polygon_hollow_section

sectionproperties.pre.library.steel_sections.polygon_hollow_section(d: float, t: float, n_sides: int, r_in: float = 0.0, n_r: int = 1, rot: float = 0.0, material: Material = Material(name='default', elastic_modulus=1, poissons_ratio=0, yield_strength=1, density=1, color='w')) → Geometry

Constructs a regular hollow polygon section.

Constructs a regular hollow polygon section centered at (0, 0), with a pitch circle diameter of bounding polygon d, thickness t, number of sides n_sides and an optional inner radius r_in, using n_r points to construct the inner and outer radii (if radii is specified).

Parameters:

• d (float) – Pitch circle diameter of the outer bounding polygon (i.e. diameter of circle that passes through all vertices of the outer polygon)

• t (float) – Thickness of the polygon section wall

• n_sides (int) – Number of sides of the polygon

• r_in (float) – Inner radius of the polygon corners. By default, if not specified, a polygon with no corner radii is generated.

• n_r (int) – Number of points discretising the inner and outer radii, ignored if no inner radii is specified

• rot (float) – Initial counterclockwise rotation in degrees. By default bottom face is aligned with x axis.

• material (Material) – Material to associate with this geometry

Raises:

ValueError – Number of sides in polygon must be greater than or equal to 3

Returns:

Regular hollow polygon section geometry

Return type:

Geometry

Example

The following example creates an octagonal section (8 sides) with a diameter of 200 mm, a thickness of 6 mm and an inner radius of 20 mm, using 12 points to discretise the inner and outer radii:

from sectionproperties.pre.library import polygon_hollow_section

polygon_hollow_section(
    d=200, t=6, n_sides=8, r_in=20, n_r=12
).plot_geometry()

(Source code, png, hires.png, pdf)

Rectangular hollow section geometry