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Reference Guide
This manual provides a detailed list of all the input keywords and options available in Radioss.
Engine Input
This manual provides a list of all the solution definition keywords and options available in Radioss.
Kinematics and Loading
Engine Keyword In this group, keywords are used to define the kinematic condition (constrain/release rotation or translation DOF) and initial condition (rotational/translational velocity).
Initial Conditions
Engine Keyword
/INIV/AXIS
Engine Keyword Initialize rotational velocity about an axis and translational velocity.

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Radioss^® is a leading explicit finite element solver for crash and impact simulation.
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This manual provides details on the features, functionality, and simulation methods available in Altair Radioss.
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This manual provides a detailed list of all the input keywords and options available in Radioss.
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  Current Radioss format uses the 12x extension format.
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  New and modified features in Radioss.
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  This manual provides a list of all the model definition keywords and options available in Radioss.
- Engine Input
  This manual provides a list of all the solution definition keywords and options available in Radioss.
  - Engine Keywords Syntax
  - General Controls
    Engine Keyword In this group keywords are used to generally define the output style, control of computation, damping and ALE setup during the computation.
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    Engine Keyword In this group, keywords are used for modification (deletion or add options) in Engine.
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    Generates animation files containing results according to the keywords specified. The keywords are specified in the topics within Animation and Post-processing Output Files.
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    Engine Keyword In this group keywords are used for implicit solution. Different implicit solver methods (linear, nonlinear, buckling or quasi-static), different options to control the implicit computation, different implicit time step method and implicit output messages are introduced.
  - Kinematics and Loading
    Engine Keyword In this group, keywords are used to define the kinematic condition (constrain/release rotation or translation DOF) and initial condition (rotational/translational velocity).
    - Kinematic Conditions
    - Initial Conditions
      Engine Keyword
      - /INIV/AXIS
        Engine Keyword Initialize rotational velocity about an axis and translational velocity.
      - /INIV/AXIS/Keyword3/1
        Engine Keyword Initialize rotational velocity about an axis and translational velocity.
      - /INIV/AXIS/Keyword3/2
        Engine Keyword Initialize rotational velocity about an axis and translational velocity on a node set.
      - /INIV/ROT
        Engine Keyword Initialize rotational velocity in the specified direction X, Y or Z.
      - /INIV/ROT/Keyword3/1
        Engine Keyword Initialize rotational velocity in the specified direction X, Y or Z.
      - /INIV/ROT/Keyword3/2
        Engine Keyword Initialize rotational velocity in the specified direction X, Y or Z on a node set.
      - /INIV/TRA
        Engine Keyword Initialize translational velocity in the specified direction X, Y or Z.
      - /INIV/TRA/Keyword3/1
        Engine Keyword Initialize translational velocity in the specified direction X, Y or Z.
      - /INIV/TRA/Keyword3/2
        Engine Keyword Initialize translational velocity in the specified direction X, Y or Z on a node set.
  - Time Step
    Engine Keyword In this group, keywords are used to define different time step control (STOP, KILL, CST or DEL, and so on) for different entities (shell, brick, beam, airbag, interface, and so on) during the computation.
  - Initial State
    Engine Keyword In this group, keywords are used to output different info (like stress, strain, orthotropy direction, temperature, and so on) in a state file (STA-File).
- LS-DYNA Input
  This manual provides a list of LS-DYNA input files available in Radioss.
- Multi-Domain
  This manual contains the description of the keywords for the Radioss Multi-Domain.
- Obsolete Keywords
  Keywords that are still supported, but no longer maintained (*) are considered obsolete.
- Other Files
- Definition
Example Guide
This manual presents examples solved using Radioss with regard to common problem types.
Verification Problems
This manual presents solved verification models.
Frequently Asked Questions
This section provides quick responses to typical and frequently asked questions regarding Radioss.
Theory Manual
This manual provides detailed information about the theory used in the Altair Radioss Solver.
User Subroutines
This manual describes the interface between Altair Radioss and user subroutines.

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/INIV/AXIS

Engine Keyword Initialize rotational velocity about an axis and translational velocity.

Format

/INIV/AXIS/Keyword3

Frame_ID

V_X^t V_Y^t V_Z^t V^r

N₁N₂..., N_N

Definition


Field	Contents	SI Unit Example
`Keyword3`	Direction X, Y, and Z of the frame defining the rotation axis.
`Frame_ID`	Frame identifier. (Integer)
`V`_X^t, `V`_Y^t, `V`_Z^t, `V`^r	Translational velocity components in the local frame and rotational velocity about the axis. (Real)	$[\frac{m}{s}]$ or $[\frac{rad}{s}]$
`N`₁`N`₂..., `N`_N	List of nodes.

Comments

If Frame_ID is not zero, the initial velocities are applied with respect to this local frame.
Once $V^{t}$ is expressed in the global system, the velocities are initialized with respect to:
$v (M) = V^{t} + V^{r} \frac{U}{‖ U ‖} Λ O M$
Where,

$U$

Vector defining the rotation axis

$O$

Represents a point on the axis and is set as the origin of the frame
For easier input and faster initialization of the velocity, use /INIV/AXIS/Keyword3/1 or /INIV/AXIS/Keyword3/2.