Add rectangular CLT section to (new) timber sections library

src/sectionproperties/pre/library/__init__.py

@@ -63,3 +63,6 @@
     tee_section,
     zed_section,
 )
+from sectionproperties.pre.library.timber_sections import (
+    clt_rectangular_section
+)

src/sectionproperties/pre/library/timber_sections.py

@@ -0,0 +1,66 @@
+"""Timber sections library."""
+
+from __future__ import annotations
+
+import sectionproperties.pre.geometry as geometry
+import sectionproperties.pre.library.primitive_sections as primitive_sections
+import sectionproperties.pre.pre as pre
+
+
+def clt_rectangular_section(
+    d: list[float],
+    lay_orient: list[int],
+    b: float,
+    timb_mat0: pre.Material = pre.DEFAULT_MATERIAL,
+    timb_mat90: pre.Material = pre.DEFAULT_MATERIAL,
+) -> geometry.CompoundGeometry:
+    """Constructs a timber rectangular section.
+
+    Constructs a timber rectangular section of depth ``d`` and width ``b``.
+
+    .. note::
+
+    Args:
+        d: Timber layer section thickness
+        lay_orient: List of layer orientation
+        b: Timber section width
+        timb_mat0: Material object to assign to the timber area
+                   parallel-to-grain
+        timb_mat90: Material object to assign to the timber area,
+                    perpendicular-to-grain
+
+    Raises:
+        ValueError: Geometry generation failed
+
+    Returns:
+        Timber rectangular section geometry
+
+    Example:
+        The following example creates a 120mm CLT cross-section.
+    """
+
+    layer_geom = list()
+    for idx in range(len(d)):
+        di = float(d[idx])
+        layer = lay_orient[idx]
+
+        if layer is int(0):
+            timb_mat = timb_mat0
+        else:
+            timb_mat = timb_mat90
+
+        # create rectangular timber geometry
+        layer = primitive_sections.rectangular_section(d=di, b=b,
+                                                       material=timb_mat)
+        offset = -d[idx] * (idx + 1)
+        layer = layer.shift_section(y_offset=offset)
+
+        layer_geom.append(layer)
+
+    # create compound geometry
+    geom = geometry.CompoundGeometry(geoms=layer_geom)
+
+    if isinstance(geom, geometry.CompoundGeometry):
+        return geom
+    else:
+        raise ValueError("Timber section generation failed.")

tests/section_library/test_timber_sections.py

@@ -0,0 +1,74 @@
+"""Tests for the timber sections library."""
+
+from __future__ import annotations
+
+import numpy as np
+import pytest
+import pytest_check as check
+
+import sectionproperties.pre.library.timber_sections as ts
+import sectionproperties.pre.library.primitive_sections as ps
+import sectionproperties.pre.pre as pre
+
+
+r_tol = 1e-6
+
+
+# material setup
+@pytest.fixture
+def get_materials() -> tuple[pre.Material, pre.Material]:
+    """Creates a timber material parallel and perpendicular-to-grain.
+
+    Returns:
+        Material objects
+    """
+
+    timb_mat0 = pre.Material(
+        name="Timber E0",
+        elastic_modulus=9.5e3,
+        poissons_ratio=0.35,
+        density=4.4e-7,
+        yield_strength=5.5,
+        color="burlywood",
+    )
+
+    timb_mat90 = pre.Material(
+        name="Timber90",
+        elastic_modulus=317,
+        poissons_ratio=0.35,
+        density=4.4e-7,
+        yield_strength=5.5,
+        color="orange",
+    )
+
+    return timb_mat0, timb_mat90
+
+
+def test_timber_clt_rectangular_section(get_materials):
+    """Tests the timber clt_rectangular_section() method."""
+    timber0, timber90 = get_materials
+
+    rect = ts.clt_rectangular_section(
+        d=[40, 40, 40],
+        lay_orient=[0, 90, 0],
+        b=1000,
+        timb_mat0=timber0,
+        timb_mat90=timber90
+    )
+
+    # check geometry is created correctly
+    timb0_area = 0
+    timb90_area = 0
+
+    for geom in rect.geoms:
+        if geom.material == timber0:
+            timb0_area += geom.calculate_area()
+        elif geom.material == timber90:
+            timb90_area += geom.calculate_area()
+
+    actual_timb0_area = 2 * 40 * 1000
+    actual_timb90_area = 40 * 1000
+
+    # check areas
+    check.almost_equal(timb0_area, actual_timb0_area)
+    check.almost_equal(timb90_area, actual_timb90_area)