How to set up seemingly simple grinding/turning scenario?

wyattwyatt Member Posts: 12

Hello, I am having difficulties determining how to set up a grinding/turning scenario. I used a microhardness test on this forum for setting up the contact scenario, except I used a frictional contact.

I would like to simulate a fixed-axis rotating cylinder, with a small tool in contact. I have the student version of Ansys, so I need to keep the mesh elements within the limitations of the program.

I first attempted a static structural analysis, where I had the tool contact the workpiece, and things seemed to work without issues. For this I followed a tutorial for a microhardness test that I found on this forum, but I used a smaller cylinder to get results faster. From here I tried a remote displacement, and ran into issues.

The materials would be structural steel or something similar for the cylinder, and something like silicon nitride or tool steel for the tool. I believe I could make the cylinder a thin walled tube, and reduce the mesh size.

I am interested in the stresses and strains in the tool, but I would also like to see if I could run a short simulation with material removal (if there would be any). If someone could provide me with some ideas or instructions on how to continue, I would really appreciate it!


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  • wyattwyatt Member Posts: 12

    I managed to get a simulation to run, however I only used a small section of the cylinder, and I increased the density to speed up the processing. The simulation ran fine in explicit dynamics, however the tool is the only part that seemed to show stress/strain, and no material erosion occurred.

    I tried running the same simulation in transient structural, but after processing, the cylinder did not move at all. I saw in another forum post that with smaller elements the time step is longer, i.e., the longer the processing for explicit dynamics.

    I hope this is rehasing something that has come up before, and someone could direct me to the relevant discussions. I am still looking through the forums as there is a lot of useful information.

    I also ran an explicit simulation on a much smaller cylinder, and the processing took nearly half a day. The results were not great, and only the tool showed damage, not the cylinder.

    My questions are:

    • Could a contact condition or the mesh be preventing the cylinder from displaying stress/strain/erosion?
    • How would you recommend meshing?
    • Is there a method to perform this explicit dynamic simulation in transient structural?

    thanks!

  • wyattwyatt Member Posts: 12
    edited October 2020

    I have managed to run two explicit dynamic simulations.

    The first simulation took a long time, and only showed material erosion in the tool. I believe I can improve the mesh for this. I used a small cylinder with a small penetration into the cylinder with the tool.

    The second simulation I used a section of the cylinder shown in the above image. To speed up the processing, I increased the density of the cylinder and tool. The simulation ran without any error messages, however the cylinder experienced no stress/strain/erosion, and the tool only experienced some stress/strain. The tool is quite small, and as I have seen on other threads, the time step increases with small elements. As recommended in another thread, I tried using transient structural instead, however I could not reproduce the motion of the cylinder section in the explicit analysis. I also saw in another thread that material erosion/failure can be seen in structural analysis, so for both time and convienince this would be great.

    • Could someone direct me to related forum posts? or perhaps guide me through improving the mesh/simulation parameters/using a transient structural analysis with material erosion in this scenario?

    thanks!

  • wyattwyatt Member Posts: 12
    edited October 2020

    Ok, Thank you. I really appreciate the support.

    In general, are these mesh and contact conditions enough, or should the cylinder have a finer mesh? Also, would you recommend changing anything in my analysis settings?


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