generalized_debonding#
Description#
This behavior 1this behavior is Z-set specific, and therefore does not apply for
Z-mat for other codes is used for the special problem of interface
debonding. See the command **create_interface_elements
(and similar)
in the Z-set user manual on how to insert cohesive elements in the mesh.
The Generalized model 2Vandellos T., Huchette C. and Carrere N., “Proposition of a framework
for the development of a cohesive zone model adapted to Carbon-Fiber
Reinforced Plastic laminated composites.”, Comp. Struct. 105
(2013), 199-206. is based on the consideration of the
characterization of interfacial properties and permits to use three
different shapes for the cohesive law (bi-linear, tri-linear and
trapezoidal). This model is described through a scalar variable
where
With respect to the interface normal
Fig. 15 Shape of the tri-linear model for a constant mixed-mode ratio in the
The damage variable
where
with
Remarks:
the parameter
is not required with the bi-linear shape;the parameter
has to be defined only with the tri-linear law;two stress criteria (puissance and reinforcement) and three propagation laws (puissance, benzeggagh and vandellos) are available;
3Turon A., Camanho P.P., Costa J. and Renart J., “Accurate simulation
of delamination growth under mixed-mode loading using cohesive
elements: Definition of interlaminar strengths and elastic
stiffness.”, Comp. Struct. 92 (2010), 1857-1864.the option
*turon
is required for applying the modification proposed by Turon 3Turon A., Camanho P.P., Costa J. and Renart J., “Accurate simulation of delamination growth under mixed-mode loading using cohesive elements: Definition of interlaminar strengths and elastic stiffness.”, Comp. Struct. 92 (2010), 1857-1864..
Syntax#
***behavior generalized_cohesive_zone
*strength
Zt
Sc
*toughness
G1c
G2c
*stiffness
K
alphac
*propagation
propagation law (puissance or benzeggagh or vandellos)
n
*initiation
stress criterion (puissance or reinforcement)
*softening
shape of the cohesive law (bi_linear or tri_linear or trapezoidal)
alpha_delta
alpha_sigma
*turon
]
Example#
***behavior generalized_cohesive_zone
*strength
Zt 100.
Sc 100.
*toughness
G1c 0.0005
G2c 0.0005
*stiffness
K 1.e8
alphac 1.e3
*propagation benzeggagh
n 1.142
*initiation puissance
*softening tri_linear
alpha_delta 0.4
alpha_sigma 0.8
***return
Fig. 16 Example in two dimensions of the evolution of the cohesive
traction as a function of the opening displacement, for two different
loading cases: