Source code for felupe.mechanics._step

# -*- coding: utf-8 -*-
This file is part of FElupe.

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it under the terms of the GNU General Public License as published by
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import numpy as np

from ..dof import apply, partition
from import newtonrhapson

[docs] class Step: """A Step with multiple substeps, subsequently depending on the solution of the previous substep. Parameters ---------- items : list of SolidBody, SolidBodyNearlyIncompressible, SolidBodyPressure, SolidBodyGravity, PointLoad, MultiPointConstraint or MultiPointContact A list of items with methods for the assembly of sparse vectors/matrices. ramp : dict, optional A dict with :class:`~felupe.Boundary` or ``item``-keys which holds the array of values to ramp (default is None). If None, only one substep is evaluated. boundaries : dict of Boundary, optional A dict with :class:`~felupe.Boundary` conditions (default is None). Examples -------- .. pyvista-plot:: >>> import felupe as fem >>> >>> mesh = fem.Cube(n=6) >>> region = fem.RegionHexahedron(mesh) >>> field = fem.FieldContainer([fem.Field(region, dim=3)]) >>> >>> boundaries = fem.dof.symmetry(field[0]) >>> boundaries["clamped"] = fem.Boundary(field[0], fx=1, skip=(True, False, False)) >>> boundaries["move"] = fem.Boundary(field[0], fx=1, skip=(False, True, True)) >>> >>> umat = fem.NeoHooke(mu=1, bulk=2) >>> solid = fem.SolidBody(umat, field) >>> >>> move = fem.math.linsteps([0, 1], num=5) >>> step = fem.Step(items=[solid], ramp={boundaries["move"]: move}, boundaries=boundaries) >>> >>> job = fem.Job(steps=[step]).evaluate() >>> ax = solid.plot("Principal Values of Cauchy Stress").show() """ def __init__(self, items, ramp=None, boundaries=None): self.items = items if ramp is None: self.ramp = {} self.nsubsteps = 1 else: self.ramp = dict(ramp) self.nsubsteps = len(list(self.ramp.values())[0]) if boundaries is None: boundaries = {} self.boundaries = boundaries
[docs] def generate(self, **kwargs): "Yield all generated substeps." substeps = np.arange(self.nsubsteps) if "x0" not in kwargs.keys(): field = self.items[0].field else: field = kwargs["x0"] stop = False for substep in substeps: if stop: break # update items for item, value in self.ramp.items(): item.update(value[substep]) # update load case dof0, dof1 = partition(field, self.boundaries) ext0 = apply(field, self.boundaries, dof0) # run newton-rhapson iterations res = newtonrhapson( items=self.items, dof0=dof0, dof1=dof1, ext0=ext0, **kwargs, ) if not res.success: stop = True break else: yield res