edvel

Mapdl.edvel(option='', cname='', vx='', vy='', vz='', omegax='', omegay='', omegaz='', xc='', yc='', zc='', angx='', angy='', angz='', **kwargs)

Applies initial velocities to nodes or node components in an explicit

APDL Command: EDVEL dynamic analysis.

Parameters:

option

Label 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 VX, VY, VZ to specify the translational velocities, and use OMEGAX, XC, YC, ZC, ANGX, ANGY, ANGZ to specify the rotational velocity and the axis of rotation.

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: VX, VY, VZ, OMEGAX, OMEGAY, OMEGAZ.

LIST - List initial velocity for the component or node specified by Cname. If Cname is

blank, all initial velocities defined on nodes and node components are listed. Remaining fields are ignored for this option.

DELE - Delete initial velocity defined for the component or node specified by Cname.

If Cname is blank, all initial velocities defined on nodes and node components are deleted. Remaining fields are ignored for this option.

cname

Name 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.

vx

Initial velocity in X direction. Defaults to 0.

vy

Initial velocity in Y direction. Defaults to 0.

vz

Initial velocity in Z direction. Defaults to 0.

omegax

For 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.

omegay

Initial nodal rotational velocity about the Y-axis (used only if Option = VELO). Defaults to 0.

omegaz

Initial nodal rotational velocity about the Z-axis (used only if Option = VELO). Defaults to 0.

Notes

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.