Merge pull request #252 from robbievanleeuwen/concrete_column_section

Update concrete_sections library to have a unified approach to working with bar diameters and areas. Added `concrete_column_section`.

Author: connorferster

sectionproperties/pre/library/concrete_sections.py

@@ -1,3 +1,4 @@
+from typing import Union, Optional
 import numpy as np
 from shapely.geometry import Polygon
 import sectionproperties.pre.pre as pre
@@ -106,53 +107,40 @@ def concrete_rectangular_section(
         x_i_side_right = b - x_i_side_left
         spacing_side = (d - 2 * cover - dia_top / 2 - dia_bot / 2) / (n_side + 1)
 
+    if area_top is None:
+        area_top = np.pi * dia_top**2 / 4
+    if area_bot is None:
+        area_bot = np.pi * dia_bot**2 / 4
+    if area_side is None and dia_side is not None:
+        area_side = np.pi * dia_side**2 / 4
+
     # add top bars
     for i in range(n_top):
-        if area_top:
-            bar = primitive_sections.circular_section_by_area(
-                area=area_top, n=n_circle, material=steel_mat
-            )
-        else:
-            bar = primitive_sections.circular_section(
-                d=dia_top, n=n_circle, material=steel_mat
-            )
-
+        bar = primitive_sections.circular_section_by_area(
+            area=area_top, n=n_circle, material=steel_mat
+        )
         bar = bar.shift_section(
             x_offset=x_i_top + spacing_top * i, y_offset=d - cover - dia_top / 2
         )
-
         geom = (geom - bar) + bar
 
     # add bot bars
     for i in range(n_bot):
-        if area_bot:
-            bar = primitive_sections.circular_section_by_area(
-                area=area_bot, n=n_circle, material=steel_mat
-            )
-        else:
-            bar = primitive_sections.circular_section(
-                d=dia_bot, n=n_circle, material=steel_mat
-            )
-
+        bar = primitive_sections.circular_section_by_area(
+            area=area_bot, n=n_circle, material=steel_mat
+        )
         bar = bar.shift_section(
             x_offset=x_i_bot + spacing_bot * i, y_offset=cover + dia_bot / 2
         )
-
         geom = (geom - bar) + bar
 
     # add side bars if specified
     if n_side != 0:
         for i in range(n_side):
-            if area_side:
-                bar_left = primitive_sections.circular_section_by_area(
-                    area=area_side, n=n_circle, material=steel_mat
-                )
-                bar_right = bar_left
-            else:
-                bar_left = primitive_sections.circular_section(
-                    d=dia_side, n=n_circle, material=steel_mat
-                )
-                bar_right = bar_left
+            bar_left = primitive_sections.circular_section_by_area(
+                area=area_side, n=n_circle, material=steel_mat
+            )
+            bar_right = bar_left
 
             bar_left = bar_left.shift_section(
                 x_offset=x_i_side_left,
@@ -168,6 +156,129 @@ def concrete_rectangular_section(
     return geom
 
