Section Cut

Evaluate sectional properties from a section cut on both 1D and 2D elements.

Restriction: Only available in the Nastran and OptiStruct solvers in the Aerospace user profile. The tool supports 1D (CBAR, CBEAM, CROD) and 2D elements and multi materials, but is limited to metallic isotropic materials.

From the menu bar, click Aerospace > Beams > Section Cut.

Use this tool to intersect a selection of elements, 1D and 2D, and evaluate sectional properties:
  • Area moments of inertia
  • Flexural stiffness
  • Torsional stiffness
  • Neutral axis position

The tool can create multiple sections at a time and hence generate beam linking each section.

Table 1. Section Cut Description
Option Values Description Result
Section method By Plane

Auto

Define how sections are defined. If Auto, all section options are disabled except Number of cuts.
Section system Global

Local

Define which system section's normal is defined. If local, a system selector is activated.
Section normal Normal axis

Reverse normal

Global vertical axis

Define section cut normal axis. Global vertical axis is projected on plane to define the local vertical axis. Defines section plane and local axis.
Section location Offset from origin

Nodes/points

Define section's base:
  • Picking node/point list
  • By offset from origin and cuts
Ends section definition.
Elements to include Element selector Select elements to include in section cut. Defaults to displayed elements if no selection.
Calculate inertia Neutral axis

Centroid

Base point

Position where area moments of inertia are reported. Centroid is geometric barycenter while neutral axis is calculated as weighted average center.
Include shells True/false

Use offset

Consider shell elems from selection. Consider or not offset on shells. Shells are supposed to be perpendicular to section. Intersection is then a rectangle with height equal to thickness.
Include beams True/false

Use offset

Consider beam elems from selection. Condsider or not beam offset. Consider contribution of beam sections to total area and MoI.
Include rods True/false Consider rod elems from selection. Rod elements contribute only to total area.
Create element set True/false Generate a set of elements intersected by the section. One entity set per section. Can be viewed in Review mode.
Create section cut data True/false

Detail data

Generate a table with all sectional properties per section. One table entity where each row is a section. Columns are sectional property attributes. This table is used in review mode.
Create node True/false

Centroid

Neutral axis

Both

Create a node at the section's center or neutral axis or at both locations. Node(s) created at each section.
Create beamsection True/false

Keep lines

Create a beamsection from shell intersection only. Keep or delete lines created at plane intersection with shells. One beamsection per section. Lines in either current or new components.
Create beam True/false

Centroid

Neutral axis

Creates a beam element between two successive sections. 1D beams with property assigned.

Expected Results

In the example below a fuselage is cut using eight nodes sampled along the x axis. Beam elements were created at centroid (in a new component) and beamsections where generated while keeping lines. The result after clicking Apply is shown in the image below.

After clicking Review the tool opens a table with sectional properties. By selecting a cell in column Table ID a graphic object displays the section intersection with mesh, with a sphere at each intersected 1D element. Clicking Plot draws selected data name along the element path.


Figure 1. . Section cuts and beam created


Figure 2. . Review sectional properties