Good morning/afternoon!
I just subscribed today for downloading the addon and I was very happy to have simple structural analysis within blender although it is limited to trusses and spaceframes apparently.
But unfortunately I faced a big issue that in many forms like a gridshell dome or a custom made steel structure or even spacetruss/frame the result of the deflection after the analysis looks exactly like a bird nest. Is it a problem in my side or is it the limitation of the addon?
Here is an example (Blender version 4.3.2, Addon version v0.2.0):
Your issue is that your structure is not a stable pin-jointed structure. Or to put it another way, a pin-jointed structure is not a suitable structural model in your case. Note the lack of triangulation.
A more appropriate structural model would be something like a grid shell structure where the joints can develop rotational resistance.
Alternatively, you might consider modifying your framing to something like a triangulated dome - like the icosphere available in Blender’s mesh menu. Even with that, you will need to be careful with the structures’ lack of out-of-plane stiffness. We model something like this (using the same solver that the addon uses) in the 3D spaceframe course - take a look there (lecture 34).
Thanks for the response!
So do I understand from what you said that the addon works inclusively with trusses, 3d trusses, and space frames only and not other steel structures like square gridshells or custom structures like the one in Heydar Aliyev?
I hope I could know what is the addon capable of doing and what it is not.
Also one of the main reasons I subscribed is just to get the addon especially for knowing if this building is doable or impossible and here is a fairly good result of the deflection part: but…
When I thought I have to make the modules smaller to increase the cantilever stiffness I did subdivided it one step and when I did similar analysis inputs and steps here is what I got:
So do I understand from what you said that the addon works inclusively with trusses, 3d trusses, and space frames only and not other steel structures like square gridshells or custom structures like the one in Heydar Aliyev?
…Yes. Currently StructureWorks is limited to structures that can be solved using the direct stiffness method. The addon basically implements what we covered in this 3D spaceframe course linked above.
I would like to get around to further enhancing its capability (bringing it up to the level covered in Finite Element Analysis of 3D Structures using Python) which should be quicker since OpenSeesPy is now implemented as the backend solver. But, I need to finish my plates and shells course first before returning to work on the addon - so no promises on timelines I’m afraid.
From the little I know of the Heydar Aliyev, it looks like it is predominantly a spaceframe structure so should lend itself to solution using the addon - it looks like you were making good progress!
Thanks a lot! But why is the deflection sometimes is messed up like in this example sepecifically or generally even looking like a nest where members are just going everywhere?
The most likely cause is a deficiency in your geometry - like a missing member or members. Fundamentally, the code requires you to put in a valid structure that will be solvable using a standard stiffness method approach in which all elements are capable of resisting axial load.
It seems from one f your screenshots, you did obtain a valid solution (based on teh deflection you showed). So, I would track back to that and investigate what you did to the structure after this analysis that may have invalidated the model - you mentioned subdivision at one point…this is likely the source of your problems.
Thanks for the fast response, I subdivided and applied before starting the addon procedure. It’s just the same as the first model but with smaller modules. Even the first picture I guess the deflection scale was 0.1 (I don’t think the deflection should be that huge).
Hi @Youssef_Deif - I replied to you via email on 6th October.
If you didn’t get see the email, it may be worth checking your junk folder - although that would be strange since my email was a reply rather than a cold email. In any event - you should see mt reply there.
Alright! Didn’t see it in the inbox. I’ve replied there but also here I’m having a gentle request, If you can just share a screenshot of the geometry node setup for the space truss please
