# Compression only material

**URL:** <https://calculix.discourse.group/t/compression-only-material/1121>\
**Category:** Uncategorized\
**Created:** [June 3, 2022, 4:02pm UTC](https://calculix.discourse.group/t/compression-only-material/1121 "2022-06-03T16:02:30Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![AndreaC91](https://avatars.discourse-cdn.com/v4/letter/a/96bed5/32.png) [@AndreaC91](https://calculix.discourse.group/u/AndreaC91)\
**Post date:** [June 3, 2022, 4:02pm UTC](https://calculix.discourse.group/t/compression-only-material/1121/1 "2022-06-03T16:02:30Z")

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Hello,

I’m trying to use the Compression\_only option to model the material of a masonry arch.  
Going through the manual, I see that the mechanical parameters required are the Young modulus and the maximum tensile stress.  
Shouldn’t the Poisson coefficient be specified as well? Doesn’t it influence the analysis?

Thanks,  
Andrea

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<div class="post-metadata">

**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\
**Post date:** [June 3, 2022, 6:34pm UTC](https://calculix.discourse.group/t/compression-only-material/1121/2 "2022-06-03T18:34:01Z")

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Check the file _concretebeam.inp_ provided with test examples here:

[http://www.dhondt.de/ccx\_2.19.test.tar.bz2](http://www.dhondt.de/ccx_2.19.test.tar.bz2)

Compression only material is used there and you can see how it works.