UMDFLUX

User subroutine for specifying moving or stationary nonuniform heat flux in a heat transfer analysis.

User subroutine UMDFLUX:

can be used to prescribe multiple moving or stationary heat fluxes as a function of position, time, temperature, etc.;
will be called once for each element to prescribe heat moving sources between start points and end points inside the element; and
applies heat fluxes as point heat sources, which will have the units of watts (no volumetric integration is performed outside the user subroutine).

The following topics are discussed:

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

User subroutine interface

            subroutine umdflux(
     *	jFlags,
	    * amplitude,
     *	noel,
     *	nElemNodes,
     *	iElemNodes,
     * mcrd,
     *	coordNodes,
     *	uNodes,
     * kstep,
     *	kinc,
     *	time,
     *	dt,
     * jltyp,
     * temp,
     *	npredef,
     *	predef,
     * nsvars,
     * svars,
     *	sol,
     *	dsol,
     * nIntp,
     * volElm,
     * volInt,
     * nHeatEvents,
     *	flux,
     * dfluxdT,
     *	csiStart,
     * csiEnd)     
C
      include 'aba_param.inc'
C
      dimension   
     *	jFlags(*),
     *	iElemNodes(nElemNodes),
     *	coordNodes(mcrd,nElemNodes),
     *	uNodes(mcrd,nElemNodes),
     *	time(2),
     *	svars(2,nsvars),
     * temp(2,nElemNodes),
     *	predef(2,npredef,nElemNodes),
     * sol(nElemNodes),
     *	dsol(nElemNodes),
     * volInt(nIntp),
     * nHeatEvents,
     *	flux(nHeatEvents),
     *	dfluxdT(nHeatEvents),
     *	csiStart(3,nHeatEvents),
     * csiEnd(3,nHeatEvents)


      user coding to define moving flux.

      return
      end

Variables to be defined

nHeatEvents: The total number of moving or stationary heat events (heat fluxes) in this element.
flux: Magnitudes of the fluxes flowing into this element.
dfluxdT: The rate of change of the fluxes with respect to temperatures.
csiStart: The isoparametric coordinates of the moving fluxes' starting points.
csiEnd: The isoparametric coordinates of the moving fluxes' ending points. If the flux is stationary, the coordinates of the end points are the same as the coordinates of the start points (csiStart=csiEnd).

Variables passed in for information

jFlags: An array containing informational flags.
amplitude: The current value of the amplitude referenced for this flux (set to unity if no amplitude is referenced). This is the amplitude defined on the *DFLUX definition.
noel: User-assigned element number.
nElemNodes: Number of element nodes.
iElemNodes: An array containing user-assigned node numbers of the element.
mcrd: The maximum of the user-defined maximum number of coordinates needed at any node point (Defining the maximum number of coordinates needed at any nodal point) and the value of the largest active degree of freedom of the user element that is less than or equal to 3. For example, if you specify that the maximum number of coordinates is 1 and the active degrees of freedom of the user element are 2, 3, and 6, mcrd will be 3. If you specify that the maximum number of coordinates is 2 and the active degrees of freedom of the user element are 11 and 12, mcrd will be 2.
coordNodes: An array containing the coordinates of the nodes of the element.
uNodes: An array containing displacements at the element nodes. In a pure heat transfer analysis the displacements are set equal to the coordinates.
kstep: Current step number.
kinc: Current increment number.
time(1): Current value of step time.
time(2): Current value of total time.
dtime: Time increment.
temp: An array containing predefined temperature at the element nodes.
npredef: Number of field variables.
predef: An array containing predefined field variables at the element nodes.
nsvars: This variable is currently not used.
svars: This variable is currently not used.
sol: An array of the solution variables (temperature in a heat transfer analysis) at the beginning of the increment.
dsol: An array of estimated values of the increment of the solution variables (temperature in a heat transfer analysis) . The values are always set equal to zero.
nIntp: Total number of integration points for this element type.

volElm: The total volume of the element.
volInt: The integration point volume.