Engine Subroutine USERWI

This subroutine calculates the internal forces and moments versus the velocity, old forces and moments, and specified variables and parameters.

Arguments

The argument list of USERWI and its individual arguments and descriptions are:

C-----------------------------------------------------------------------------------------
     SUBROUTINE USERWI(
    1   IIN    ,IOUT   ,NUVAR  ,NUVARI ,NUMNOD ,NCYCLE  ,
    2   LENWA  ,IUVAR  ,ITAB   ,
    3   TT     ,DT1    ,DT2    ,USREINT,EXWORK ,
    4   UVAR   ,D      ,X       ,V      ,VR     ,MASS   ,
    5   INER   ,STIFN  ,STIFR  ,A      ,AR     ,WA     )
C-----------------------------------------------------------------------------------------

Definitions

Argument	Format	Description
`IIN`	Integer read only scalar	Input file unit (Engine file).
`IOUT`	Integer read only scalar	Output file unit (output file).
`NUVAR`	Integer read only scalar	Size of user float array.
`NUVARI`	Integer read only scalar	Size of user integer array.
`NUMNOD`	Integer read only scalar	Number of nodes.
`NCYCLE`	Integer read only scalar	Current cycle number.
`IUVAR(NUVARI)`	Integer read write array	An array of size `NUVARI`. This array contains user data and variables and is saved on restart file.
`ITAB(NUMNOD)`	Integer read only array	An array of size `NUMNOD`. This array defines the node ID versus Radioss internal node number.
`TT`	Float read only scalar	Current time.
`DT1`	Float read only scalar	Current time step.
`DT2`	Float write only scalar	User stability time step. With element time step formulation, `DT2` has to be computed at each cycle.
`USREINT`	Float read write scalar	User window internal energy.
`EXWORK`	Float read write scalar	External work. Variable can be increased.
`UVAR(NUVAR)`	Float read-write array	An array of size `NUVAR`. This array contains user data and variables and is saved on restart file.
`D(3,NUMNOD)`	Float read only array	Nodal displacements.
`X(3,NUMNOD)`	Float read only array	Nodal coordinates.
`V(3,NUMNOD)`	Float read only array	Nodal initial velocities.
`VR(3,NUMNOD)`	Float read only array	Nodal mass.
`INER(NUMNOD)`	Float read only array	Nodal spherical inertia.
`STIFEN(NUMNOD)`	Float read write array	Nodal stiffness for nodal time step formulation. The added user stiffness has to be added to `STIFEN`.
`STIFR(NUMNOD)`	Float read write array	Nodal rotational stiffness for nodal time step formulation. The added user stiffness has to be added to `STIFR`.
`A(3,NUMNOD)`	Float read write array	Nodal forces. User forces have to be added to `A`.
`AR(3,NUMNOD)`	Float read write array	Nodal moments. User moments have to be added to `AR`.