Commit 4a7f5ed1 authored by Henry Weller's avatar Henry Weller
Browse files

applications/test/rigidBodyDynamics/sphericalJoint: Test for the quaternion-based spherical joint

parent b2563a8f
sphericalJoint.C
EXE = $(FOAM_USER_APPBIN)/Test-sphericalJoint
EXE_INC = \
-I$(LIB_SRC)/rigidBodyDynamics/lnInclude
EXE_LIBS = \
-lrigidBodyDynamics
solver
{
type Newmark;
}
// It is necessary to iterate for the Newmark solver
nIter 2;
bodies
{
pendulum
{
type rigidBody;
mass 1;
centreOfMass (0 -1 0);
inertia (0.001 0 0 0.001 0 0.001);
parent root;
transform (1 0 0 0 1 0 0 0 1) (0 0 0);
joint
{
type Rs;
}
}
}
/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2016 OpenFOAM Foundation
\\/ M anipulation |
-------------------------------------------------------------------------------
License
This file is part of OpenFOAM.
OpenFOAM 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.
OpenFOAM 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 OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
Application
sphericalJoint
Description
Simple spherical-joint pendulum.
\*---------------------------------------------------------------------------*/
#include "rigidBodyMotion.H"
#include "masslessBody.H"
#include "sphere.H"
#include "joints.H"
#include "rigidBodyRestraint.H"
#include "rigidBodyModelState.H"
#include "IFstream.H"
#include "OFstream.H"
using namespace Foam;
using namespace RBD;
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
int main(int argc, char *argv[])
{
dictionary sphericalJointDict(IFstream("sphericalJoint")());
// Create the sphericalJoint model from dictionary
rigidBodyMotion sphericalJoint(sphericalJointDict);
label nIter(readLabel(sphericalJointDict.lookup("nIter")));
Info<< sphericalJoint << endl;
// Create the joint-space force field
scalarField tau(sphericalJoint.nDoF(), Zero);
// Create the external body force field
Field<spatialVector> fx(sphericalJoint.nBodies(), Zero);
// Set the angle of the pendulum to 0.3rad
sphericalJoint.joints()[1]
(
quaternion(quaternion::ZYX, vector(0.3, 0, 0)),
sphericalJoint.state().q(),
sphericalJoint.state().w()
);
// Set the gravitational acceleration
sphericalJoint.g() = vector(0, -9.81, 0);
OFstream omegaFile("omegaVsTime");
// Integrate the motion of the sphericalJoint for 4.1s
scalar deltaT = 0.01;
for (scalar t=0; t<4.1; t+=deltaT)
{
sphericalJoint.newTime();
for (label i=0; i<nIter; i++)
{
sphericalJoint.solve(deltaT, tau, fx);
}
// Write the results for graph generation
// using 'gnuplot sphericalJoint.gnuplot'
omegaFile
<< t << " "
<< sphericalJoint.joints()[1]
(
sphericalJoint.state().q(),
sphericalJoint.state().w()
).eulerAngles(quaternion::ZYX).x()
<< endl;
}
Info<< "\nEnd\n" << endl;
return 0;
}
// ************************************************************************* //
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