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ENH: Transferring momentOfInertia calc from utils to meshTools lib.
Adding mesh cell inertia calc.
This commit is contained in:
graham
@ -1,5 +1,6 @@
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EXE_INC = \
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-I$(LIB_SRC)/meshTools/lnInclude
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-I$(LIB_SRC)/meshTools/lnInclude \
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-I$(LIB_SRC)/triSurface/lnInclude
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EXE_LIBS = \
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-lmeshTools
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@ -26,180 +26,38 @@ Application
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Description
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Calculates the inertia tensor and principal axes and moments of a
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test face and tetrahedron.
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test face, tetrahedron and mesh.
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\*---------------------------------------------------------------------------*/
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#include "argList.H"
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#include "Time.H"
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#include "polyMesh.H"
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#include "ListOps.H"
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#include "face.H"
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#include "tetPointRef.H"
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#include "triFaceList.H"
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#include "OFstream.H"
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#include "meshTools.H"
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#include "momentOfInertia.H"
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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using namespace Foam;
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void massPropertiesSolid
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(
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const pointField& pts,
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const triFaceList triFaces,
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scalar density,
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scalar& mass,
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vector& cM,
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tensor& J
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)
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{
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// Reimplemented from: Wm4PolyhedralMassProperties.cpp
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// File Version: 4.10.0 (2009/11/18)
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// Geometric Tools, LC
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// Copyright (c) 1998-2010
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// Distributed under the Boost Software License, Version 1.0.
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// http://www.boost.org/LICENSE_1_0.txt
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// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
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// Boost Software License - Version 1.0 - August 17th, 2003
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// Permission is hereby granted, free of charge, to any person or
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// organization obtaining a copy of the software and accompanying
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// documentation covered by this license (the "Software") to use,
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// reproduce, display, distribute, execute, and transmit the
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// Software, and to prepare derivative works of the Software, and
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// to permit third-parties to whom the Software is furnished to do
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// so, all subject to the following:
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// The copyright notices in the Software and this entire
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// statement, including the above license grant, this restriction
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// and the following disclaimer, must be included in all copies of
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// the Software, in whole or in part, and all derivative works of
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// the Software, unless such copies or derivative works are solely
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// in the form of machine-executable object code generated by a
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// source language processor.
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
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// NON-INFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
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// ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE FOR ANY DAMAGES OR
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// OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
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// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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// USE OR OTHER DEALINGS IN THE SOFTWARE.
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const scalar r6 = 1.0/6.0;
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const scalar r24 = 1.0/24.0;
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const scalar r60 = 1.0/60.0;
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const scalar r120 = 1.0/120.0;
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// order: 1, x, y, z, x^2, y^2, z^2, xy, yz, zx
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scalarField integrals(10, 0.0);
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forAll(triFaces, i)
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{
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const triFace& tri(triFaces[i]);
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// vertices of triangle i
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vector v0 = pts[tri[0]];
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vector v1 = pts[tri[1]];
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vector v2 = pts[tri[2]];
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// cross product of edges
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vector eA = v1 - v0;
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vector eB = v2 - v0;
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vector n = eA ^ eB;
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// compute integral terms
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scalar tmp0, tmp1, tmp2;
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scalar f1x, f2x, f3x, g0x, g1x, g2x;
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tmp0 = v0.x() + v1.x();
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f1x = tmp0 + v2.x();
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tmp1 = v0.x()*v0.x();
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tmp2 = tmp1 + v1.x()*tmp0;
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f2x = tmp2 + v2.x()*f1x;
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f3x = v0.x()*tmp1 + v1.x()*tmp2 + v2.x()*f2x;
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g0x = f2x + v0.x()*(f1x + v0.x());
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g1x = f2x + v1.x()*(f1x + v1.x());
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g2x = f2x + v2.x()*(f1x + v2.x());
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scalar f1y, f2y, f3y, g0y, g1y, g2y;
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tmp0 = v0.y() + v1.y();
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f1y = tmp0 + v2.y();
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tmp1 = v0.y()*v0.y();
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tmp2 = tmp1 + v1.y()*tmp0;
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f2y = tmp2 + v2.y()*f1y;
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f3y = v0.y()*tmp1 + v1.y()*tmp2 + v2.y()*f2y;
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g0y = f2y + v0.y()*(f1y + v0.y());
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g1y = f2y + v1.y()*(f1y + v1.y());
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g2y = f2y + v2.y()*(f1y + v2.y());
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scalar f1z, f2z, f3z, g0z, g1z, g2z;
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tmp0 = v0.z() + v1.z();
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f1z = tmp0 + v2.z();
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tmp1 = v0.z()*v0.z();
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tmp2 = tmp1 + v1.z()*tmp0;
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f2z = tmp2 + v2.z()*f1z;
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f3z = v0.z()*tmp1 + v1.z()*tmp2 + v2.z()*f2z;
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g0z = f2z + v0.z()*(f1z + v0.z());
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g1z = f2z + v1.z()*(f1z + v1.z());
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g2z = f2z + v2.z()*(f1z + v2.z());
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// update integrals
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integrals[0] += n.x()*f1x;
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integrals[1] += n.x()*f2x;
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integrals[2] += n.y()*f2y;
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integrals[3] += n.z()*f2z;
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integrals[4] += n.x()*f3x;
