Differences

This shows you the differences between two versions of the page.

--- doc:user:elements:contact:laws [2013/07/10 18:01] – joris
+++ doc:user:elements:contact:laws [2025/04/29 15:37] (current) – papeleux
@@ Line 1: / Line 1: @@
+====== Contact materials ======
+===== Description =====
+For all contact materials, a penalty along the normal direction and a depth at which contact is detected are required. Contact can be:
+  * positively unilateral  (''UNILATERAL_POSITIF''), contact for  $\mbox{gap} \geq 0$  (by default)
+  * negatively unilateral (''UNILATERAL_NEGATIF''), contact for  $\mbox{gap} \leq 0$
+  * bilateral (''BILATERAL''), contact for both  $\mbox{gap} \geq 0$  and  $\mbox{gap}\leq 0$
+__Choice of depth at which contact is detected:__ If the contact matrix is made of circles, the depth must be smaller than the smallest radius. If it is planar, the depth is arbitrary, but a large depth leads to a slow contact detection, when if the depth is too small some contacts can be missed.
+===== FrictionlessContactMaterial =====
+=== Description ===
+Contact without friction.
+=== Parameters ===
+^   Name                                          ^     Metafor Code     ^  Dependency ^  Default  ^
+| Penalty along normal direction       |   ''PEN_NORMALE''    |        ''TM''        |            |
+| Depth at which contact is detected   |    ''PROF_CONT''     |          -           |             |
+| Type of contact                      |    ''TYPE_CONT''     |          -           |  ''UNILATERAL_POSITIF''  |
+===== FrictionlessVariablePenaltyContactMaterial =====
+=== Description ===
+Contact without friction where penalty can depend on the gap.
+=== Parameters ===
+^   Name                                          ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction                     |   ''PEN_NORMALE''    |        ''GD''        |
+:!: No ''TM'' dependency here!
+An evolution function must be associated to ''PEN_NORMALE'' (depending on generalized displacements GD).
+===== StickingContactMaterial =====
+=== Description ===
+Sticking contact. A penalty along the tangential direction is added.
+=== Parameters ===
+^   Name                                          ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction                     |   ''PEN_NORMALE''    |        ''TM''        |
+| Penalty along tangential direction                    |   ''PEN_TANGENT''    |        ''TM''        |
+| Depth at which contact is detected   |    ''PROF_CONT''     |          -           |
+| Type of contact                      |    ''TYPE_CONT''     |          -           |
+===== StickingVariablePenaltyContactMaterial =====
+=== Description ===
+Sticking contact where penalty can depend on the gap.
+=== Parameters ===
+^   Name                               ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction                     |   ''PEN_NORMALE''    |        ''GD''        |
+| Penalty along tangential direction                    |   ''PEN_TANGENT''    |        ''GD''        |
+:!: No ''TM'' dependency here!
+An evolution function must be associated to ''PEN_NORMALE'' and/or ''PEN_TANGENT'' (depending on generalized displacements GD). These function can be different.
+===== AdhesiveStickingContactMaterial =====
+=== Description ===
+Adhesive sticking contact is a sticking Contact material that is initialized with an unilateral type of contact (positive or negative) and that each slave node where contact is detected becomes bilateral (adhesive behavior).
+Up to now, forces are computed forces are computed as classical sticking depending to Normal and Tangential Penalty.
+=== Parameters ===
+^   Name                               ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction       |   ''PEN_NORMALE''    |        ''TM''        |
+| Penalty along tangential direction   |   ''PEN_TANGENT''    |        ''TM''        |
+| Depth at which contact is detected   |    ''PROF_CONT''     |          -           |
+| Initial Type of contact              |    ''TYPE_CONT''     |          -           |
+===== CoulombContactMaterial =====
+=== Description ===
+Coulomb's friction law. A tangential penalty, a coefficient of static friction (setting the maximal tangential force before sliding) and a coefficient of dynamic friction (setting the value of the sliding force) are required.
+=== Parameters ===
+^   Name                              ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction       |   ''PEN_NORMALE''    |        ''TM''        |
+| Penalty along tangential direction   |   ''PEN_TANGENT''    |        ''TM''        |
+| Depth at which contact is detected   |    ''PROF_CONT''     |          -           |
+| Coefficient of static friction       |  ''COEF_FROT_STA''   |        ''TM''        |
+| Coefficient of dynamic friction      |  ''COEF_FROT_DYN''   |        ''TM''        |
+| Type of contact                      |    ''TYPE_CONT''     |          -           |
+===== TrescaContactMaterial =====
+=== Description ===
+Tresca's friction law. Friction do not depend on pressure. It is computed using penalty method with sticking contact, and starts sliding once the tangential stress reaches a threshold entered by the user.
