How are spatial and temporal discretization related to each other in how they affect convergence ?

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in General Language Questions

I am an undergrad and I have been facing some difficulty with respect to an APDL code I have written for transient thermal analysis of Laser DED driven deposition of single track of a certain material. The process parameters are 400W, 8mm/s and feed-rate of 0.5g/min. I have tried up to 500 sub-steps with auto time-stepping strategy. It still stops converging at the 3rd sub-step of the load-step defined in the code attached below:

/PREP7
!*
ET,1,SOLID70
!*
!MPDATA,Lab,MAT,SLOC,C1,C2,C3,C4,C5,C6
!MPTEMP,SLOC,T1,T2,T3,T4,T5,T6
!*
!Material properties for transient analysis of gamma tial- check out conductivity from solidus point and latent heat consideration
TOFFST,273
!*
MPTEMP,1,400,500,600,700,800,900 ! 6 temperatures (temps 1-6)
MPTEMP,7,1000,1100,1200,1300,1400,1430 ! 6 more temps (temps 7-12)
MPTEMP,13,1500,1515,1530,1545,1572.8
MPDATA,C,1,1,648.05,654.98,666.67,684.92,711.5,748.2
MPDATA,C,1,7,796.8,859.08,936.82,1031.8,1145.8,1184
MPDATA,C,1,13,7357.1,7357.1,7357.1,7357.1,7357.1
MPDATA,DENS,1,1,4162,4147,4132,4116,4099,4082
MPDATA,DENS,1,7,4064,4044,4020,3977,3929.061,3915.351
MPDATA,DENS,1,13,3883.36,3876.506,3869.651,3862.796,3850.0914
MPDATA,KXX,1,1,19.340,20.28,21.109,21.828,22.421,22.843
MPDATA,KXX,1,7,22.991,22.691,21.675,19.509,15.802,14.324
MPDATA,KXX,1,13,14.324,14.324,14.324,14.324,14.324
!*
!GEOMETRY CREATION
SET,TW,995e-6
*SET,SW,0.005
*SET,ZS1,(SW-TW)/2
*SET,ZS2,(SW+TW)/2
/VIEW,1,1,2,3
/ANG,1
/REP,FAST
BLOCK,0,0.002,0,0.002,0,ZS1
BLOCK,0.002,0.008,0,0.002,0,ZS1
BLOCK,0.008,0.01,0,0.002,ZS1
BLOCK,0,0.002,0,0.002,ZS1,ZS2
BLOCK,0.002,0.008,0,0.002,ZS1,ZS2
BLOCK,0.008,0.01,0,0.002,ZS1,ZS2
BLOCK,0,0.002,0,0.002,ZS2,SW
BLOCK,0.002,0.008,0,0.002,ZS2,SW
BLOCK,0.008,0.01,0,0.002,ZS2,SW
!Track definition
BLOCK,0.002,0.008,0.002,0.00225,ZS1,ZS2
VGLUE,ALL
!Substrate dimensions are: 10x5x2 and single track dimension is 6x0.6x0.25
!
!The following snippet includes all aspects of meshing from dividing track to segments by line and map meshing to meshing substrating
LPLOT
/PNUM,KP,0
/PNUM,LINE,1
/PNUM,AREA,0
/PNUM,VOLU,0
/PNUM,NODE,0
/PNUM,TABN,0
/PNUM,SVAL,0
/NUMBER,0
!*
/PNUM,ELEM,0
/REPLOT
!*
!Manual Sizing For Meshing Track
LSEL,S,LOC,X,0.002,0.008
LSEL,R,LOC,Y,0.002,0.002
LSEL,A,LOC,Y,0.00225,0.00225
LSEL,R,LOC,Z,ZS1,ZS1
LESIZE,ALL,,,80,1,1,,,0
!LESIZE,NL1,SIZE,ANGSIZ,NDIV,SPACE,KFORC,LAYER1,LAYER2,KYNDIV
LSEL,S,LOC,X,0.002,0.008
LSEL,R,LOC,Y,0.002,0.002
LSEL,A,LOC,Y,0.00225,0.00225
LSEL,R,LOC,Z,ZS2,ZS2
LESIZE,ALL,,,80,1,1,,,0
!LESIZE,NL1,SIZE,ANGSIZ,NDIV,SPACE,KFORC,LAYER1,LAYER2,KYNDIV
LSEL,S,LOC,Z,ZS1,ZS2
LSEL,R,LOC,Y,0.002,0.002
LSEL,A,LOC,Y,0.00225,0.00225
LSEL,R,LOC,X,0.002,2e-3
LESIZE,ALL,,,10,1,1,,,0
!LESIZE,NL1,SIZE,ANGSIZ,NDIV,SPACE,KFORC,LAYER1,LAYER2,KYNDIV
LSEL,S,LOC,Z,ZS1,ZS2
LSEL,R,LOC,Y,0.002,0.002
LSEL,A,LOC,Y,0.00225,0.00225
LSEL,R,LOC,X,0.008,8e-3
LESIZE,ALL,,,10,1,1,,,0
