# Archive of User Elements? **URL:** \ **Category:** Uncategorized\ **Created:** [September 2, 2022, 9:59am UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245 "2022-09-02T09:59:14Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![OliverKunc](https://avatars.discourse-cdn.com/v4/letter/o/aca169/32.png) [@OliverKunc](https://calculix.discourse.group/u/OliverKunc)\ **Post date:** [September 2, 2022, 9:59am UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/1 "2022-09-02T09:59:14Z")
I am wishing for a few more element types in CalculiX. Is there an archive or a repository of User Elements availble anywhere? ---
**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:** [September 2, 2022, 10:50am UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/2 "2022-09-02T10:50:03Z")
Two user elements are implemented: beam with general cross-section and true shell. The documentation also describes the implementation of a network element. I haven’t seen any other examples of user elements for CalculiX. Which types of elements are missing in CalculiX in your opinion ? This can be interesting on its own. ---
**Author:** ![OliverKunc](https://avatars.discourse-cdn.com/v4/letter/o/aca169/32.png) [@OliverKunc](https://calculix.discourse.group/u/OliverKunc)\ **Post date:** [September 2, 2022, 11:34am UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/3 "2022-09-02T11:34:28Z")
I am missing a performant hexahedron with 8 nodes, e.g. enhanced by bubble modes. Those give virtually the same results as C3D20. Also I know some other solvers like to automatically substitute C3D27 for C3D20 in contact analysis because the latter has bad equivalence properties. I wanted to compare them in CalculiX but C3D27 is not available. ---
**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:** [September 2, 2022, 6:11pm UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/4 "2022-09-02T18:11:23Z")
> [@OliverKunc](#): > > I am missing a performant hexahedron with 8 nodes, e.g. enhanced by bubble modes. Abaqus also doesn’t have elements with bubble functions. Instead, it relies on enhanced hourglass control for reduced integration elements. CalculiX has some form of hourglass control too. It’s activated by default for C3D8R elements. ---
**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:** [September 2, 2022, 7:03pm UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/5 "2022-09-02T19:03:28Z")
> [@OliverKunc](#): > > I am missing a performant hexahedron with 8 nodes, e.g. enhanced by bubble modes. it’s available. you can use incompatible mode of hexahedral element (C3D8I). an advanced linear hexahedral (improved strain) known implemented also, but not yet available. ---
**Author:** ![jbr](https://avatars.discourse-cdn.com/v4/letter/j/ecccb3/32.png) [@jbr](https://calculix.discourse.group/u/jbr)\ **Post date:** [September 3, 2022, 1:10am UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/6 "2022-09-03T01:10:36Z")
> [@xyont](#): > > an advanced linear hexahedral (improved strain) known implemented also, but not yet available. Where can we find this? ---
**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:** [September 3, 2022, 1:33am UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/7 "2022-09-03T01:33:39Z")
> [@jbr](#): > > Where can we find this? [https://calculix.discourse.group/t/c3d8i-element-in-calculix/792](https://calculix.discourse.group/t/c3d8i-element-in-calculix/792) ---
**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:** [September 3, 2022, 2:03pm UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/8 "2022-09-03T14:03:24Z")
> [@OliverKunc](#): > > Also I know some other solvers like to automatically substitute C3D27 for C3D20 in contact analysis because the latter has bad equivalence properties. interesting, i heard about it before. ---
**Author:** ![OliverKunc](https://avatars.discourse-cdn.com/v4/letter/o/aca169/32.png) [@OliverKunc](https://calculix.discourse.group/u/OliverKunc)\ **Post date:** [September 5, 2022, 9:02am UTC](https://calculix.discourse.group/t/archive-of-user-elements/1245/9 "2022-09-05T09:02:53Z")
Thanks for the hint. Should have read the manual more carefully. Hanven’t tried C3D8I yet, but if they are as I expect them to be, then there is no need for C3D27 anyway.