# Pipe bending simulation

**URL:** <https://www.simscale.com/forum/t/pipe-bending-simulation/82796>\
**Category:** Project Support\
**Created:** [July 17, 2018, 11:34am UTC](https://www.simscale.com/forum/t/pipe-bending-simulation/82796 "2018-07-17T11:34:21Z")\
**Posts on this page:** 1\
**Showing post:** 43

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**Author:** ![BenLewis](https://www.simscale.com/forum/user_avatar/www.simscale.com/benlewis/32/99_2.png) [@BenLewis](https://www.simscale.com/forum/u/BenLewis)\
**Post date:** [July 31, 2018, 7:44am UTC](https://www.simscale.com/forum/t/pipe-bending-simulation/82796/43 "2018-07-31T07:44:41Z")

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Hi Richard (@tenshinshoden),

Your simulation will run much faster (and be more stable) with a first-order mesh but the results will not be very accurate. Sometimes it is beneficial to start with a first-order mesh to get some preliminary results. Then you can do a final pass with a second-order mesh. Please see [this](https://www.simscale.com/forum/t/when-should-i-use-a-second-order-mesh/25899) post for more details.

Note that the plastic transition zone (circled in the image below) will take much longer to solve than the bits either side.

 ![image](https://www.simscale.com/forum/uploads/default/original/3X/7/3/7396e34ccde3c4ef97cbee0990a4ad1f5e78b732.png)

Using a coarse mesh will reduce the computation time. You could drop back to one element through the thickness of the pipe but only with a second-order mesh. And even then I don’t expect you will save much, your mesh is already pretty efficient.

I took a quick look at your simulation setup and I can see you are not using the center roller contact (only the support roller). Therefore your non-convergence issue (and possibly long computation time) is probably coming from this contact. You could try to improve this region to make it more stable. For example:

- Provide a larger contact surface area to reduce the local plasticity.
- Change the bottom of the pipe to have a small flat face. This may allow the pipe to slide over the roller more freely.

You could increase the residual (by a factor of 10 or 100) but that would be a last resort. Non-convergence is usually a sign that there is something else wrong and increasing the residual usually won’t help. The default value is generally pretty good for most situations.

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_[View the full topic](https://www.simscale.com/forum/t/pipe-bending-simulation/82796)._