impl asymmetric roll pass

Author: axtimhaus

pyroll/core/__init__.py

@@ -2,7 +2,7 @@
 
 from .grooves import *
 from .transport import Transport, CoolingPipe
-from .roll_pass import BaseRollPass, RollPass, DeformationUnit, ThreeRollPass
+from .roll_pass import BaseRollPass, RollPass, DeformationUnit, ThreeRollPass, AsymmetricTwoRollPass
 from .unit import Unit
 from .roll import Roll
 from .profile import *
@@ -16,6 +16,8 @@
 
 root_hooks.extend(
     [
+        AsymmetricTwoRollPass.InProfile.pass_line,
+        AsymmetricTwoRollPass.InProfile.cross_section,
         BaseRollPass.roll_force,
         BaseRollPass.Roll.roll_torque,
         BaseRollPass.elongation_efficiency,

pyroll/core/roll_pass/__init__.py

@@ -1,5 +1,6 @@
 from .base import BaseRollPass
 from .two_roll_pass import TwoRollPass
+from .asymmetric_two_roll_pass import AsymmetricTwoRollPass
 from .three_roll_pass import ThreeRollPass
 from .deformation_unit import DeformationUnit
 

pyroll/core/roll_pass/asymmetric_two_roll_pass.py

@@ -0,0 +1,114 @@
+from typing import List, cast
+
+import numpy as np
+from shapely.affinity import translate, scale
+from shapely.geometry import LineString
+
+from .base import BaseRollPass
+from ..hooks import Hook
+from ..roll import Roll as BaseRoll
+
+
+class AsymmetricTwoRollPass(BaseRollPass):
+    """Represents a symmetric roll pass with equal upper and lower working roll."""
+
+    def __init__(
+            self,
+            upper_roll: BaseRoll,
+            lower_roll: BaseRoll,
+            label: str = "",
+            **kwargs
+    ):
+        super().__init__(label, **kwargs)
+
+        self.upper_roll = self.Roll(upper_roll, self)
+        """The upper working roll of this pass."""
+
+        self.lower_roll = self.Roll(lower_roll, self)
+        """The upper working roll of this pass."""
+
+    @property
+    def contour_lines(self) -> List[LineString]:
+        if self._contour_lines:
+            return self._contour_lines
+
+        upper = translate(self.upper_roll.contour_line, yoff=self.gap / 2)
+        lower = scale(
+            translate(self.lower_roll.contour_line.reverse(), yoff=self.gap / 2),
+            xfact=1, yfact=-1, origin=(0, 0)
+        )
+
+        self._contour_lines = [upper, lower]
+        return self._contour_lines
+
+    @property
+    def classifiers(self):
+        """A tuple of keywords to specify the shape type classifiers of this roll pass.
+        Shortcut to ``self.groove.classifiers``."""
+        return set(self.upper_roll.groove.classifiers) | set(self.lower_roll.groove.classifiers) | {"asymmetric"}
+
+    @property
+    def disk_elements(self) -> List['AsymmetricTwoRollPass.DiskElement']:
+        """A list of disk elements used to subdivide this unit."""
+        return list(self._subunits)
+
+    def get_root_hook_results(self):
+        super_results = super().get_root_hook_results()
+        upper_roll_results = self.upper_roll.evaluate_and_set_hooks()
+        lower_roll_results = self.lower_roll.evaluate_and_set_hooks()
+        return np.concatenate([super_results, upper_roll_results, lower_roll_results], axis=0)
+
+    def reevaluate_cache(self):
+        super().reevaluate_cache()
+        self.upper_roll.reevaluate_cache()
+        self.lower_roll.reevaluate_cache()
+        self._contour_lines = None
+
+    class Profile(BaseRollPass.Profile):
+        """Represents a profile in context of a roll pass."""
+
+        @property
+        def roll_pass(self) -> 'AsymmetricTwoRollPass':
+            """Reference to the roll pass. Alias for ``self.unit``."""
+            return cast(AsymmetricTwoRollPass, self.unit)
+
+    class InProfile(Profile, BaseRollPass.InProfile):
+        """Represents an incoming profile of a roll pass."""
+
+        pass_line = Hook[tuple[float, float, float]]()
+        """Point (x, y, z) where the incoming profile centroid enters the roll pass."""
+
+    class OutProfile(Profile, BaseRollPass.OutProfile):
+        """Represents an outgoing profile of a roll pass."""
+
+        filling_ratio = Hook[float]()
+
+    class Roll(BaseRollPass.Roll):
+        """Represents a roll applied in a :py:class:`RollPass`."""
+
+        @property
+        def roll_pass(self) -> 'AsymmetricTwoRollPass':
+            """Reference to the roll pass."""
+            return cast(AsymmetricTwoRollPass, self._roll_pass())
+
+    class DiskElement(BaseRollPass.DiskElement):
+        """Represents a disk element in a roll pass."""
+
+        @property
+        def roll_pass(self) -> 'AsymmetricTwoRollPass':
+            """Reference to the roll pass. Alias for ``self.parent``."""
+            return cast(AsymmetricTwoRollPass, self.parent)
+
+        class Profile(BaseRollPass.DiskElement.Profile):
+            """Represents a profile in context of a disk element unit."""
+
+            @property
+            def disk_element(self) -> 'AsymmetricTwoRollPass.DiskElement':
+                """Reference to the disk element. Alias for ``self.unit``"""
+                return cast(AsymmetricTwoRollPass.DiskElement, self.unit)
+
+        class InProfile(Profile, BaseRollPass.DiskElement.InProfile):
+            """Represents an incoming profile of a disk element unit."""
+
+        class OutProfile(Profile, BaseRollPass.DiskElement.OutProfile):
+            """Represents an outgoing profile of a disk element unit."""

