.. _U3.13.14:

**u3.13.14** Modelings x_ JOINT, x_, x_ ELDI, x_ INTERFACE and x_ INTERFACE_S
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**Summary:**

This document describes, for models PLAN_JOINT, AXIS_JOINT, 3D_ JOINT, PLAN_ELDI, 3D_,, AXIS_ELDI,, PLAN_INTERFACE, AXIS_INTERFACE, 3D_ INTERFACE, PLAN_INTERFACE_S, AXIS_INTERFACE_S, and 3D_, the following points: INTERFACE_S


* the degrees of freedom carried by the finite elements that support modeling,


* the related support meshes,


* non-linear possibilities,


* test cases implementing the models.

Type JOINT models (Phenomenon: mechanical) correspond to finite joint elements. They are based on a penalization formulation, and make it possible to model the opening of a crack. Their geometric supports are degenerate finite elements, whose nodes are combined two by two (QUAD4, HEXA8 and PENTA6). These finite elements can support behavior laws CZM_EXP_REG and CZM_LIN_REG (cohesive laws: doc [R7.02.11]). In addition, the elements PLAN_JOINT, AXIS_JOINT support the law of behavior JOINT_BA (steel to concrete link: doc [R7.01.21]).

The models PLAN_ELDI and AXIS_ELDI (Phenomenon: mechanical) correspond to elements with internal discontinuity. Their geometric supports are solid elements (QUAD4) crossed by a discontinuity. They also make it possible to model the opening of a crack. Such finite elements can support the law of behavior: CZM_EXP (cohesive law: see doc [:external:ref:`R7.02.14 <R7.02.14>`]).

The models PLAN_INTERFACE, AXIS_INTERFACE, 3D_ INTERFACE, PLAN_INTERFACE_S, AXIS_INTERFACE_S and 3D_ INTERFACE_S (Phenomenon: mechanics) correspond to mixed interface finite elements, based on an augmented Lagrangian formulation. Their geometric supports are degenerate finite elements (QUAD8, HEXA20 and PENTA15). Such elements can support cohesive laws CZM_OUV_MIX, CZM_EXP_MIX,, CZM_TAC_MIX,,, CZM_FAT_MIX, CZM_TRA_MIX, and CZM_LAB_MIX (see doc [R7.02.11] and [:external:ref:`R3.06.13 <R3.06.13>`]).

Afterwards, the characters' XXX 'can be replaced by' PLAN 'or' AXIS '.


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    self

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    :maxdepth: 2
    :numbered:

    Discr_tisation
    Possibilit_s_non-lin_aires
    Exemples_de_mise_en__uvre___cas-tests