# Explicit direct-integration dynamic

**URL:** <https://calculix.discourse.group/t/explicit-direct-integration-dynamic/2352>\
**Category:** Uncategorized\
**Created:** [July 23, 2024, 9:17am UTC](https://calculix.discourse.group/t/explicit-direct-integration-dynamic/2352 "2024-07-23T09:17:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![letsgochat](https://avatars.discourse-cdn.com/v4/letter/l/bb73d2/32.png) [@letsgochat](https://calculix.discourse.group/u/letsgochat)\
**Post date:** [July 23, 2024, 9:17am UTC](https://calculix.discourse.group/t/explicit-direct-integration-dynamic/2352/1 "2024-07-23T09:17:22Z")

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Hi, I’m posting this to get a better idea and more insight on the explicit dynamic analysis.

I am trying to simulate stress waves within a solid this way:  
\*Excert load on a Boundary  
\*Stress Propagates through material

I looked at Elmer, Abaqus and Calculix.

If I understood correctly Abaqus and Calculix both have a dynamic explicit solver, maybe even a similar implementation? (With calculix having some limitations according to my previous thread ([Nonreflecting BC - #5 by letsgochat](https://calculix.discourse.group/t/nonreflecting-bc/2345/5))

I also looked at Elmer, and if I’m right such implementation demands a combination of two equations (Wave and Elasticity).

Am I thinking correctly, or there are some concepts I’m overlooking.

Thanks for giving us a platform where we can exchange ideas!

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**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:** [July 23, 2024, 11:07am UTC](https://calculix.discourse.group/t/explicit-direct-integration-dynamic/2352/2 "2024-07-23T11:07:25Z")

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Yes, CalculiX has explicit dynamics based on Abaqus but still with lots of limitations and some bugs. Check this thread, for instance: [Can't get simple explicit dynamics impact analysis to work](https://calculix.discourse.group/t/cant-get-simple-explicit-dynamics-impact-analysis-to-work/1910)

I would recommend OpenRadioss for explicit dynamics.

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**Author:** ![letsgochat](https://avatars.discourse-cdn.com/v4/letter/l/bb73d2/32.png) [@letsgochat](https://calculix.discourse.group/u/letsgochat)\
**Post date:** [July 23, 2024, 12:04pm UTC](https://calculix.discourse.group/t/explicit-direct-integration-dynamic/2352/3 "2024-07-23T12:04:55Z")

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It seems promising, will check it out. Thanks!

EDIT: Are there any tutorials around how to start writing .rad tests in OpenRadioss? I seem only to find pre-implemented models.