# Bending Moment + Rotation Simulation **URL:** \ **Category:** General Questions\ **Created:** [November 5, 2025, 5:50pm UTC](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063 "2025-11-05T17:50:14Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![ANYS](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/anys/32/7737_2.png) [@ANYS](https://prepomax.discourse.group/u/ANYS)\ **Post date:** [November 7, 2025, 8:31am UTC](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063/23 "2025-11-07T08:31:15Z")
I can’t share pmx files sorry. Rigid body on the base and imposed rotation by means of an amplitude. Amplitude can be read to it’s equivalent angle. Rigid body on the tip with point mass on the ref. You can extract displacement of the ref . You can validate your set up by rotating a hallow tube (Less elements than solid and same inertia in all directions). Ref node deflection should remain constant during a full rotation. ![screenshot.65](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/4/4eacf9d6db8a458c93e333090a3a49214d6bda95.png) ---
**Author:** ![kkuehn](https://avatars.discourse-cdn.com/v4/letter/k/cab0a1/32.png) [@kkuehn](https://prepomax.discourse.group/u/kkuehn)\ **Post date:** [November 7, 2025, 5:17pm UTC](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063/24 "2025-11-07T17:17:29Z")
Why can’t you share the .pmx files? ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [November 7, 2025, 10:55pm UTC](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063/25 "2025-11-07T22:55:46Z")
> [@ANYS](#): > > Rigid body on the tip with point mass on the ref. It’s just important to note that point and distributed masses require some additional setup: [A developer/preview PrePoMax version v2.0.4 has been released](https://prepomax.discourse.group/t/a-developer-preview-prepomax-version-v2-0-4-has-been-released/1503) ---
**Author:** ![ANYS](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/anys/32/7737_2.png) [@ANYS](https://prepomax.discourse.group/u/ANYS)\ **Post date:** [November 8, 2025, 6:34am UTC](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063/26 "2025-11-08T06:34:13Z")
Yep. Good to remember. Additionally, use a base material which doesn’t have density defined. It makes it easier to verify results using hand calculations. What still feels odd to me is that gravity can be applied only partially in Prepomax. Other softwares doesn’t even ask about that. I can’t imagine a situation where it applies but… ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [November 8, 2025, 8:27am UTC](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063/27 "2025-11-08T08:27:25Z")
> [@ANYS](#): > > What still feels odd to me is that gravity can be applied only partially in Prepomax. Other softwares doesn’t even ask about that. I can’t imagine a situation where it applies but… Abaqus also has this option (even though it defaults to whole model). After all, \*DLOAD takes an element set as an input. ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [November 9, 2025, 6:45am UTC](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063/28 "2025-11-09T06:45:47Z")
> [@ANYS](#): > > What still feels odd to me is that gravity can be applied only partially in Prepomax. Other softwares doesn’t even ask about that. I can’t imagine a situation where it applies but… It is true that the load is called gravity, but it is actually an acceleration load. The acceleration load is not necessarily constant or active on all mesh elements. So maybe a special case could be created for gravity, where all elements would be affected. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [November 9, 2025, 8:27am UTC](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063/29 "2025-11-09T08:27:36Z")
> [@Matej](#): > > So maybe a special case could be created for gravity, where all elements would be affected. Maybe it could default to the whole model like in Abaqus. I wouldn’t change other aspects. ![gravity](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/5/5bccc76788e4fa641719239bd83a74387236b4d2.png) [Previous page](https://prepomax.discourse.group/t/bending-moment-rotation-simulation/3063.md?page=1)