Learning Forum

[Naeel D]

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

[John Doyle]

Seems like an error in your select logic.  What happens if you select all the elements before the last plot (as a test)?

[Naeel D]

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. 

 

[John Doyle]

I think it still comes down to select logic.  The gray elements are what remain killed.

[mrife]

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