feat: add ACI 318-19 concrete and reinforcement material properties

structuralcodes/codes/__init__.py

@@ -3,9 +3,10 @@
 import types
 import typing as t
 
-from . import ec2_2004, ec2_2023, mc2010, mc2020
+from . import aci318, ec2_2004, ec2_2023, mc2010, mc2020
 
 __all__ = [
+    'aci318',
     'mc2010',
     'mc2020',
     'ec2_2023',
@@ -23,6 +24,7 @@
 
 # Design code registry
 _DESIGN_CODES = {
+    'aci318': aci318,
     'mc2010': mc2010,
     'mc2020': mc2020,
     'ec2_2004': ec2_2004,

structuralcodes/codes/aci318/__init__.py

@@ -0,0 +1,37 @@
+"""ACI 318-19."""
+
+import typing as t
+
+from ._concrete_material_properties import (
+    Ec,
+    alpha1,
+    beta1,
+    eps_cu,
+    fct,
+    fr,
+    lambda_factor,
+)
+from ._reinforcement_material_properties import (
+    Es,
+    epsyd,
+    fy_design,
+    reinforcement_grade_props,
+)
+
+__all__ = [
+    'Ec',
+    'Es',
+    'alpha1',
+    'beta1',
+    'eps_cu',
+    'epsyd',
+    'fct',
+    'fr',
+    'fy_design',
+    'lambda_factor',
+    'reinforcement_grade_props',
+]
+
+__title__: str = 'ACI 318-19'
+__year__: str = '2019'
+__materials__: t.Tuple[str] = ('concrete', 'reinforcement')

structuralcodes/codes/aci318/_concrete_material_properties.py

@@ -0,0 +1,164 @@
+"""Concrete material properties according to ACI 318-19."""
+
+from __future__ import annotations
+
+import math
+import typing as t
+
+LAMBDA_FACTORS = {
+    'normalweight': 1.0,
+    'sand-lightweight': 0.85,
+    'all-lightweight': 0.75,
+}
+
+
+def Ec(fc: float, wc: float = 2320.0) -> float:
+    """The modulus of elasticity of concrete.
+
+    ACI 318-19, Table 19.2.2.1.
+
+    Args:
+        fc (float): The specified compressive strength of concrete in
+            MPa.
+
+    Keyword Args:
+        wc (float): The unit weight of concrete in kg/m3.
+            Default is 2320 kg/m3 (normalweight concrete).
+
+    Returns:
+        float: The modulus of elasticity in MPa.
+
+    Raises:
+        ValueError: If fc is not positive.
+        ValueError: If wc is outside the range 1440-2560 kg/m3.
+    """
+    if fc <= 0:
+        raise ValueError(f'fc={fc} must be positive')
+    if wc < 1440 or wc > 2560:
+        raise ValueError(f'wc={wc} must be between 1440 and 2560 kg/m3')
+    return wc**1.5 * 0.043 * math.sqrt(fc)
+
+
+def fr(fc: float, lambda_s: float = 1.0) -> float:
+    """The modulus of rupture of concrete.
+
+    ACI 318-19, Eq. 19.2.3.1.
+
+    Args:
+        fc (float): The specified compressive strength of concrete in
+            MPa.
+
+    Keyword Args:
+        lambda_s (float): The modification factor for lightweight
+            concrete. Default is 1.0 (normalweight).
+
+    Returns:
+        float: The modulus of rupture in MPa.
+
+    Raises:
+        ValueError: If fc is not positive.
+        ValueError: If lambda_s is not in (0, 1].
+    """
+    if fc <= 0:
+        raise ValueError(f'fc={fc} must be positive')
+    if lambda_s <= 0 or lambda_s > 1.0:
+        raise ValueError(f'lambda_s={lambda_s} must be in the range (0, 1]')
+    return 0.62 * lambda_s * math.sqrt(fc)
+
+
+def beta1(fc: float) -> float:
+    """The Whitney stress block depth factor.
+
+    ACI 318-19, Table 22.2.2.4.3.
+
+    Args:
+        fc (float): The specified compressive strength of concrete in
+            MPa.
+
+    Returns:
+        float: The stress block depth factor (dimensionless).
+
+    Raises:
+        ValueError: If fc is not positive.
+    """
+    if fc <= 0:
+        raise ValueError(f'fc={fc} must be positive')
+    if fc <= 28:
+        return 0.85
+    if fc >= 55:
+        return 0.65
+    return 0.85 - 0.05 * (fc - 28) / 7
+
+
+def eps_cu() -> float:
+    """The maximum usable strain at the extreme concrete compression fiber.
+
+    ACI 318-19, Section 22.2.2.1.
+
+    Returns:
+        float: The ultimate concrete strain (dimensionless).
+    """
+    return 0.003
+
+
+def lambda_factor(
+    concrete_type: t.Literal[
+        'normalweight', 'sand-lightweight', 'all-lightweight'
+    ],
+) -> float:
+    """The modification factor for lightweight concrete.
+
+    ACI 318-19, Table 19.2.4.2.
+
+    Args:
+        concrete_type (str): The concrete type. One of
+            'normalweight', 'sand-lightweight', or 'all-lightweight'.
+
+    Returns:
+        float: The lightweight modification factor (dimensionless).
+
+    Raises:
+        ValueError: If concrete_type is not recognized.
+    """
+    result = LAMBDA_FACTORS.get(concrete_type.lower())
+    if result is None:
+        raise ValueError(
+            f'Unknown concrete type: {concrete_type}. '
+            f'Valid types: {list(LAMBDA_FACTORS.keys())}'
+        )
+    return result
+
+
+def fct(fc: float, lambda_s: float = 1.0) -> float:
+    """The approximate splitting tensile strength of concrete.
+
+    ACI 318-19, Section 19.2.4.3.
+
+    Args:
+        fc (float): The specified compressive strength of concrete in
+            MPa.
+
+    Keyword Args:
+        lambda_s (float): The modification factor for lightweight
+            concrete. Default is 1.0 (normalweight).
+
+    Returns:
+        float: The splitting tensile strength in MPa.
+
+    Raises:
+        ValueError: If fc is not positive.
+    """
+    if fc <= 0:
+        raise ValueError(f'fc={fc} must be positive')
+    return 0.56 * lambda_s * math.sqrt(fc)
+
+
+def alpha1() -> float:
+    """The ratio of equivalent rectangular stress block intensity.
+
+    ACI 318-19, Section 22.2.2.4.1.
+
+    Returns:
+        float: The stress block intensity factor (dimensionless).
+    """
+    return 0.85

