Calculate allowable stress amplitude from the number of stress cycles, or allowable number of stress cycles from the stress amplitude (DNVGL-RP-C203 section 2.4).
The SN curves include allowances for design temperature, material thickness and system effects. The design fatigue factor (DFF) is taken from DNVGL OS C101. The stress concentration factor is in addition to any embedded factor in the SN curve. Enter stress values as nominal stress amplitude.
Tool Input
- jointtype : Joint Or Material Type
- csntype : SN Curve Type
- sntype : SN Parameter Type
- Snomu : User Defined Nominal Stress Amplitude (Without SCF)
- Nu : User Defined Number Of Cycles
- walltype : Weld Joint Type
- tru : User Defined Reference Thickness
- kfactype : Thickness Exponent Type
- ku : User Defined Thickness Exponent
- scftype : Stress Concentration Factor TypeWithout
- SCFu : User Defined Stress Concentration Factor
- dfftype : Design Fatigue Factor Type
- DFFu : User Defined Design Fatigue Factor
- ratype : Forging Surface Roughness Type
- temptype : Temperature Derating Type
- Tu : User Defined Design Temperature
- systype : System Effect Factor Type
- Rsu : User Defined System Effect Log Factor
- tn : Wall Thickness
Tool Output
- DFF : Design Fatigue Factor
- N : Number Of Cycles
- Rm : Material Thickness Derating Log Factor
- Rs : System Effect Log Factor
- Rt : Temperature Derating Log Factor
- SCF : Stress Concentration Factor
- Sd : Design Stress Amplitude (With SCF)
- Sn : Nominal Stress Amplitude (Without SCF)
- k : Thickness Exponent
- tref : Reference Thickness