Analysis & loading · Seismic & dynamic
Fatigue damage (Miner's rule) calculator
Cycles to failure for each stress range block from N = 2×10⁶ (ff/fr)³ (m = 3) and the cumulative damage sum.
Standard: AS 4100 Section 11 S–N form · Palmgren–Miner
Open the live calculator → All analysis & loading calculators
Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Detail category (2 million cycle strength) | 80 | MPa |
| Blocks: stress range (MPa), cycles | 60, 500000 40, 2000000 25, 10000000 | |
| Capacity reduction (1/φ) | 1 |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Cumulative damage ΣD | 0.383 | |
| Limit | 1.00 |
- ✓ Damage ≤ 1.0
Method, formulas and assumptions
- Cumulative damage ΣD = SUM([t.D]) = 0.38306
- Limit = 1 = 1
- AS 4100 also uses m = 5 below the constant-amplitude fatigue limit; this tool keeps m = 3 throughout (conservative).
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.