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NextFEM Admin
KeymasterDear Luciano,
thanks for your appreciation.
NextFEMpy was developed to allowing everyone to use NextFEM Designer without loading all the libraries, but through the REST API server (included in NextFEM Designer plugins).
A sample code for VIKTOR platform is already available in our GitHub page, we’ll show the usage also with VIKTOR asap.NextFEMpy was designed to be compatible with all the previous API used with pythonnet. There’s no need to convert old code for more perfomance, it should be the same with both approaches.
Also NextFEM Server could be used with the same approach; we’ll provide samples.
NextFEM Admin
KeymasterHello,
thanks for your suggestion; if you tried with our scripting engine to compile a script for the so-called “sandwich” model for shell design, let us know and we’ll try to improve/implement it.
Btw, we considered to implement this in the past, but by now there’s no request from our paid customer for this, hence we suspended the development. Instead, we implemented the shear check for slabs into Concrete module.NextFEM Admin
KeymasterHello,
CatenaryCableElement is already supported for model import and export. Actually, some distributed loads could not be applied to the element, but lumped to equivalent nodal loads. You can test it with version 2.3.EDIT: I forgot to mention: to set a truss as a cable, in Element Properties set CableNL to 1.
NextFEM Admin
KeymasterAs told, the program does not have internal automatic meshing. Hence, I simply mean breaking the beam in 2 pieces. Please note that this is required only for single beam model, general structures always have internal (not bounded) nodes.
NextFEM Admin
KeymasterThe important thing to do is to have a model with at least an internal node, otherwise the solver tries, as said, to compensate the residuals (especially for rotations) on end nodes.
NextFEM Admin
KeymasterDear Alain,
the beam formulation for built-in solver does not account for automatic mesher or p-delta effects correction for a single beam element.
As a result, for p-delta and second-order effects, you have to consider more than one element for a model. Fortunately, all the model having internal nodes (e.g. structures) does not suffer from this.
Considering the single-beam model, the moment at middle-span for LC1 is the same for all loadcases, but translated of the initial/ending moment (e.g. 34.186 – 7.629 = 26.55). The unrealistic initial and ending moment is due to the fact that the iterative solver cannot compensate the residual in internal nodes.NextFEM Admin
KeymasterDear Luciano,
your post is much appreciated! Thanks also for sharing your python script!NextFEM Admin
KeymasterThanks, Luciano. In the next patch you’ll find alignShellXaxis API function.
NextFEM Admin
KeymasterDear Luciano,
you obtain “bad” diagram because you don’t have aligned shell local axes. Every force/moment for shells is plotted against local axes for NextFEM Designer.
We currently read the mesh given by Gmsh (not via API, but from GUI only).To solve the problem, align the local axes with Assign / Local axes command.
ps.
we have free internal tria mesher. For regular slab as yours, a structured mesh (made by division) is more suitable. By using a mesh like the one you have, you’re implicitly introducing approximations in results, because finite elements involved (quad) are made to be more accurate when regular (e.g. square).NextFEM Admin
KeymasterYou already have such option in Options / mask Solver / Mesh and output preferences box / Beam max output stations
NextFEM Admin
KeymasterHello,
the beam output is shown at fixed beam stations (hence not necessarily including maximum), unless you activate “More output stations”.NextFEM Admin
Keymasterpsi values can be specified from the Load combination generation mask (Assign / Generate combinations).
NextFEM Admin
KeymasterHello,
the principal variable loading case is assumed automatically as the case with the highest combination multiplier amongst all the variable cases. In you model, it is Q-CatH. This is always conservative, as the greatest factor in combination leads to the higher factor for deflection calculation as per NTC2018 C4.4.7.With kdef=0.8 (SCL=2) you may have (values in m):
Secondary-variable Neve: (psi0 + psi2 * kdef) * f = 0.0004886155
Permanent G1-PP: (1 + kdef) * f = 0.00010358946
Permanent G2-Cop: (1 + kdef) * f = 0.0017873568
Principal-variable Q-CatH: (1 + psi2 * kdef) * f = 0.00053534396
Secondary-variable Vento_press: (psi0 + psi2 * kdef) * f = 0.000373014for a final sum of 0.00328791972.
It seems the model you sent behaves differently – we’re investigating the issue, please keep your program up to date – if this is the case, we’ll release a patch asap.NextFEM Admin
KeymasterHello,
thanks for your interest in NextFEM Designer. Actually, the program can perform implicit dynamic analysis – there’s no specialization for what you ask.NextFEM Admin
KeymasterIn the next patch your sample model will be supported (when quad with opposite edges are parallel) – otherwise, mesh area command should be used for complex boundaries.
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