> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/developers/paramml-developer-guide/core-objects/finite-elements-objects/fesurface.md).

# FESurface

The "FESurface" Object is a component of the finite element model that represents foundations or slabs. It requires at least three different "Node" Objects and a Material object, and the thickness must also be specified using the Thickness parameter.

**Example Syntax:**

```
...
<O T="FESurface">
...
...
</O>
```

**Example:**

```xml
<O N="FESurfaceObject1" T="Project" Category="FEM Objects" TransAlignRule="Right">
    <!-- created by ParamML Examples on 07.02.2023 -->
    <O N="Inputs" T="Group">
        <P N="h_col" V="500" D="column height" Role="Input" Category="Inputs" />
        <P N="b_bm" V="400" D="beam width" Role="Input" Category="Inputs" />
        <P N="d_bm" V="500" D="beam depth" Role="Input" Category="Inputs" />
    </O>
    <O N="Column" T="Line">
        <O T="Point" X="b_bm" Y="0" Z="0" />
        <O T="Point" X="b_bm" Y="0" Z="h_col" />
        <O N="ColSec1" T="Section">
            <O T="Shape">
                <O T="Point" X="0" Y="0" />
                <O T="Point" X="0" Y="b_bm" />
                <O T="Point" X="d_bm" Y="b_bm" />
                <O T="Point" X="d_bm" Y="0" />
            </O>
            <O N="ColConcrete" T="Material">
                <P N="E" V="519120" />
                <P N="G" V="221904" />
                <P N="d" V="0.15" />
                <P N="a" V="0.0000055" />
                <P N="Fc28" V="576" />
            </O>
        </O>
    </O>
    <O N="NB1" T="Node" Z="0" Y="0" X="0" Rz="-1" Ry="-1" Rx="-1" Tz="-1" Ty="-1" Tx="-1" />
    <O N="NB2" T="Node" Z="0" Y="0" X="b_bm" Rz="-1" Ry="-1" Rx="-1" Tz="-1" Ty="-1" Tx="-1" />
    <O N="NB3" T="Node" Z="0" Y="d_bm" X="b_bm" Rz="-1" Ry="-1" Rx="-1" Tz="-1" Ty="-1" Tx="-1" />
    <O N="NB4" T="Node" Z="0" Y="d_bm" X="0" Rz="-1" Ry="-1" Rx="-1" Tz="-1" Ty="-1" Tx="-1" />
    <O N="N1" T="Node" X="0" Y="0" Z="h_col" />
    <O N="N2" T="Node" X="b_bm" Y="0" Z="h_col" />
    <O N="N3" T="Node" X="b_bm" Y="d_bm" Z="h_col" />
    <O N="N4" T="Node" X="0" Y="d_bm" Z="h_col" />
    <O N="L1" T="FELine">
        <P N="Node1" V="NB1" T="Node" />
        <P N="Node2" V="N1" T="Node" />
        <P N="Section" V="ColSec1" T="Section" />
        <P N="Beta" V="0" />
    </O>
    <O N="L2" T="FELine">
        <P N="Node1" V="NB2" T="Node" />
        <P N="Node2" V="N2" T="Node" />
        <P N="Section" V="ColSec1" T="Section" />
        <P N="Beta" V="0" />
    </O>
    <O N="L3" T="FELine">
        <P N="Node1" V="NB3" T="Node" />
        <P N="Node2" V="N3" T="Node" />
        <P N="Section" V="ColSec1" T="Section" />
        <P N="Beta" V="0" />
    </O>
    <O N="L4" T="FELine">
        <P N="Node1" V="NB4" T="Node" />
        <P N="Node2" V="N4" T="Node" />
        <P N="Section" V="ColSec1" T="Section" />
        <P N="Beta" V="0" />
    </O>
    <O N="TopMeshSurface" T="FESurface">
        <P N="Material" V="ColConcrete" T="Material" />
        <P N="Node1" V="N1" T="Node" />
        <P N="Node2" V="N2" T="Node" />
        <P N="Node3" V="N3" T="Node" />
        <P N="Node4" V="N4" T="Node" />
        <P N="Thickness" V="10" />
    </O>
</O>
```

![](https://openbrim.atlassian.net/wiki/download/attachments/2161967173/image-20230207-121440.png?api=v2) In the above example, 8 "FENode", 4 "FELine", material class and finally "FESurface" were defined. To view this example in the library, see (<https://openbrim.org/platform/?application=inc&author=ParamML_Examples_OpenBrIM+Platform&folder=FEM+Objects&obj=objid4faplfilk9xmwl79y0h1d9>)

**Parameters of FESurface Object:**

\| | **Label** | **Mandatory** | **Name and Type Attributes** | **Default Description and Value Attributes** | **Other Attributes** | | --- | --- | --- | --- | --- | | 1 | Node 1 | Yes | N="Node1" T="Node" | D="Node 1: The first node of the finite element." V="" | Role="Input" | | 2 | Node 2 | Yes | N="Node2" T="Node" | D="Node 2: The second node of the finite element." V="" | Role="Input" | | 3 | Node 3 | Yes | N="Node3" T="Node" | D="Node 3: The third node of the finite element." V="" | Role="Input" | | 4 | Node 4 | Yes | N="Node4" T="Node" | D="Node 4: The fourth node of the finite element." V="" | Role="Input" | | 5 | Thickness | Yes | N="Thickness" | D="Thickness: The thickness of the surface." V="0" | Role="Input" | | 6 | Material | Yes | N="Material" T="Material" | D="Material: The material property of the finite element." V="" | Role="Input" |


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