FEM EquationDeformation: Difference between revisions

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<!--T:4-->
{{Docnav
{{Docnav
|[[FEM_SolverZ88|Solver Z88]]
|[[FEM_EquationElasticity|Elasticity equation]]
|[[FEM_EquationElasticity|Elasticity equation]]
|[[FEM_EquationElectrostatic|Electrostatic equation]]
|[[FEM_Workbench|FEM]]
|[[FEM_Workbench|FEM]]
|IconL=FEM_SolverZ88.svg
|IconL=FEM_EquationElasticity.svg
|IconR=FEM_EquationElasticity.svg
|IconR=FEM_EquationElectrostatic.svg
|IconC=Workbench_FEM.svg
|IconC=Workbench_FEM.svg
}}
}}
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{{GuiCommand
{{GuiCommand
|Name=FEM EquationDeformation
|Name=FEM EquationDeformation
|MenuLocation=Solve → Deformation equation
|MenuLocation=Solve → Mechanical equations → Deformation equation
|Workbenches=[[FEM_Workbench|FEM]]
|Workbenches=[[FEM_Workbench|FEM]]
|Version=1.0
|Version=0.21
|SeeAlso=[[FEM_EquationElasticity|Elasticity equation]]
|SeeAlso=[[FEM_EquationElasticity|Elasticity equation]], [[FEM_tutorial|FEM tutorial]]
}}
}}


==Description==
==Description== <!--T:5-->


<!--T:6-->
This equation describes the nonlinear elastic deformation of rigid bodies.
This equation describes the nonlinear elastic deformation of solid bodies.


<!--T:7-->
For info about the math of the equation, see the [http://www.elmerfem.org/blog/documentation/ Elmer models manual], section ''Finite Elasticity''.
For info about the math of the equation, see the [http://www.elmerfem.org/blog/documentation/ Elmer models manual], section ''Finite Elasticity''.


==Usage==
==Usage== <!--T:8-->


<!--T:9-->
# After adding an Elmer solver as described [[FEM_SolverElmer#Equations|here]], select it in the [[Tree_view|tree view]].
# After adding an Elmer solver as described [[FEM_SolverElmer#Equations|here]], select it in the [[Tree_view|tree view]].
# Now either use the toolbar button [[Image:FEM_EquationElasticity.svg|24px]] or the menu {{MenuCommand|Solve → Deformation equation}}.
# Now either use the toolbar button [[Image:FEM_EquationDeformation.svg|24px]] or the menu {{MenuCommand|Solve → Mechanical equations → Deformation equation}}.
# Change the [[#Solver_Settings|equation's solver settings]] or the [[FEM_SolverElmer_SolverSettings|general solver settings]] if necessary.
# Change the [[#Solver_Settings|equation's solver settings]] or the [[FEM_SolverElmer_SolverSettings|general solver settings]] if necessary.


==Solver Settings==
==Solver Settings== <!--T:10-->


<!--T:11-->
For the general solver settings, see the [[FEM_SolverElmer_SolverSettings|Elmer solver settings]].
For the general solver settings, see the [[FEM_SolverElmer_SolverSettings|Elmer solver settings]].


<!--T:12-->
The deformationequation provides these special settings:
The deformation equation provides these special settings:
* {{PropertyData|Calculate Pangle}}: If the principal angles should be calculated.
* {{PropertyData|Calculate Pangle}}: If the principal angles should be calculated.
* {{PropertyData|Calculate Principal}}: If all stresses should be calculated.
* {{PropertyData|Calculate Principal}}: If all stresses should be calculated.
* {{PropertyData|Calculate Strains}}: If strains will be calculated. This will also calculate the stresses, even if {{PropertyData|Calculate Principal}} or {{PropertyData|Calculate Stresses}} is ''false''.
* {{PropertyData|Calculate Strains}}: If strains will be calculated. This will also calculate the stresses, even if {{PropertyData|Calculate Principal}} or {{PropertyData|Calculate Stresses}} is ''false''.
* {{PropertyData|Calculate Stresses}}: If stresses should be calculated. Compared to {{PropertyData|Calculate Principal}} the Tresca yield criterion and the principal stress will not be calculated.
* {{PropertyData|Calculate Stresses}}: If stresses should be calculated. Compared to {{PropertyData|Calculate Principal}} the Tresca yield criterion and the principal stress will not be calculated.
* {{PropertyData|Constant Bulk System}}: See the Elmer manual for more info.
* {{PropertyData|Initialize State Variables}}: See the Elmer manual for more info.
* {{PropertyData|Variable}}: The variable for the elasticity equation. Only change there the ''3'' to ''2'' if you have a 2D geometry.
* {{PropertyData|Mixed Formulation}}: See the Elmer manual for more info.
* {{PropertyData|Neo Hookean Model}}: Uses the neo-Hookean material model.
* {{PropertyData|Variable}}: The variable for the deformation equation. Change there the ''3'' to ''2'' if you have a 2D geometry. For the special case that you have {{PropertyData|Mixed Formulation}} and {{PropertyData|Neo Hookean Model}} set to ''true'', the variable number must be geometry dimensions + 1, so for 3D geometry the ''3'' must be changed to ''4''.


