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Punch and slitting hot forging simulation

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Hi,

I am having trouble with a simulation of a project that I'm are doing for a hot forging company.

This company forge rings and I have to simulate the slitting process of the material that remains in the bottom of the center of the ring after it was punched.

I need to cut a cylinder of 340mm of diameter and 50 mm of height at a temperature of 1000ºC with a cutting tool that is a cylinder of 340 mm of diameter and 320 mm of height connected to an hydraulic press.

We are using solid mechanics with a time-dependent study, we have the physics: heat transfer, creep, thermal expansion, etc. We have used contact pairs, but it doesn't cut the piece, the cutting tool only pass throung the cylinder like if it doesn't was there.

1 Reply Last Post Oct 30, 2015, 2:57 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 9 years ago Oct 30, 2015, 2:57 a.m. EDT
Hi

That looks like an interesting project. Which Physics do you plan to use ?
I'm not sure which non-linear structural or rather Fluid flow to choose, that would be #1 on my priority list, but probably there are a few out there that has already tried this, else use "support".

I would start first without any HT, to get the punching process working, then to add any relevant heat exchange, and possibly heat generation by friction too, as a last step.

Then one other issues you might have is the topology change, at start and at the end of the punching process. To overcome that I would propose (if you do not get a better suggestion from someone that has tried this before) to start with a little recess in the material and make an internal boundary at the punching diameter, and then stop when you still have a little material connected. Entities in COMSOL might "grow", or "shrink", but cannot "appear" nor "disappear fully", they need an "id" and this must remain so.

Now, there is another way I have seen in fluidics, i.e. check the example of the valve that is throttling a fluid flow by local change of the density of the valve material, which such "appear" in the middle of the fluid flow.

--
Good luck
Ivar
Hi That looks like an interesting project. Which Physics do you plan to use ? I'm not sure which non-linear structural or rather Fluid flow to choose, that would be #1 on my priority list, but probably there are a few out there that has already tried this, else use "support". I would start first without any HT, to get the punching process working, then to add any relevant heat exchange, and possibly heat generation by friction too, as a last step. Then one other issues you might have is the topology change, at start and at the end of the punching process. To overcome that I would propose (if you do not get a better suggestion from someone that has tried this before) to start with a little recess in the material and make an internal boundary at the punching diameter, and then stop when you still have a little material connected. Entities in COMSOL might "grow", or "shrink", but cannot "appear" nor "disappear fully", they need an "id" and this must remain so. Now, there is another way I have seen in fluidics, i.e. check the example of the valve that is throttling a fluid flow by local change of the density of the valve material, which such "appear" in the middle of the fluid flow. -- Good luck Ivar

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