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Seção transversal da viga

From FreeCAD Documentation
This page is a translated version of the page FEM ElementGeometry1D and the translation is 38% complete.
Outdated translations are marked like this.

FEM ElementGeometry1D

Menu location
Model → Element Geometry → Beam Cross Section
Workbenches
FEM
Default shortcut
C B
Introduced in version
-
See also
FEM tutorial

Solvers
CalculiX, Mystran, Z88

Descrição

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.

Utilização

  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

Propriedades

  • DadosSection Type: specifies the type of the beam section (Rectangular, Circular, Pipe, 1.1 and above: Elliptical and Box)
  • 1.1 and above: DadosBox Height: height of box section, used if DadosSection Type is Box
  • 1.1 and above: DadosBox T1: thickness T1 of box section, used if DadosSection Type is Box
  • 1.1 and above: DadosBox T2: thickness T2 of box section, used if DadosSection Type is Box
  • 1.1 and above: DadosBox T3: thickness T3 of box section, used if DadosSection Type is Box
  • 1.1 and above: DadosBox T4: thickness T4 of box section, used if DadosSection Type is Box
  • 1.1 and above: DadosBox Width: width of box section, used if DadosSection Type is Box
  • DadosCirc Diameter: diameter of circular section, used if DadosSection Type is Circular
  • 1.1 and above: DadosAxis 1 Length: lenth of axis 1 of elliptical section, used if DadosSection Type is Elliptical
  • 1.1 and above: DadosAxis 2 Length: lenth of axis 2 of elliptical section, used if DadosSection Type is Elliptical
  • DadosPipe Diameter: outer diameter of pipe section, used if DadosSection Type is Pipe
  • DadosPipe Thickness: thickness of pipe section, used if DadosSection Type is Pipe
  • DadosRect Height: height of rectangular section, used if DadosSection Type is Rectangular
  • DadosRect Width: width of rectangular section, used if DadosSection Type is Rectangular
  • 1.1 and above: DadosTruss Area: cross-sectional area of truss elements, used if DadosExclude Bending Stiffness is enabled in the CalculiX solver

Limitações

  • 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.

Notas

  • 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.