Hello,

CALC_CHAMP with this syntax, LIAISON_SOLID_SPH and IMPR_FONC_MULT are not part of code_aster standard commands.

In the uses of EDF, having a very good precision of the stresses  is essential.
This is not necessarily the case for forming problems (such as stamping), we are more interested in the global force for example and in the kinematics.
Nevertheless, it is possible to have linear elements in incompressible formulation, for example INCO_UP or INCO_UPO instead of INCO_UPG.

Hello,

MODELISATION='C_PLAN', 'D_PLAN', 'AXIS' => 2D (skin element are edges)

DTAN is only one value. You must have two in 3D (skin elements are 2D) => you cannot use DTAN is MODELISAITON='3D'

Hello,

The FORMULATION='DISCRETE' is not recommanded

Use:
FORMULATION = 'CONTINUE'
ALGO_CONT='PENALISATION'
GLISSIERE='OUI'

NB: from a theroertical point of view a very large friction coefficient is not equivalent to clamped boundary condition (and it's not a good idea for convergence and ther is no unicity of solution)

Say no to drugs

Hello,

Technical problem I think.
No one can ban Jean-Pierre from the forum. I have nothing in the administration interface in any case.

You're right !

Please, everyone, try to be kind !

A mistake from myself, I forgot to validate my previous post.

To use underintegrated elements, you can use 3D_SI instead of 3D in AFFE_MODELE/MODELISATION
For instance;
HEXA20 => 3D => 20 integration points
HEXA20 => 3D_SI => 8 integration points
HEXA8 => 3D => 8 integration points
HEXA8 => 3D_SI => 1 integration points with hourglass control

Hello,

Of course, code_aster uses a complete integration, why use bad elements?

AFFE_CARA_ELEM / MASS_REP ?

Hello,

Theory ?
Kinematic relation between DOF by orthogonal projection (master/slave).
Multi-Point Constraint in strong form

Hello,

For FORMULATION=' DISCRET' and FORMULATION=' CONTINUE' the problem with elements QUAD8 on the surface is the same one: as the shape functions of these elements are NOT positive, the efforts of contact can oscillate of a node with another.
By doing INTEGRATION="GAUSS" instead of INTEGRATION="NOEUD", one can have better results in FORMULATION='CONTINUE', because one obtains an approximation of the mortar methods. But it doesn't always work.
Using QUAD9 (or TRIA6) is the best solution.
Only the LAC-type mortar-P0 method does not have this problem

https://www.code-aster.org/forum2/viewt … p?id=26213 ?