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integrals[5] += n.y()*f3y;
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integrals[6] += n.z()*f3z;
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integrals[7] += n.x()*(v0.y()*g0x + v1.y()*g1x + v2.y()*g2x);
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integrals[8] += n.y()*(v0.z()*g0y + v1.z()*g1y + v2.z()*g2y);
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integrals[9] += n.z()*(v0.x()*g0z + v1.x()*g1z + v2.x()*g2z);
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}
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integrals[0] *= r6;
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integrals[1] *= r24;
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integrals[2] *= r24;
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integrals[3] *= r24;
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integrals[4] *= r60;
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integrals[5] *= r60;
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integrals[6] *= r60;
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integrals[7] *= r120;
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integrals[8] *= r120;
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integrals[9] *= r120;
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// mass
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mass = integrals[0];
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// center of mass
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cM = vector(integrals[1], integrals[2], integrals[3])/mass;
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// inertia relative to origin
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J.xx() = integrals[5] + integrals[6];
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J.xy() = -integrals[7];
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J.xz() = -integrals[9];
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J.yx() = J.xy();
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J.yy() = integrals[4] + integrals[6];
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J.yz() = -integrals[8];
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J.zx() = J.xz();
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J.zy() = J.yz();
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J.zz() = integrals[4] + integrals[5];
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// inertia relative to center of mass
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J -= mass*((cM & cM)*I - cM*cM);
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// Apply density
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mass *= density;
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J *= density;
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}
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int main(int argc, char *argv[])
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{
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argList::addOption
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(
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"cell",
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"label",
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"cell to use for inertia calculation, defaults to 0"
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);
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#include "setRootCase.H"
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#include "createTime.H"
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#include "createPolyMesh.H"
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scalar density = 1.0;
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{
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@ -286,16 +144,7 @@ int main(int argc, char *argv[])
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vector cM = vector::zero;
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tensor J = tensor::zero;
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massPropertiesSolid
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(
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pts,
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tetFaces,
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density,
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m,
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cM,
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J
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);
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momentOfInertia::massPropertiesSolid(pts, tetFaces, density, m, cM, J);
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vector eVal = eigenValues(J);
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@ -344,7 +193,50 @@ int main(int argc, char *argv[])
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{
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str << "l " << nPts + 1 << ' ' << i + 1 << endl;
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}
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}
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{
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const label cellI = args.optionLookupOrDefault("cell", 0);
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tensorField mI = momentOfInertia::meshInertia(mesh);
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tensor& J = mI[cellI];
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vector eVal = eigenValues(J);
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Info<< nl
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<< "Inertia tensor of cell " << cellI << " " << J << nl
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<< "eigenValues (principal moments) " << eVal << endl;
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J /= cmptMax(eVal);
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tensor eVec = eigenVectors(J);
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Info<< "eigenVectors (principal axes, from normalised inertia) " << eVec
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<< endl;
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OFstream str("cell_" + name(cellI) + "_inertia.obj");
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Info<< nl << "Writing scaled principal axes of cell " << cellI << " to "
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<< str.name() << endl;
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const point& cC = mesh.cellCentres()[cellI];
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scalar scale = mag
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(
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(cC - mesh.faceCentres()[mesh.cells()[cellI][0]])
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/eVal.component(findMin(eVal))
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);
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meshTools::writeOBJ(str, cC);
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meshTools::writeOBJ(str, cC + scale*eVal.x()*eVec.x());
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meshTools::writeOBJ(str, cC + scale*eVal.y()*eVec.y());
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meshTools::writeOBJ(str, cC + scale*eVal.z()*eVec.z());
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for (label i = 1; i < 4; i++)
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{
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str << "l " << 1 << ' ' << i + 1 << endl;
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}
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}
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Info<< nl << "End" << nl << endl;
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@ -33,9 +33,6 @@ Description
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#include "argList.H"
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#include "ListOps.H"
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#include "face.H"
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#include "tetPointRef.H"
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#include "triFaceList.H"
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#include "triSurface.H"
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#include "OFstream.H"
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#include "meshTools.H"
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@ -43,242 +40,12 @@ Description
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#include "transform.H"
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#include "IOmanip.H"
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#include "Pair.H"
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#include "momentOfInertia.H"
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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using namespace Foam;
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void massPropertiesSolid
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(
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const pointField& pts,
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const triFaceList& triFaces,
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scalar density,
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scalar& mass,
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vector& cM,
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tensor& J
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)
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{
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// Reimplemented from: Wm4PolyhedralMassProperties.cpp
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// File Version: 4.10.0 (2009/11/18)
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// Geometric Tools, LC
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// Copyright (c) 1998-2010
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// Distributed under the Boost Software License, Version 1.0.
