The Stress-Life, or in short, S-N approach typically relates nominal stresses to total failure and is suited primarily to problems where there are a large number of cycles to failure, i.e. >103 or 104 cycles or so-called "long life".
High Cycle Fatigue
The primary application of the Stress-Life method is high-cycle fatigue (long lives), where nominal stress controls the fatigue life. A wide range of methods are available for defining the S-N curves, including the ability to interpolate multiple material data curves for factors such as mean stress or temperature. We also account for stress gradients and surface finishes. When custom fatigue methods are required, we use Python scripting to enable the definition of custom fatigue methods and material models. Features include:
- Material models:
- Standard S-N
- S-N Mean multi-curve
- S-N R-ratio multi-curve
- S-N Haigh multi-curve
- S-N Temperature multi-curve
- Bastenaire S-N
- Custom S-N using Python scripting
- Stress combination methods or critical plane analysis
- Back calculation to target life
- Multiaxial assessment
- Biaxial
- 3D Multiaxial
- Auto-correction
- Mean stress corrections
- FKM Guidelines
- Goodman
- Gerber
- Walker
- Interpolate multiple curves
- Notch Correction - stress gradient corrections
- FKM Guidelines
- Critical distance