Problem with modeling keyhole laser welding

Numerical methods and mathematical models of Elmer
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stroop
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Joined: 22 Nov 2016, 17:26
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Location: Germany

Problem with modeling keyhole laser welding

Post by stroop »

Hi,
I am trying to model keyhole mode laser welding but for some reason there only seems to be a pulse at the middle of the weld path and then the heat dissaptes soon after. This worked for a normal volumetric heat source but when I try to add anything that would make it resemble the heat disribution during keyhole welding this odd behavior appears. I tried reducing the mesh size around the welding path and the timestep but the results didn't change. I have attached the SIF file and the mesh.

The UDF for heat source is: alp*(2*p/(pi*((rx+ry+rz)**2)))*exp(-1*(((x-(x0 + v*time)/rx))**2 + ((y-y0)/ry)**2 + ((z-z0)/rz)**2))
with

x0 = -0.008
y0 = 0.0045
z0 = 0
p = 2000
v = 0.005
alp = 2700
rx = 1e-3
ry = 1e-3
rz = 5e-3


Thanks
Attachments
casef3.sif
(2.8 KiB) Downloaded 365 times
keyholeWeld.7z
(1.91 MiB) Downloaded 386 times
stroop
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Re: Problem with modeling keyhole laser welding

Post by stroop »

This is working now, I changed the function for the heat source such that the spot size depends on z. :)
sebastien ROUQUETTE
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Location: Nimes, France

Re: Problem with modeling keyhole laser welding

Post by sebastien ROUQUETTE »

Hi stroop

Yes i know, i had a look to it in the afternoon and noticed two errors in your heat source expression. On "(" is badly written and an other one is missing!

I also noticed that you imposed your heat source on the opposite side to the refined one. The right z is around -0.01... You've got high temperatures values around 1e+37!!! now the heating is lower! Another point, you have to divide by the aluminium density (alp parameter) instead of multiplying the value by alp.

I attached the fortran file corrected.

Just another question where do you apply exactly your heat source? on which face is the laser beam?

Cheers
Attachments
transweld.f90
(2.32 KiB) Downloaded 357 times
Rouquette Sébastien
University of Montpellier / Mechanical and Civil Engineering Lab. / Welding Group
stroop
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Location: Germany

Re: Problem with modeling keyhole laser welding

Post by stroop »

Hi Sebastien,

Thanks for your reply,
I apply the heat source starting from the point (x0,y0,z0) so the laser beam is on face 11 and moves in the x direction which is the refined face.
Jameson4170
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Re: Problem with modeling keyhole laser welding

Post by Jameson4170 »

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