Parameters
KI (Mode I)20.0 MPa√m
KII (Mode II)10.0 MPa√m
KIII (Mode III)5.0 MPa√m
KIC (Mode I fracture toughness)50.0 MPa√m
KIIC / KIC ratio0.80
Crack length a (mm)10.0 mm
Young's Modulus E (GPa)200 GPa
Poisson's Ratio ν0.30
Analysis Condition
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Keff [MPa√m]
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θc Kink Angle [°]
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G_total [J/m²]
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ψ Mode Mixity [°]
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Fracture Margin
Mixed-Mode Fracture Locus
Kink Angle vs KII/KI
Theory
Stress intensity factors:
$$K_I = F_I \sigma\sqrt{\pi a},\quad K_{II} = F_{II}\tau\sqrt{\pi a},\quad K_{III} = F_{III}\tau\sqrt{\pi a}$$MCS criterion (kink angle):
$$\theta_c = 2\arctan\!\left(\frac{K_I - \sqrt{K_I^2+8K_{II}^2}}{4K_{II}}\right)$$Strain energy release rate:
$$G_{eff} = \frac{K_I^2+K_{II}^2}{E'} + \frac{K_{III}^2}{2\mu}$$
CAE Integration: Extract J-integral and KI/KII from ABAQUS/Fracture, then evaluate fracture margin and kink angle with this tool. Suitable for welded joints, adhesive bonds, and composite interlaminar delamination analysis. ASTM E1820 and ISO 15653 compliant evaluation.