Source code for felupe.mechanics._pointload
# -*- coding: utf-8 -*-
"""
This file is part of FElupe.
FElupe is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
FElupe is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FElupe. If not, see <http://www.gnu.org/licenses/>.
"""
import numpy as np
from scipy.sparse import csr_matrix
from ._helpers import Assemble, Results
[docs]
class PointLoad:
"A point load with methods for the assembly of sparse vectors/matrices."
def __init__(self, field, points, values=None, apply_on=0, axisymmetric=False):
self.field = field
self.points = points
if values is None:
self.values = 0
else:
self.values = values
self.apply_on = apply_on
self.axisymmetric = axisymmetric
self.results = Results()
self.assemble = Assemble(vector=self._vector, matrix=self._matrix)
[docs]
def update(self, values):
self.__init__(self.field, self.points, values, self.apply_on, self.axisymmetric)
def _vector(self, field=None, parallel=False):
if field is not None:
self.field = field
force = [np.zeros_like(f.values) for f in self.field.fields]
force[self.apply_on][self.points] += self.values
if self.axisymmetric:
mesh_points = self.field[0].region.mesh.points
radius = mesh_points[self.points, 1].reshape(-1, 1)
force[self.apply_on][self.points] *= 2 * np.pi * radius
self.results.force = csr_matrix(
np.concatenate([f.ravel() for f in force]).reshape(-1, 1)
)
return -self.results.force
def _matrix(self, field=None, parallel=False):
if field is not None:
self.field = field
n = np.sum(self.field.fieldsizes)
self.results.stiffness = csr_matrix(([0], ([0], [0])), shape=(n, n))
return self.results.stiffness