Material

C (×10⁻¹¹) 0.30 m (Paris exponent) 3.0 K_IC (MPa·√m) 50 Initial crack a₀ (mm) 1.0 σ_max (MPa) 200 σ_min (MPa) 20 Specimen width W (mm) 80 Y geometry factor 1.12 Cycles per frame 200

Stats

Cycles N0

Crack a (mm)1.00

Δσ (MPa)180

ΔK (MPa·√m)—

K_max / K_IC—

da/dN (mm/cyc)—

Regimestable

Cycles to failure—

Paris law: da/dN = C·(ΔK)^m, where ΔK = Y·Δσ·√(πa). Failure when K_max = Y·σ_max·√(πa) ≥ K_IC. Doubling Δσ shortens life by ~2^m — for m≈3, life drops ~8×.