pyroll/core/roll_pass/base.py

@@ -109,6 +109,12 @@ def __init__(
 
         self._contour_lines = None
 
+        self.given_in_profile: BaseProfile | None = None
+        """The incoming profile as was given to the ``solve`` method."""
+
+        self.rotated_in_profile: BaseProfile | None = None
+        """The incoming profile after rotation."""
+
     @property
     @abstractmethod
     def contour_lines(self):
@@ -128,6 +134,8 @@ def disk_elements(self) -> List['BaseRollPass.DiskElement']:
         return list(self._subunits)
 
     def init_solve(self, in_profile: BaseProfile):
+        self.given_in_profile = in_profile
+
         if self.rotation:
             rotator = Rotator(
                 # make True determining from hook functions
@@ -136,14 +144,15 @@ def init_solve(self, in_profile: BaseProfile):
                 duration=0, length=0, parent=self
             )
             rotator.solve(in_profile)
-            in_profile = rotator.out_profile
+            self.rotated_in_profile = rotator.out_profile
+        else:
+            self.rotated_in_profile = in_profile
 
-        super().init_solve(in_profile)
+        super().init_solve(self.rotated_in_profile)
         self.out_profile.cross_section = self.usable_cross_section
 
     def reevaluate_cache(self):
         super().reevaluate_cache()
-        self.roll.reevaluate_cache()
         self._contour_lines = None
 
     class Profile(DiskElementUnit.Profile, DeformationUnit.Profile):

pyroll/core/roll_pass/hookimpls/__init__.py

@@ -1,6 +1,7 @@
 from . import base_roll_pass
 from . import symmetric_roll_pass
 from . import two_roll_pass
+from . import asymmetric_two_roll_pass
 from . import three_roll_pass
 from . import profile
 from . import roll

