I am currently developing a structural system model in Karamba3D as part of my master’s thesis.
I am using the Create Linear Element component for the structural members, such as columns and beams. For these elements, I assign C30/37 concrete as the material. However, I have a question regarding whether Karamba3D considers reinforcement details within this concrete material definition.
If reinforcement is not automatically taken into account, I noticed that there is also a ReinfSteel material option among the available materials. In that case, if I assign this material, how can I define or understand the spacing, amount, and placement of reinforcement within the structural members?
More specifically, I would like to ask:
Does Karamba3D assume any default reinforcement arrangement when concrete material is assigned to linear elements?
Does the C30/37 concrete material include any reinforcement by default?
If reinforcement is not included by default, how should reinforcement be properly defined for concrete columns and beams in Karamba3D?
I would be very grateful if you could clarify how Karamba3D handles reinforcement in reinforced concrete linear elements.
currently (version 3.1.) Karamba3D can not consider reinforcement in beams directly. For shells there is a reinforcement design component available - this is the reasson why reinforcement steel materials appear in the material table.
However, you can use Karamba3D to obtain an estimate of the RC cross section via the “Optimize Cross Section”-component: To do this, adjust the tensile strength of the concrete material so that it implicitly represents the intended amount of reinforcement—for example, by using about 20% of the actual tensile strength of concrete.
The required amount of reinforcement can then be computed externally based on the resulting cross‑sectional forces. Further information can be found here.
Just adding a workflow note to Clemens’ answer, since detailed RC design of beams and columns is currently outside Karamba’s scope: One fairly established approach for this kind of topic is to keep Karamba for the parametric / early-design part inside Grasshopper (form-finding, topology studies, cross-section pre-sizing with the tensile-strength trick Clemens mentioned), and then hand the model over to a dedicated FE tool for the actual EC2 reinforcement design.
If you have access to RFEM (Dlubal) at your university, there are two practical handover paths worth knowing for a thesis:
That way Karamba does what it’s good at (fast feedback in Grasshopper), and the rebar design (crack width, ULS/SLS, detailing) happens in a tool built for it. Methodologically that can also be a clean structure for the thesis itself: parametric design upstream, verification in a standard FE package downstream.