Cohesive-Zone Modelling Reference

A quick reference for cohesive-zone modelling — traction-separation law, parameters, mesh requirements and verification tests.

Advanced Damage & Failure3 min read

referencecohesive zonetraction-separationparametersmeshverification

Key Parameters

Cohesive traction-separation law:

  K = initial stiffness (penalty)
  T_max = peak traction (strength)
  G_c = fracture energy (area under curve)
  δ_init = T_max / K (separation at initiation)
  δ_fail = 2 × G_c / T_max (separation at failure)

Initiation: quadratic interaction
  (T_n/N)² + (T_s/S)² = 1.0

Evolution: energy-based, mixed-mode
  Power law: (G_I/G_Ic)^α + (G_II/G_IIc)^β = 1
  B-K: G_c = G_Ic + (G_IIc−G_Ic)×(G_II/(G_I+G_II))^η

Verification tests:
  DCB — Mode I
  ENF — Mode II
  MMB — Mixed mode