# -*- coding: utf-8 -*-
# ---------------------------------------------------------------------
#
# _____ _ _ _
# | ____|__| | ___| |_ _____(_)___ ___
# | _| / _` |/ _ \ \ \ /\ / / _ \ / __/ __|
# | |__| (_| | __/ |\ V V / __/ \__ \__ \
# |_____\__,_|\___|_| \_/\_/_\___|_|___/___/
# | \/ | ___ ___| |__ / _|_ __ ___ ___
# | |\/| |/ _ \/ __| '_ \| |_| '__/ _ \/ _ \
# | | | | __/\__ \ | | | _| | | __/ __/
# |_| |_|\___||___/_| |_|_| |_| \___|\___|
#
#
# Unit of Strength of Materials and Structural Analysis
# University of Innsbruck,
#
# Research Group for Computational Mechanics of Materials
# Institute of Structural Engineering, BOKU University, Vienna
#
# 2023 - today
#
# Matthias Neuner | matthias.neuner@boku.ac.at
# Thomas Mader | thomas.mader@bokut.ac.at
#
# This file is part of EdelweissMeshfree.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# The full text of the license can be found in the file LICENSE.md at
# the top level directory of EdelweissMeshfree.
# ---------------------------------------------------------------------
import numpy as np
from edelweissfe.timesteppers.timestep import TimeStep
from edelweissmeshfree.sets.cellset import CellSet
from edelweissmeshfree.stepactions.base.mpmbodyloadbase import MPMBodyLoadBase
[docs]
class BodyLoad(MPMBodyLoadBase):
def __init__(self, name, model, journal, cells, bodyLoadType: str, loadVector, **kwargs):
"""
This is a classical body load for MPM models.
Parameters
----------
name : str
Name of the distributed load.
model : MPMModel
The MPM model tree.
journal : Journal
The journal to write messages to.
cells: CellSet
The cells to apply the distributed load to.
bodyLoadType: str
The type of the body load, e.g., "gravity".
loadVector : np.ndarray
The load vector to apply to the particles.
**kwargs
Additional keyword arguments. The following are supported:
- f_t : Callable[[float], float]
The amplitude function of the distributed load.
"""
self.name = name
self._loadVector = loadVector
self._loadAtStepStart = np.zeros_like(self._loadVector)
self._loadType = bodyLoadType
self._cells = cells
if len(self._loadVector) < model.domainSize:
raise Exception("BodyForce {:}: load vector has wrong dimension!".format(self.name))
self._delta = self._loadVector
if "f_t" in kwargs:
self._amplitude = kwargs["f_t"]
else:
self._amplitude = lambda x: x
self._idle = False
@property
def cellSet(self) -> CellSet:
return self._cells
@property
def loadType(self) -> str:
return self._loadType
[docs]
def applyAtStepEnd(self, model, stepMagnitude=None):
if not self._idle:
if stepMagnitude is None:
# standard case
self._loadAtStepStart += self._delta * self._amplitude(1.0)
else:
# set the 'actual' increment manually, e.g. for arc length method
self._loadAtStepStart += self._delta * stepMagnitude
self._delta = 0
self._idle = True
[docs]
def getCurrentLoad(self, timeStep: TimeStep):
if self._idle:
t = 1.0
else:
t = timeStep.stepProgress
return self._loadAtStepStart + self._delta * self._amplitude(t)