# Reference point output **URL:** \ **Category:** General Questions\ **Tags:** results\ **Created:** [May 8, 2025, 5:34pm UTC](https://prepomax.discourse.group/t/reference-point-output/2682 "2025-05-08T17:34:09Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![frank](https://avatars.discourse-cdn.com/v4/letter/f/3d9bf3/32.png) [@frank](https://prepomax.discourse.group/u/frank)\ **Post date:** [May 8, 2025, 5:34pm UTC](https://prepomax.discourse.group/t/reference-point-output/2682/1 "2025-05-08T17:34:09Z")
Hello, I have seen previous questions on reference points but somehow it hasn’t helped. For consistency, I like to output the displacement and stresses at the same points. I therefore add a history output to the static step, a sandwich panel with uniform loading. If I do select the reference point in the menu (Section Region), I then find that the .dat file has only 0 values for displacement and forces. If I do select the actual node underneath the reference point, I do get the correct displacement and force output. Here is an example result for the reference point and the actual node: displacements (vx,vy,vz) for set REFERENCE\_POINT-2\_ROT\_888112 and time 0.1000000E+01 88813 0.000000E+00 0.000000E+00 0.000000E+00 displacements (vx,vy,vz) for set INTERNAL\_SELECTION-1\_NODE\_SELECTION-1 and time 0.1000000E+01 34064 -7.041871E-02 0.000000E+00 -1.816511E+01 Why would this be? Earlier posts from 2023 suggested that Calculix does not output the reference point displacements? ![reference point output](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/2/29972d28165bbf70e8d1941f170a8b6ed747b369.png) Also, I would like to get the stresses at these nodes. Technically, this would be the element stress I guess and these can be visualised with the Query Tool at any given node. But I have not found a way to output these stresses automatically. Is there a way of getting this somehow automatically as output in the dat file? Many thanks! ---
**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:** [May 8, 2025, 5:36pm UTC](https://prepomax.discourse.group/t/reference-point-output/2682/2 "2025-05-08T17:36:30Z")
Are the reference points used for rigid body constraint definitions ? Only then you will get the results from them. And you won’t get the stresses - they only store displacements and forces for the cloud of nodes used in rigid body constraint. ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [May 9, 2025, 9:34am UTC](https://prepomax.discourse.group/t/reference-point-output/2682/3 "2025-05-09T09:34:09Z")
> [@frank](#): > > Also, I would like to get the stresses at these nodes. Stresses can only be outputted in the element integration points. But if you add the user history output (not the query tool), in post-processing, you can output the nodal stresses. ---
**Author:** ![frank](https://avatars.discourse-cdn.com/v4/letter/f/3d9bf3/32.png) [@frank](https://prepomax.discourse.group/u/frank)\ **Post date:** [May 9, 2025, 12:05pm UTC](https://prepomax.discourse.group/t/reference-point-output/2682/4 "2025-05-09T12:05:22Z")
> [@Matej](#): > > ed in the element integration points. > > But if you add the user history output (not the query tool), in post-processing, you can output the nodal stresses. Just to confirm, this is under the results tab → History Outputs → Create → From Field Output and then select the node of interest? Yes, thank you that seems to give all the different stress components as desired. ![results tab](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/d/dd57cd0f2b6cf05b4bfd24702eec3db7d2db9dac.png) Wouldn’t it be much more convenient to add a “Prepomax reference point” option which could provide all this output? It may be more natural to set such reference point up when preparing the model and using the in-built selection tools? I understand that the Calculix reference points are a bit different and it seems that this causes confusion more often than not (or it may just be me 😉 )?! ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [May 9, 2025, 4:45pm UTC](https://prepomax.discourse.group/t/reference-point-output/2682/5 "2025-05-09T16:45:52Z")
> [@frank](#): > > Wouldn’t it be much more convenient to add a “Prepomax reference point” option which could provide all this output? This could be called a sensor. But integrating it could be problematic in some cases, so currently there is no support for that. ---
**Author:** ![frank](https://avatars.discourse-cdn.com/v4/letter/f/3d9bf3/32.png) [@frank](https://prepomax.discourse.group/u/frank)\ **Post date:** [May 12, 2025, 8:25pm UTC](https://prepomax.discourse.group/t/reference-point-output/2682/6 "2025-05-12T20:25:04Z")
Might be a nice little student project then. Implementing this into Prepomax and validation on actual test specimens 😉