Error in Additive simulation via ANSYS APDL

- March 16, 2023 at 8:38 am
  
  Naeel D
  Subscriber
  
  Hello all,
  I have attempted to simulate additive manufacturing using ANSYS APDL. I have already applied an element type of SOLID278 with relevant material properties for aluminum 7075. I have also used 'Mapped Meshing' due to my design parameters. In addition to this, I have used the 'Element Birth and Death Technique' with a 'DO* LOOP' to simulate the additive manufacturing of 'Laser Cladding'. However, after running my PYANSYS code, I am running into this error where physical gaps are visible once the simulation is complete (shown in the image below). I would appreciate the solution to this cause.
  The following code below is my code used for the full process in ANSYS APDL:
  !----------------!Pre-processing----------------
  
  /PREP7
  !*
  ET,1,SOLID70 !Thermal 3D element
  
  !----------------!Defining Material Properties----------------
  
  !*
  /UNIT,SI
  MPTEMP,,,,,,,,
  MPTEMP,1,0
  MPDATA,EX,1,,71.7e09
  MPDATA,PRXY,1,,0.32
  MPTEMP,,,,,,,,
  MPTEMP,1,0
  MPDATA,KXX,1,,130
  MPTEMP,,,,,,,,
  MPTEMP,1,0
  MPDATA,C,1,,960
  MPTEMP,,,,,,,,
  MPTEMP,1,0
  MPDATA,DENS,1,,2810
  
  !----------------!Geometry----------------
  
  /PREP7
  K, ,0,0,0, !Modelling with Keypoints to create geometry
  K, ,0.004,0,0,
  K, ,0.005,0,0,
  K, ,0.005,0,0.002,
  K, ,0.004,0,0.002,
  K, ,0,0,0.002,
  
  K, ,0,0.004,0,
  K, ,0.004,0.004,0,
  K, ,0.005,0.004,0,
  K, ,0.005,0.004,0.002,
  K, ,0.004,0.004,0.002,
  K, ,0,0.004,0.002,
  
  K, ,0,0.005,0,
  K, ,0.004,0.005,0,
  K, ,0.005,0.005,0,
  K, ,0.005,0.005,0.002,
  K, ,0.004,0.005,0.002,
  K, ,0,0.005,0.002,
  !*
  CYL4,0.005,0.005,0.0005, , , ,0.002 !Create Cyclinder
  lplot
  KL,7,0.5, ,
  KL,2,0.5, ,
  !*
  /REPLO !Create Volumes from Keypoints
  V, 1, 2, 5, 6, 7, 8, 11, 12
  V, 2, 3, 4, 5, 8, 9, 10, 11
  V, 7, 8, 11, 12, 13, 14, 17, 18
  V, 14, 21, 25, 17, 8, 28, 27, 11
  V, 8, 28, 27, 11, 9, 19, 26, 10
  !*
  FLST,2,2,6,ORDE,2 !Substract Cyclinder from Main Volume
  FITEM,2,5
  FITEM,2,-6
  VSBV,P51X, 1
  
  !----------------!Optimised Mesh (Mesh Size 0.4mm)----------------
  
  lplot
  FLST,5,41,4,ORDE,10
  FITEM,5,9
  FITEM,5,11
  FITEM,5,-40
  FITEM,5,42
  FITEM,5,-43
  FITEM,5,45
  FITEM,5,47
  FITEM,5,-48
  FITEM,5,50
  FITEM,5,-54
  CM,_Y,LINE
  LSEL, , , ,P51X
  CM,_Y1,LINE
  CMSEL,,_Y
  !*
  LESIZE,_Y1,0.0004, , , , , , ,1
  !*
  
