EDVEL, Option, Cname, VX, VY, VZ, OMEGAX, OMEGAY, OMEGAZ, XC, YC, ZC, ANGX, ANGY, ANGZ
Applies initial velocities to nodes or node components in an explicit
dynamic analysis.
OptionLabel identifying the option to be performed.
VGEN | — | Define initial velocities 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 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 component or
node specified by |
DELE | — | Delete initial velocity defined for the component
or node specified by |
CnameName of existing component [CM] or node number to which the initial velocity is to be applied. If a component is used, it must consist of nodes.
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 component (or node) 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 component. 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 nodal component 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 EDVEL command again for the same component
or node (Cname) will overwrite previous initial
velocities defined for that component or node.
To set the initial velocities to zero, issue the EDVEL command
with only the Option (use VELO or VGEN) and Cname 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 EDVEL,VELO
changes the velocity of the specified nodes. If you don't change the velocity
of the nodes, 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 EDVEL command is not supported in a full restart analysis (EDSTART,3). You can list initial velocities defined in the previous analysis with the command EDVEL,LIST. However, you cannot change initial velocities for nodes or node components 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 nodes that are added in the full restart; the velocity of new nodes will be zero.
To apply initial velocities to parts or part assemblies, use the EDPVEL 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.