+:!: This law requires the use of ''AREAINCONTACT'' = ''AIC_ONCEPERSTEP''
+=== Parameters ===
+^   Name                                          ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction                     |   ''PEN_NORMALE''    |        ''TM''        |
+| Penalty along tangential direction                 |   ''PEN_TANGENT''    |        ''TM''        |
+| Depth at which contact is detected                 |    ''PROF_CONT''     |          -           |
+| Static frictional shear factor |  ''TRESCA_STA_M''   |        ''TM''        |
+| Dynamic frictional shear factor |  ''TRESCA_DYN_M''   |        ''TM''        |
+| Initial shear yield stress  |  ''TRESCA_K''   |        -        |
+| Type of contact                                    |    ''TYPE_CONT''     |          -           |
+The threshold is usually computed using  $m\,\sigma_0\,/\sqrt{3}$  where //m// is Tresca's coefficient of friction  and  $\sigma_0$  is the tensile yield stress of the material.
+===== TmFrictionlessContactMaterial =====
+Thermomechanical contact without friction.
+The heat flux  $q_{N}$  normal to the contact interaction (going out of the slave surface) is given by
+ $q_{N} = h_c \left(p_{N} \right) \left(T^{S} - T^{M}\left(\bf{\xi}^{S}\right)\right),$
+where
+  *  $p_{N}$  is the contact pressure,
+  *  $T^{S}$  is the temperature of the slave node,
+  *  $T^{M}\left(\bf{\xi}^{S}\right)$  is the temperature of a point on the master surface corresponding to the closest projection of the slave node on the master surface,
+  *  $h_c$  is the thermal resistance under conduction.
+This thermal resistance under conduction  $h_c$  is modeled as
+ $h_c \left(p_{N} \right) = h_{c0} \left(\frac{p_{N}}{H_v}\right)^{w},$
+where
+     *  $H_v$  Vickers's material hardness ,
+     *  $w$  is an exponent,
+     *  $h_{c0}$  is the nominal thermal resistance under conduction.
+=== Parameters ===
+^   Name                               ^     Metafor Code     ^  Dependency          ^
+| Penalty along normal direction       |   ''PEN_NORMALE''    |        ''TM''        |
+| Depth at which contact is detected   |    ''PROF_CONT''     |          -           |
+| Nominal thermal resistance           |  ''CTM_H_NOMINAL''   |          -           |
+| Exponent                             |  ''CTM_EXPONENT_E''  |          -           |
+| Material hardness                    |   ''CTM_HARDNESS''   |          -           |
+| Type of contact                      |    ''TYPE_CONT''     |          -           |
+:!: Not tested in 3D :!:
+===== TmStickingContactMaterial =====
+Sticking thermomechanical contact
+=== Parameters ===
+^   Name                                          ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction                     |   ''PEN_NORMALE''    |        ''TM''        |
+| Penalty along tangential direction                    |   ''PEN_TANGENT''    |        ''TM''        |
+| Depth at which contact is detected   |    ''PROF_CONT''     |          -           |
+| Nominal thermal resistance           |  ''CTM_H_NOMINAL''   |          -           |
+| Exponent                             |  ''CTM_EXPONENT_E''  |          -           |
+| Material hardness                    |   ''CTM_HARDNESS''   |          -           |
+| Type of contact                      |    ''TYPE_CONT''     |          -           |
+:!: Not tested in 3D :!:
+===== TmCoulombContactMaterial =====
+=== Description ===
+Thermomechanical contact using Coulomb's friction law
+=== Parameters ===
+^   Name                                          ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction                     |   ''PEN_NORMALE''    |        ''TM''        |
+| Penalty along tangential direction                    |   ''PEN_TANGENT''    |        ''TM''        |
+| Depth at which contact is detected   |    ''PROF_CONT''     |          -           |
+| Coefficient of static friction       |  ''COEF_FROT_STA''   |        ''TM''        |
+| Coefficient of dynamic friction      |  ''COEF_FROT_DYN''   |        ''TM''        |
+| Nominal thermal resistance           |  ''CTM_H_NOMINAL''   |          -           |
+| Exponent                             |  ''CTM_EXPONENT_E''  |          -           |
+| Material hardness                    |   ''CTM_HARDNESS''   |          -           |
+| Type of contact                      |    ''TYPE_CONT''     |          -           |
+:!: Not tested in 3D :!:
+===== TmTrescaContactMaterial =====
+=== Description ===
+Thermomechanical contact using Tresca's friction law
+=== Parameters ===
+^   Name                                          ^     Metafor Code     ^  Dependency ^
+| Penalty along normal direction       |   ''PEN_NORMALE''    |        ''TM''        |
+| Penalty along tangential direction   |   ''PEN_TANGENT''    |        ''TM''        |
+| Depth at which contact is detected   |    ''PROF_CONT''     |          -           |
+| Static frictional shear factor |  ''TRESCA_STA_M''   |        ''TM''        |
+| Dynamic frictional shear factor |  ''TRESCA_DYN_M''   |        ''TM''        |
+| Initial shear yield stress  |  ''TRESCA_K''   |        -        |
+| Nominal thermal resistance           |  ''CTM_H_NOMINAL''   |          -           |
+| Exponent                             |  ''CTM_EXPONENT_E''  |          -           |
+| Material hardness                    |   ''CTM_HARDNESS''   |          -           |
+| Type of contact                      |    ''TYPE_CONT''     |          -           |
+The threshold is usually computed using  $m\,\sigma_0\,/\sqrt{3}$  where //m// is Tresca's coefficient of friction  and  $\sigma_0$  is the tensile yield stress of the material.
+:!: Not tested in 3D :!: