**impose_element_dof#

Description#

This command is used to impose degrees of freedom which are defined at element integration points. These DOFs are commonly part of mixed formulations, such as pressure-displacement, and plane-stress elements.

Syntax#

**impose_element_dof \(~\,~\,\) elset  dof  value  table

Example#

Making a 2.5 D case of planar displacements and an imposed \(\epsilon_{33}\) strain formulation.

***mesh plane_stress
 ...
***bc
  **impose_nodal_dof
     bottom U2 0.
     top    U2 1. time
     left   U1 0.
  **impose_element_dof 1 EZ 1.e-3 time

Element DOFs are also imposed for the RVE elements, with a full strain tensor being the element DOFs.

***bc
 **impose_element_dof
  ALL_ELEMENT E12 1. time

**impose_element_dof_rate#

This command allows to impose element DOFs on a rate basis. It applies the instantaneous value of a DOF multiplied by time increment. The syntax is similar to the previous command:

**impose_element_dof_rate \(~\,~\,\) elset  dof  value  table

Example#

This example provides a comparison between **impose_element_dof_rate

***bc
 **impose_element_dof_rate
   ALL_ELEMENT F22  2.0 time

and **impose_element_dof

***bc
 **impose_element_dof
   ALL_ELEMENT F22  2.0 time % i.e. F22 will be incremented by 2 starting from 1.
../../_images/impose_el_dof_vs_rate.png

For example at \(time=1\), the value of \(F_{22}-2\) to be imposed is 2. But for rate based boundary condition, it is interpreted as the rate and the value to be applied is 2 multiplied by \(\Delta t=0.1\).