# Tied contact on curved surface and clearences

**URL:** <https://calculix.discourse.group/t/tied-contact-on-curved-surface-and-clearences/2476>\
**Category:** Uncategorized\
**Created:** [November 18, 2024, 12:41pm UTC](https://calculix.discourse.group/t/tied-contact-on-curved-surface-and-clearences/2476 "2024-11-18T12:41:17Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![xyont](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/xyont/32/3553_2.png) [@xyont](https://calculix.discourse.group/u/xyont)\
**Post date:** [November 18, 2024, 12:41pm UTC](https://calculix.discourse.group/t/tied-contact-on-curved-surface-and-clearences/2476/1 "2024-11-18T12:41:17Z")

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hi, i get unexpected result when tied contact assign to curved surface with some distance. Even though, documentation given notify spring is generated no matter the size of clearances. Not only affected the model with some distance offset or clearance, previous fit model also. I can not understand the problem in solver, several models with different setup (Element type, Nlgeom, Contact adjust) did not help.

continous mesh and tied contact with zero clearances,

 ![2024-11-18 19_18_16-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/8/829958a5c8ab830c4585c924d109d3e98b19a1e3.png)

 ![2024-11-18 19_20_58-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/d/d91ae6e0b6e3a6f29235153f23594f28c460a5df.png)

 ![2024-11-18 19_21_35-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/f/f79161100b0260e554919e6b76756bc73fc418ba.png)

tied contact with zero clearances and some offset distances,

 ![2024-11-18 19_13_36-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/a/a75087f3a791bbc240508d76e0f0b6dbb4d230fd.png)

 ![2024-11-18 19_15_08-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/5/56d58abb3fdf913b97caf87592a23a3f99c43aa5.png)

 ![2024-11-18 19_15_33-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/e/eccd9524647f57e48ff8bfc74ba152e869aaff2e.png)

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<div class="post-metadata">

**Author:** ![xyont](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/xyont/32/3553_2.png) [@xyont](https://calculix.discourse.group/u/xyont)\
**Post date:** [November 18, 2024, 3:35pm UTC](https://calculix.discourse.group/t/tied-contact-on-curved-surface-and-clearences/2476/2 "2024-11-18T15:35:01Z")

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i took another test, compared element type linear and quadratic with zero clearances, results given some insight. It seems projected element face need to exactly the same for both master and slave, lead to unexpected result when it did not satisfy. However, i’m still not clearly understand about the reason of highly spotted stress. Hopefully there will be an improvement for this limitation or disadvantages, thank you.

 ![2024-11-18 22_16_59-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/c/c22f115dfc72f9e4ecc4dfaa6b6425786c63a9bd.png)

 ![2024-11-18 22_18_53-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/f/fef0bf09412bace9d6776588e6c0195ca5c68a7f.png)

and using tie constraint as comparison,

 ![2024-11-19 12_28_33-CalculiX GraphiX](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/7/7ca97b7a58662ef83c27b1066ba266b60f728fc8.png)

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**Author:** ![rsmith](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/rsmith/32/1684_2.png) [@rsmith](https://calculix.discourse.group/u/rsmith)\
**Post date:** [November 19, 2024, 7:35pm UTC](https://calculix.discourse.group/t/tied-contact-on-curved-surface-and-clearences/2476/3 "2024-11-19T19:35:00Z")

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How did you generate the tied contact?

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<div class="post-metadata">

**Author:** ![xyont](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/xyont/32/3553_2.png) [@xyont](https://calculix.discourse.group/u/xyont)\
**Post date:** [November 19, 2024, 8:06pm UTC](https://calculix.discourse.group/t/tied-contact-on-curved-surface-and-clearences/2476/4 "2024-11-19T20:06:07Z")

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i do surface partition, define names for master and slave as commonly in contact models. But it seems not have any relation, since the problem due to mismatched mesh in linear element or distance clearances. Quadraic element with zero clearances shown not problem since mid-side nodes following curved geometry.