symcad.parts.endcaps.Hemisphere

  1#!/usr/bin/env python3
  2# Copyright (C) 2022, Will Hedgecock
  3#
  4# This program is free software: you can redistribute it and/or modify
  5# it under the terms of the GNU General Public License as published by
  6# the Free Software Foundation, either version 3 of the License, or
  7# (at your option) any later version.
  8#
  9# This program is distributed in the hope that it will be useful,
 10# but WITHOUT ANY WARRANTY; without even the implied warranty of
 11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12# GNU General Public License for more details.
 13#
 14# You should have received a copy of the GNU General Public License
 15# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 16
 17from __future__ import annotations
 18from PyFreeCAD.FreeCAD import FreeCAD, Part
 19from typing import Dict, Optional, Tuple, Union
 20from sympy import Expr, Symbol
 21from . import EndcapShape
 22import math
 23
 24class Hemisphere(EndcapShape):
 25   """Model representing a hollow, parametric, hemispherical endcap.
 26
 27   By default, the endcap is oriented such that its base is perpendicular to the z-axis:
 28
 29   ![Hemisphere](https://symbench.github.io/SymCAD/images/Hemisphere.png)
 30
 31   The `geometry` of this shape includes the following parameters:
 32
 33   - `radius`: Radius (in `m`) of the Hemisphere
 34   - `thickness`: Thickness (in `m`) of the shell of the Hemisphere
 35
 36   Note that the above dimensions should be interpreted as if the Hemisphere is unrotated.
 37   In other words, any shape rotation takes place *after* the Hemisphere dimensions have been
 38   specified.
 39   """
 40
 41   # Constructor ----------------------------------------------------------------------------------
 42
 43   def __init__(self, identifier: str, material_density_kg_m3: Optional[float] = 1.0) -> None:
 44      """Initializes a hollow, parametric, hemispherical endcap object.
 45
 46      Parameters
 47      ----------
 48      identifier : `str`
 49         Unique identifying name for the object.
 50      material_density_kg_m3 : `float`, optional, default=1.0
 51         Uniform material density in `kg/m^3` to be used in mass property calculations.
 52      """
 53      super().__init__(identifier, self.__create_cad__, None, material_density_kg_m3)
 54      setattr(self.geometry, 'radius', Symbol(self.name + '_radius'))
 55      setattr(self.geometry, 'thickness', Symbol(self.name + '_thickness'))
 56
 57
 58   # CAD generation function ----------------------------------------------------------------------
 59
 60   @staticmethod
 61   def __create_cad__(params: Dict[str, float], fully_displace: bool) -> Part.Solid:
 62      """Scripted CAD generation method for a `Hemisphere`."""
 63      thickness_mm = 1000.0 * params['thickness']
 64      outer_radius_mm = 1000.0 * params['radius']
 65      inner_radius_mm = outer_radius_mm - thickness_mm
 66      outer = Part.makeSphere(outer_radius_mm, FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(0, 0, 1), 0, 90, 360)
 67      if not fully_displace:
 68         inner = Part.makeSphere(inner_radius_mm, FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(0, 0, 1), 0, 90, 360)
 69         return outer.cut(inner)
 70      else:
 71         return outer
 72
 73
 74   # Geometry setter ------------------------------------------------------------------------------
 75
 76   def set_geometry(self, *, radius_m: Union[float, None],
 77                             thickness_m: Union[float, None]) -> Hemisphere:
 78      """Sets the physical geometry of the current `Hemisphere` object.
 79
 80      See the `Hemisphere` class documentation for a description of each geometric parameter.
 81      """
 82      self.geometry.set(radius=radius_m, thickness=thickness_m)
 83      return self
 84
 85   def get_geometric_parameter_bounds(self, parameter: str) -> Tuple[float, float]:
 86      parameter_bounds = {
 87         'radius': (0.0, 2.0),
 88         'thickness': (0.0, 0.05)
 89      }
 90      return parameter_bounds.get(parameter, (0.0, 0.0))
 91
 92
 93   # Geometric properties -------------------------------------------------------------------------
 94
 95   @property
 96   def material_volume(self) -> Union[float, Expr]:
 97      volume = self.displaced_volume
 98      volume -= ((2.0 * math.pi / 3.0) * (self.geometry.radius - self.geometry.thickness)**3)
 99      return volume
100
101   @property
102   def displaced_volume(self) -> Union[float, Expr]:
103      return (2.0 * math.pi / 3.0) * self.geometry.radius**3
104
105   @property
106   def surface_area(self) -> Union[float, Expr]:
107      return 2.0 * math.pi * self.geometry.radius**2
108
109   @property
110   def unoriented_center_of_gravity(self) -> Tuple[Union[float, Expr],
111                                                   Union[float, Expr],
112                                                   Union[float, Expr]]:
113      return self.geometry.radius, self.geometry.radius, 0.5 * self.geometry.radius
114
115   @property
116   def unoriented_center_of_buoyancy(self) -> Tuple[Union[float, Expr],
117                                                    Union[float, Expr],
118                                                    Union[float, Expr]]:
119      return self.geometry.radius, self.geometry.radius, 3.0 * self.geometry.radius / 8.0
120
121   @property
122   def unoriented_length(self) -> Union[float, Expr]:
123      return 2.0 * self.geometry.radius
124
125   @property
126   def unoriented_width(self) -> Union[float, Expr]:
127      return self.unoriented_length
128
129   @property
130   def unoriented_height(self) -> Union[float, Expr]:
131      return self.geometry.radius
132
133   @property
134   def oriented_length(self) -> Union[float, Expr]:
135      # TODO: Implement this
136      return 0
137
138   @property
139   def oriented_width(self) -> Union[float, Expr]:
140      # TODO: Implement this
141      return 0
142
143   @property
144   def oriented_height(self) -> Union[float, Expr]:
145      # TODO: Implement this
146      return 0