Robot Structural Analysis Professional is structural load analysis software that verifies code compliance and uses BIM-integrated workflows to exchange data with Revit. It can help you to create more resilient, constructible designs that are accurate, coordinated, and connected to BIM.
Robot Structural Analysis Professional is available only in the Architecture, Engineering & Construction Collection, an essential set of integrated Building Information Modeling (BIM) tools. The collection includes:
I have been working on a project recently and have become a little confused on the correct way to model support for a ground bearing slab - If anyone can shed some light on the following for me It would be greatly appreciated.
Initially when I started using Robot I created an elastic support definition and created spring stiffnesses to match my modulus of subgrade reactions that I needed for the structure (See image 1.)This was how I effectivley modelled a ground bearing slab. One thing that I had discovered is that using this I could never get base pressure plots (soil reactions pressures) on the results map section and had no idea why this was.
Recently I have discovered that I can create parameters of foundation elasticity when specifying the structural element thickness (see image 2) however when doing this the model will not calculate as you still need to apply supports - however the benefit now is that I can view the soil reactions (see image 3).
What I am wondering (and hoping someone can help me understand) - Why is there an option to specify the foundation elasticity when specifying the shell thickness If you still need to apply springs of the same stiffness to support the model? My fear here is that I am perhaps changing the slab properties unknowingly, or that I am going about this all wrong. I don't like the fact that to get soil reaction maps, I have to create a slab with foundation elassticity properties then apply supports that match these properties - it is entering the same information twice that can always lead to mistakes / contradiction on more complex structures
The best option is to define elastic soil under a panel (thickness dialog). You need to define KZ value (no need for any additional vertical supports) and if you expect a chance for an uplift select UZ+ (assuming that the local Z of a panel points upwards). What you need to define are horizontal supports (UX and UY) which you can define in nodes or in the thickness definition (as on the picture 2 you attached). For the latter you just ignore the lack of support warning as for this particular situation it is only intended to point your attention that there is a possible mistake (which is not) in the definition of boundary conditions.
Thanks Artur - I have carried out a few small scale tests using the method you have suggested and I am happy that the results in this way are correct. I noticed that if you apply both the foundation properties to the plate and also to supporting springs that the effective bearing pressure plots are likely to be in the region of half what they should be, so for future work I intent only to enter subgrade supports to the plate properties and not apply elastic spring supports. Thanks as always for your help.
I have attached a file. It is a small building modelled with a core for an elevator. For foundations it is used piles that cannot be exposed to tension. The idea is to analyse the forces in the concrete beams under windy conditions. Do you have any idea why this model get convergence issues? I tried to do as you said in the previous post.
Morning @Artur.Kosakowski , I had the same problem and followed the instruction on your comments above. But I can't visualise the Map results, all the results are zero, I tried to follow the instruction on -structural-analysis-products/troubleshooting/caas/sfdca... but I still having the same problem as you can see attached. Can you help?
Snapping is Really Hard and It seems that Robot does not trully recognize its snapping options because it does not snap to where it was supposed to be. As a result, Panels made from contours are often created over lapping each other and meshing is a big problem.
Yes, Grids can help but is not accurate. Compared to other 3D analysis software, STAAD and ETABS, robot has failed on the modelling part because it does not snap accurately even on Grid Line Intersections.
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