Convert Beams to Equivalent 2D Shell Mesh or 3D Solids

Use the Inflate tool to create 2D shell mesh or 3D solids from 1D beams.

This tool allows you to create the following:
  • Surfaces
  • Shell Mesh
  • Solids

It also supports options to create surfaces/mesh congruent with beam nodes.

Elements with standard and shell beamsection configs are supported. Valid shapes are thinwall or hollow sections like for instance: Z, T, I, H L, Boxes, C, U, HAT, Bulbs (idealized as L) as they will be modelled as midsurfaces. Solid kinds of shapes like ROD are skipped.

Figure 1. Standard beamsections converted
Figure 2. Shell beamsections converted
  • To convert to 2D shell mesh/surfaces:
    1. From the 1D ribbon, click the Inflate tool.

      Figure 3.
    2. Select the elements or components you want to convert.
      The tool filters your selection so only bar2 elements are retained.
    3. On the guide bar, click to define various options.
    4. Choose on the of the following:
    Option Description
    Generate surfaces from beams but not 2D elements
    1. Check Surface only.
    2. Click to create surfaces and remain in the tool or click to create surfaces and exit the tool.
    Generate surfaces and 2D elements from beams
    1. Clear the Surface only checkbox.
    2. In the microdialog, select the element size and type for the shells.
    3. Click in the microdialog.

    During surface extraction, the thickness is mapped to surfaces but properties are not created directly from this tool.

  • To convert to 3D solids:
    1. From the Mesh ribbon, click the Beams to Solids tool.

      Figure 4.
    2. Select the elements you want to convert.
    3. On the guide bar, click to define various options.
    4. Click to create solids and remain in the tool or click to create solids and exit the tool.


Reference Point

Section shear center
Consider beam node matching the section’s shear center.
Section centroid
Consider beam node matching the section’s centroid.
Beam node
  • Valid only for some standard sections, such as Channels (C, U) L, T (and variants) Bulbs, I.
  • The shape is positioned congruent with beam nodes no matter what the exact offset value if beams are connected to shell elements. The offset along the element normal places created surfaces on the correct side.
  • Whenever this option is set, the resulting mesh is connected to the beam node; mesh size is honored only in remaining edges trying to achieve a panel mesh.

Surface Continuity

Path vertex angle
Threshold vertex angle between adjacent beams under which surfaces are interpolated.
Orientation tolerance
Threshold angle between local Y axis of adjacent beams under which surfaces are interpolated.
Shell parts
How to generate surfaces from shell beamsection parts (see further explanation).


The destination defines where surfaces/shell mesh is created. It can be different for standard and shell beamsections, as the later offers more options.

Shell destinations include:

Current component
Use current component.
Beam component
Create surface/shell mesh in a 1D beam component.
Split by part
Create components using the part of the shell beamsection with same name as the part name.
Split by part thickness
Create components using the part of the shell beamsection with the same name as the part name_partthickness.
Option to capture thickness or not during conversion.
Assign thickness
Create properties | nodal thickness
Number of decimal
Thickness decimals to account for round-off


  1. Nodal thickness defines the thickness directly on each element card.
  2. Properties are created and assigned at the element level, except if all elements belonging to a single component share the same thickness; in this case, the property is assigned to the component.
  3. Tapered beams are supported both for standard and shell beamsections. Smooth surfaces are created between stations.

Further Explanation of Shell Beamsections

Shell beamsections are a collection of parts with a name. Parts with the name weld* are ignored.

Parts are a collection of ordered vertices. Lines are first generated by parts either as straight segments or smooth lines and used to create surfaces from station to station.

The Shell parts option in the guide bar menu can be used to control:
  • Whether straight segments are created from points
  • If a smooth line is generated while keeping straight regions if more than 2 points were originally aligned.
If 2 adjacent elements have different beamsection IDs, but the beamsections (config shell) share parts with the same name, then the tool will attempt to interpolate surfaces between the 2 beamsections on those parts. It results in continuous interpolated surfaces for a given part.

Figure 5.