VHETVAL

User subroutine to provide internal heat generation in a heat transfer analysis.

User subroutine VHETVAL:

can be used to define a heat flux due to internal heat generation in a material (for example, as might be associated with phase changes occurring during the solution);
will be called for blocks of material calculation points for which the material definition contains internal heat generation;
can be useful if it is necessary to include a kinetic theory for a phase change associated with latent heat release (for example, in the prediction of crystallization in a polymer casting process);
can use and update solution-dependent state variables as an alternative to user subroutine VUMATHT without a requirement to completely define material thermal behavior;
can use any field variables that are passed in;
can be used with thermally coupled continuum elements and Eulerian elements; and
cannot be used with user subroutine VUMATHT.

The following topics are discussed:

User subroutine interface
Variables to be defined
Variables passed in for information

User subroutine interface

      subroutine vhetval (
C Read only (unmodifiable) variables -
     *     nblock, nElem, nIntPt, nLayer, nSectPt, 
     *     ntgrad, nstatev, nfieldv, nprops,
     *     cmname, stepTime, totalTime, dt, 
     *     coordMp, density, props,
     *     tempOld, fieldOld, stateOld, 
     *     tempNew, tempgradNew, fieldNew, 
C Write only (modifiable) variables -
     *     stateNew, flux )
C
      include 'vaba_param.inc'
C
      dimension nElem(nblock)
C
      dimension coordMp(nblock,*), density(nblock), props(nprops),
     *    tempOld(nblock), fieldOld(nblock, nfieldv), 
     *    stateOld(nblock, nstatev), tempNew(nblock), 
     *    tempgradNew(nblock, ntgrad), fieldNew(nblock, nfieldv), 
     *    stateNew(nblock, nstatev), flux(nblock)
C
      character*80 cmname
C
      do km = 1, nblock
C         user coding
      end do
C
      return
      end

Variables to be defined

flux(nblock): Volumetric heat flux at each material point.
stateNew(nblock, nstatev): State variables at each material point at the end of the increment.

Variables passed in for information

nblock: Number of material points to be processed in this call to user subroutine VHETVAL.
nElem(nblock): User-defined element number.
nIntPt: Integration point number.
nLayer: Layer number.
nSectPt: Section point number in the current layer.
ntgrad: Number of spatial gradients of temperature.
nstatev: Number of user-defined state variables that are associated with this material type (see Allocating space).
nfieldv: Number of user-defined external field variables.
nprops: User-specified number of user-defined material properties.
cmname: User-specified material name, left justified. It is passed in as an uppercase character string. Some internal material models are given names starting with the “ABQ_” character string. To avoid conflict, you should not use “ABQ_” as the leading string for cmname.
stepTime: Value of time since the step began.
totalTime: Value of total time. The time at the beginning of the step is given by totalTime - stepTime.
dt: Time increment size.
coordMp(nblock,*): Material point coordinates.
density(nblock): Current density at the material points in the midstep configuration.
props(nprops): User-supplied material properties.
tempOld(nblock): Temperatures at each material point at the beginning of the increment.
fieldOld(nblock, nfieldv): Values of the user-defined field variables at each material point at the beginning of the increment.
stateOld(nblock, nstatev): State variables at each material point at the beginning of the increment.
tempNew(nblock): Temperatures at each material point at the end of the increment.
tempgradNew(nblock, ntgrad): Current values of the spatial gradients of temperature.
fieldNew(nblock, nfieldv): Values of the user-defined field variables at each material point at the end of the increment.