.. _R7.02.21:

**r7.02.21** Law of cohesive behavior
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**r7.02.21** depending on the mix of loading: CZM_TURON
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**Summary:**

The law of cohesive behavior CZM_TURON makes it possible to model the damage to a cracking interface such that the opening of the crack generates cohesion forces between the lips of the crack.

It relates the cohesive forces, homogeneous to a constraint, to the discontinuity of movement across the interface according to a bi-linear law, which depends on the mixed loading rate: an interface subjected to mixed loading will be damaged sooner than in pure mode.

This model was developed by the Turon team from the University of Girona (Spain) [:ref:`1 <RefNumPara__371857051>`]. For example, it is used in the context of modeling glued joints made of composite material in wind turbine blades.

The law is supported by finite joint elements whose degrees of freedom are the jumps in movement when passing the interface (see R3.06.13).

Here we present the formulation of the cohesive law as well as the internal variables of the model. The existence of instabilities during the propagation of cracks requires control by elastic prediction, the elements of which are specific to these laws are presented.




.. _RefNumPara__37184505:


.. toctree::
    :hidden:

    self

.. toctree::
    :maxdepth: 2
    :numbered:

    G_n_ralit_s_sur_les_lois_coh_sives
    D_finition_de_la_loi_CZM_TURON
    Pilotage_du_chargement_par_pr_diction__lastique
    Mots-cl_s
    R_f_rences