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// http://www.boost.org/LICENSE_1_0.txt
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// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
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// Boost Software License - Version 1.0 - August 17th, 2003
|
||||
|
||||
// Permission is hereby granted, free of charge, to any person or
|
||||
// organization obtaining a copy of the software and accompanying
|
||||
// documentation covered by this license (the "Software") to use,
|
||||
// reproduce, display, distribute, execute, and transmit the
|
||||
// Software, and to prepare derivative works of the Software, and
|
||||
// to permit third-parties to whom the Software is furnished to do
|
||||
// so, all subject to the following:
|
||||
|
||||
// The copyright notices in the Software and this entire
|
||||
// statement, including the above license grant, this restriction
|
||||
// and the following disclaimer, must be included in all copies of
|
||||
// the Software, in whole or in part, and all derivative works of
|
||||
// the Software, unless such copies or derivative works are solely
|
||||
// in the form of machine-executable object code generated by a
|
||||
// source language processor.
|
||||
|
||||
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||||
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
||||
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
|
||||
// NON-INFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
|
||||
// ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE FOR ANY DAMAGES OR
|
||||
// OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
|
||||
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
|
||||
// USE OR OTHER DEALINGS IN THE SOFTWARE.
|
||||
|
||||
const scalar r6 = 1.0/6.0;
|
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const scalar r24 = 1.0/24.0;
|
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const scalar r60 = 1.0/60.0;
|
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const scalar r120 = 1.0/120.0;
|
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|
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// order: 1, x, y, z, x^2, y^2, z^2, xy, yz, zx
|
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scalarField integrals(10, 0.0);
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forAll(triFaces, i)
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{
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const triFace& tri(triFaces[i]);
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|
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// vertices of triangle i
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vector v0 = pts[tri[0]];
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vector v1 = pts[tri[1]];
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vector v2 = pts[tri[2]];
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|
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// cross product of edges
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vector eA = v1 - v0;
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vector eB = v2 - v0;
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vector n = eA ^ eB;
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|
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// compute integral terms
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scalar tmp0, tmp1, tmp2;
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|
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scalar f1x, f2x, f3x, g0x, g1x, g2x;
|
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|
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tmp0 = v0.x() + v1.x();
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f1x = tmp0 + v2.x();
|
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tmp1 = v0.x()*v0.x();
|
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tmp2 = tmp1 + v1.x()*tmp0;
|
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f2x = tmp2 + v2.x()*f1x;
|
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f3x = v0.x()*tmp1 + v1.x()*tmp2 + v2.x()*f2x;
|
