This is a fun one! MES simulation

[grausch]

Hi Guys,

I've been lurking on this forum for the last couple of weeks trying to hone in my skills using simulation mechanical. I will be honest; this is one very time consuming application to learn how to use properly!. I have quite a bit more experience in the CFD simulations, but I am determined to get comfortable with this too!

I'm currently working on a project in which I intend to look at the strain (or perhaps the deformation) of a hollowed out "roller" when put under pressure by another roller on top of it. I've attached the file for those kind enough (and brave I suppose) to take a look.

I would like to see how the body of the hollow roller might deform over a life cycle of finite rotations. My path so far has been to run an MES in which the system rotates at least one time (obviously for every rotation of the larger roller, the smaller one will rotate more) and then perhaps run a fatigue analysis to see what one might expect after lets say 100,000 cycles (just a random number).

Since I am so new to the software, I am not even sure that's the best path to take, however, I figure it sure is a start! The problem I'm having is one of more than one issue. Specifically, I don't believe I'm setting up the model correctly to allow it to rotate. Also, I believe I may need to define the hollow roller differently, as each time I mesh, it seems to change automatically to a shell element from a brick element.

For some more background, the bottom roller is held in place by a pin constraint to act as if bearings are allowing it to rotate only. The top roller is able to move in the vertical direction (y) and allowed to rotate within the races I've included in the model. Likewise, the races can only translate in the y direction. A force is applied to the races which in-turn puts pressure on the lower hollow roller from the top solid roller.

For whatever reason, I simply cannot get everything in tune to run this simulation properly. I'm beginning to wonder if I have gotten into a territory of difficulty in which I had not anticipated!

Any comments/criticism would be greatly appreciated as with just about everything in life, the clock is ticking with this project. Thanks in advance,

Regards,

Garrett Rausch

Design Engineer

P.S. if anyone knows how to compress an archive file to a small enough size (this one turned out to be 18K) please let me know and I will GLADLY post the file on here for any help at all.

[AstroJohnPE]

Hi Garrett,

Glad you came out of lurking. 🙂 Your description and image look reasonable to me. (Thanks for the details in those. You look like another Snagit user to me.)

About the part changing to a Shell element type, this implies that the mesh type got set to a "plate/shell" mesh type -- probably by accident. Right-click on that part number in the browser, and somewhere under "CAD something" is an option to use a "Part" mesh or "Model" mesh. I'm guessing that it is set to "Part" which is fine. But if you click on "Part" to get the mesh settings dialog, it will hopefully show that the mesh type is "plate/shell" instead of solid. That fixes one issue.

This thread discusses how to reduce the size of an archive to make it smaller -- hopefully small enough to post. "Create, Post, or Provide an Archive of your model"

My last suggestion is to rotate the hollow wheel just 45 degrees. Because of symmetry (from what I can see in the image), the stress pattern that occurs in 45 degrees of rotation is the same that occurs in a full rotation. The maximum stress that occurs will be somewhere between 0 and 45 degrees, and the minimum stress will be 0 (when the spot is opposite from the contact). The Fatigue Wizard will enable you to specify this type of loading history; that is, 0 to max to 0. The goal is to reduce the quantity of results that the fatigue wizard needs to handle.

[eng_hhg]

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@AstroJohnPE wrote:

Hi Garrett,

Glad you came out of lurking. 🙂 Your description and image look reasonable to me. (Thanks for the details in those. You look like another Snagit user to me.)

About the part changing to a Shell element type, this implies that the mesh type got set to a "plate/shell" mesh type -- probably by accident. Right-click on that part number in the browser, and somewhere under "CAD something" is an option to use a "Part" mesh or "Model" mesh. I'm guessing that it is set to "Part" which is fine. But if you click on "Part" to get the mesh settings dialog, it will hopefully show that the mesh type is "plate/shell" instead of solid. That fixes one issue.

This thread discusses how to reduce the size of an archive to make it smaller -- hopefully small enough to post. "Create, Post, or Provide an Archive of your model"

My last suggestion is to rotate the hollow wheel just 45 degrees. Because of symmetry (from what I can see in the image), the stress pattern that occurs in 45 degrees of rotation is the same that occurs in a full rotation. The maximum stress that occurs will be somewhere between 0 and 45 degrees, and the minimum stress will be 0 (when the spot is opposite from the contact). The Fatigue Wizard will enable you to specify this type of loading history; that is, 0 to max to 0. The goal is to reduce the quantity of results that the fatigue wizard needs to handle.

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Dear all,

How can I assign the displacement value before simulation if I want to replace it with force which is subjected before.

Thanks