 
+def concrete_column_section(
+    b: float,
+    d: float,
+    cover: float,
+    n_bars_b: int,
+    n_bars_d: int,
+    dia_bar: float,
+    bar_area: Optional[float] = None,
+    conc_mat: pre.Material = pre.DEFAULT_MATERIAL,
+    steel_mat: pre.Material = pre.DEFAULT_MATERIAL,
+    filled: bool = False,
+    n_circle: int = 4,
+) -> geometry.CompoundGeometry:
+    """Constructs a concrete rectangular section of width *b* and depth *d*, with
+    steel bar reinforcing organized as an *n_bars_b* by *n_bars_d* array, discretised
+    with *n_circle* points with equal sides and top/bottom *cover* to the steel which
+    is taken as the clear cover (edge of bar to edge of concrete).
+
+    :param float b: Concrete section width, parallel to the x-axis
+    :param float d: Concrete section depth, parallel to the y-axis
+    :param float cover: Clear cover, calculated as distance from edge of reinforcing bar to edge of section.
+    :param int n_bars_b: Number of bars placed across the width of the section, minimum 2.
+    :param int n_bars_d: Number of bars placed across the depth of the section, minimum 2.
+    :param float dia_bar: Diameter of reinforcing bars. Used for calculating bar placement and,
+        optionally, for calculating the bar area for section capacity calculations.
+    :param Optional[float] bar_area: Area of reinforcing bars. Used for section capacity calculations.
+        If not provided, then dia_bar will be used to calculate the bar area.
+    :param Optional[sectionproperties.pre.pre.Material] conc_mat: Material to
+        associate with the concrete
+    :param Optional[sectionproperties.pre.pre.Material] steel_mat: Material to
+        associate with the reinforcing steel
+    :param bool filled: When True, will populate the concrete section with an equally
+        spaced 2D array of reinforcing bars numbering 'n_bars_b' by 'n_bars_d'.
+        When False, only the bars around the perimeter of the array will be present.
+    :param int n_circle: The number of points used to discretize the circle of the reinforcing
+        bars. The bars themselves will have an exact area of 'bar_area' regardless of the
+        number of points used in the circle. Useful for making the reinforcing bars look
+        more circular when plotting the concrete section.
+
+    :raises ValueError: If the number of bars in either 'n_bars_b' or 'n_bars_d' is not greater
+        than or equal to 2.
+
+    The following example creates a 600D x 300W concrete column with 25 mm diameter
+    reinforcing bars each with 500 mm**2 area and 35 mm cover in a 3x6 array without
+    the interior bars being filled::
+
+        from sectionproperties.pre.library.concrete_sections import concrete_column_section
+        from sectionproperties.pre.pre import Material
+
+        concrete = Material(
+            name='Concrete', elastic_modulus=30.1e3, poissons_ratio=0.2, yield_strength=32,
+            density=2.4e-6, color='lightgrey'
+        )
+        steel = Material(
+            name='Steel', elastic_modulus=200e3, poissons_ratio=0.3, yield_strength=500,
+            density=7.85e-6, color='grey'
+        )
+
+        geometry = concrete_column_section(
+            b=300, d=600, dia_bar=25, bar_area=500, cover=35, n_bars_b=3, n_bars_d=6,
+            conc_mat=concrete, steel_mat=steel, filled=False, n_circle=4
+        )
+        geometry.create_mesh(mesh_sizes=[500])
+
+    ..  figure:: ../images/sections/concrete_rectangular_section_geometry.png
+        :align: center
+        :scale: 50 %
+
+        Concrete rectangular section geometry.
+
+    ..  figure:: ../images/sections/concrete_rectangular_section_mesh.png
+        :align: center
+        :scale: 50 %
+
+        Mesh generated from the above geometry.
+    """
+    concrete_geometry = primitive_sections.rectangular_section(b, d, material=conc_mat)
+    bar_extents = concrete_geometry.offset_perimeter(
+        -cover - dia_bar / 2
+    ).calculate_extents()
+    bar_x_min, bar_x_max, bar_y_min, bar_y_max = bar_extents
+
+    b_edge_bars_x = np.linspace(bar_x_min, bar_x_max, n_bars_b)
+    d_edge_bars_y = np.linspace(bar_y_min, bar_y_max, n_bars_d)
+
+    if not filled:
+        b_edge_bars_y1 = [bar_y_min] * n_bars_b
+        b_edge_bars_y2 = [bar_y_max] * n_bars_b
+
+        d_edge_bars_x1 = [bar_x_min] * n_bars_d
+        d_edge_bars_x2 = [bar_x_max] * n_bars_d
+
+        b_edge_bars_top = list(zip(b_edge_bars_x, b_edge_bars_y2))
+        b_edge_bars_bottom = list(zip(b_edge_bars_x, b_edge_bars_y1))
+        d_edge_bars_right = list(zip(d_edge_bars_x2, d_edge_bars_y))
+        d_edge_bars_left = list(zip(d_edge_bars_x1, d_edge_bars_y))
+
+        all_bar_coords = list(
+            set(
+                b_edge_bars_top
+                + b_edge_bars_bottom
+                + d_edge_bars_right
+                + d_edge_bars_left
+            )
+        )
+    if filled:
+        xy = np.meshgrid(b_edge_bars_x, d_edge_bars_y)
+        all_bar_coords = np.append(xy[0].reshape(-1, 1), xy[1].reshape(-1, 1), axis=1)
+
+    if bar_area is None:
+        bar_area = np.pi * dia_bar**2 / 4
+    for bar_coord in all_bar_coords:
+        concrete_geometry = add_bar(
+            concrete_geometry,
+            area=bar_area,
+            material=steel_mat,
+            x=bar_coord[0],
+            y=bar_coord[1],
+            n=n_circle,
+        )
+    return concrete_geometry
+
+
 def concrete_tee_section(
     b: float,
     d: float,
@@ -261,38 +372,29 @@ def concrete_tee_section(
     spacing_top = (b_f - 2 * cover - dia_top) / (n_top - 1)
     spacing_bot = (b - 2 * cover - dia_bot) / (n_bot - 1)
 
