Fiber Point

One fibre of a fibre section: a point, an area, and a material. Typically a single reinforcing bar.

🔧 Grasshopper component

Fiber PointAlpaca4d ▸ MomentCurvature_βeta

Inputs

PointPointWhere the fibre sits, in m.

Its X is the section's local y, its Y the local z.

AreaFiberNumber2.011e-4Area of the fibre, in m².

The default is one 16 mm bar.

MaterialMaterialB450CMaterial of the fibre. Defaults to ReinforcingSteel B450C.

Outputs

PointFiberPointFiberFor the PointFiber input of Fiber Section.

The component previews the fibre in blue.

📈 When to use it

Use it when

• Bars are placed individually and irregularly — corner bars, a bundled group, a single bar that differs from the rest.
• You are placing one fibre exactly.

Do not use it when

• The bars sit in a row → Layer Fiber spaces them for you from one curve.
• You are filling an area → Patch.

💡 Common bar areas

Diameter	Area (m²)
10 mm	7.854e-5
12 mm	1.131e-4
14 mm	1.539e-4
16 mm	2.011e-4 (default)
20 mm	3.142e-4
25 mm	4.909e-4

🔗 Relation to OpenSees

Inside the enclosing section Fiber block:

fiber $yLoc $zLoc $area $matTag