Wear
Wear is the damaging, gradual removal or deformation of material at solid surfaces, caused by mechanical forces (e.g., erosion, friction) or chemical processes (e.g., corrosion). It is the primary driver of the wear-out phase in reliability engineering, where hazard rates increase, leading to eventual functional failure.
In shop floor maintenance, wear is monitored via condition-based maintenance (CBM) and predictive maintenance (PdM) using sensors such as vibration, temperature, and oil analysis. These tools track degradation trajectories, enabling Remaining Useful Life (RUL) predictions and preemptive replacement before functional failure. This approach is critical for asset reliability in CMMS systems, as it allows maintenance teams to schedule interventions based on actual wear rather than fixed intervals, reducing unexpected breakdowns and optimizing resource allocation.
How is wear modeled for Remaining Useful Life (RUL) prediction?
Wear is modeled using Gamma process trajectories (monotonic, non-decreasing) to better represent its irreversible nature compared to Wiener processes, enhancing RUL accuracy.
What is the wear coefficient?
A physical coefficient used to quantify, characterize, and correlate material wear rates, critical for predicting reliability of mechanical equipment under specific operating environments.
When are wear-out failures considered negligible in reliability prediction?
If the standard deviation of an item's life is < μ/6 (where μ is mean life), wear-out failures are assumed negligible up to t = 150 hours (one-half of μ).