/FXBODY

Block Format Keyword Describes the flexible bodies.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/FXBODY/fxbody_ID
fxbody_title
node_IDm Ianim Imin Imax            
Filename

Definition

Field Contents SI Unit Example
fxbody_ID Flexible body identifier.

(Integer, maximum 10 digits)

  
fxbody_title Flexible body title.

(Character, maximum 100 characters)

  
node_IDm Main node identifier.

(Integer)

  
Ianim (Optional) Animation output flag.
= 1
Displacement and stress fields corresponding to local modes of the flexible body are written in Radioss Starter Animation file (refer to /ANIM/VERS for details about this file).

(Integer)

  
Imin (Optional) Minimum index of local mode for animation. 2

(Integer)

  
Imax (Optional) Maximum index of local mode for animation. 2
≠ 0
All local modes whose index lie in the range (Imin, Imax) will be taken into account for Animation file.
= 0
All local modes whose index exceeds Imin will be taken into account for Animation file.

(Integer)

  
Filename Flexible body input file name.

Input files with the (*.pch) extension are assumed to be a PCH file flexible body defined in the DMIG format. 3

(Character, maximum 100 characters)

  

Comments

  1. The flexible body can be defined using the Flexible Body Input File format or in the DMIG format using a punch file.
  2. When using the Flexible Body Input File format, the index of local modes for a flexible body is given by the order in which the modes are written in the Flexible Body Input File.
    • If Imax ≠ 0: All local modes whose index lie in the range (Imax, Imin) will be taken into account for Animation File.
    • If Imax = 0: All local modes whose index exceeds Imin will be taken into account for Animation File.
  3. The superelement DMIG (Direct Matrix Input) format in a punch file is assumed when the input file extension ends in *.pch. The flexible body is automatically defined using the stiffness and mass matrix defined in the punch file.
    • One PCH file must be defined for each flexible body
    • The flexible body must have at least 3 nodes and be non-aligned
    • Only the stiffness and mass matrix can be read
    • Stiffness matrix is mandatory and is identified by the keyword ‘KAAX’
    • Mass matrix can also be input and is identified by keyword ‘MAAX’. If the mass matrix is not input in the PCH file, then a lumped mass matrix is automatically computed according to nodal masses and nodal inertias of the connected nodes.
    • Only symmetric matrixes can be read, IFO =6 in DMIG format
    • Only real matrixes can be read, TIN =1 or 2 in DMIG format
    • Matrixes must be input in the global coordinate system
    • The flexible body is treated as a kinematic condition in Radioss and is not compatible with other kinematic conditions. Thus, a flexible body can not be connected to other flexible bodies.