**impose_nodal_dof_density

Description

The command imposes the flux (associated reaction) density across a surface (nset or faset). It is a general boundary condition, which can mean imposed pressure in the X-Y-Z directions for mechanical problems. The condition **fluconv is a special case of this condition as well.

Note that the **pressure command adjusts itself for updated elements according to the surface normal, and for 3D meshes there is no **shear option because the face tangent is not fixed. This option differs because it is related to the density of the DOF reactions and therefore rests in their coordinate space.

Syntax

**impose_nodal_dof_density \(~\,~\,\) bset  dof  value  table

where bset is a boundary set name (liset or faset), dof is a degree of freedom name (e.g. U1), value is a scaling value (decimal point number), and table is the name of a loading table input elsewhere.

Example

Pressure defined in the U1-U2 directions.

***bc
 **impose_nodal_dof
   left   U1 0.0
   bottom U2 0.0
   fix    U3 0.0
 **impose_nodal_dof_density
   face.2 U1 0.25  tab1
   face.2 U2 0.25  tab2