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g0x = f2x + v0.x()*(f1x + v0.x());
|
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g1x = f2x + v1.x()*(f1x + v1.x());
|
||||
g2x = f2x + v2.x()*(f1x + v2.x());
|
||||
|
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scalar f1y, f2y, f3y, g0y, g1y, g2y;
|
||||
|
||||
tmp0 = v0.y() + v1.y();
|
||||
f1y = tmp0 + v2.y();
|
||||
tmp1 = v0.y()*v0.y();
|
||||
tmp2 = tmp1 + v1.y()*tmp0;
|
||||
f2y = tmp2 + v2.y()*f1y;
|
||||
f3y = v0.y()*tmp1 + v1.y()*tmp2 + v2.y()*f2y;
|
||||
g0y = f2y + v0.y()*(f1y + v0.y());
|
||||
g1y = f2y + v1.y()*(f1y + v1.y());
|
||||
g2y = f2y + v2.y()*(f1y + v2.y());
|
||||
|
||||
scalar f1z, f2z, f3z, g0z, g1z, g2z;
|
||||
|
||||
tmp0 = v0.z() + v1.z();
|
||||
f1z = tmp0 + v2.z();
|
||||
tmp1 = v0.z()*v0.z();
|
||||
tmp2 = tmp1 + v1.z()*tmp0;
|
||||
f2z = tmp2 + v2.z()*f1z;
|
||||
f3z = v0.z()*tmp1 + v1.z()*tmp2 + v2.z()*f2z;
|
||||
g0z = f2z + v0.z()*(f1z + v0.z());
|
||||
g1z = f2z + v1.z()*(f1z + v1.z());
|
||||
g2z = f2z + v2.z()*(f1z + v2.z());
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||||
|
||||
// update integrals
|
||||
integrals[0] += n.x()*f1x;
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||||
integrals[1] += n.x()*f2x;
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||||
integrals[2] += n.y()*f2y;
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||||
integrals[3] += n.z()*f2z;
|
||||
integrals[4] += n.x()*f3x;
|
||||
integrals[5] += n.y()*f3y;
|
||||
integrals[6] += n.z()*f3z;
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||||
integrals[7] += n.x()*(v0.y()*g0x + v1.y()*g1x + v2.y()*g2x);
|
||||
integrals[8] += n.y()*(v0.z()*g0y + v1.z()*g1y + v2.z()*g2y);
|
||||
integrals[9] += n.z()*(v0.x()*g0z + v1.x()*g1z + v2.x()*g2z);
|
||||
}
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||||
|
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integrals[0] *= r6;
|
||||
integrals[1] *= r24;
|
||||
integrals[2] *= r24;
|
||||
integrals[3] *= r24;
|
||||
integrals[4] *= r60;
|
||||
integrals[5] *= r60;
|
||||
integrals[6] *= r60;
|
||||
integrals[7] *= r120;
|
||||
integrals[8] *= r120;
|
||||
integrals[9] *= r120;
|
||||
|
||||
// mass
|
||||
mass = integrals[0];
|
||||
|
||||
// center of mass
|
||||
cM = vector(integrals[1], integrals[2], integrals[3])/mass;
|
||||
|
||||
// inertia relative to origin
|
||||
J.xx() = integrals[5] + integrals[6];
|
||||
J.xy() = -integrals[7];
|
||||
J.xz() = -integrals[9];
|
||||
J.yx() = J.xy();
|
||||
J.yy() = integrals[4] + integrals[6];
|
||||
J.yz() = -integrals[8];
|
||||
J.zx() = J.xz();
|
||||
J.zy() = J.yz();
|
||||
J.zz() = integrals[4] + integrals[5];
|
||||
|
||||
// inertia relative to center of mass
|
||||
J -= mass*((cM & cM)*I - cM*cM);
|
||||
|
||||
// Apply density
|
||||
mass *= density;
|
||||
J *= density;
|
||||
}
|
||||
|
||||
|
||||
void massPropertiesShell
|
||||
(
|
||||
const pointField& pts,
|
||||
const triFaceList& triFaces,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
)
|
||||
{
|
||||
// Reset properties for accumulation
|
||||
|
||||
mass = 0.0;
|
||||
cM = vector::zero;
|
||||
J = tensor::zero;
|
||||
|
||||
// Find centre of mass
|
||||
|
||||
forAll(triFaces, i)
|
||||
{
|
||||
const triFace& tri(triFaces[i]);
|
||||
|
||||
triPointRef t
|
||||
(
|
||||
pts[tri[0]],
|
||||
pts[tri[1]],
|
||||
pts[tri[2]]
|
||||
);
|
||||
|
||||
scalar triMag = t.mag();
|
||||
|
||||
cM += triMag*t.centre();
|
||||
|
||||
mass += triMag;
|
||||
}
|
||||
|
||||
cM /= mass;
|
||||
|
||||
mass *= density;
|
||||
|
||||
// Find inertia around centre of mass
|
||||
|
||||
forAll(triFaces, i)
|
||||
{
|
||||
const triFace& tri(triFaces[i]);
|
||||
|
||||
J += triPointRef
|
||||
(
|
||||
pts[tri[0]],
|
||||
pts[tri[1]],
|
||||
pts[tri[2]]
|
||||
).inertia(cM, density);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
tensor applyParallelAxisTheorem
|
||||
(
|
||||
scalar m,
|
||||
const vector& cM,
|
||||
const tensor& J,
|
||||
const vector& refPt
|
||||
)
|
||||
{
|
||||
// The displacement vector (refPt = cM) is the displacement of the
|
||||
// new reference point from the centre of mass of the body that
|
||||
// the inertia tensor applies to.