!LESIZE,NL1,SIZE,ANGSIZ,NDIV,SPACE,KFORC,LAYER1,LAYER2,KYNDIV
LSEL,S,LOC,Y,2e-3,2.25e-3
LSEL,R,LOC,Z,ZS1,ZS1
LSEL,A,LOC,Z,ZS2,ZS2
LSEL,R,LOC,X,0.002,2e-3
LESIZE,ALL,,,6,1,1,,,0
!LESIZE,NL1,SIZE,ANGSIZ,NDIV,SPACE,KFORC,LAYER1,LAYER2,KYNDIV
LSEL,S,LOC,Y,2e-3,2.25e-3
LSEL,R,LOC,Z,ZS1,ZS1
LSEL,A,LOC,Z,ZS2,ZS2
LSEL,R,LOC,X,0.008,8e-3
LESIZE,ALL,,,6,1,1,,,0
!LESIZE,NL1,SIZE,ANGSIZ,NDIV,SPACE,KFORC,LAYER1,LAYER2,KYNDIV
VSEL,S,LOC,X,0.002,0.008
VSEL,R,LOC,Y,0.002,0.0025
VSEL,R,LOC,Z,ZS1,ZS2
CM,TRACK,VOLU
CMSEL,S,TRACK
MSHAPE,0,3d
MSHKEY,1
VMESH,TRACK
MSHKEY,0
VSEL,INVERT,TRACK
SMRT,3
MSHAPE,1,3D
ALLSEL,ALL,VOLU
CM,FULL,VOLU
CMSEL,S,FULL
VMESH,FULL
!*
!END OF MESHING
!*
!Grouping of elements for birth and kill sequencing
SET,XI,0.002
!I is the iteration count and should be set as 1 to N div of line along deposition length divided by 2
*DO,I,1,10
*SET,XN,XI+6E-04 !The constant being added is determined as nL/N where n is the desired num of elements along length
ESEL,S,CENT,X,XI,XN
ESEL,R,CENT,Y,0.002,0.00225
ESEL,R,CENT,Z,ZS1,ZS2
CM,CM_%I%,ELEM
SET,XI,XN
*ENDDO
ESEL,S,CENT,X,0,0.01
ESEL,R,CENT,Y,0,0.002
ESEL,R,CENT,Z,0,0.005
CM,SUB,ELEM
ALLSEL,ALL
EKILL,ALL
!
!END OF GROUPING COMPONENTS
!*
EALIVE,SUB
EALIVE,CM_1
ESEL,S,LIVE
!END OF PRE-PROCESSING
FINISH
!Enter solution processor
/SOL
RESCONTROL,,ALL,
!
ANTYPE,4
!*
NROPT,FULL
TRNOPT,FULL
LUMPM,0
!*
TUNIF,25, ! Initial condition
!*
!Boundary conditions- No convection on any of the faces, temperature at base of substrate is ambient
NSEL,S,LOC,Y,0,0
NSEL,R,LOC,X,0,0.01
NSEL,R,LOC,Z,0,0.005
D,ALL,TEMP,25 !Applied to base of substrate
ALLSEL,ALL
NSEL,S,LOC,X,0,0
NSEL,R,LOC,Z,0,0.005
NSEL,R,LOC,Y,0,0.002
SF,ALL,CONV,0,25
NSEL,S,LOC,X,0.01,0.01
NSEL,R,LOC,Z,0,0.005
NSEL,R,LOC,Y,0,0.002
SF,ALL,CONV,0,25
NSEL,S,LOC,Z,0,0
NSEL,R,LOC,X,0,0.01
NSEL,R,LOC,Y,0,0.002
SF,ALL,CONV,0,25
NSEL,S,LOC,Z,0.005,0.005
NSEL,R,LOC,X,0,0.01
NSEL,R,LOC,Y,0,0.002
SF,ALL,CONV,0,25
!APPLY B.C TO SIDE FACES OF SUBSTRATE
NSEL,S,LOC,Y,0.002,0.002
NSEL,R,LOC,X,0,0.002
NSEL,A,LOC,X,0.008,0.01
SF,ALL,CONV,0,25
NSEL,S,LOC,Y,0.002,0.002
NSEL,R,LOC,X,0.002,0.008
NSEL,R,LOC,Z,0,ZS1
NSEL,A,LOC,Z,ZS2,0.005
SF,ALL,CONV,0,25
!APPLY B.C TO TOP FACE OF SUBSTRATE
NSEL,S,LOC,Z,ZS1,ZS1
NSEL,R,LOC,X,0.002,0.008
NSEL,R,LOC,Y,0.002,0.00225
SF,ALL,CONV,0,25
NSEL,S,LOC,Z,ZS2,ZS2
NSEL,R,LOC,X,0.002,0.008
NSEL,R,LOC,Y,0.002,0.00225
SF,ALL,CONV,0,25
NSEL,S,LOC,X,0.002,0.002
NSEL,R,LOC,Z,ZS1,ZS2
NSEL,R,LOC,Y,0.002,0.00225
SF,ALL,CONV,0,25
NSEL,S,LOC,X,0.008,0.008
NSEL,R,LOC,Y,0.002,0.00225
NSEL,R,LOC,Z,ZS1,ZS2
SF,ALL,CONV,0,25
NSEL,S,LOC,Y,0.00225,0.00225
NSEL,R,LOC,X,0.002,0.008
NSEL,R,LOC,Z,0.0022,0.0028
SF,ALL,CONV,0,25
!B.C applied to all faces of SINGLE TRACK
!BOUNDARY CONDITIONS DEFINED
!*
!Local co-ord system at centre of element component0 like centre of mass types- it's at the body centre point
LOCAL,11,1,0.0023,0.00225,0.0025, , , ,1,1,
/VIEW,1,,,1
/ANG,1
/REP,FAST
DEL,_FNCNAME
*DEL,_FNCMTID
*DEL,_FNCCSYS
*SET,_FNCNAME,'GAUSS'
*SET,_FNCCSYS,11
! /INPUT,GAUSS.func,,,1
*DIM,%_FNCNAME%,TABLE,6,21,1,,,,%_FNCCSYS%
!
