NGsolveCreateFFRFreducedOrder.py

You can view and download this file on Github: NGsolveCreateFFRFreducedOrder.py

#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
# This is an EXUDYN example
#
# Details:  New CreateFFRFReducedOrderObject function using NGsolve and ObjectGenericODE2;
#           uses super-functions to simplify creating of flexible bodies
#
# Author:   Sebastian Weyrer, Johannes Gerstmayr
# Date:     2025-12-27
#
# Copyright:This file is part of Exudyn. Exudyn is free software. You can redistribute it and/or modify it under the terms of the Exudyn license. See 'LICENSE.txt' for more details.
#
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


import exudyn as exu
from exudyn.itemInterface import *
from exudyn.utilities import * #includes itemInterface and rigidBodyUtilities
import exudyn.graphics as graphics
from exudyn.FEM import *

SC = exu.SystemContainer()
mbs = SC.AddSystem()

import numpy as np

import exudyn as exu
import exudyn.graphics as graphics
from exudyn.FEM import * # includes fem functionality
from exudyn.utilities import * #includes itemInterface and rigidBodyUtilities
from netgen import occ
import ngsolve as ngs
SC = exu.SystemContainer()
mbs = SC.AddSystem()

materials = {'steel':{'youngsModulus':2e11, 'poissonsRatio':0.3, 'density':7850}}
L = 1
W = 0.1
cuboid = occ.Box((0, -W/2, -W/2), (L, W/2, W/2))
boundaryNamesList = ['boundary0', 'boundary1']
cuboid.faces.Min((1, 0, 0)).name = boundaryNamesList[0]
cuboid.faces.Max((1, 0, 0)).name = boundaryNamesList[1]
cuboid.name = 'steel'
geo = occ.OCCGeometry(cuboid)

mesh = ngs.Mesh(geo.GenerateMesh(maxh=0.025))

cuboidFemInterface = FEMinterface()
cuboidFemInterface.ImportMeshFromNGsolve(mesh=mesh,
                                         materials=materials,
                                         boundaryNamesList=boundaryNamesList,
                                         meshOrder=1)
[boundaryNodesList, boundaryWeightsList] = cuboidFemInterface.GetBoundaryNodeSetsAsLists()
cuboidFemInterface.ComputeHurtyCraigBamptonModes(boundaryNodesList=boundaryNodesList,
                                                 nEigenModes=6,
                                                 boundaryNodesWeights=boundaryWeightsList)
createFFRFObjectDict0 = mbs.CreateFFRFReducedOrderObject(name='cuboid0',
                                                        femInterface=cuboidFemInterface,
                                                        gravity=[0,0,-9.81])
mBoundary00 = createFFRFObjectDict0['cuboid0:boundary0']
mBoundary01 = createFFRFObjectDict0['cuboid0:boundary1']

createFFRFObjectDict1 = mbs.CreateFFRFReducedOrderObject(name='cuboid1',
                                                        femInterface=cuboidFemInterface,
                                                        referencePosition=[L,0,0],
                                                        gravity=[0,0,-9.81])
mBoundary10 = createFFRFObjectDict1['cuboid1:boundary0']
mBoundary11 = createFFRFObjectDict1['cuboid1:boundary1']

gGround = graphics.CheckerBoard(point=[0,0,-2.5], size=8, nTiles=10, normal=[0.,0,1])
oGround = mbs.CreateGround(referencePosition=[0,0,0],
                           graphicsDataList=[gGround])

#joints:
mbs.CreateSphericalJoint(itemNumbers=[mBoundary00, oGround], jointRadius = W/4)
mbs.CreateSphericalJoint(itemNumbers=[mBoundary01, mBoundary10], jointRadius = W/4)

mbs.Assemble()
simulationSettings = exu.SimulationSettings() #takes currently set values or default values
simulationSettings.timeIntegration.numberOfSteps = 1000
simulationSettings.timeIntegration.endTime = 2
SC.visualizationSettings.nodes.show = False
SC.visualizationSettings.openGL.light0.shadow = 0.2
SC.visualizationSettings.openGL.multiSampling = 2

SC.renderer.Start()
SC.renderer.RestoreSavedState() #load last model view

SC.renderer.DoIdleTasks() #press space to continue

mbs.SolveDynamic(simulationSettings)

SC.renderer.Stop() #safely close rendering window!

mbs.SolutionViewer()