# High velocity impact problem:How do you output pseudo strain energy

**URL:** <https://calculix.discourse.group/t/high-velocity-impact-problem-how-do-you-output-pseudo-strain-energy/1514>\
**Category:** Uncategorized\
**Created:** [March 2, 2023, 7:17am UTC](https://calculix.discourse.group/t/high-velocity-impact-problem-how-do-you-output-pseudo-strain-energy/1514 "2023-03-02T07:17:39Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![zyx](https://avatars.discourse-cdn.com/v4/letter/z/6a8cbe/32.png) [@zyx](https://calculix.discourse.group/u/zyx)\
**Post date:** [March 2, 2023, 7:17am UTC](https://calculix.discourse.group/t/high-velocity-impact-problem-how-do-you-output-pseudo-strain-energy/1514/1 "2023-03-02T07:17:39Z")

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If the pseudo-strain energy cannot be output in calculix, how to evaluate the hourglass phenomenon and determine whether the mesh size is appropriate？  
Thanks a lot! 😊

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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:** [March 2, 2023, 8:40am UTC](https://calculix.discourse.group/t/high-velocity-impact-problem-how-do-you-output-pseudo-strain-energy/1514/2 "2023-03-02T08:40:58Z")

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I’m afraid that the only way is to check the scaled deformed shape of the model for hourglass modes.

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**Author:** ![zyx](https://avatars.discourse-cdn.com/v4/letter/z/6a8cbe/32.png) [@zyx](https://calculix.discourse.group/u/zyx)\
**Post date:** [April 18, 2023, 2:33am UTC](https://calculix.discourse.group/t/high-velocity-impact-problem-how-do-you-output-pseudo-strain-energy/1514/3 "2023-04-18T02:33:55Z")

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May I ask your advice on how to do it

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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:** [April 18, 2023, 12:45pm UTC](https://calculix.discourse.group/t/high-velocity-impact-problem-how-do-you-output-pseudo-strain-energy/1514/4 "2023-04-18T12:45:14Z")

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Hourglassing results in a quite specific deformation pattern:

 ![hourglass](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/a/aeb20aebb92a48b3c8f5ebf917bd92d3d7a6c130.png)