|
||||
|
||||
vector d = (refPt - cM);
|
||||
|
||||
return J + m*((d & d)*I - d*d);
|
||||
}
|
||||
|
||||
|
||||
int main(int argc, char *argv[])
|
||||
{
|
||||
argList::addNote
|
||||
@ -321,40 +88,17 @@ int main(int argc, char *argv[])
|
||||
|
||||
triSurface surf(surfFileName);
|
||||
|
||||
triFaceList faces(surf.size());
|
||||
|
||||
forAll(surf, i)
|
||||
{
|
||||
faces[i] = triFace(surf[i]);
|
||||
}
|
||||
|
||||
scalar m = 0.0;
|
||||
vector cM = vector::zero;
|
||||
tensor J = tensor::zero;
|
||||
|
||||
if (args.optionFound("shellProperties"))
|
||||
{
|
||||
massPropertiesShell
|
||||
(
|
||||
surf.points(),
|
||||
faces,
|
||||
density,
|
||||
m,
|
||||
cM,
|
||||
J
|
||||
);
|
||||
momentOfInertia::massPropertiesShell(surf, density, m, cM, J);
|
||||
}
|
||||
else
|
||||
{
|
||||
massPropertiesSolid
|
||||
(
|
||||
surf.points(),
|
||||
faces,
|
||||
density,
|
||||
m,
|
||||
cM,
|
||||
J
|
||||
);
|
||||
momentOfInertia::massPropertiesSolid(surf, density, m, cM, J);
|
||||
}
|
||||
|
||||
if (m < 0)
|
||||
@ -583,7 +327,7 @@ int main(int argc, char *argv[])
|
||||
showTransform = false;
|
||||
}
|
||||
|
||||
Info<< nl << setprecision(10)
|
||||
Info<< nl << setprecision(12)
|
||||
<< "Density: " << density << nl
|
||||
<< "Mass: " << m << nl
|
||||
<< "Centre of mass: " << cM << nl
|
||||
@ -615,7 +359,7 @@ int main(int argc, char *argv[])
|
||||
if (calcAroundRefPt)
|
||||
{
|
||||
Info<< nl << "Inertia tensor relative to " << refPt << ": " << nl
|
||||
<< applyParallelAxisTheorem(m, cM, J, refPt)
|
||||
<< momentOfInertia::applyParallelAxisTheorem(m, cM, J, refPt)
|
||||
<< endl;
|
||||
}
|
||||
|
||||
|
||||
@ -41,6 +41,7 @@ SourceFiles
|
||||
#include "tetPointRef.H"
|
||||
#include "triPointRef.H"
|
||||
#include "polyMesh.H"
|
||||
#include "triFace.H"
|
||||
#include "face.H"
|
||||
|
||||
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
||||
@ -146,6 +147,10 @@ public:
|
||||
// mesh face for this tet from the supplied mesh
|
||||
inline triPointRef faceTri(const polyMesh& mesh) const;
|
||||
|
||||
//- Return the point indices corresponding to the tri on the mesh
|
||||
// face for this tet from the supplied mesh
|
||||
inline triFace faceTriIs(const polyMesh& mesh) const;
|
||||
|
||||
//- Return the geometry corresponding to the tri on the
|
||||
// mesh face for this tet from the supplied mesh using
|
||||
// the old position
|
||||
|
||||
@ -122,6 +122,21 @@ Foam::triPointRef Foam::tetIndices::faceTri(const polyMesh& mesh) const
|
||||
}
|
||||
|
||||
|
||||
Foam::triFace Foam::tetIndices::faceTriIs(const polyMesh& mesh) const
|
||||
{
|
||||
const faceList& pFaces = mesh.faces();
|
||||
|
||||
const Foam::face& f = pFaces[faceI_];
|
||||
|
||||
return triFace
|
||||
(
|
||||
f[faceBasePtI_],
|
||||
f[facePtAI_],
|
||||
f[facePtBI_]
|
||||
);
|
||||
}
|
||||
|
||||
|
||||
Foam::triPointRef Foam::tetIndices::oldFaceTri(const polyMesh& mesh) const
|
||||
{
|
||||
const pointField& oldPPts = mesh.oldPoints();
|
||||
|
||||
@ -127,6 +127,7 @@ $(cellZoneSources)/setToCellZone/setToCellZone.C
|
||||
pointZoneSources = sets/pointZoneSources
|
||||
$(pointZoneSources)/setToPointZone/setToPointZone.C
|
||||
|
||||
momentOfInertia/momentOfInertia.C
|
||||
|
||||
surfaceSets/surfaceSets.C
|
||||
|
||||
|
||||
@ -21,382 +21,328 @@ License
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
|
||||
|
||||
Class
|
||||
momentOfInertia
|
||||
|
||||
Description
|
||||
Reimplementation of volInt.c by Brian Mirtich.
