ansys.mapdl.core.Mapdl.dj#

Mapdl.dj(elem='', label='', value='', **kwargs)#

Specifies boundary conditions on the components of relative motion of a joint element.

Mechanical APDL Command: DJ

Parameters:
elemstr

Element number or ALL to be specified.

labelstr

Valid labels are:

  • UX - Displacement in local x direction.

  • UY - Displacement in local y direction.

  • UZ - Displacement in local z direction.

  • ROTX - Rotation about local x axis.

  • ROTY - Rotation about local y axis.

  • ROTZ - Rotation about local y axis.

  • VELX - Linear velocity in local x direction.

  • VELY - Linear velocity in local y direction.

  • VELZ - Linear velocity in local z direction.

  • OMGX - Angular velocity in local x direction.

  • OMGY - Angular velocity in local y direction.

  • OMGZ - Angular velocity in local z direction.

  • ACCX - Linear acceleration in local x direction.

  • ACCY - Linear acceleration in local y direction.

  • ACCZ - Linear acceleration in local z direction.

  • DMGX - Angular acceleration in local x direction.

  • DMGY - Angular acceleration in local y direction.

  • DMGZ - Angular acceleration in local z direction.

valuestr

Value of the label.

Notes

This command is valid for MPC184 joint elements. See djdele for information about deleting boundary conditions applied via this command.

You can apply only one displacement, velocity, or acceleration load at any relative degree of freedom. If multiple loads are specified, the last applied load overrides the previous ones. For example, the following commands apply loads to element 100:

  • D,100,UX, Value

  • D,100,VELX, Value

In this case, the velocity load (VELX) applied in the last command will override the displacement load (UX).

Tabular boundary conditions ( VALUE = tabname) can be used.

%_FIX% is a Mechanical APDL reserved table name. When VALUE is set to %_FIX%, the program sprescribe the degree of freedom to the current relative displacement value. This option is only valid for the following labels: UX, UY, UZ, ROTX, ROTY, ROTZ. In most cases, %_FIX% usage is efficient and recommended for all structural degrees of freedom.

In a modal analysis, the values of the eigenvectors at the degree of freedom connected via dj may be insufficiently accurate to satisfy the dj constraint conditions.