3.3.1: Beam Cross Sections

Karamba3D offers five basic types of beam cross section:

  • circular tube – the default

  • hollow box section

  • filled trapezoid section

  • I-profile

Fig. 3.3.1: Cantilever with four different kinds of cross section

Fig. 3.3.1 shows a cantilever with cross section properties defined directly at the “LineToBeam”-component. Without eccentricities defined, the beam axis always coincides with the centroid of a cross section. Changing e.g the upper flange width of an I-section therefore results in a slight movement of the whole section in the local Z-direction. In case the position of e.g. the upper side of a cross section needs to be fixed, specify an eccentricity. This can be done either via a specific component (see section 3.3.7) or through the input-plug “Ecce-loc”. Provide a vector there in order to move the cross sections relative to the beam axis. The given eccentricity is relative to the local coordinate system of the beam. The resulting position of the centroid can be retrieved from the “Disassemble Cross Section”-component (see section 3.3.4).

Apart from the input-plugs that define the cross section geometry, the “Elem|Id”- and the “Ecce-loc”-input there are:


Each cross section belongs to a family. When doing cross section optimization (see section 3.5.8), Karamba3D selects only profiles that belong to the same family as the original section. Families can be composed of arbitrary section types


The identifier of a cross section – need not be unique. Enable “CroSec names” in "ModelView"s “RenderSettings”-submenu in order to view them.


Lets one define a color for a cross section. In order to see it enable “Cross sections” in submenu “Colors” of the “ModelView”-component and activate “CroSec section” in submenu “Render Settings” of the “BeamView”-component.


Sets the material of the cross section. Indirect material assignments via the __“Assemble”-component override direct definition of the cross section material.