Infinite-life Design
- Design for stresses that never exceed the endurance limit
- Plastic strain is almost entirely avoided
- Applications that need to sustain over a million stress cycles
- Used with stress-life method
Safe-life Design
- Finite-life (< 1 million cycle)
- Applications may have limited stress cycles or imprecision in estimating fatigue life
- Uses significant safety margins
- Used with stress-life method and strain-life method
Fail-safe design
- Design so that if one part fails, the entire system does not fail
- Not trying to entirely prevent crack initiation and growth
Damage-tolerant design