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Beam Cross Section

In one sentence: Assign a cross-section shape and dimensions to edges modelled as 1-D beam elements, providing the area and moment of inertia the solver needs.

Overview

Workbench: FEM
Menu: FEM → Model → Element Geometry → Beam Cross Section

Assigns a cross-section shape and dimensions to selected edges that will be solved as 1-D beam elements. The cross-section provides the area and second moment of area used for bending and shear calculations.

Supported cross-section types

Type Required dimensions
Rectangular Width, Height
Circular (solid) Radius
Circular (hollow/tube) Inner radius, Outer radius
Elliptical Radius 1, Radius 2
Box (hollow rectangle) Width, Height, Wall thickness
I-section Web height, Web thickness, Flange width, Flange thickness
T-section Web height, Web thickness, Flange width, Flange thickness
L-section (angle) Leg 1 length, Leg 2 length, Thickness

Step-by-step

  1. Select the edge(s) to be modelled as beams.
  2. Choose FEM → Model → Element Geometry → Beam Cross Section.
  3. Select the Section Type and enter dimensions.
  4. Click OK.

Common mistakes and pitfalls

Cross-section dimensions are in model units

All dimensions are in the document's working unit. If the document is in millimetres, enter 50 for a 50 mm dimension — not 0.05.

Mesh must use 1-D beam elements

Beam cross-sections apply only to edges meshed as 1-D elements. If the mesh is a 3-D tetrahedral mesh, the cross-section has no effect.

Python API

import ObjectsFem
doc = App.ActiveDocument
analysis = doc.getObject("Analysis")

beam_sec = ObjectsFem.makeElementGeometry1D(doc, "BeamSection")
beam_sec.SectionType = "Rectangular"
beam_sec.RectWidth = 50.0    # mm
beam_sec.RectHeight = 100.0  # mm
analysis.addObject(beam_sec)
doc.recompute()

See also