Engine Subroutine RUSERnn for Spring Elements

This subroutine calculates the internal forces and moment versus the velocity, old forces, moments, and user’s variables and parameters.

Arguments

The argument list of RUSERnn and its individual arguments and descriptions are:
C--------------------------------------------------------------------------
     SUBROUTINE RUSERnn(NEL    ,IOUT   ,IPROP ,UVAR  ,NUVAR ,
    2                                      FX       ,FY       ,FZ       ,XMOM ,YMOM  ,
    3                                      ZMOM ,E         ,OFF    ,STIFM  ,STIFR   ,
    4                                      VISCM ,VISCR ,MASS ,XINER ,DT        ,
    5                                      XL       ,VX       ,RY1    ,RZ1       ,RX        ,
    6                                      RY2     ,RZ2      ,FR_WAVE)
C--------------------------------------------------------------------------

Definition

Argument Format Description
NEL Integer read only scalar Number of elements per group. In Radioss Engine subroutines, the element data are treated by groups for vectorization. This argument is machine-dependent and set by Radioss.
IOUT Integer read only scalar Output file unit (ROOTL00).
IPROP Integer read only scalar Property number.
UVAR Float array read write Array of size NEL*NUVAR containing user element variables.
NUVAR Integer read only scalar Number of user element variables.
FX Float array read write Array of size NEL containing an internal local X force as input and a new force as output.

Nodal X forces at nodes 1 and 2 in a local frame are defined as FX1 = FX and FX2 = -FX.
FY Float array read write Array of size NEL containing an internal local Y force as input and a new force as output.

Nodal X forces at nodes 1 and 2 in a local frame are defined as FY1 = FY and FY2 = -FY.
FZ Float array read write Array of size NEL containing an internal local Z force as input and a new force as output.

Nodal X forces at nodes 1 and 2 in a local frame are defined as FZ1 = FZ and FZ2 = -FZ.
XMOM Float array read write Array of size NEL containing an old internal local X moment as input and a new moment as output.

Nodal X moments at nodes 1 and 2 in a local frame are defined as MX1 = MX and MX2 = -MX.
YMOM Float array read write Array of size NEL containing an old internal local Y moment as input and a new moment as output.

Nodal Y moments at nodes 1 and 2 in a local frame are defined as MY1 = MY – 1/2*XL*FZ and

MY2 = -MY – 1/2*XL*FZ.
ZMOM Float array read write Array of size NEL containing an old internal local Z moment as input and a new moment as output.

Nodal Z moments at nodes 1 and 2 in a local frame are defined as MZ1 = MZ + 1/2*XL*FZ and MZ2 = -MZ – 1/2*XL*FZ.
EINT Float array read only Array of size NEL containing internal energy.
OFF Float array read write Array of size NEL containing deleted element flags.
0
If the element is OFF
1
If the element is ON
STIFM Float array write only Array of size NEL containing element translational stiffness in time step computation.
STIFR Float array write only Array of size NEL containing element rotational stiffness in time step computation.
VISCM Float array write only Array of size NEL containing element translational viscosity in time step computation.
VISCR Float array write only Array of size NEL containing element rotational viscosity in time step computation.
MASS Flat array write only Array of size NEL containing element mass in time step computation.
XINER Float array write only Array of size NEL containing element spherical inertia.
DT Float read only Current time step
XL Float array read only Array of size NEL containing element length
VX Float array read only Array of size NEL containing X velocity.

Nodal velocities at nodes 1 and 2 in a local frame are defined as VX1 = -VX/2 and

VX2 = VX/2.
RY1 Float array read only Array of size NEL containing Y rotational velocity at node 1.
RZ1 Float array read only Array of size NEL containing Z rotational velocity at node 1.
RX Float array read only Array of size NEL containing torsional velocity.

Nodal torsional velocities at nodes 1 and 2 in a local frame are defined as RX1 = -RX/2 and

RX2 = RX/2.
RY2 Float array read only Array of size NEL containing Y rotational velocity at node 2.
RZ2 Float array read only Array of size NEL containing Z rotational velocity at node 2.
FR_WAVE Float array read only Array of size NEL not yet used.