> For the complete documentation index, see [llms.txt](https://manual.karamba3d.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://manual.karamba3d.com/2-getting-started/2-getting-started-1/setting-up-a-structural-analysis/2.2.6-provide-cross-sections.md).

# 2.2.6 Provide Cross Sections

There are two methods for attaching cross sections to elements:

1. **Direct Assignment:** Directly at the component where the element is created, as shown in Fig. 2.2.6.1.
2. **Assignment via Names or Regular Expressions:** Using element names (“B” and “S” in Fig. 2.2.6.2) or regular expressions by plugging cross sections into the **“Assemble”** component.

<figure><img src="/files/0MsV1aPqRdlb1oBNJ9jV" alt=""><figcaption><p>Fig. 2.2.6.1: Definition of a cross section.</p></figcaption></figure>

Figure 2.2.6.1 illustrates how to attach a custom cross section to an element. The example shows an I-profile with a height and width of 50 cm. The physical unit of any input or output value is indicated in the help text that appears when hovering over the corresponding plug.

{% hint style="info" %}
Assignment via the **“Assemble”**-component overrides direct assignment at the element.
{% endhint %}

![ Fig. 2.2.6.2: Definition of a cross section via element names.](/files/-MCkEZqa5h3AZAiNTQu1)

Figure 2.2.6.2 shows how cross sections can be attached to elements via their names **“Elem|Id”**:

1. Definition of a beam cross section.
2. Definition of a shell cross section.
3. Selection of a cross section from the default cross section library.

An element's index can be used as its default name.

Arbitrary I-, hollow box, filled trapezoid, and hollow circular cross sections can be defined for beams. Alternatively, Karamba3D allows users to select a predefined standard cross section. For shells, it is possible to attach a different cross section to each element.

Karamba3D cross sections are available as multi-components and can be accessed via the single **“Cross Sections”** component. The drop-down menu allows for the selection of the cross section type.

{% hint style="info" %}
Should you not assign a cross section to your beam or shell elements, the [default cross section ](/2-getting-started/2-getting-started-1/karamba3d-entities.md#default-settings)will be used.
{% endhint %}