Material group 1 : GTS (perl.), St, V, GGG (perl. bai.) |
| 2 | Material group 2 : Eh, IF (root) |
| 3 | Material group 3 : NT, NV (nitr.), GGG (ferr.), GG |
| 4 | Material group 4 : NV (nitrocar.) |
Examples:
- Material group 1 with number of load cycles NL=4*104 → YN=2.0
- All material groups with number of load cycles NL=5*108 → YN=0.9
Source: American Bureau of Shipping (ABS): Rules for Building and Classing Steel Vessels, Paramus, New Jersey - edition 2011 and 2019, 4-3-1A1/Table 5.