Coverage for src/beamme/four_c/element_beam.py: 93%
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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."""
47 four_c_type = _INPUT_FILE_MAPPINGS["four_c_type_to_four_c_type"][_BeamType.reissner]
48 four_c_cell = _INPUT_FILE_MAPPINGS["element_type_and_n_nodes_to_four_c_cell"][
49 _bme.element_type.beam, n_nodes
50 ]
51 element_technology = {"HERMITE_CENTERLINE": is_hermite_centerline}
52 data = _FourCElementData(
53 four_c_type=four_c_type,
54 four_c_cell=four_c_cell,
55 element_technology=element_technology,
56 )
58 if is_hermite_centerline:
59 coupling_fix_dict = {"NUMDOF": 9, "ONOFF": [1, 1, 1, 1, 1, 1, 0, 0, 0]}
60 coupling_joint_dict = {"NUMDOF": 9, "ONOFF": [1, 1, 1, 0, 0, 0, 0, 0, 0]}
61 else:
62 coupling_fix_dict = {"NUMDOF": 6, "ONOFF": [1, 1, 1, 1, 1, 1]}
63 coupling_joint_dict = {"NUMDOF": 6, "ONOFF": [1, 1, 1, 0, 0, 0]}
65 return type(
66 "BeamFourCSimoReissner",
67 (_generate_beam_class(n_nodes),),
68 {
69 "element_type": _bme.element_type.beam,
70 "beam_type": _BeamType.reissner,
71 "data": data,
72 "coupling_fix_dict": coupling_fix_dict,
73 "coupling_joint_dict": coupling_joint_dict,
74 },
75 )
78def get_four_c_kirchhoff_beam(
79 constraint: _BeamKirchhoffConstraintType = _BeamKirchhoffConstraintType.weak,
80 parametrization: _BeamKirchhoffParametrizationType = _BeamKirchhoffParametrizationType.rot,
81 is_fad: bool = True,
82) -> type[_Beam]:
83 """Return a Kirchhoff-Love beam for 4C."""
84 # Show warning when not using rotvec.
85 if not parametrization == _BeamKirchhoffParametrizationType.rot:
86 _warnings.warn(
87 "Use tangent based parametrization with caution, especially when "
88 " applying the boundary conditions and couplings."
89 )
91 n_nodes = 3
93 four_c_type = _INPUT_FILE_MAPPINGS["four_c_type_to_four_c_type"][
94 _BeamType.kirchhoff
95 ]
96 four_c_cell = _INPUT_FILE_MAPPINGS["element_type_and_n_nodes_to_four_c_cell"][
97 _bme.element_type.beam, n_nodes
98 ]
99 element_technology = {
100 "CONSTRAINT": constraint.name,
101 "PARAMETRIZATION": parametrization.name,
102 "USE_FAD": is_fad,
103 }
104 data = _FourCElementData(
105 four_c_type=four_c_type,
106 four_c_cell=four_c_cell,
107 element_technology=element_technology,
108 )
110 coupling_fix_dict = {"NUMDOF": 7, "ONOFF": [1, 1, 1, 1, 1, 1, 0]}
111 coupling_joint_dict = {"NUMDOF": 7, "ONOFF": [1, 1, 1, 0, 0, 0, 0]}
113 return type(
114 "BeamFourCKirchhoffLove",
115 (_generate_beam_class(n_nodes),),
116 {
117 "element_type": _bme.element_type.beam,
118 "beam_type": _BeamType.kirchhoff,
119 "kirchhoff_parametrization": parametrization,
120 "data": data,
121 "coupling_fix_dict": coupling_fix_dict,
122 "coupling_joint_dict": coupling_joint_dict,
123 },
124 )
127class BeamFourCEulerBernoulli(_Beam2):
128 """Represents a Euler Bernoulli beam element."""
130 element_type = _bme.element_type.beam
131 beam_type = _BeamType.euler_bernoulli
132 data = _FourCElementData(
133 four_c_type=_INPUT_FILE_MAPPINGS["four_c_type_to_four_c_type"][
134 _BeamType.euler_bernoulli
135 ],
136 four_c_cell=_INPUT_FILE_MAPPINGS["element_type_and_n_nodes_to_four_c_cell"][
137 _bme.element_type.beam, len(_Beam2.nodes_create)
138 ],
139 )
141 def check(self) -> None:
142 """Check that the beam is straight and that the two rotations are the same."""
143 # Perform checks from the parent class.
144 super().check()
146 # The two rotations must be the same and the x1 vector must point from
147 # the start point to the end point.
148 if not self.nodes[0].rotation == self.nodes[1].rotation:
149 raise ValueError(
150 "The two nodal rotations in Euler Bernoulli beams must be the same,"
151 "i.e., the beam has to be straight!"
152 )
153 direction = self.nodes[1].coordinates - self.nodes[0].coordinates
154 t1 = self.nodes[0].rotation * [1, 0, 0]
155 if _np.linalg.norm(direction / _np.linalg.norm(direction) - t1) >= _bme.eps_pos:
156 raise ValueError(
157 "The rotations do not match the direction of the Euler Bernoulli beam!"
158 )
161def get_four_c_beam(
162 beam_type: _BeamType,
163 *,
164 n_nodes: int | None = None,
165 is_hermite_centerline: bool | None = None,
166 **kwargs,
167) -> type[_Beam]:
168 """Return an object that can be used to create beams with 4C."""
170 def _check_arguments(name, value, expected):
171 """Check that if an argument is given, it has the expected value."""
172 if value is not None and not value == expected:
173 raise ValueError(
174 f"Parameter {name} with the value {value} does not match the expected value {expected}"
175 )
177 match beam_type:
178 case _BeamType.reissner:
179 # Set default values for centerline interpolation
180 if n_nodes is None:
181 n_nodes = 3
182 if is_hermite_centerline is None:
183 is_hermite_centerline = True
184 return get_four_c_reissner_beam(
185 n_nodes=n_nodes, is_hermite_centerline=is_hermite_centerline, **kwargs
186 )
187 case _BeamType.kirchhoff:
188 _check_arguments("n_nodes", n_nodes, 3)
189 _check_arguments("is_hermite_centerline", is_hermite_centerline, True)
190 return get_four_c_kirchhoff_beam(**kwargs)
191 case _BeamType.euler_bernoulli:
192 _check_arguments("n_nodes", n_nodes, 2)
193 _check_arguments("is_hermite_centerline", is_hermite_centerline, True)
194 return BeamFourCEulerBernoulli
195 case _:
196 raise ValueError("Got unexpected beam type.")
199# Provide shortcuts for backwards compatibility
200Beam3rHerm2Line3 = get_four_c_beam(
201 _BeamType.reissner, n_nodes=3, is_hermite_centerline=True
202)
203Beam3rLine2Line2 = get_four_c_beam(
204 _BeamType.reissner, n_nodes=2, is_hermite_centerline=False
205)
206Beam3eb = get_four_c_beam(_BeamType.euler_bernoulli)