! Begin of equation: 848.826E+06exp(-21E+06({x}^2+{z}^2)/(0.3)^2)
SET,%_FNCNAME%(0,0,1), 0.0, -999
*SET,%_FNCNAME%(2,0,1), 0.0
*SET,%_FNCNAME%(3,0,1), 0.0
*SET,%_FNCNAME%(4,0,1), 0.0
*SET,%_FNCNAME%(5,0,1), 0.0
*SET,%_FNCNAME%(6,0,1), 0.0
*SET,%_FNCNAME%(0,1,1), 1.0, -1, 0, 0, 0, 0, 0
*SET,%_FNCNAME%(0,2,1), 0.0, -2, 0, 1, 0, 0, -1
*SET,%_FNCNAME%(0,3,1), 0, -3, 0, 1, -1, 2, -2
*SET,%_FNCNAME%(0,4,1), 0.0, -1, 0, 2, 0, 0, -3
*SET,%_FNCNAME%(0,5,1), 0.0, -2, 0, 1, -3, 3, -1
*SET,%_FNCNAME%(0,6,1), 0.0, -1, 0, 1E+06, 0, 0, -2
*SET,%_FNCNAME%(0,7,1), 0.0, -3, 0, 1, -2, 3, -1
*SET,%_FNCNAME%(0,8,1), 0.0, -1, 0, 2, 0, 0, 2
*SET,%_FNCNAME%(0,9,1), 0.0, -2, 0, 1, 2, 17, -1
*SET,%_FNCNAME%(0,10,1), 0.0, -1, 0, 2, 0, 0, 4
*SET,%_FNCNAME%(0,11,1), 0.0, -4, 0, 1, 4, 17, -1
*SET,%_FNCNAME%(0,12,1), 0.0, -1, 0, 1, -2, 1, -4
*SET,%_FNCNAME%(0,13,1), 0.0, -2, 0, 1, -3, 3, -1
*SET,%_FNCNAME%(0,14,1), 0.0, -1, 0, 0.3, 0, 0, 0
*SET,%_FNCNAME%(0,15,1), 0.0, -3, 0, 2, 0, 0, -1
*SET,%_FNCNAME%(0,16,1), 0.0, -4, 0, 1, -1, 17, -3
*SET,%_FNCNAME%(0,17,1), 0.0, -1, 0, 1, -2, 4, -4
*SET,%_FNCNAME%(0,18,1), 0.0, -1, 7, 1, -1, 0, 0
*SET,%_FNCNAME%(0,19,1), 0.0, -2, 0, 848.826E+06, 0, 0, -1
*SET,%_FNCNAME%(0,20,1), 0.0, -3, 0, 1, -2, 3, -1
*SET,%_FNCNAME%(0,21,1), 0.0, 99, 0, 1, -3, 0, 0
! End of equation: 848.826E+06exp(-21E+06({x}^2+{z}^2)/(0.3)^2)
!-->
ESEL,S,LIVE
CSYS,11 ! Switch to your custom local CS for CM_2
NSEL,S,LOC,X,-0.0003,0.0003
NSEL,R,LOC,Y,0,0
NSEL,R,LOC,Z,-0.0003,0.0003
SF,ALL,HFLUX,%GAUSS%
CSYS,0 ! Go back to global CS
!ESEL,INVE,LIVE
!Set loadstep opts
TIME,0.075
AUTOTS,0
NSUBST,10,300,20,0
KBC,1
!KBC1 is for stepped load
TSRES,ERASE
OUTRES,ERASE
OUTRES,ALL,ALL
ALLSEL,ALL
/STATUS,SOLU
SAVE
SOLVE

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