Definition
A failure mechanism is the physical or chemical process (fatigue, corrosion, wear, fretting) through which an initiating cause actually degrades a component over time until a function is lost. It explains "how" damage progressed, sitting between the cause that triggered it and the failure mode that resulted.
Key facts
- Describes "how" degradation physically or chemically progresses, not why it started or how the function ultimately failed.
- Examples include fatigue, corrosion, wear, cavitation, and fretting: each a distinct physical process.
- Often diagnosable from specific evidence (fracture surface pattern, corrosion type) that distinguishes one mechanism from another.
- Sits between failure cause (why it started) and failure mode (how the function stopped) in the analysis chain.
What does Failure mechanism reveal about failures?
A failure mechanism explains the specific physical or chemical process carrying an initiating cause forward to component damage, for example, how repeated cyclic stress (the cause) progresses through fatigue (the mechanism) to a crack that eventually fractures the part.
How do teams use Failure mechanism in failure analysis?
Failure cause is the initiating circumstance; failure mechanism is the process that follows from it; failure mode is the resulting way the function actually fails. Fatigue is a mechanism, not a cause (cyclic loading is the cause) or a mode (the mode might be "fractures under load").
FAQ
Frequently asked questions
Through which process does a failure develop?
The failure mechanism: the specific physical or chemical process (such as fatigue, corrosion, or wear) through which an initiating cause degrades a component over time until a function is lost.
Last reviewed: