Meaning
Linear damage accumulation model calculates the fatigue life of a material subjected to varying stress amplitudes. This design tool, Miner cumulative damage, adds the fraction of life consumed at each stress level to predict structural failure. The total accumulated damage is compared to a critical value of one.
Fatigue Model
Structural components experience complex stress histories during their operating life. This fatigue model of Miner cumulative damage assumes that every stress cycle consumes a portion of the component’s fatigue life. Designers utilize this approach due to its simplicity and computational efficiency.
Life Expectancy
Maintenance schedules are planned around the predicted time to failure of critical parts. The life expectancy of Miner cumulative damage calculations must be adjusted with safety factors to account for scatter in material fatigue limits. Overestimating life can lead to catastrophic failure in the field.
Liability Allocation
Supply contracts for structural components designate which party is responsible for fatigue analysis and validation testing. The liability allocation of Miner cumulative damage discrepancies is determined by the accuracy of the operating stress history provided by the buyer. Clear communication of expected load spectra is essential.
When structural failure occurs before the calculated lifespan, disputes are resolved by comparing actual operational flight data against the design load spectrum appended to the original equipment supply agreement.
