Load–Displacement (refined XEFG)
Spline
Current
(I)(II)(III)
0
(I) 0.140
(II) 0.270
(III) 0.320
0.450
Load (F):
0.00 kN
Upper-right uy:
+0.000 mm
Lower-right uy:
−0.000 mm
Crack length (a):
120 mm
Peak traction:
0.00 MPa
Tip traction:
0.00 MPa
State:
Elastic
Cohesive traction along ligament $\sigma(x)$
Ahead of crack tip — green elastic · amber softening · gap = broken
Traction–separation law $\sigma(\delta_n)$
Points = active cohesive stations (current openings)
Specimen & Kinematics
- Length / height: 400 mm × 200 mm
- Initial notch $a_0$: 120 mm
- $\delta$ on the curve: vertical displacement of the upper/lower right load nodes (not CMOD)
- Motion: upper-right node $u_y=+\delta$, lower-right $u_y=-\delta$; arms meet at crack tip $x=a$, with $x$ measured from the loaded end
- Support: pinned at left midplane
Cohesive Zone Traction Law
- $\sigma_c$: 10 MPa peak cohesive strength
- $\delta_0$: 0.02 mm damage initiation
- $\delta_f$: 0.08 mm complete separation
- Purple arrows on the midplane = local cohesive tractions (length ∝ $\sigma$)