Coverage for src/beamme/four_c/element_beam.py: 88%
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1# The MIT License (MIT)
2#
3# Copyright (c) 2018-2026 BeamMe Authors
4#
5# Permission is hereby granted, free of charge, to any person obtaining a copy
6# of this software and associated documentation files (the "Software"), to deal
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9# copies of the Software, and to permit persons to whom the Software is
10# furnished to do so, subject to the following conditions:
11#
12# The above copyright notice and this permission notice shall be included in
13# all copies or substantial portions of the Software.
14#
15# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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21# THE SOFTWARE.
22"""This file implements beam elements for 4C."""
24import warnings as _warnings
26import numpy as _np
28from beamme.core.conf import bme as _bme
29from beamme.core.element_beam import Beam as _Beam
30from beamme.core.element_beam import Beam2 as _Beam2
31from beamme.core.element_beam import generate_beam_class as _generate_beam_class
32from beamme.four_c.element_data import FourCElementData as _FourCElementData
33from beamme.four_c.four_c_types import (
34 BeamKirchhoffConstraintType as _BeamKirchhoffConstraintType,
35)
36from beamme.four_c.four_c_types import (
37 BeamKirchhoffParametrizationType as _BeamKirchhoffParametrizationType,
38)
39from beamme.four_c.four_c_types import BeamType as _BeamType
40from beamme.four_c.input_file_mappings import (
41 INPUT_FILE_MAPPINGS as _INPUT_FILE_MAPPINGS,
42)
45def get_four_c_reissner_beam(n_nodes: int, is_hermite_centerline: bool) -> type[_Beam]:
46 """Return a Simo-Reissner beam for 4C."""
48 four_c_type = _INPUT_FILE_MAPPINGS["four_c_type_to_four_c_type"][_BeamType.reissner]
49 four_c_cell = _INPUT_FILE_MAPPINGS["element_type_and_n_nodes_to_four_c_cell"][
50 _bme.element_type.beam, n_nodes
51 ]
52 element_technology = {"HERMITE_CENTERLINE": is_hermite_centerline}
53 data = _FourCElementData(
54 four_c_type=four_c_type,
55 four_c_cell=four_c_cell,
56 element_technology=element_technology,
57 )
59 if is_hermite_centerline:
60 coupling_fix_dict = {"NUMDOF": 9, "ONOFF": [1, 1, 1, 1, 1, 1, 0, 0, 0]}
61 coupling_joint_dict = {"NUMDOF": 9, "ONOFF": [1, 1, 1, 0, 0, 0, 0, 0, 0]}
62 else:
63 coupling_fix_dict = {"NUMDOF": 6, "ONOFF": [1, 1, 1, 1, 1, 1]}
64 coupling_joint_dict = {"NUMDOF": 6, "ONOFF": [1, 1, 1, 0, 0, 0]}
66 return type(
67 "BeamFourCSimoReissner",
68 (_generate_beam_class(n_nodes),),
69 {
70 "element_type": _bme.element_type.beam,
71 "beam_type": _BeamType.reissner,
72 "data": data,
73 "coupling_fix_dict": coupling_fix_dict,
74 "coupling_joint_dict": coupling_joint_dict,
75 },
76 )
79def get_four_c_kirchhoff_beam(
80 constraint: _BeamKirchhoffConstraintType = _BeamKirchhoffConstraintType.weak,
81 parametrization: _BeamKirchhoffParametrizationType = _BeamKirchhoffParametrizationType.rot,
82 is_fad: bool = True,
83) -> type[_Beam]:
84 """Return a Kirchhoff-Love beam for 4C."""
86 # Show warning when not using rotvec.
87 if not parametrization == _BeamKirchhoffParametrizationType.rot:
88 _warnings.warn(
89 "Use tangent based parametrization with caution, especially when "
90 " applying the boundary conditions and couplings."