pyroll/core/roll_pass/hookimpls/asymmetric_two_roll_pass.py

@@ -0,0 +1,140 @@
+import numpy as np
+import scipy.optimize
+import shapely.affinity
+from shapely import Polygon
+
+from . import helpers
+from ..asymmetric_two_roll_pass import AsymmetricTwoRollPass
+from ...grooves import GenericElongationGroove
+
+
+@AsymmetricTwoRollPass.usable_width
+def usable_width(self: AsymmetricTwoRollPass):
+    return min(self.upper_roll.groove.usable_width, self.lower_roll.groove.usable_width)
+
+
+@AsymmetricTwoRollPass.tip_width
+def tip_width(self: AsymmetricTwoRollPass):
+    if isinstance(self.upper_roll.groove, GenericElongationGroove) and isinstance(
+        self.lower_roll.groove, GenericElongationGroove
+    ):
+        return min(
+            self.upper_roll.groove.usable_width + self.gap / 2 / np.tan(self.upper_roll.groove.flank_angle),
+            self.lower_roll.groove.usable_width + self.gap / 2 / np.tan(self.lower_roll.groove.flank_angle),
+        )
+
+
+@AsymmetricTwoRollPass.usable_cross_section
+def usable_cross_section(self: AsymmetricTwoRollPass) -> Polygon:
+    return helpers.out_cross_section(self, self.usable_width)
+
+
+@AsymmetricTwoRollPass.tip_cross_section
+def tip_cross_section(self: AsymmetricTwoRollPass) -> Polygon:
+    return helpers.out_cross_section(self, self.tip_width)
+
+
+@AsymmetricTwoRollPass.gap
+def gap(self: AsymmetricTwoRollPass):
+    if self.has_set_or_cached("height"):
+        return self.height - self.upper_roll.groove.depth - self.lower_roll.groove.depth
+
+
+@AsymmetricTwoRollPass.height
+def height(self: AsymmetricTwoRollPass):
+    if self.has_set_or_cached("gap"):
+        return self.gap + self.upper_roll.groove.depth + self.lower_roll.groove.depth
+
+
+@AsymmetricTwoRollPass.contact_area
+def contact_area(self: AsymmetricTwoRollPass):
+    return self.upper_roll.contact_area + self.lower_roll.contact_area
+
+
+@AsymmetricTwoRollPass.target_cross_section_area
+def target_cross_section_area_from_target_width(self: AsymmetricTwoRollPass):
+    if self.has_value("target_width"):
+        target_cross_section = helpers.out_cross_section(self, self.target_width)
+        return target_cross_section.area
+
+
+@AsymmetricTwoRollPass.power
+def roll_power(self: AsymmetricTwoRollPass):
+    return self.upper_roll.roll_power + self.lower_roll.roll_power
+
+
+@AsymmetricTwoRollPass.velocity
+def velocity(self: AsymmetricTwoRollPass):
+    if self.upper_roll.has_value("neutral_angle") and self.lower_roll.has_value("neutral_angle"):
+        return (
+            self.upper_roll.working_velocity * np.cos(self.upper_roll.neutral_angle)
+            + self.lower_roll.working_velocity * np.cos(self.lower_roll.neutral_angle)
+        ) / 2
+    else:
+        return (self.upper_roll.working_velocity + self.lower_roll.working_velocity) / 2
+
+
+@AsymmetricTwoRollPass.roll_force
+def roll_force(self: AsymmetricTwoRollPass):
+    return (
+        (self.in_profile.flow_stress + 2 * self.out_profile.flow_stress)
+        / 3
+        * (self.upper_roll.contact_area + self.lower_roll.contact_area)
+        / 2
+    )
+
+
+@AsymmetricTwoRollPass.InProfile.pass_line
+def pass_line(self: AsymmetricTwoRollPass.InProfile) -> tuple[float, float, float]:
+    rp = self.roll_pass
+
+    if not self.has_set("pass_line"):
+        height_change = self.height - rp.height
+        x_guess = -(
+            np.sqrt(height_change)
+            * np.sqrt(
+                (2 * rp.upper_roll.min_radius - height_change)
+                * (2 * rp.lower_roll.min_radius - height_change)
+                * (2 * rp.upper_roll.min_radius + 2 * rp.lower_roll.min_radius - height_change)
+            )
+        ) / (2 * (rp.upper_roll.min_radius + rp.lower_roll.min_radius - height_change))
+        y_guess = 0
+    else:
+        x_guess, y_guess, _ = self.pass_line
+
+    def contact_objective(xy):
+        shifted_cross_section = shapely.affinity.translate(rp.rotated_in_profile.cross_section, yoff=xy[1])
+
+        upper_contour = shapely.geometry.LineString(np.stack([
+            rp.upper_roll.surface_z,
+            rp.upper_roll.surface_interpolation(xy[0], rp.upper_roll.surface_z).squeeze(axis=1)
+        ], axis=1))
+        upper_contour = shapely.affinity.translate(upper_contour,yoff=self.roll_pass.gap / 2)
+        lower_contour = shapely.geometry.LineString(np.stack([
+            rp.lower_roll.surface_z,
+            rp.lower_roll.surface_interpolation(xy[0], rp.lower_roll.surface_z).squeeze(axis=1)
+        ], axis=1))
+        lower_contour = shapely.affinity.scale(shapely.affinity.translate(lower_contour, yoff=self.roll_pass.gap / 2), xfact=1, yfact=-1, origin=(0,0))
+
+        upper_intersection = shapely.intersection(upper_contour, shifted_cross_section)
+        lower_intersection = shapely.intersection(lower_contour, shifted_cross_section)
+
+        upper_value = upper_intersection.length if not upper_intersection.is_empty else shapely.shortest_line(upper_contour, shifted_cross_section).length
+        lower_value = lower_intersection.length if not lower_intersection.is_empty else shapely.shortest_line(lower_contour, shifted_cross_section).length
+
+        return upper_value ** 2 + lower_value ** 2
+
+    sol = scipy.optimize.minimize(contact_objective, (x_guess, y_guess), method="BFGS", options=dict(xrtol=1e-2))
+
+    return sol.x[0], sol.x[1], 0
+
+
+@AsymmetricTwoRollPass.InProfile.cross_section
+def in_cross_section(self:AsymmetricTwoRollPass.InProfile):
+    return shapely.affinity.translate(self.roll_pass.rotated_in_profile.cross_section, xoff=self.pass_line[2], yoff=self.pass_line[1])
+
+
+@AsymmetricTwoRollPass.entry_point
+def entry_point(self: AsymmetricTwoRollPass):
+    return self.in_profile.pass_line[0]
+

pyroll/core/roll_pass/hookimpls/helpers.py

@@ -7,10 +7,11 @@
 
 from ..two_roll_pass import TwoRollPass
 from ..three_roll_pass import ThreeRollPass
+from ..asymmetric_two_roll_pass import AsymmetricTwoRollPass
 from ...profile.profile import refine_cross_section
 
 
-def out_cross_section(rp: TwoRollPass, width: float) -> Polygon:
+def out_cross_section(rp: TwoRollPass | AsymmetricTwoRollPass, width: float) -> Polygon:
     poly = Polygon(np.concatenate([cl.coords for cl in rp.contour_lines]))
     poly = clip_by_rect(poly, -width / 2, -math.inf, width / 2, math.inf)
     return refine_cross_section(poly)