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(2),
     *	iElemNodes(nElemNodes),
     *	coordNodes(mcrd,nElemNodes),
     *	uNodes(mcrd,nElemNodes),
     *	time(2),dt(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 the flags that define the current solution procedure and analysis type.

jFlags(1)	Defines the procedure type. See Results file for the key used for each procedure.
jFlags(2)=0	Small-displacement analysis.
jFlags(2)=1	Large-displacement analysis (nonlinear geometric effects included in the step; see General and perturbation procedures).

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.

dt(1)

Time increment.

dt(2)

New suggested time increment (modifiable); to use the analysis time increment, leave this unchanged.

jlTyp

Identifies the moving flux type for which this call to UMDFLUX is being made; only the concentrated heat flux type is supported (jlTyp=1).

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.