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A question about compressed ring simulation — Ansys Learning Forum

A question about compressed ring simulation

Han-yuHan-yu CharlottesvilleMember Posts: 39

Hi,

I recently am working on a compressed ring simulation.

The whole process is divided into three steps.

First, The ring is clamped by certain force and deformed.

Secondly, the deformed ring slot into a pocket which diameter is a little smaller than the ring. (The clamped force still applied.)

Thirdly, remove the compressed force and see how much spring force and pressure generated on the ring and pocket wall.

Could you show me how to run this simulation process?

The setting of my simulation is attached to this discussion.

Thank you for your time.

Best Regards

Han-Yu

Best Answers

  • peteroznewmanpeteroznewman Member Posts: 11,369
    Accepted Answer

    @Han-yu

    There are several issues with this model. What version of ANSYS are you using.

    1. You should be using Contact Step Control, which means the contact is turned off in step 1 when you compress the object, then turn contact on in step 2. This is not available in old versions of Mechanical. https://forum.ansys.com/discussion/10032/contact-step-control
    2. You therefore don't move the parts in space, move the solid bodies so that they are in position.
    3. Cut the size of the block to be slightly larger than the spring. You are wasting time computing elements that do nothing.
    4. You must have 4 elements through the thickness of the spring and 4 elements along the width of the spring.
  • peteroznewmanpeteroznewman Member Posts: 11,369
    Accepted Answer

    Hi @Han-yu

    Since there is only a small interference, you might not even need step control. You can try to let contact alone resolve the interference, but you need at least 3 elements across the thickness.

    Attached is an ANSYS 2020 R1 archive.

Answers

  • peteroznewmanpeteroznewman Member Posts: 11,369
    Accepted Answer

    @Han-yu

    There are several issues with this model. What version of ANSYS are you using.

    1. You should be using Contact Step Control, which means the contact is turned off in step 1 when you compress the object, then turn contact on in step 2. This is not available in old versions of Mechanical. https://forum.ansys.com/discussion/10032/contact-step-control
    2. You therefore don't move the parts in space, move the solid bodies so that they are in position.
    3. Cut the size of the block to be slightly larger than the spring. You are wasting time computing elements that do nothing.
    4. You must have 4 elements through the thickness of the spring and 4 elements along the width of the spring.
  • Han-yuHan-yu CharlottesvilleMember Posts: 39

    Hi Peter,

    I tried your suggestions today.

    I upgraded the Workbench to the newest version and applied the Contact Step Control.

    But the part behavior doesn't look right, could you help me figure it out?

    Thank you very much for your time and help.


    Best Regards

  • peteroznewmanpeteroznewman Member Posts: 11,369
    Accepted Answer

    Hi @Han-yu

    Since there is only a small interference, you might not even need step control. You can try to let contact alone resolve the interference, but you need at least 3 elements across the thickness.

    Attached is an ANSYS 2020 R1 archive.

  • Han-yuHan-yu CharlottesvilleMember Posts: 39

    Hi Peter,

    May I asked what did you modify in this model?

    The goal of this simulation is to simulate the silicon compressed ring assembly process.

    The substrate pocket will be slightly smaller than the ring, and I assumed the forces I applied will create enough bending to make the ring fit into the slot.

    And after the force release, the ring should generate a spring force on the slot.

    After all, the attached file in the reply didn't work on my computer, the error shows as below.

    "Your product license has numerical problem size limits, you have exceeded these problem size limits and the solver cannot proceed."

    I tried to remove the mesh or steps, but it doesn't fix the simulation.

    What should I do to make the simulation work properly?

    Thank you for your help.


    Best Regards

  • peteroznewmanpeteroznewman Member Posts: 11,369
    edited February 17

    @Han-yu

    Since you are on a Student license, you must keep the node number < 32,000. I suggested you cut down the size of the block.

    Check how many elements under the Statistics category of the Mesh Details.

    You don't need to simulate the squeezing of the ends to simulate the ring in the block.

  • Han-yuHan-yu CharlottesvilleMember Posts: 39

    Hi Peter,

    I followed your suggestions and try to generate the mesh, however, it still crashed.

    And after several crashes, it occupies my disk storage and slows down my computer.

    Could you teach me how to solve this problem?

    And also are there some tips to reduce the number of mesh?

    Thank you.

  • Han-yuHan-yu CharlottesvilleMember Posts: 39

    Hi Peter,

    I switched my license from the student version license to the research license.

    The mesh limit is now fixed.

    However, the simulation still failed.

    The error message shows: An internal solution magnitude limit was exceeded. Please check your Environment for inappropriate load values or insufficient supports.

    "Element 26590 (type = 2, SOLID186) (and maybe other elements) has become highly distorted. Excessive distortion of elements is usually a symptom indicating the need for corrective action elsewhere. Try incrementing the load more slowly (increase the number of substeps or decrease the time step size). "

    But I didn't apply load in my simulation.

    Could you help me take a look and teach me how to correct it?

    Please refer to the attached file for my simulation.


    Thank you

    Best Regard


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