|
||||
* mirtich@cs.berkeley.edu *
|
||||
* http://www.cs.berkeley.edu/~mirtich *
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
*/
|
||||
\*---------------------------------------------------------------------------*/
|
||||
|
||||
#include "momentOfInertia.H"
|
||||
//#include "pyramidPointFaceRef.H"
|
||||
|
||||
// * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //
|
||||
// * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
|
||||
|
||||
//Foam::tensor Foam::momentOfInertia
|
||||
//(
|
||||
// const pointField& points,
|
||||
// const faceList& faces,
|
||||
// const cell& cFaces,
|
||||
// const point& cc
|
||||
//)
|
||||
//{
|
||||
// tensor t(tensor::zero);
|
||||
//
|
||||
// forAll(cFaces, i)
|
||||
// {
|
||||
// const face& f = faces[cFaces[i]];
|
||||
//
|
||||
// scalar pyrVol = pyramidPointFaceRef(f, cc).mag(points);
|
||||
//
|
||||
// vector pyrCentre = pyramidPointFaceRef(f, cc).centre(points);
|
||||
//
|
||||
// vector d = pyrCentre - cc;
|
||||
//
|
||||
// t.xx() += pyrVol*(sqr(d.y()) + sqr(d.z()));
|
||||
// t.yy() += pyrVol*(sqr(d.x()) + sqr(d.z()));
|
||||
// t.zz() += pyrVol*(sqr(d.x()) + sqr(d.y()));
|
||||
//
|
||||
// t.xy() -= pyrVol*d.x()*d.y();
|
||||
// t.xz() -= pyrVol*d.x()*d.z();
|
||||
// t.yz() -= pyrVol*d.y()*d.z();
|
||||
// }
|
||||
//
|
||||
// // Symmetric
|
||||
// t.yx() = t.xy();
|
||||
// t.zx() = t.xz();
|
||||
// t.zy() = t.yz();
|
||||
//
|
||||
// return t;
|
||||
//}
|
||||
|
||||
|
||||
#define sqr(x) ((x)*(x))
|
||||
#define pow3(x) ((x)*(x)*(x))
|
||||
|
||||
// compute various integrations over projection of face
|
||||
void Foam::compProjectionIntegrals
|
||||
void Foam::momentOfInertia::massPropertiesSolid
|
||||
(
|
||||
const pointField& points,
|
||||
const face& f,
|
||||
const direction A,
|
||||
const direction B,
|
||||
|
||||
scalar& P1,
|
||||
scalar& Pa,
|
||||
scalar& Pb,
|
||||
scalar& Paa,
|
||||
scalar& Pab,
|
||||
scalar& Pbb,
|
||||
scalar& Paaa,
|
||||
scalar& Paab,
|
||||
scalar& Pabb,
|
||||
scalar& Pbbb
|
||||
)
|
||||
{
|
||||
P1 = Pa = Pb = Paa = Pab = Pbb = Paaa = Paab = Pabb = Pbbb = 0.0;
|
||||
|
||||
forAll(f, i)
|
||||
{
|
||||
scalar a0 = points[f[i]][A];
|
||||
scalar b0 = points[f[i]][B];
|
||||
scalar a1 = points[f[(i+1) % f.size()]][A];
|
||||
scalar b1 = points[f[(i+1) % f.size()]][B];
|
||||
scalar da = a1 - a0;
|
||||
scalar db = b1 - b0;
|
||||
|
||||
scalar a0_2 = a0 * a0;
|
||||
scalar a0_3 = a0_2 * a0;
|
||||
scalar a0_4 = a0_3 * a0;
|
||||
|
||||
scalar b0_2 = b0 * b0;
|
||||
scalar b0_3 = b0_2 * b0;
|
||||
scalar b0_4 = b0_3 * b0;
|
||||
|
||||
scalar a1_2 = a1 * a1;
|
||||
scalar a1_3 = a1_2 * a1;
|
||||
|
||||
scalar b1_2 = b1 * b1;
|
||||
scalar b1_3 = b1_2 * b1;
|
||||
|
||||
scalar C1 = a1 + a0;
|
||||
|
||||
scalar Ca = a1*C1 + a0_2;
|
||||
scalar Caa = a1*Ca + a0_3;
|
||||
scalar Caaa = a1*Caa + a0_4;
|
||||
|
||||
scalar Cb = b1*(b1 + b0) + b0_2;
|
||||
scalar Cbb = b1*Cb + b0_3;
|
||||
scalar Cbbb = b1*Cbb + b0_4;
|
||||
|
||||
scalar Cab = 3*a1_2 + 2*a1*a0 + a0_2;
|
||||
scalar Kab = a1_2 + 2*a1*a0 + 3*a0_2;
|
||||
|
||||
scalar Caab = a0*Cab + 4*a1_3;
|
||||
scalar Kaab = a1*Kab + 4*a0_3;
|
||||
|
||||
scalar Cabb = 4*b1_3 + 3*b1_2*b0 + 2*b1*b0_2 + b0_3;
|
||||
scalar Kabb = b1_3 + 2*b1_2*b0 + 3*b1*b0_2 + 4*b0_3;
|
||||
|
||||
P1 += db*C1;
|
||||
Pa += db*Ca;
|
||||
Paa += db*Caa;
|
||||
Paaa += db*Caaa;
|
||||
Pb += da*Cb;
|
||||
Pbb += da*Cbb;
|
||||
Pbbb += da*Cbbb;
|
