Equivalent Stress

Hello everone,

I’m using the new WIP of Karamba and I realized a change in the shell view component.
Is Equivalent stress in the Shell view component the same thing as Van mises Stress?

All the best,


Hello @mahanmotamedi1991,
in case of a material with strength hypothesis ‘Mises’ - like steel - it is the Van Mises Stress.
In Karamba3D 2.0.0 it is possible to define different strength hypotheses like ‘Mises’, ‘Tresca’ and ‘Rankine’ for materials via the ‘S-Hypo’ input-plug of the ‘MatProps’-component.
– Clemens


Dear Clemens,
I am using WIP version. Is it possible for you to add more yield criterions suitable for concrete like Möhr-Coulomb; Kupfer-Hilsdorf-Rusch; Drucker-Prager; etc… ?

…and actually I have one more related question. Do you think it would be reasonable and possible to add some combined yield criterion for reinforced concrete elements (shells in case of Karamba3D). For example, when I run optimization using Wallacei one of my fitness values is utilization…but in compressive region the yield criterion should be connected with concrete and in tension region it should be connected with reinforcement in order to get some reasonable utilization values. Otherwise I can get >100% utilization using Rankine for concrete in regions with relatively low tensile stresses which would be easily carried by reinforcement. What is your opinion?

Thank you in advance!


Dear @martin.petrik,
it is possible to add more yield criteria. I will put those that you mentioned on my todo-list.
For reinforced concrete it will be necessary to compute the overall cross section utilization assuming cracked in tensile regions - also a todo item.
– Clemens

Thank you @karamba3d that will be a huge step! Can not wait. Maybe another todo item could be rendering of mx my mxy in Shell View so I can use it in my class.

Hello @martin.petrik,
I will add that to the TODO list.
– Clemens

In beam as shell example from the Karamba website, a shell is analysed in steel - however, when inspecting the equivalent stresses the legend displays strains in [mm/m]:

Shouldn’t it show stresses in [kN/cm²]?


Dear @rudolf.neumerkel,
sorry for the inconvenience. The problem is fixed in the current service release (see https://github.com/karamba3d/K3D_NightlyBuilds/releases).
– Clemens