good morning, I have to create a particular cross-section and not available in karamba. through the “modify cross-section” command I can perfectly insert parameters such as Inertia Area and resistance module. Unfortunately it doesn’t allow me to enter the center of gravity. therefore the analysis turns out to be wrong… just think of the Navier equation sigma=M*y/I… he takes the distance from the center of gravity which is the wrong one for karamba… do you know how I can solve it? thank you very much

Hi @Loris_Liotti,

the extreme stresses at a cross section are calculated via the moments of resistance Wely+, Wely-, Wply (in case of plastic design),… These implicitly define the center of gravity.

The stress comes out as sigma = M/W in case od unaxial bending. So from

sigma = My / I * zmax: Wely+ = I/zmax.

– Clemens