||||
Pab += db*(b1*Cab + b0*Kab);
|
||||
Paab += db*(b1*Caab + b0*Kaab);
|
||||
Pabb += da*(a1*Cabb + a0*Kabb);
|
||||
}
|
||||
|
||||
P1 /= 2.0;
|
||||
Pa /= 6.0;
|
||||
Paa /= 12.0;
|
||||
Paaa /= 20.0;
|
||||
Pb /= -6.0;
|
||||
Pbb /= -12.0;
|
||||
Pbbb /= -20.0;
|
||||
Pab /= 24.0;
|
||||
Paab /= 60.0;
|
||||
Pabb /= -60.0;
|
||||
}
|
||||
|
||||
|
||||
void Foam::compFaceIntegrals
|
||||
(
|
||||
const pointField& points,
|
||||
const face& f,
|
||||
const vector& n,
|
||||
const scalar w,
|
||||
const direction A,
|
||||
const direction B,
|
||||
const direction C,
|
||||
|
||||
scalar& Fa,
|
||||
scalar& Fb,
|
||||
scalar& Fc,
|
||||
scalar& Faa,
|
||||
scalar& Fbb,
|
||||
scalar& Fcc,
|
||||
scalar& Faaa,
|
||||
scalar& Fbbb,
|
||||
scalar& Fccc,
|
||||
scalar& Faab,
|
||||
scalar& Fbbc,
|
||||
scalar& Fcca
|
||||
)
|
||||
{
|
||||
scalar P1, Pa, Pb, Paa, Pab, Pbb, Paaa, Paab, Pabb, Pbbb;
|
||||
|
||||
compProjectionIntegrals
|
||||
(
|
||||
points,
|
||||
f,
|
||||
A,
|
||||
B,
|
||||
|
||||
P1,
|
||||
Pa,
|
||||
Pb,
|
||||
Paa,
|
||||
Pab,
|
||||
Pbb,
|
||||
Paaa,
|
||||
Paab,
|
||||
Pabb,
|
||||
Pbbb
|
||||
);
|
||||
|
||||
scalar k1 = 1 / n[C];
|
||||
scalar k2 = k1 * k1;
|
||||
scalar k3 = k2 * k1;
|
||||
scalar k4 = k3 * k1;
|
||||
|
||||
Fa = k1 * Pa;
|
||||
Fb = k1 * Pb;
|
||||
Fc = -k2 * (n[A]*Pa + n[B]*Pb + w*P1);
|
||||
|
||||
Faa = k1 * Paa;
|
||||
Fbb = k1 * Pbb;
|
||||
Fcc = k3 * (sqr(n[A])*Paa + 2*n[A]*n[B]*Pab + sqr(n[B])*Pbb
|
||||
+ w*(2*(n[A]*Pa + n[B]*Pb) + w*P1));
|
||||
|
||||
Faaa = k1 * Paaa;
|
||||
Fbbb = k1 * Pbbb;
|
||||
Fccc = -k4 * (pow3(n[A])*Paaa + 3*sqr(n[A])*n[B]*Paab
|
||||
+ 3*n[A]*sqr(n[B])*Pabb + pow3(n[B])*Pbbb
|
||||
+ 3*w*(sqr(n[A])*Paa + 2*n[A]*n[B]*Pab + sqr(n[B])*Pbb)
|
||||
+ w*w*(3*(n[A]*Pa + n[B]*Pb) + w*P1));
|
||||
|
||||
Faab = k1 * Paab;
|
||||
Fbbc = -k2 * (n[A]*Pabb + n[B]*Pbbb + w*Pbb);
|
||||
Fcca = k3 * (sqr(n[A])*Paaa + 2*n[A]*n[B]*Paab + sqr(n[B])*Pabb
|
||||
+ w*(2*(n[A]*Paa + n[B]*Pab) + w*Pa));
|
||||
}
|
||||
|
||||
|
||||
void Foam::compVolumeIntegrals
|
||||
(
|
||||
const pointField& points,
|
||||
const faceList& faces,
|
||||
const cell& cFaces,
|
||||
const vectorField& fNorm,
|
||||
const scalarField& fW,
|
||||
|
||||
scalar& T0,
|
||||
vector& T1,
|
||||
vector& T2,
|
||||
vector& TP
|
||||
)
|
||||
{
|
||||
T0 = 0;
|
||||
T1 = vector::zero;
|
||||
T2 = vector::zero;
|
||||
TP = vector::zero;
|
||||
|
||||
forAll(cFaces, i)
|
||||
{
|
||||
const vector& n = fNorm[i];
|
||||
|
||||
scalar nx = mag(n[0]);
|
||||
scalar ny = mag(n[1]);
|
||||
scalar nz = mag(n[2]);
|
||||
|
||||
direction A, B, C;
|
||||
|
||||
if (nx > ny && nx > nz)
|
||||
{
|
||||
C = 0;
|
||||
}
|
||||
else
|
||||
{
|
||||
C = (ny > nz) ? 1 : 2;
|
||||
}
|
||||
|
||||
A = (C + 1) % 3;
|
||||
B = (A + 1) % 3;
|
||||
|
||||
scalar Fa, Fb, Fc, Faa, Fbb, Fcc, Faaa, Fbbb, Fccc, Faab, Fbbc, Fcca;
|
||||
compFaceIntegrals
|
||||
(
|
||||
points,
|
||||
faces[cFaces[i]],
|
||||
n,
|
||||
fW[i],
|
||||
A,
|
||||
B,
|
||||
C,
|
||||
|
||||
Fa,
|
||||
Fb,
|
||||
Fc,
|
||||
Faa,
|
||||
Fbb,
|
||||
Fcc,
|
||||
Faaa,
|
||||
Fbbb,
|
||||
Fccc,
|
||||
Faab,
|
||||
Fbbc,
|
||||
Fcca
|
||||
);
|
||||
|
||||
T0 += n[0] * ((A == 0) ? Fa : ((B == 0) ? Fb : Fc));
|
||||
|
||||
T1[A] += n[A] * Faa;
|
||||
T1[B] += n[B] * Fbb;
|
||||
T1[C] += n[C] * Fcc;
|
||||
|
||||
T2[A] += n[A] * Faaa;
|
||||
T2[B] += n[B] * Fbbb;
|
||||
T2[C] += n[C] * Fccc;
|
||||
|
||||
TP[A] += n[A] * Faab;
