One thing to consider is that your high stress area might be more real than you think. If you have a large load at a small contact point, you almost certainly have localized yielding. This sort of yielding occurs all the time and usually is inconsequential. For example, any high spots or surface roughness on a bolted connection will get mashed down during the torqueing of the bolt. So, it may be that you can just ignore this high stress level and look only at the stresses as you push the rod farther into the hole.
The other thing to consider here is that you might want to substantially increase your mesh density and allow for all the geometry, i.e., is there a small radius that you have not included. Doing this will of course complicate your problem. Not knowing exactly what you are after, I would guess you don't need or want to do this. It is more of an academic question than anything.
TWD
> Brower Brent (DTUS/CENGDE) wrote:
> This is a problem that has bugged me in the past and I am now having > trouble with it in a contact problem that I am working on:
> I am analyzing a press fit of a "rod" into a hole. The rod that is > pressed into the hole has circumferancial rings turned on it. The > problem is that one of the elements on the edge of the rod where the > press fit is occurring has a huge stress differential across it. > Increasing the mesh density just increases the maximum stress at the > node "touching" the hole wall. The stress is so high at the one > element that when VonMise's stress is plotted it is red and the rest > of the model is blue.
> I have had this problem before, usually when constraining > displacement. Using pressure loads instead of fixing displacement > would work in the past, but since the stresses are caused by contact > this is not an option.
> Any help here would be appreciated.
> The model is 2D axysemmetric, with plane 82 elements.
> This is ASCII attempt to illustrate my problem.
> 000000 | > 000000 | > 000000 | Centerline is at the left edge. > 000000000| > "ROD" 000| > 000000000| > 000000 | > 000000 | > 000000 | > 000000000| > 000000000| > 00000000X| High Stress at the X > 000000 | > 000000 |_______
> Brent Brower
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