Elasticity context

The <elasticity> context is for input specific for Elasticity applications. It can have the following sub-contexts:

<isotropic>

Use this to define a isotropic material property.

Attributes:

• set - The topology set to apply the material property to.
• E - Youngs modulus. Ignored if the <stiffness> sub-context is used.
• nu - Poisson's ratio. Ignored if the <poisson> sub-context is used.
• rho - Mass density. Ignored if the <density> sub-context is used.
• alpha - Thermal expansion coefficient. Ignored if the <thermalexpansion> sub-context is used.
• cp - Specific heat capacity. Ignored if the <heatcapacity> sub-context is used.
• kappa - Thermal conductivity. Ignored if the <conductivity> sub-context is used.

Value: Any combination of the following sub-context:

• <stiffness> - Spatial function describing the Young's modulus
  • Attribute: type - Function type
  • Value: Function definition depending on the chosen type
• <poisson> - Spatial function describing the Poisson's ratio
  • Attribute: type - Function type
  • Value: Function definition depending on the chosen type
• <density> - Spatial function describing the mass density
  • Attribute: type - Function type
  • Value: Function definition depending on the chosen type
• <thermalexpansion> - Temporal function describing the thermal expansion
  • Attribute: type - Function type
  • Value: Function definition depending on the chosen type
• <heatcapacity> - Temporal function describing the specific head capacity
  • Attribute: type - Function type
  • Value: Function definition depending on the chosen type
• <conductivity> - Temporal function describing the thermal conductivity
  • Attribute: type - Function type
  • Value: Function definition depending on the chosen type

<texturematerial>

Use this to define a material property from a texture mapping from file.

Attributes:

• set - The topology set to apply the material property to.
• file - Name of png-file with texture mapping as an RGB image.

Value: Multiple entries of the following sub-context, each one defining a constant material property:

• <range> - Definition of a constant material region
  • Attributes: min and max - Range of the color value defining this material region. In addition, all the <isotropic> attributes may be specified here to define the actual properties
  • Value: Same as for the <isotropic> context.

<bodyforce>

Use this to define a body force for the elasticity problem.

Attributes:

• set - The topology set to apply this body force to.
• type - The type of the body force specification (either "constant" or "expression").

Value: The constant or expression function vector in accordance with the given type, defining the body force vector.

See the expression functions page for the symbolic expression syntax.

<boundaryforce>

Use this to specify a boundary for which to calculate reaction force resultant.

Attributes:

• set - The topology set defining the boundary to consider.

Value: None

<dualfield>

Use this to specify extraction functions for Variationally Consistent Postprocessing (VCP).

Attributes:

• patch - One-based index of the patch that this extraction function is defined on.
• comp - Component index (one-based) to perform VCP for.
• X0 - Cartesion coordinates of cross section origin or stress reference point.
• X1, X2 - Lower left and upper right corners of stress extraction function domain.
• u0, v0, z0 - Parametric coordinates of stress reference point.
• normal - Normal vector of cross section.
• depth - Depth of the extraction function domain, in opposite direction of the normal vector.
• width - Width of the extraction function domain.
• XZp - Point in the local XZ-plane of the cross section for 3D problems.
• weight - Weighting factor of this extraction function in goal-oriented adaptive simulations.
• eps - Geometry tolerance.

Value: None

<temperature>

Use this to define a temperature field for calculation of temperature strains.

Attributes:

• type - The type of the temperature field specification (either "constant" or "expression").

Value: The constant or expression function vector in accordance with the given type, defining the temperature field.

See the expression functions page for the symbolic expression syntax.

<initialtemperature>

Use this to define an initial temperature field for calculation of initial temperature strains.

Attributes: Same as for <temperature> context.

Value: Same as for <temperature> context.

<gravity>

Use this to specify the gravity vector to be used for calculation of gravitation forces.

Attributes:

• x - Global X-component of the gravity vector.
• x - Global Y-component of the gravity vector.
• x - Global Z-component of the gravity vector.

Value: None

<localsystem>

Use this to specify a local axis system for stress calculation.

Attributes: None

Value: One of the following sub-contexts:

• <cylindricz> - Cylindric coordinate system along the global Z-axis
  • Attribute: None
  • Value: None
• <cylinder+sphere> - Cylindric coordinate system along the global Z-axis combined with a spherical one
  • Attribute: H - Height of the cylinder, i.e., for all points whose global Z-coordinate is larger than H, a spherical coordinate system is used, for all other points a cylindric system is used.
  • Value: None

<stabilization>

Use this to specify stabilization for immersed boundary calculations.

Attributes:

• gamma - Stiffness scaling factor applied to the stabilization terms.

Value: None

<anasol>

Use this to specify the analytical solution.

Attributes:

• type - The type of the analytical solution specification ("expression", "fields", and several names each corresponding to some hard-coded solution fields)
• file - Name of HDF5-file to read field values from in case type="fields"
• file_basis - Name of field basis on the HDF5-file in case type="fields"
• level - Time level on the HDF5-file to read field values from in case type="fields"

Value: Any of the following sub-contexts:

• <variables> - Variables definitions, in case type="expression"
• <stress> - Analytical stress field definitions

See the expression functions page for the symbolic expression syntax.