Value of the cross section heights from moments

Hi everyone,

I would like to know the cross section heights from a complex structure. Therefore for a better understanding of how to use the 'cross section heights from moments' I have made two examples. The first example is a simple beam and the other example is a grid structure of beams supported by multiple columns. I have used the set-up's from 'cross section height from moments' and 'smooth cross section height from moments'. As you can see for these set up's the output of cross section heights is different from the examples, see attachment. If you would calculate the cross section height from moments, the higher the bending moments the higher the cross section should be. For the simple beam the cross section from the smooth set-up is not the correct one.

1) Does anybody know how the calculation/set-up exactly works?

The default settings from karamba uses steel as material properties and for the cross section steel tubes with a diameter of 143 mm and thickness 4 mm. If a change the material properties and cross section as input, the value of the deformation and bending moment changes but the cross section height stays exactly the same. For calculation the cross section height is part of the resistance moment, which depends on the bending moment and stresses of the material. Formula: bending stress = moment divided by section modulus. You could extract the height or diameter from the section modulus and use it as a variable.

2) Is it possible to get exact cross section heights?

The values also changes when you change the display scales. For now I have used the display settings: 'model view' deformation 0.0 and 'beam view' bending moments 0.1

Thank you in advance!

Kind regards, Tessa