I am using stationary heat source for friction stir welding simulation making the heat source stationary(tool) as it is given in the solved example.I want to do it for moving tool(heat source) time dependent one.I have made little modification in the given example of stationary heat source like,I have dis able the stationary mode and use transient one,but it seems it is not enough .can any one help me in this direction the primary stages.and what is moving mesh technique.how to do it and is it help full in this context.
Solved with COMSOL Multiphysics 4.3b
Friction Stir Welding
Dear Abhijit; First of all one has to define the geometry and the boundary conditions of your test modulus. In your modified version of the simulation, one of the boundary condition where the moving heat injection takes place becomes time and space dependent Then I could help you what type of modification is necessary in the numerical solution of your problem. Regards
No need of both values i.e only geometry is enough . No need of boundary conditions because friction strirring , the specifications you need are: Speed and no of rotations per sec, radius of rotation of stirrer, Frequency of waves formation, etc etc. From this you can find the path of heat flow and rate of heat transfer.
From those values you can find out temperature distribution. tthat's it man.
Mr. Varaprasad, I think you! haven't even once exposed to the solution of the heat transport problem. Since it was assumed that the process is adiabatic then you don't have to worry about heat flux coming in and out from the weld zone. The heat generated due to friction is also assumed be acting as a source. All these assumption are wrong since you apply a mechanical force (torque on the tool to generate sever plastic deformation as such extent that dynamic recrystallization occurs there. This process is not an adiabatic process what so ever. The rate of mechanical energy injected to the system, POWER = torgue x angular velocity of the tool.
here is an attachment of stationary heat source solved problem . I just change the stationary mode with time dependent.if possible please go over the programme and advised me some modification for time dependent.thanks for your kind attention.
Dear Abhijit I have checked the derivation of your equations they are all right. The boundary conditions from the upper and lower surfaces are okay. But for the traverse sides, you haven' made any comment, which may due to fact that it may be neglected because of the thickness is too small compared to other dimensions. But the left and right edges where material is coming and going can't be neglected as long as there is temperature difference between two edges. To assume that they are insulating boundary that will be over simplification, I think. Since we are treating this problem as a steady state you can consider the following BC: Jright= density Cp U Tright and Jleft=- density Cp U Tleft .
Next I will check your program. But it seems your temperature counters are proper, They are shifted towards the left edge. This would be in opposite direction if your tool moves towards the right edge while keeping test piece stationary.
dear Tarik omer sir ,thanks for your kind attention and valuable advice.
with time dependent mode following problems and errors are showing.
1.failed to find consistent initial values.
2.Time dependent solver 1(sol1/t1)
Please can any help me there meaning
Tarik Ömer Oğurtani sir can you tell me what are the rules followed while doing the simulation with moving friction stir tool.or simply how to move the tool while welding.
Dear Abhijit; all you have to do make an coordinate transformation in your differential equation regardless what it is:,, Fr one dimensional space: X= Xo + V t, where V is uniform motion of you reference system. Example for diffusion equation:
dC/dt = D d2 C / dx2 + V dC/dx this way you have a new convective term.
Tarik Ömer Oğurtani sir I have solved the programme for moving tool using the deformed geometry in comsol. but the thermal contours are not showing properly.And there is a blank creates at the initial position of the tool in the work piece when i run the progarmme.i have attuched the programme file .sir please advise me what is wrong in rthe programme.
This paper may help you.
Article A Comparison of Different Finite Element Methods in the Ther...
- Badges
- Science topic
- Similar topics
- Heat