structuralcodes/codes/aci318/_reinforcement_material_properties.py

@@ -0,0 +1,100 @@
+"""Reinforcement material properties according to ACI 318-19."""
+
+from __future__ import annotations
+
+import typing as t
+
+REINFORCEMENT_GRADES = {
+    '40': {'fy': 280.0, 'fu': 420.0},
+    '60': {'fy': 420.0, 'fu': 550.0},
+    '80': {'fy': 550.0, 'fu': 690.0},
+    '100': {'fy': 690.0, 'fu': 860.0},
+}
+
+
+def Es() -> float:
+    """The modulus of elasticity of reinforcement.
+
+    ACI 318-19, Section 20.2.2.2.
+
+    Returns:
+        float: The modulus of elasticity in MPa.
+    """
+    return 200000.0
+
+
+def fy_design(fy: float, phi: float = 1.0) -> float:
+    """The design yield strength of reinforcement.
+
+    ACI 318-19 applies strength reduction factors (phi) at the
+    member capacity level, not the material level. The default
+    phi=1.0 returns the unreduced yield strength, which is the
+    standard ACI convention for material properties.
+
+    Args:
+        fy (float): The specified yield strength in MPa.
+
+    Keyword Args:
+        phi (float): Optional strength reduction factor.
+            Default is 1.0 (no reduction).
+
+    Returns:
+        float: The design yield strength in MPa.
+
+    Raises:
+        ValueError: If fy is not positive.
+        ValueError: If phi is not in (0, 1].
+    """
+    if fy <= 0:
+        raise ValueError(f'fy={fy} must be positive')
+    if phi <= 0 or phi > 1.0:
+        raise ValueError(f'phi={phi} must be in the range (0, 1]')
+    return phi * fy
+
+
+def epsyd(fy: float, _Es: float = 200000.0) -> float:
+    """The yield strain of reinforcement.
+
+    Args:
+        fy (float): The specified yield strength in MPa.
+
+    Keyword Args:
+        _Es (float): The modulus of elasticity in MPa.
+            Default is 200000 MPa.
+
+    Returns:
+        float: The yield strain (dimensionless).
+
+    Raises:
+        ValueError: If fy is not positive.
+    """
+    if fy <= 0:
+        raise ValueError(f'fy={fy} must be positive')
+    return fy / _Es
+
+
+def reinforcement_grade_props(
+    grade: t.Literal['40', '60', '80', '100'],
+) -> t.Dict[str, float]:
+    """Return the minimum specified properties for a reinforcement grade.
+
+    ACI 318-19, Table 20.2.2.4a (SI equivalents).
+
+    Args:
+        grade (str): The ASTM reinforcement grade designation.
+            One of '40', '60', '80', or '100'.
+
+    Returns:
+        Dict[str, float]: A dict with keys 'fy' (yield strength in
+        MPa) and 'fu' (ultimate strength in MPa).
+
+    Raises:
+        ValueError: If the grade is not recognized.
+    """
+    props = REINFORCEMENT_GRADES.get(str(grade))
+    if props is None:
+        raise ValueError(
+            f'Unknown reinforcement grade: {grade}. '
+            f'Valid grades: {list(REINFORCEMENT_GRADES.keys())}'
+        )
+    return dict(props)

structuralcodes/materials/concrete/__init__.py

@@ -5,19 +5,22 @@
 from structuralcodes.codes import _use_design_code
 
 from ._concrete import Concrete
+from ._concreteACI318 import ConcreteACI318
 from ._concreteEC2_2004 import ConcreteEC2_2004
 from ._concreteEC2_2023 import ConcreteEC2_2023
 from ._concreteMC2010 import ConcreteMC2010
 
 __all__ = [
     'create_concrete',
     'Concrete',
+    'ConcreteACI318',
     'ConcreteMC2010',
     'ConcreteEC2_2023',
     'ConcreteEC2_2004',
 ]
 
 CONCRETES: t.Dict[str, Concrete] = {
+    'ACI 318-19': ConcreteACI318,
     'fib Model Code 2010': ConcreteMC2010,
     'EUROCODE 2 1992-1-1:2004': ConcreteEC2_2004,
     'EUROCODE 2 1992-1-1:2023': ConcreteEC2_2023,