IniVel (Initial Velocity)

Purpose:

One of the most common initial conditions for crash simulations is some type initial velocity. There are some basic methods of defining initial velocity states in LS_DYNA using *INITIAL_VELOCITY and *INITIAL_VELOCITY_GENERATION, and these methods are effective for simple situations like assigning velocities to all nodes.

In contrast creating initial velocity definitions for directions other than Global XYZ can be more complex and requires additional facilities. This interface allows the flexibility to define velocities in global or local systems, along a vector, in polar coordinates, and even using a combination of angular plus translational. This interface is often used to generate initial velocity conditions for door slam, head impact, and full vehicle crash analysis.

Sample:

no sample.

  • Show : Show existing *INITIAL_VELOCITY entities.

  • Cre : Create new *INITIAL_VELOCITY entities.

  • Mod : Modify existing *INITIAL_VELOCITY entities .

  • Del : Delete existing *INITIAL_VELOCITY entities.

  • Create Type : Set current inivel create type.

  • All : Select all *INITIAL_VELOCITY entities.

  • None : Deselect all *INITIAL_VELOCITY entities.

  • Rev : Reverse selection.

  • AList : Select all entities within the selected range (Only applies when there are 20+ entities).

  • Apply : Apply entries for creation/modification or selections for deletion.

Create Type as Global:

  • Vx : Enter initial velocity in x direction.

  • Vy : Enter initial velocity in y direction.

  • Vz : Enter initial velocity in z direction.

  • Vrx : Enter initial rotational velocity in x direction.

  • Vry : Enter initial rotational velocity in y direction.

  • Vrz : Enter initial rotational velocity in z direction.

Create Type as Local:

  • Coordsys : Popup lind dialog to get coordsys ID.

  • Vx : Enter initial velocity in x direction.

  • Vy : Enter initial velocity in y direction.

  • Vz : Enter initial velocity in z direction.

Create Type as AlongVect:

  • Direction : Get Direction.

  • Velocity : Enter velocity.

Create Type as Angular:

  • Rot.Axis : Get position and direction.

  • Omega : Enter omega .

Create Type as Ang+Tran:

  • Rot.Axis : Get position and direction.

  • Omega : Enter omega .

  • Vx : Enter initial velocity in x direction.

  • Vy : Enter initial velocity in y direction.

  • Vz : Enter initial velocity in z direction.