Fatigue (116/117)

Chapter Outline

Fatigue-Crack-Growth Rate
How Materials Behave: The S-N Curve
Factors Influencing Fatigue Behavior
Stress Concentration
Photoelasticity
Fracture Mechanics
- Fracture Toughness
- Fracture Toughness of Some Common Materials
Crack Propagation
- Crack Growth Rate
Fracture Surfaces
- Fatigue Crack Growth Prevention
Forensics
Failure Models
Failure Mechanism
Time-Dependent Failures
First Passage Model (Time to Failure)
The Goodman Diagram
The Constant Life Diagram
Exceeding a Critical Stress During Random Vibration
Inverse Power Law Model - Time to Failure
- Inverse Power Law Model, Example
Fatigue Damage Model Based Upon S-N Curve - Number of Cycles to Failure
- Idealized S-N Curve for Structural Materials
- Actual Fatigue Data
- Fatigue Testing with Electromagnetic Shaker
Fatigue Damage Model Based on Crack Growth Rate
Crack Growth Rate vs. Stress Intensity Factor
Stress Intensity Factors
Miner's Hypothesis for Fatigue Damage Accumulation
- Miner's "Rule" Cautions
Determination of Effective Excitation
Fatigue, Miner’s Rule Example
Typical Endurance Limits
"S-N" Curve from Fatigue Testing
Fatigue Case Study
Example: Rating a Printed Circuit Board