Longitudinal stiffeners

[Anonymous]

Hi everyone,

I was wondering if you can add longitudinal stiffeners to a closed box cross section as seen in an attached pic. I suppose either by modeling the arch as a shell (any tips on that?- I've never modeled a shell structure before) or designing an entirely new profile (have not done that either)?

Any help and guidance would be greatly appreciated.

[Rafacascudo]

It depends on what you want to achieve. If it is detailed stress analysis of the plates, then go for the shell model. If you are intending a global analysis, internal forces, displacements then go for a bar model with custom cross section that you can create on the section module

[Anonymous]

Thank you for such a quick answer. For now I think I will go with a custom profile module but I will be later on doing a detailed analysis or the arch. I found a webinar episode (How to create and run code verification of user defined section) that is quite helpful for the first option, however I would appreciate if you could guide me on creating a shell model. Anything really, to grasp the idea on working with shell models.

[Rafacascudo · Accepted solution]

Shell type structure in Robot is created using panels . Every plate/slab/wall you intend to create will be a panel object.

There are some ways to create a panel . My favorite is using nodes , bars , translate+drag  and panels dialog window. This method  doesn´t generate "snapping to the point" errors which are the main cause of mesh generation problems.

Better explained on the video below . Full box section with stiffners beam , shell model ,created in 10 min and without errors . Model attached