Home
Radioss 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.
Animation and Post-processing Output Files
Generates animation files containing results according to the keywords specified. The keywords are specified in the topics within Animation and Post-processing Output Files.
Nodal Animations
/ANIM/NODA
Engine Keyword Generates animation files containing nodal scalar data.

Welcome
What's New
View new features for Radioss 2026.
Radioss Overview
Radioss is a leading explicit finite element solver for crash and impact simulation.
Tutorials
Discover Radioss functionality with interactive tutorials.
Radioss User Guide
This manual provides details on the features, functionality, and simulation methods available in Altair Radioss.
Radioss Reference Guide
This manual provides a detailed list of all the input keywords and options available in Radioss.
- File Extensions and Formats
  Current Radioss format uses the 12x extension format.
- Single File Input
  This format allows running either Starter or Engine with the same file.
- New Keywords in 2026
  New and modified features in Radioss.
- Starter Input
  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.
  - Deletion/Input Modifications
    Engine Keyword In this group, keywords are used for modification (deletion or add options) in Engine.
  - Animation and Post-processing Output Files
    Generates animation files containing results according to the keywords specified. The keywords are specified in the topics within Animation and Post-processing Output Files.
    - Nodal Animations
      - /ANIM/GPS/STRAIN/TENS
        Engine Keyword Generates animation files containing averaged grid point strain data calculated by bilinear extrapolation using shape functions from the integration point results. The average value at each node is calculated by each element which connected to this node.
      - /ANIM/GPS/STRESS/TENS
        Engine Keyword Generates animation files containing averaged grid point stress data calculated by bilinear extrapolation using shape functions from the integration point results. The average value at each node is calculated by each element which connected to this node.
      - /ANIM/GPS1
        Engine Keyword Generates animation files containing simple average GPS data. The average value at node is calculated by the mean stress of all elements, which are connected to this node.
      - /ANIM/GPS2
        Engine Keyword Generates animation files containing volume based averaged GPS data, which is done by the relative element volumes (connected to same node use Vi/V total).
      - /ANIM/MASS
        Engine Keyword Generates animation files containing nodal masses.
      - /ANIM/NODA
        Engine Keyword Generates animation files containing nodal scalar data.
      - /ANIM/VECT
        Engine Keyword Generates animation files containing vectorial data for the specified variable.
    - Element Animations
    - Brick Animations
    - Shell Animations
    - Other Animations
    - Curve Plots
      Engine Keyword
    - H3D Output
    - Other Output Files
      Engine Keyword
  - Implicit Solution
    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).
  - 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
Radioss Example Guide
This manual presents examples solved using Radioss with regard to common problem types.
Radioss Verification Problems
This manual presents solved verification models.
Radioss Frequently Asked Questions
This section provides quick responses to typical and frequently asked questions regarding Radioss.
Radioss Theory Manual
This manual provides detailed information about the theory used in the Altair Radioss Solver.
Radioss User Subroutines
This manual describes the interface between Altair Radioss and user subroutines.

View All Altair HyperWorks Help

/ANIM/NODA

Engine Keyword Generates animation files containing nodal scalar data.

Format

/ANIM/NODA/Restype

Definition


Field	Contents	SI Unit Example
`Restype`	Nodal data type: `DT` Nodal time step `DMAS` Mass variation (see time step control /DT/Eltyp/Keyword3/Iflag). 1 `DINER` Output of added inertia per nodes. 2 `NDMAS` Non-diagonal mass variation (see time step control /DT/AMS). 3 `DAMA2` Damage for TYPE2 interface. 4 `DENS` Nodal density. 6 `P` Nodal pressure. 6 `TEMP` Nodal temperature. 5 6 `SSP` Nodal sound speed. This output is only available for FVMBAG1. `VFRAC` Nodal volumetric fraction, used with LAW37 and LAW51. `PEXT` External pressure.

Comments

$DMAS = \frac{DM}{M_{0}}$ with $D M = M - M_{0}$ .
Where,

$M_{0}$

Nodal mass at the beginning of the restart

$M$

Current mass
$D M$ is re-set to 0 at the beginning of each restart file.
$D I N E R = (\frac{I n e r t i a (t) - l_{0}}{l_{0}})$
Where,

$l_{0}$

Nodal inertia at the beginning of the current run

$I n e r t i a (t)$

Current inertia
In case /DT/AMS is used, a non-diagonal mass matrix is used, which allows to increase the time step on each line of the mass matrix, the lumped mass M $M_{0}$ is increased with some value $Δ M$ which is compensated with non-diagonal terms, in order for the total mass to remain constant. Then:
$N D M A S = (\frac{Δ M}{M_{0}})$
DAMA2 damage percentages for /INTER/TYPE2 with rupture (Spot_flag = 20, 21, or 22):
$\min (100, 100 \cdot \frac{n o r m a l r e l a t i v e d i s p l a c e m e n t}{\max n o r m a l r e l a t i v e d i s p l a c e m e n t})$
$\min (100, 100 \cdot \frac{tangent r e l a t i v e d i s p l a c e m e n t}{\max t a n g e n t r e l a t i v e d i s p l a c e m e n t})$
/ANIM/NODA/TEMP is used generally to output nodal temperature for finite element formulation of thermal exchange.
These options are also available for 3D ALE and FVM airbag problems. The material density, pressure, and temperature is extrapolated to the element nodes, in this case. For FVM airbags the values are extrapolated only to nodes of external and internal airbag surfaces.
/ANIM/NODA/PEXT is computed by averaging the element pressures from load cases (such as /LOAD/PBLAST, /LOAD/PFLUID, etc.) and then projected them onto the nodes by averaging over the connected faces.