EDPVEL, Option, PID, VX, VY, VZ, OMEGAX, OMEGAY, OMEGAZ, XC, YC, ZC, ANGX, ANGY, ANGZ
Applies initial velocities to parts or part assemblies in an explicit
dynamic analysis.
OptionLabel identifying the option to be performed.
VGEN | — | Define initial velocities for the part or
part assembly based on translational velocities (relative to global Cartesian)
and the rotational velocity about an arbitrary axis. For this option, use
the fields |
VELO | — | Define initial velocity for the part or part
assembly based on translational velocities and nodal rotational velocities
input relative to the global Cartesian axes. For this option, use the following
fields to define the initial velocity: |
LIST | — | List initial velocity for the part or part
assembly specified by |
DELE | — | Delete initial velocity defined for the part
or part assembly specified by |
PIDPart ID or part assembly ID to which the initial velocity is to be applied. The part or assembly ID must be defined (EDPART or EDASMP) before issuing this command.
VXInitial velocity in X direction. Defaults to 0.
VYInitial velocity in Y direction. Defaults to 0.
VZInitial velocity in Z direction. Defaults to 0.
OMEGAXFor Option = VGEN, OMEGAX is
the initial rotational velocity of the part or part assembly about the specified
rotational axis. For Option = VELO, OMEGAX is
the initial nodal rotational velocity about the X-axis. OMEGAX defaults
to 0.
OMEGAYInitial nodal rotational velocity about the Y-axis (used only
if Option = VELO). Defaults to 0.
OMEGAZInitial nodal rotational velocity about the Z-axis (used only
if Option = VELO). Defaults to 0.
The remaining fields are used only if Option =
VGEN.
| — | X coordinate on rotational axis. Defaults to 0. |
| — | Y coordinate on rotational axis. Defaults to 0. |
| — | Z coordinate on rotational axis. Defaults to 0. |
| — | Angle (in degrees) of the rotational axis relative to the global X-axis. Defaults to 0. |
| — | Angle (in degrees) of the rotational axis relative to the global Y-axis. Defaults to 0. |
| — | Angle (in degrees) of the rotational axis relative to the global Z-axis. Defaults to 0. |
You cannot mix the two methods of initial velocity input (Option =
VELO and Option = VGEN) in the same analysis. You
must use only one method for all initial velocity definitions.
The VGEN and VELO methods differ in how the rotational velocity is defined.
Use Option = VGEN to input the initial velocities
of a rotating part or part assembly. Use Option =
VELO to apply the rotations directly to the nodes' rotation degrees of freedom.
Since only shell and beam elements have rotation degrees of freedom, the rotations
input with Option = VELO are only applicable to SHELL163 and BEAM161 elements.
The rotational velocities input with Option = VELO
are ignored for nodes not having rotational degrees of freedom (such as nodes
attached to a SOLID164 or SOLID168 element).
It is normally acceptable to mix nodes belonging to deformable bodies and rigid bodies in the part assembly used in an initial velocity definition. However, when defining initial velocities in an implicit-to-explicit sequential solution, this is not an acceptable practice. In order for the initial velocities to be defined correctly in this type of analysis, you must define the initial velocities on the deformable body nodes separately from the initial velocities on the rigid body nodes.
Issuing the EDPVEL command again for the same part
or part assembly (PID) will overwrite previous
initial velocities defined for that part or part assembly.
To set the initial velocities to zero, issue the EDPVEL command
with only the Option (use VELO or VGEN) and PID fields
specified.
In a small restart analysis (EDSTART,2), you can
only use the Option = VELO method to change initial
velocities. When used in a small restart, the command EDPVEL,VELO
changes the velocity of the specified part or part assembly. If you don't
change the velocity of the parts and assemblies, their velocity at the beginning
of the restart will be the same as the velocity at the end of the previous
analysis.
Except for the LIST option, the EDPVEL command is not supported in a full restart analysis (EDSTART,3). You can list initial velocities defined in the previous analysis with the command EDPVEL,LIST. However, you cannot change initial velocities for parts that existed in the previous analysis; their velocity at the beginning of the analysis will be the same as the velocity at the end of the previous analysis. In addition, you cannot define initial velocities for any parts that are added in the full restart; the velocity of new parts will be zero.
To apply initial velocities to node components or nodes, use the EDVEL command.
You can use EDPVEL and EDVEL in the same analysis. If a node or node component input on the EDVEL command shares common nodes with a part or part assembly input on the EDPVEL command, the initial velocities defined on the common nodes will be determined by the last command input.
This command is also valid in PREP7.
Distributed ANSYS Restriction This command is not supported in Distributed ANSYS.