# Modeling Uniaxial and bi-axial geogrid in FLAC 3D

**URL:** <https://forum.itascainternational.com/t/modeling-uniaxial-and-bi-axial-geogrid-in-flac-3d/1835>\
**Category:** Uncategorized\
**Created:** [December 3, 2024, 5:05am UTC](https://forum.itascainternational.com/t/modeling-uniaxial-and-bi-axial-geogrid-in-flac-3d/1835 "2024-12-03T05:05:43Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Newuser](https://avatars.discourse-cdn.com/v4/letter/n/3e96dc/32.png) [@Newuser](https://forum.itascainternational.com/u/Newuser)\
**Post date:** [December 3, 2024, 5:05am UTC](https://forum.itascainternational.com/t/modeling-uniaxial-and-bi-axial-geogrid-in-flac-3d/1835/1 "2024-12-03T05:05:43Z")

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[@itascan](https://forum.itascainternational.com/groups/itascan),

How can we differentiate bi-axial and uni-axial geogrid while assigning properties or creating the structural elements in FLAC 3D?

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**Author:** ![dblanksma](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@dblanksma](https://forum.itascainternational.com/u/dblanksma)\
**Post date:** [December 3, 2024, 9:23pm UTC](https://forum.itascainternational.com/t/modeling-uniaxial-and-bi-axial-geogrid-in-flac-3d/1835/2 "2024-12-03T21:23:45Z")

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Hello @Newuser,

You can assign an Orthotropic or Anisotropic elastic material properties to your shell with the command:  
`structure shell cmodel assign anisotropic` (or orthotropic) see [here](https://docs.itascacg.com/itasca920/common/sel/doc/manual/sel_manual/shelltypes/shelltypes.html?node1677#shell-elastic-constitutive-models) under the section “Orthotropic and Anisotropic Elastic Material Properties”.