<!--T:13-->
Equation:
Equation:
* {{PropertyData|Plane Stress}}: Computes solution according to the plane stress situation. Applies only for 2D geometry.
* {{PropertyData|Plane Stress}}: Computes solution according to the plane stress situation. Applies only for 2D geometry.


==Constraint Information==
==Analysis Feature Information== <!--T:14-->


<!--T:15-->
The elasticity equation takes the following constraints into account if they are set:
The deformation equation takes the following analysis features into account if they are set:


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* [[Image:FEM_ConstraintFixed.svg|32px]] [[FEM_ConstraintFixed|Constraint fixed]]
* [[Image:FEM_ConstraintDisplacement.svg|32px]] [[FEM_ConstraintDisplacement|Constraint displacement]]
* [[Image:FEM_ConstraintFixed.svg|32px]] [[FEM_ConstraintFixed|Fixed boundary condition]]
* [[Image:FEM_ConstraintForce.svg|32px]] [[FEM_ConstraintForce|Constraint force]]
* [[Image:FEM_ConstraintDisplacement.svg|32px]] [[FEM_ConstraintDisplacement|Displacement boundary condition]]
* [[Image:FEM_ConstraintInitialTemperature.svg|32px]] [[FEM_ConstraintInitialTemperature|Constraint initial temperature]]
* [[Image:FEM_ConstraintForce.svg|32px]] [[FEM_ConstraintForce|Force load]]
* [[Image:FEM_ConstraintPressure.svg|32px]] [[FEM_ConstraintPressure|Constraint pressure]]
* [[Image:FEM_ConstraintInitialTemperature.svg|32px]] [[FEM_ConstraintInitialTemperature|Initial temperature condition]]
* [[Image:FEM_ConstraintSelfWeight.svg|32px]] [[FEM_ConstraintSelfWeight|Constraint self weight]]
* [[Image:FEM_ConstraintPressure.svg|32px]] [[FEM_ConstraintPressure|Pressure load]]
* [[Image:FEM_ConstraintSpring.svg|32px]] [[FEM_ConstraintSpring|Constraint spring]]
* [[Image:FEM_ConstraintSelfWeight.svg|32px]] [[FEM_ConstraintSelfWeight|Gravity load]]
* [[Image:FEM_ConstraintSpring.svg|32px]] [[FEM_ConstraintSpring|Spring]]


===Note===
===Note=== <!--T:17-->


<!--T:18-->
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.
* Except for calculations in 2D, for all the above analysis features it is important that they act on a face. Features in 3D set to lines or vertices are not recognized by the Elmer solver.


==Results==
==Results== <!--T:19-->


<!--T:20-->
The available results depend on the [[#Solver_Settings|solver settings]]. If none of the {{PropertyData|Calculate *}} settings was set to ''true'', only the displacement is calculated. Otherwise also the corresponding results will be available.
The available results depend on the [[#Solver_Settings|solver settings]]. If none of the {{PropertyData|Calculate *}} settings was set to ''true'', only the displacement is calculated. Otherwise also the corresponding results will be available.




<!--T:21-->
{{Docnav
{{Docnav
|[[FEM_SolverZ88|Solver Z88]]
|[[FEM_EquationElasticity|Elasticity equation]]
|[[FEM_EquationElasticity|Elasticity equation]]
|[[FEM_EquationElectrostatic|Electrostatic equation]]
|[[FEM_Workbench|FEM]]
|[[FEM_Workbench|FEM]]
|IconL=FEM_SolverZ88.svg
|IconL=FEM_EquationElasticity.svg
|IconR=FEM_EquationElasticity.svg
|IconR=FEM_EquationElectrostatic.svg
|IconC=Workbench_FEM.svg
|IconC=Workbench_FEM.svg
}}
}}
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Latest revision as of 23:42, 21 November 2023

Other languages:

FEM EquationDeformation

Menu location
Solve → Mechanical equations → Deformation equation
Workbenches
FEM
Default shortcut
None
Introduced in version
0.21
See also
Elasticity equation, FEM tutorial

Description

This equation describes the nonlinear elastic deformation of solid 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:

  • DataCalculate Pangle: If the principal angles should be calculated.
  • DataCalculate Principal: If all stresses should be calculated.
  • DataCalculate Strains: If strains will be calculated. This will also calculate the stresses, even if DataCalculate Principal or DataCalculate Stresses is false.
  • DataCalculate Stresses: If stresses should be calculated. Compared to DataCalculate Principal the Tresca yield criterion and the principal stress will not be calculated.
  • DataInitialize State Variables: See the Elmer manual for more info.
  • DataMixed Formulation: See the Elmer manual for more info.
  • DataNeo Hookean Model: Uses the neo-Hookean material model.
  • DataVariable: The variable for the deformation equation. Change there the 3 to 2 if you have a 2D geometry. For the special case that you have DataMixed Formulation and DataNeo 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:

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

Analysis Feature Information

The deformation equation takes the following analysis features into account if they are set:

Note

  • Except for calculations in 2D, for all the above analysis features it is important that they act on a face. Features in 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 DataCalculate * settings was set to true, only the displacement is calculated. Otherwise also the corresponding results will be available.