Double Box

@MATERIAL_01 {Mat1}
@COMMENTS {CommentText}


  • ShapeBuilder can generate beam cross-sections in the shape of a double box. To define a double box, use the following parameters.
  • The double box consists of a single zone. No options can be defined for this sectional shape.
  • Optional dimensions @DIMENSION_16 and @DIMENSION_17 define two shaping parameters, denoted α and β, respectively, which are used to round the corners of the section. (Default value: α = β = 0.5).
  • Sectional shapes are defined in their own local coordinate system, which is assumed to coincide with the global coordinate system. If a fixed frame, FrameName, is specified, the local coordinate system coincides with this fixed frame.
  • The mesh density parameter, md, determines the level of mesh refinement. (Default: md = 4)
  • It is possible to attach comments to the definition of the object; these comments have no effect on its definition.

The double box: base configuration

Component Dimension Symbol Default Nb.
double box width w required 01
double box location dT 0.0 02
double box location dB dT 03
Right box height hR required 04
Right box thickness tR required 05
Right box angle αR 90° 06
Right box thickness tL tR 07
Right box thickness tT tR 08
Right box thickness tB tR 09
Left box height hL hR 10
Left box thickness tL tR 11
Left box angle αL 90° 12
Left box thickness tR tR 13
Left box thickness tT tR 14
Left box thickness tB tR 15
Table 1. Dimensions defining the geometry of the double box.
  • The base configuration of the double box is shown in fig. 1, 2, 3, and 4. No options are available for this shape.
  • The geometric configuration of the double box if defined by the dimensions listed in table 1, which are also indicated in fig. 1, 2, 3, and 4. Dimensions labeled in red are required. Dimensions labeled in blue are optional and are assigned the default value indicated in table 1.
  • The double box features a single zone.
    1. Zone 1.
      • The left box comprises the following faces: Lbox_TopFlangeLeft, Lbox_TopFlange, Lbox_TopFlangeRight, Lbox_RightWebTop, Lbox_RightWeb, Lbox_RightWebBot, Lbox_BotFlangeRight, Lbox_BotFlange, Lbox_BotFlangeLeft, Lbox_LeftWebBot, Lbox_LeftWeb, and Lbox_LeftWebTop.
      • The right box comprises the following faces: Rbox_TopFlangeLeft, Rbox_TopFlange, Rbox_TopFlangeRight, Rbox_RightWebTop, Rbox_RightWeb, Rbox_RightWebBot, Rbox_BotFlangeRight, Rbox_BotFlange, Rbox_BotFlangeLeft, Rbox_LeftWebBot, Rbox_LeftWeb, and Rbox_LeftWebTop.
      • Is associated with homogeneous material properties, Mat1.
  • Figure 1. Overall configuration of the double box
    Figure 2. Detailed configuration of the left box        Figure 3. Detailed configuration of the right box
    Figure 4. Detailed configuration of the central web