INITIAL: Defining Initial Conditions

INITIAL: Defining Initial Conditions

Initial conditions may be defined for a range of items with Ansys LS-Dyna.

• Selecting the *INITIAL sub-keyword
• Editing panels
• Create/Edit panel for *INITIAL_VOLUME_FRACTION_GEOMETRY
• Create/Edit panel for *INITIAL_VELOCITY_GENERATION
• Visualisation

*INITIAL cards can be edited with the generic "Keyword" editor. All * INITIAL subtypes except VOLUME_FRACTION_GEOMETRY and VELOCITY_GENERATION (which have their own specific Create/Edit panel) can be processed in this way.

The other commands ( COPY, DELETE, ...) function in the standard fashion as defined in Standard Keyword Top Level Menu Options.

This shows an example of the Keyword editor for * INITIAL_VELOCITY

*INITIAL_VOLUME_FRACTION_GEOMETRY items are created using a specific editing panel. New geometries can be added by clicking on the Add new geometry button.

*INITIAL_VELOCITY_GENERATION items are created using a specific editing panel.

Visualising *INITIAL items
* INITIAL items are not displayed by default, but can be selected for display and labelling in the ENTity Viewing panel. At present only * INITIAL_VELOCITY (_<type>) cards are drawn fully. These are shown as arrows in the direction of the velocity. In this example there is a translational velocity at node 10333, and a rotational one at 10341. If multiple initial velocities are defined at a node (an error) then all will be drawn separately.
Using the VEC plotting mode to display initial velocities Initial velocities from any source (not just * INITIAL cards) can also be visualised in "vector contour" form via the Vect plot command.

Other *INITIAL items are not drawn explicitly, but can still be visualised by turning on (in ENTity Viewing) the display of the items they reference: sets, nodes, elements, etc. Labels referring to the initial velocity type are generated correctly.