+    if area_top is None:
+        area_top = np.pi * dia_top**2 / 4
+    if area_bot is None:
+        area_bot = np.pi * dia_bot**2 / 4
+
     # add top bars
     for i in range(n_top):
-        if area_top:
-            bar = primitive_sections.circular_section_by_area(
-                area=area_top, n=n_circle, material=steel_mat
-            )
-        else:
-            bar = primitive_sections.circular_section(
-                d=dia_top, n=n_circle, material=steel_mat
-            )
-
+        bar = primitive_sections.circular_section_by_area(
+            area=area_top, n=n_circle, material=steel_mat
+        )
         bar = bar.shift_section(
             x_offset=x_i_top + spacing_top * i, y_offset=d - cover - dia_top / 2
         )
-
         geom = (geom - bar) + bar
 
     # add bot bars
     for i in range(n_bot):
-        if area_bot:
-            bar = primitive_sections.circular_section_by_area(
-                area=area_bot, n=n_circle, material=steel_mat
-            )
-        else:
-            bar = primitive_sections.circular_section(
-                d=dia_bot, n=n_circle, material=steel_mat
-            )
-
+        bar = primitive_sections.circular_section_by_area(
+            area=area_bot, n=n_circle, material=steel_mat
+        )
         bar = bar.shift_section(
             x_offset=x_i_bot + spacing_bot * i, y_offset=cover + dia_bot / 2
         )
-
         geom = (geom - bar) + bar
 
     return geom
@@ -380,20 +482,41 @@ def concrete_circular_section(
     r = d / 2 - cover - dia / 2
     d_theta = 2 * np.pi / n_bar
 
+    if area_bar is None:
+        area_bar = np.pi * dia**2 / 4
     for i in range(n_bar):
-        if area_bar:
-            bar = primitive_sections.circular_section_by_area(
-                area=area_bar, n=n_circle, material=steel_mat
-            )
-        else:
-            bar = primitive_sections.circular_section(
-                d=dia, n=n_circle, material=steel_mat
-            )
-
+        bar = primitive_sections.circular_section_by_area(
+            area=area_bar, n=n_circle, material=steel_mat
+        )
         bar = bar.shift_section(
             x_offset=r * np.cos(i * d_theta), y_offset=r * np.sin(i * d_theta)
         )
-
         geom = (geom - bar) + bar
 
     return geom
+
+
+def add_bar(
+    geometry: Union[geometry.Geometry, geometry.CompoundGeometry],
+    area: float,
+    material: pre.DEFAULT_MATERIAL,
+    x: float,
+    y: float,
+    n: int = 4,
+) -> geometry.CompoundGeometry:
+    """Adds a reinforcing bar to a *sectionproperties* geometry.
+    Bars are discretised by four points by default.
+    :param geometry: Reinforced concrete geometry to which the new bar will be added
+    :param area: Bar cross-sectional area
+    :param material: Material object for the bar
+    :param x: x-position of the bar
+    :param y: y-position of the bar
+    :param n: Number of points to discretise the bar circle
+    :return: Reinforced concrete geometry with added bar
+    """
+
+    bar = primitive_sections.circular_section_by_area(
+        area=area, n=n, material=material  # type: ignore
+    ).shift_section(x_offset=x, y_offset=y)
+
+    return (geometry - bar) + bar