Parameters
Material
KIC (MPa√m)
50
Yield stress σy (MPa)
300
Crack Geometry
Crack size a (mm)
10.0 mm
Geometry factor Y (override)
— (auto)
Move slider to use manual value
Applied stress σ (MPa)
100 MPa
Target safety factor
2.0
—
KI (MPa√m)
—
KIC (MPa√m)
—
Safety factor KIC/KI
—
Critical crack a_cr (mm)
—
Residual strength σ_r (MPa)
Failure Assessment Diagram (FAD)
Residual Strength vs. Crack Size
Theory
Stress intensity factor: $K_I = Y \sigma \sqrt{\pi a}$
Fracture condition: $K_I = K_{IC}$
Critical crack size: $a_{cr} = \dfrac{1}{\pi}\left(\dfrac{K_{IC}}{Y\sigma}\right)^2$
Residual strength: $\sigma_r = \dfrac{K_{IC}}{Y\sqrt{\pi a}}$
CTOD: $\delta = \dfrac{K_I^2}{E \sigma_y}$
FAD assessment line (R6 Option 1): $K_r = \left(1 - 0.14L_r^2\right)\left(0.3 + 0.7\,e^{-0.65 L_r^6}\right)$, $L_r = \sigma/\sigma_y$
CAE Integration: Input stresses from FEM solvers (ABAQUS/ANSYS) as σ for damage tolerance pre-screening. Useful for safety evaluation of aircraft, pressure vessels, and bridge structures, as well as inspection interval planning.