Forum Replies Created
-
Posts
-
Hello,
please try version 2.3.0.3; the patch for quad elements has been released. For tria, we’re still getting lower results, we’ll get in deep. For quads, we get a good agreement with results you already have. Always use a proper mesh (at least 5 quads per side).You can also run a parametric analysis automatically with Python in this version, please see the sample at https://github.com/NextFEM/API-Python/blob/main/wall_buckling.py
Hello,
we fixed a bug on quad elements that was causing the low factor you got – we’ll release the fix during this week, hopefully.
Regarding the comparison, results depend also on mesh fineness. We suppose you have the same mesh size and load (20kN) on all models. Another thing that affect results is the element formulation: in the built-in solver, tria elements are built by a membrane and plate, while quad elements have MITC4 formulation, which is generally more reliable.
Before releasing the patch we’ll do a parametric test on shell buckling, we’ll let you know when the update will be available.Hello,
have you checked deformed shapes for local buckling modes?
If you’re interested in in-plane buckling modes, you should model the wall in XY plane and set elements as plane stress (Edit / Change element type).
To perform a proper comparison, please make sure the mode is treated the in same way.Hello,
NextFEM Designer works with “.” (dot) as decimal separator. In your screenshot, you have 10,000 as load value, you have to use “10.000”.
Let us know if this solves the problem.Hello,
yes, there are 2 problems:
– all the columns must be beam, otherwise the assembly is obviously labile. Considering for instance node 5, you have all trusses and beams with end releases.
– you must restraint the rotation (torsion of columns) at the base.Please find attached the corrected model.
The rafters and roof ridge then should be beams with end releases for both moments at ends. Don’t apply restraints on the internal nodes, use them only at the base.
Beams with end releases are generally labile, so you have to take care of the assembly. Your model “wooden-house-ALL-RAFTERS-END-RELESED” is correct, except that the side beams is deforming too much (see displacements in case LOAD 1 – 33cm!). In any case, the moment is not transmitted as tou can see in Diagrams view.
Hello,
here we’re discussing about the static scheme to adopt, this is up to you to decide assumptions for your model. Answering your questions:
1. End releases are a constraint inside the beam, while resraints are applied to the nodes. Hence, if you release moments in a simply supported end, this is redundant: use only a simple simple support without end releases, or a fixed support and rotational end release. So yes, it’s just the same behaviour without end releases, but the contemporary presence of both can cause labilities
2. no, constraints tie degrees of freedom of 2 different nodes together, this is not your case.Trusses have only axial response – no releases for them. Only beams can have releases.
I hope this clarifies, regardsHello,
please clarify your question, in particular the final one. The program allows any kind of modelling, hence simply check end releases at the end. I see from your model that the moment is correctly released at the top of the pillars.
It is not clear why you want to apply restraints on the joints; you may want to apply only internal constraints or releases.Hello,
as stated, IronPython is not officially supported.You can try compiling the script to see if the issue is more clear. Use:
ipyc /main:yourScript.py /target:exe
and then launch the resulting .exe . If it works, it’s an issued on IPy side.
Hello,
IronPython is not officialy supported, however I can suggest trying with IronPython 3.4.1 instead of 2, with .NET Framework.Dear Luciano,
update is out, please see API https://www.nextfem.it/api/html/M_NextFEMapi_API_addThermalDistLoad.htmLet us know, regards
Dear Luciano,
thanks for your inquiry, please wait the next minor patch for having this solved. We’ll also try to add an API method for adding temperature loads.Regarding the sign of temperature gradient: starting from a user’s dT, the gradient is applied to the section as to have -dT/2 on the positive Y+ face of the section, and dT/2 on the negative Y- face of the section. We’re evaluating to invert this sign as to have positive temperature on Y+.