VUTEMP

User subroutine to prescribe temperatures at the nodes of a model.

User subroutine VUTEMP:

allows you to prescribe temperatures at the nodes of a model;
can be called for blocks of nodes for which the temperature values are defined in the user subroutine; and
ignores any temperature values specified directly outside the user subroutine.

This page discusses:

User Subroutine Interface
Variables to Be Defined
Variables Passed in for Information

User Subroutine Interface

      SUBROUTINE VUTEMP(TEMP, NBLOCK, NCOMP, NFIELD,
     1                   KSTEP, JFLAGS, JNODEUID, TIME, FIELD,
     2                   COORDS, U, V, A)
C
      INCLUDE 'VABA_PARAM.INC'

C     indices for the time array TIME
      PARAMETER( i_utmp_Current   = 1,
     *           i_utmp_Increment = 2,
     *           i_utmp_Period    = 3,
     *           i_utmp_Total     = 4,
     *           n_utmp_Time      = 4 )

C     indices for the coordinate array COORDS
      PARAMETER( i_utmp_CoordX = 1,
     *           i_utmp_CoordY = 2,
     *           i_utmp_CoordZ = 3 )

C     indices for the displacement array U
      PARAMETER( i_utmp_SpaDisplX = 1,
     *           i_utmp_SpaDisplY = 2,
     *           i_utmp_SpaDisplZ = 3,
     *           i_utmp_RotDisplX = 4,
     *           i_utmp_RotDisplY = 5,
     *           i_utmp_RotDisplZ = 6,
     *           i_utmp_AcoPress  = 7,
     *           n_utmp_SolU      = 7 )

C     indices for the velocity array V
      PARAMETER( i_utmp_SpaVelX   = 1,
     *           i_utmp_SpaVelY   = 2,
     *           i_utmp_SpaVelZ   = 3,
     *           i_utmp_RotVelX   = 4,
     *           i_utmp_RotVelY   = 5,
     *           i_utmp_RotVelZ   = 6,
     *           i_utmp_DAcoPress = 7,
     *           n_utmp_SolV      = 7 )

C     indices for the acceleration array A
      PARAMETER( i_utmp_SpaAccelX  = 1,
     *           i_utmp_SpaAccelY  = 2,
     *           i_utmp_SpaAccelZ  = 3,
     *           i_utmp_RotAccelX  = 4,
     *           i_utmp_RotAccelY  = 5,
     *           i_utmp_RotAccelZ  = 6,
     *           i_utmp_DDAcoPress = 7,
     *           n_utmp_SolA       = 7 )

C     indices for JFLAGS
      PARAMETER( i_utmp_kInc   = 1,
     *           i_utmp_kPass  = 2,
     *           n_utmp_Flags  = 2 )
C
      DIMENSION TEMP(NBLOCK,NCOMP)
      DIMENSION FIELD(NBLOCK,NCOMP,NFIELD)
      DIMENSION JFLAGS(n_utmp_Flags), JNODEUID(NBLOCK), TIME(n_utmp_Time), 
     *          COORDS(3,NBLOCK)
      DIMENSION U(n_utmp_SolU,NBLOCK), V(n_utmp_SolV,NBLOCK), A(n_utmp_SolA,NBLOCK)
C

      user coding to define TEMP

      RETURN
      END

Variables to Be Defined

TEMP(NBLOCK,NCOMP)

Array of temperature values at a collective number of nodes NBLOCK (see NBLOCK below).

For temperatures applied to nodes that are not part of pipe, beam, or shell elements, only one value of temperature is required (NCOMP=1), and the user subroutine is invoked in a single pass. For nodes that are part of pipe, beam, or shell elements, VUTEMP is invoked in two passes per increment for these elements, and the number of values to be returned depends on the mode of temperature input selected for the beam or shell section. The following cases are possible:

Temperatures are given as values at the points on the shell or beam section. For a beam section, the number of values required is determined by the particular section type specified, as described in Beam Cross-Section Library. For a shell section, temperatures and field variables are given as values at n equally spaced points through each layer of a shell section. In the first pass NCOMP is passed in with the value of 1 to define the temperature values at the first point. The second pass is used to define temperatures at the remaining points.
Temperatures for the shell or beam section are given as values at the origin of the cross-section together with gradients along the cross-section. The number of gradient values required is 2 for three-dimensional beams, 1 for two-dimensional beams, and 1 for shells. In the first pass NCOMP is passed in with the value of 1 to define the field variable values at the origin of the cross-section. The gradients are defined in the second pass.

Because temperatures can also be defined directly, it is important to understand the hierarchy used in situations with conflicting information (see Predefined Fields).

When the array TEMP is passed into user subroutine VUTEMP, it will contain the temperatures values from the previous increment.

Variables Passed in for Information

NBLOCK: User-specified number of nodes to be processed as a block in this call to VUTEMP. The value is equal to the total number of nodes given in a node set.
NCOMP: Maximum number of section values to be defined for any node in the model in the current pass. NCOMP is passed in with the value of 1 in the first pass to user subroutine VUTEMP.
NFIELD: Number of field variables passed in the array FIELD (see below) .
KSTEP: Current step number.
JFLAGS(i_utmp_kInc): Increment number for step KSTEP.
JFLAGS(i_utmp_kPass): This flag is equal to 1 for the first pass to user subroutine VUTEMP and is equal to 2 for the second pass.
JNODEUID(NBLOCK): Array for user-defined node numbers. This array is dimensioned based on the size of NBLOCK, and the contained node numbers are identical to those defined in the input file.
TIME(n_utmp_Time): Array for information of analysis time. You can retrieve any time information from this array by using the parameters given above. TIME(i_utmp_Current) stores the current analysis time, TIME(i_utmp_Increment) gives the time increment at this instance, TIME(i_ufld_Period) is the time period of the current step, and TIME(i_ufld_Total) is the total analysis time up to this point.
FIELD(NBLOCK,NCOMP,NFIELD): Array containing the field variables in the analysis.
COORDS(3,NBLOCK): Coordinates for nodes in the array JNODEUID. This array stores the current coordinates of nodes in which the order of coordinates stored corresponds to the order of nodes listed in the array JNODEUID. The coordinates can be retrieved by using the parameters given above.
U(N_UTMP_SOLU,NBLOCK), V(N_UTMP_SOLV,NBLOCK), and A(N_UTMP_SOLA,NBLOCK): Arrays containing solution variables of displacements, rotations, and pressures and their corresponding temporal derivatives. The order in which these solutions are stored follows the order defined in the array JNODEUID. For a specific node, its solution variables can be retrieved by using the parameter indices given above. Depending on the degrees of freedom, some solution variables are not valid for a given node. The displacement values correspond to the current increment. However, the acceleration is from a configuration that is one increment behind, and the velocity is such that it is consistent with the displacement increment and the time increment between the two successive configurations.