91 )
93 n_nodes = 3
95 four_c_type = _INPUT_FILE_MAPPINGS["four_c_type_to_four_c_type"][
96 _BeamType.kirchhoff
97 ]
98 four_c_cell = _INPUT_FILE_MAPPINGS["element_type_and_n_nodes_to_four_c_cell"][
99 _bme.element_type.beam, n_nodes
100 ]
101 element_technology = {
102 "CONSTRAINT": constraint.name,
103 "PARAMETRIZATION": parametrization.name,
104 "USE_FAD": is_fad,
105 }
106 data = _FourCElementData(
107 four_c_type=four_c_type,
108 four_c_cell=four_c_cell,
109 element_technology=element_technology,
110 )
112 coupling_fix_dict = {"NUMDOF": 7, "ONOFF": [1, 1, 1, 1, 1, 1, 0]}
113 coupling_joint_dict = {"NUMDOF": 7, "ONOFF": [1, 1, 1, 0, 0, 0, 0]}
115 return type(
116 "BeamFourCKirchhoffLove",
117 (_generate_beam_class(n_nodes),),
118 {
119 "element_type": _bme.element_type.beam,
120 "beam_type": _BeamType.kirchhoff,
121 "kirchhoff_parametrization": parametrization,
122 "data": data,
123 "coupling_fix_dict": coupling_fix_dict,
124 "coupling_joint_dict": coupling_joint_dict,
125 },
126 )
129class BeamFourCEulerBernoulli(_Beam2):
130 """Represents a Euler Bernoulli beam element."""
132 element_type = _bme.element_type.beam
133 beam_type = _BeamType.euler_bernoulli
134 data = _FourCElementData(
135 four_c_type=_INPUT_FILE_MAPPINGS["four_c_type_to_four_c_type"][
136 _BeamType.euler_bernoulli
137 ],
138 four_c_cell=_INPUT_FILE_MAPPINGS["element_type_and_n_nodes_to_four_c_cell"][
139 _bme.element_type.beam, len(_Beam2.nodes_create)
140 ],
141 )
143 def check(self) -> None:
144 """Check that the beam is straight and that the two rotations are the
145 same."""
147 # Perform checks from the parent class.
148 super().check()
150 # The two rotations must be the same and the x1 vector must point from
151 # the start point to the end point.
152 if not self.nodes[0].rotation == self.nodes[1].rotation:
153 raise ValueError(
154 "The two nodal rotations in Euler Bernoulli beams must be the same,"
155 "i.e., the beam has to be straight!"
156 )
157 direction = self.nodes[1].coordinates - self.nodes[0].coordinates
158 t1 = self.nodes[0].rotation * [1, 0, 0]
159 if _np.linalg.norm(direction / _np.linalg.norm(direction) - t1) >= _bme.eps_pos:
160 raise ValueError(
161 "The rotations do not match the direction of the Euler Bernoulli beam!"
162 )
165def get_four_c_beam(
166 beam_type: _BeamType,
167 *,
168 n_nodes: int | None = None,
169 is_hermite_centerline: bool | None = None,
170 **kwargs,
171) -> type[_Beam]:
172 """Return an object that can be used to create beams with 4C."""
174 def _check_arguments(name, value, expected):
175 """Check that if an argument is given, it has the expected value."""
176 if value is not None and not value == expected:
177 raise ValueError(
178 f"Parameter {name} with the value {value} does not match the expected value {expected}"
179 )
181 match beam_type:
182 case _BeamType.reissner:
183 # Set default values for centerline interpolation
184 if n_nodes is None:
185 n_nodes = 3
186 if is_hermite_centerline is None:
187 is_hermite_centerline = True
188 return get_four_c_reissner_beam(
189 n_nodes=n_nodes, is_hermite_centerline=is_hermite_centerline, **kwargs
190 )
191 case _BeamType.kirchhoff:
192 _check_arguments("n_nodes", n_nodes, 3)
193 _check_arguments("is_hermite_centerline", is_hermite_centerline, True)
194 return get_four_c_kirchhoff_beam(**kwargs)
195 case _BeamType.euler_bernoulli:
196 _check_arguments("n_nodes", n_nodes, 2)
197 _check_arguments("is_hermite_centerline", is_hermite_centerline, True)
198 return BeamFourCEulerBernoulli
199 case _:
200 raise ValueError("Got unexpected beam type.")
203# Provide shortcuts for backwards compatibility
204Beam3rHerm2Line3 = get_four_c_beam(
205 _BeamType.reissner, n_nodes=3, is_hermite_centerline=True
206)
207Beam3rLine2Line2 = get_four_c_beam(
208 _BeamType.reissner, n_nodes=2, is_hermite_centerline=False
209)
210Beam3eb = get_four_c_beam(_BeamType.euler_bernoulli)