  !----------------!Creating the Mesh (0.4mm)----------------
  
  FLST,5,5,6,ORDE,4
  FITEM,5,2
  FITEM,5,-4
  FITEM,5,7
  FITEM,5,-8
  CM,_Y,VOLU
  VSEL, , , ,P51X
  CM,_Y1,VOLU
  CHKMSH,'VOLU'
  CMSEL,S,_Y
  !*
  !*
  VCLEAR,_Y1
  VMESH,_Y1
  !*
  CMDELE,_Y
  CMDELE,_Y1
  CMDELE,_Y2
  !*
  
  !----------------!Solutions-Settings----------------
  
  /SOL
  TUNIF,293, !Uniform temperature
  TREF,293, !Reference temperature
  KBC,0 !Ramped loading
  NEQIT,100 !No. of iteration
  
  !*
  ANTYPE,4 !Define model Transient Analysis
  !*
  TRNOPT,FULL !Define Solution Method
  LUMPM,0 !Use of 'Lumped Mass approx.'
  !*
  NROPT,FULL !Specify Newton-Raphson as Full Transient Analysis
  TIME,1 !End of Time Step
  
  !----------------!Kill all ELEMENTS----------------
  
  !*
  FLST,5,114,1,ORDE,2 !Select all NODES
  FITEM,5,1
  FITEM,5,-114
  NSEL,S, , ,P51X
  ESLN,S !Select all ELEMENTS attached to those NODES
  /GRAPHICS,FULL !Turn Off POWERGRAPHICS
  EKILL,ALL !Deactivate all ELEMENTS
  ESEL,S,LIVE !To confirm success of EKILL command: Select all 'Live ELEMENTS'
  /REPLO
  
  !----------------!DO LOOP COMMAND----------------
  
  *set,user_time,0
  
  !*do,variable_z,0,0.002,0.001
  !*do,variable_y,0,0.005,0.0012
  *do,variable_x,0,0.0012,0.0012
  
  NSEL,S,LOC,X,1*variable_x,0.0012+variable_x
  NSEL,R,LOC,Y,1*variable_y,0.0012+variable_y
  NSEL,R,LOC,Z,1*variable_z,*0.001+variable_z
  
  ESLN,S
  EALIVE,ALL !Re-Activate Selected NODES
  SFE,ALL, ,HFLUX, ,10e05
  !DELTIM,0.1,0,0 !Time step size, 0.1 s
  user_time=user_time+1
  TIME,user_time !Total time, 1 s
  AllSEL,ALL
  SOLVE
  SFEDELE,all,all,all !Removing surface element load
  /GRAPIHCS,POWER !Turn On POWERGRAPHICS
  esel,s,live
  eplot
  *enddo
  !*enddo
  !*enddo
  
  Thank you,
  Naeel D
- March 22, 2023 at 12:41 pm
  
  John Doyle
  Ansys Employee
  
  Seems like an error in your select logic. What happens if you select all the elements before the last plot (as a test)?
  - March 22, 2023 at 3:02 pm
    
    Naeel D
    Subscriber
    
    Hello John Doyle,
    Thanks for the response. I have applied 'ALLSEL,ALL' in replacement of the 'esel,s,live' command and found there has been no significant change in the solution.
- March 22, 2023 at 6:34 pm
  
  John Doyle
  Ansys Employee
  
  I think it still comes down to select logic. The gray elements are what remain killed.
- May 30, 2023 at 2:17 pm
  
  mrife
  Ansys Employee
  
  Hi Naeel
  Check this code block as there are more than 114 nodes in the model. Instead of using picking commands, maybe change to nsel,all and esel,all etc
  
  !----------------!Kill all ELEMENTS----------------
  
  !*
  FLST,5,114,1,ORDE,2 !Select all NODES
  FITEM,5,1
  FITEM,5,-114
  NSEL,S, , ,P51X
  ESLN,S !Select all ELEMENTS attached to those NODES
  /GRAPHICS,FULL !Turn Off POWERGRAPHICS
  EKILL,ALL !Deactivate all ELEMENTS
  ESEL,S,LIVE !To confirm success of EKILL command: Select all 'Live ELEMENTS'
  /REPLO