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Material Editor

Beam Rotation

FEM

Description

ElementGeometry1D is used to define cross sections for beam elements. Currently, the following types of cross sections are available: rectangular, circular and pipe.

1.1 and above: Box and elliptical cross sections are also available.

Usage

1. There are several ways to invoke the command:
   • Press the Beam Cross Section button.
   • Select the Model → Element Geometry → Beam Cross Section option from the menu.
2. Choose the type of cross section and specify the necessary dimensions:
   • Rectangular: width and height,
   • Circular: diameter,
   • Pipe: outer diameter and thickness,
   • 1.1 and above: Elliptical: axis 1 length and axis 2 length,
   • 1.1 and above: Box: width, height, thicknesses T1 - T4.
3. Optionally, press the Add button in the task panel and then click on the edge you want to have a prescribed cross section. If the edge selection is free, all the remaining edges (whose cross section is not defined by other FEM ElementGeometry1D objects) will be automatically assigned. introduced in 1.1: To remove edges from the selection, press the Remove button.

Beam section types, local axes used by CalculiX and dimensions specified in FreeCAD FEM

Properties

• DataSection Type: specifies the type of the beam section (Rectangular, Circular, Pipe, 1.1 and above: Elliptical and Box)
• 1.1 and above: DataBox Height: height of box section, used if DataSection Type is Box
• 1.1 and above: DataBox T1: thickness T1 of box section, used if DataSection Type is Box
• 1.1 and above: DataBox T2: thickness T2 of box section, used if DataSection Type is Box
• 1.1 and above: DataBox T3: thickness T3 of box section, used if DataSection Type is Box
• 1.1 and above: DataBox T4: thickness T4 of box section, used if DataSection Type is Box
• 1.1 and above: DataBox Width: width of box section, used if DataSection Type is Box
• DataCirc Diameter: diameter of circular section, used if DataSection Type is Circular
• 1.1 and above: DataAxis 1 Length: lenth of axis 1 of elliptical section, used if DataSection Type is Elliptical
• 1.1 and above: DataAxis 2 Length: lenth of axis 2 of elliptical section, used if DataSection Type is Elliptical
• DataPipe Diameter: outer diameter of pipe section, used if DataSection Type is Pipe
• DataPipe Thickness: thickness of pipe section, used if DataSection Type is Pipe
• DataRect Height: height of rectangular section, used if DataSection Type is Rectangular
• DataRect Width: width of rectangular section, used if DataSection Type is Rectangular
• 1.1 and above: DataTruss Area: cross-sectional area of truss elements, used if DataExclude Bending Stiffness is enabled in the CalculiX solver or (1.2 and above) Z88 solver.

Limitations

• 1.0 and below: Other types of cross sections available in CalculiX (elliptical, box and general) are not currently supported. One can edit the input file to use them.
• 1.1 and above: General beam section is not currently supported. One can edit the input file to use it.

Notes

• For viewing results from CalculiX solver on the mesh expanded to the prescribed cross section, property Beam Shell Result Output 3D in the FEM SolverCalculixCcxtools needs to be set to True.
• Some sections require specific element types:
  • circular section - 2nd order elements
  • pipe section - 2nd order elements with reduced integration (introduced in 1.0: reduced integration is enabled by default for beam elements and can be switched using the Beam Reduced Integration property of the CalculiX solver)
  • 1.1 and above: elliptical section - 2nd order elements
  • 1.1 and above: box section - 2nd order elements with reduced integration (as explained above)
• This feature uses the *BEAM SECTION card in CalculiX. The direction of the local axis 1 is automatically determined by FreeCAD FEM and written as the direction vector in the second data line of this keyword.

Material Editor

Beam Rotation

FEM