UDSECURRENT

User subroutine to define nonuniform surface current density in an eddy current or magnetostatic analysis.

User subroutine UDSECURRENT:

can be used to define the variation of surface current density vector as a function of position, time, element number, load integration point number, etc. for a transient eddy current or magnetostatic analysis or as a function of position, excitation frequency, phase, element number, load integration point number, etc. for a time-harmonic eddy current analysis;
will be called at each surface load integration point for each nonuniform surface current density definition during eddy current and magnetostatic analyses; and
ignores any amplitude references that may appear with the associated step definition or nonuniform distributed surface current density definition.

The following topics are discussed:

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

User subroutine interface

      subroutine udsecurrent (
C Write only - 
     *   surfacecurrent, 
C Read only - 
     *   coords, nBlock,
     *   i_array, niarray, 
     *   r_array, nrarray,
     *   c_array, ncarray )
C
      include 'aba_param.inc'
C
      dimension surfacecurrent(nBlock,*),
     *   coords(nBlock,*),
     *   i_array(*),
     *   r_array(*)
C
      character*80 c_array(*) 
C
      parameter( i_udsecurr_kstep   = 1,
     *           i_udsecurr_kinc    = 2,
     *           i_udsecurr_noel    = 3,
     *           i_udsecurr_currtyp = 4,
     *           i_udsecurr_phase   = 5,
     *           i_udsecurr_proc    = 6)
C
      parameter( ir_udsecurr_time_1 = 1,
     *           ir_udsecurr_time_2 = 2,
     *           ir_udsecurr_time_3 = 3 )
C
      parameter( ic_udsecurr_surf = 1)
C
      parameter( i_currtyp_tangential = 1 )
C
      parameter( i_proc_lf_th = 1,
     *           i_proc_lf_td = 2,
     *           i_proc_ms    = 3 )
C
      parameter( i_udsecurr_phase_real   = 1,      
     *           i_udsecurr_phase_imag   = 2 )
C

      user coding to define surfacecurrent

      return
      end

Variables to be defined

surfacecurrent(nBlock,*): Components of the surface current density vector at a block of surface integration points. The units are CL⁻¹T⁻¹. surfacecurrent will be passed into the routine as the vector specified as part of the surface-based distributed surface current density definition. If the vector is not defined, surfacecurrent will be passed in as zero.

Variables passed in for information

coords(nBlock,*): An array containing the coordinates of a block of surface load integration points.
nBlock: Number of surface integration points in this block. Currently equal to 1.
i_array(i_udsecurr_kstep): Step number.
i_array(i_udsecurr_kinc): Increment number.
i_array(i_udsecurr_noel): Element number.
i_array(i_udsecurr_currtyp): Currently equal to 1.
i_array(i_udsecurr_phase): This value is relevant only for a time-harmonic eddy current analysis and is either 1 (i_udsecurr_phase_real) or 2 (i_udsecurr_phase_imag), depending on whether the current call to the user subroutine defines the real (in-phase) or the imaginary (out-of-phase) part of the surface current density vector.
i_array(i_udsecurr_proc): Equal to 1 for a time-harmonic eddy current procedure, 2 for a transient eddy current procedure, and 3 for a magnetostatic procedure.
niarray: Size of array i_array. Currently equal to 6.
r_array(ir_udsecurr_time_1): Excitation frequency in cycles/time for a time-harmonic eddy current analysis; alternatively, the value of step time at the beginning of the current increment for a transient eddy current or magnetostatic analysis.
r_array(ir_udsecurr_time_2): Excitation frequency in radians/time for a time-harmonic eddy current analysis; alternatively, the value of total time at the beginning of the current increment for a transient eddy current or magnetostatic analysis.
r_array(ir_udsecurr_time_3): Time increment for a transient eddy current or magnetostatic analysis.
nrarray: Size of array r_array. Currently equal to 3.
c_array(ic_udsecurr_surf): Surface name.
ncarray: Size of array c_array. Currently equal to 1.