## Beam Section Types

A beam element is characterized by its cross section. This cross section is defined by a *BEAM SECTION card. All beam sections which are not rectangular (including square) or elliptical (including circular) are considered as “beam general sections” and are internally expanded into a rectangular cross section (C3D20R-type element) and the actual section of the beam is simulated by an appropriate integration point scheme. A section type is characterized by a finite number of parameters, which must be entered immediately underneath the *BEAM SECTION card. A new section type can be added by changing the following routines:

• allocation.f (define the new section underneath the *BEAMSECTION if-statement)
• calinput.f (define the new section underneath the *BEAMSECTION if-statement)
• beamgeneralsections.f (here, the one-letter abbreviation for the section has to be added. For instance, the pipe section is characterized by 'P'. Furthermore, the programmer must define the number of parameters needed to characterize the section).
• beamintscheme.f (here, the integration point scheme has to be defined)
• beamextscheme.f (here, the extrapolation of the integration point variables such as stresses or strains to the nodes of the expanded C3D20R element).

Right now, the following section types are available:

Subsections