FEM Équation de déformation

From FreeCAD Documentation
Revision as of 15:00, 25 March 2023 by David69 (talk | contribs) (Created page with "{{Docnav/fr |Solveur Z88 |Équation d'élasticité |Atelier FEM |IconL=FEM_SolverZ88.svg |IconR=FEM_EquationElasticity.svg |IconC=Workbench_FEM.svg }}")
Other languages:

FEM EquationDeformation

Menu location
Solve → Mechanical equations → Deformation equation
Workbenches
FEM
Default shortcut
None
Introduced in version
1.0
See also
FEM Elasticity equation, FEM tutorial

Description

This equation describes the nonlinear elastic deformation of rigid bodies.

For info about the math of the equation, see the Elmer models manual, section Finite Elasticity.

Usage

  1. After adding an Elmer solver as described here, select it in the tree view.
  2. Now either use the toolbar button or the menu Solve → Mechanical equations → Deformation equation.
  3. Change the equation's solver settings or the general solver settings if necessary.

Solver Settings

For the general solver settings, see the Elmer solver settings.

The deformation equation provides these special settings:

  • DonnéesCalculate Pangle: If the principal angles should be calculated.
  • DonnéesCalculate Principal: If all stresses should be calculated.
  • DonnéesCalculate Strains: If strains will be calculated. This will also calculate the stresses, even if DonnéesCalculate Principal or DonnéesCalculate Stresses is false.
  • DonnéesCalculate Stresses: If stresses should be calculated. Compared to DonnéesCalculate Principal the Tresca yield criterion and the principal stress will not be calculated.
  • DonnéesInitialize State Variables: See the Elmer manual for more info.
  • DonnéesMixed Formulation: See the Elmer manual for more info.
  • DonnéesNeo Hookean Model: Uses the neo-Hookean material model.
  • DonnéesVariable: The variable for the elasticity equation. Change there the 3 to 2 if you have a 2D geometry. For the special case that you have DonnéesMixed Formulation and DonnéesNeo Hookean Model set to true, the variable number must be geometry dimensions + 1, so for 3D geometry the 3 must be changed to 4.

Equation:

  • DonnéesPlane Stress: Computes solution according to the plane stress situation. Applies only for 2D geometry.

Constraint Information

The elasticity equation takes the following constraints into account if they are set:

Notes

  • Except for calculations in 2D, for all above constraints it is important that they act on a face.
  • Constraints for 3D set to lines or vertices are not recognized by the Elmer solver.

Results

The available results depend on the solver settings. If none of the DonnéesCalculate * settings was set to true, only the displacement is calculated. Otherwise also the corresponding results will be available.