A servo-hydraulic fatigue fixture repeatedly opens a pre-existing central crack. Accelerated cycle count drives a Paris-law growth model; a magnified inspection strip records successive crack lengths.
• 3D scene parts: servo-hydraulic actuator and grips; pre-cracked wide-plate coupon; advancing crack tips; crack-length inspection strip; cyclic load indicator. • Controls: initial half-crack length (1–8 mm), maximum cyclic stress (40–160 MPa), stress ratio R (0–0.8), paris C × 10⁻¹¹ (1–10 m/cycle/(MPa√m)³), δK threshold (0–8 MPa√m), cycles per animation second (100–3000 cycles/s). • Live readouts: half-crack length; accumulated cycles; stress-intensity range; da/dN; peak stress intensity; kmax reaches 40 · 1=yes. • Guided experiments: Below threshold; Larger cyclic range; Higher stress ratio. • Four tabs (visual laboratory, curves and measurements, experiments, learn and assess), a model-verification run, a timestamped event log and a trial report.
Δσ=(1−R)σmax; ΔK=Δσ√(πa) da/dN=C(ΔK)³ for ΔK>ΔKth; otherwise no growth a(N)=[a₀^(−1/2)−C(Δσ√π)³ N/2]^(−2) Stop at Kmax=40 MPa√m or a=40 mm; distances in metres inside the law.
Constant-amplitude, constant-geometry Paris region with exponent 3 and a hard threshold. No initiation life, closure, overload retardation, residual stress, finite-width correction or variable-amplitude spectrum. The closed-form integration stops at the toughness/length boundary; displayed physical cycles are accelerated. Parameters are illustrative, not a material fatigue-life database. Try the preset experiments, then compare the live readouts with the equations.
No, the initial crack already exists. The Paris model covers propagation of an existing flaw.
No. The fixture is slowed; the accumulated-cycle measurement is authoritative.
Constant-amplitude, constant-geometry Paris region with exponent 3 and a hard threshold. No initiation life, closure, overload retardation, residual stress, finite-width correction or variable-amplitude spectrum. The closed-form integration stops at the toughness/length boundary; displayed physical cycles are accelerated. Parameters are illustrative, not a material fatigue-life database.