|
||||
TP[B] += n[B] * Fbbc;
|
||||
TP[C] += n[C] * Fcca;
|
||||
}
|
||||
|
||||
T1 /= 2;
|
||||
T2 /= 3;
|
||||
TP /= 2;
|
||||
}
|
||||
|
||||
|
||||
// Calculate
|
||||
// - r: centre of mass
|
||||
// - J: inertia around origin (point 0,0,0)
|
||||
void Foam::momentOfIntertia
|
||||
(
|
||||
const pointField& points,
|
||||
const faceList& faces,
|
||||
const cell& cFaces,
|
||||
point& r,
|
||||
const pointField& pts,
|
||||
const triFaceList& triFaces,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
)
|
||||
{
|
||||
// Face normals
|
||||
vectorField fNorm(cFaces.size());
|
||||
scalarField fW(cFaces.size());
|
||||
// Reimplemented from: Wm4PolyhedralMassProperties.cpp
|
||||
// File Version: 4.10.0 (2009/11/18)
|
||||
|
||||
forAll(cFaces, i)
|
||||
// Geometric Tools, LC
|
||||
// Copyright (c) 1998-2010
|
||||
// Distributed under the Boost Software License, Version 1.0.
|
||||
// http://www.boost.org/LICENSE_1_0.txt
|
||||
// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
|
||||
|
||||
// Boost Software License - Version 1.0 - August 17th, 2003
|
||||
|
||||
// Permission is hereby granted, free of charge, to any person or
|
||||
// organization obtaining a copy of the software and accompanying
|
||||
// documentation covered by this license (the "Software") to use,
|
||||
// reproduce, display, distribute, execute, and transmit the
|
||||
// Software, and to prepare derivative works of the Software, and
|
||||
// to permit third-parties to whom the Software is furnished to do
|
||||
// so, all subject to the following:
|
||||
|
||||
// The copyright notices in the Software and this entire
|
||||
// statement, including the above license grant, this restriction
|
||||
// and the following disclaimer, must be included in all copies of
|
||||
// the Software, in whole or in part, and all derivative works of
|
||||
// the Software, unless such copies or derivative works are solely
|
||||
// in the form of machine-executable object code generated by a
|
||||
// source language processor.
|
||||
|
||||
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||||
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
||||
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
|
||||
// NON-INFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
|
||||
// ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE FOR ANY DAMAGES OR
|
||||
// OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
|
||||
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
|
||||
// USE OR OTHER DEALINGS IN THE SOFTWARE.
|
||||
|
||||
const scalar r6 = 1.0/6.0;
|
||||
const scalar r24 = 1.0/24.0;
|
||||
const scalar r60 = 1.0/60.0;
|
||||
const scalar r120 = 1.0/120.0;
|
||||
|
||||
// order: 1, x, y, z, x^2, y^2, z^2, xy, yz, zx
|
||||
scalarField integrals(10, 0.0);
|
||||
|
||||
forAll(triFaces, i)
|
||||
{
|
||||
label faceI = cFaces[i];
|
||||
const triFace& tri(triFaces[i]);
|
||||
|
||||
const face& f = faces[faceI];
|
||||
// vertices of triangle i
|
||||
vector v0 = pts[tri[0]];
|
||||
vector v1 = pts[tri[1]];
|
||||
vector v2 = pts[tri[2]];
|
||||
|
||||
fNorm[i] = f.normal(points);
|
||||
fNorm[i] /= mag(fNorm[i]) + VSMALL;
|
||||
// cross product of edges
|
||||
vector eA = v1 - v0;
|
||||
vector eB = v2 - v0;
|
||||
vector n = eA ^ eB;
|
||||
|
||||
fW[i] = - (fNorm[i] & points[f[0]]);
|
||||
// compute integral terms
|
||||
scalar tmp0, tmp1, tmp2;
|
||||
|
||||
scalar f1x, f2x, f3x, g0x, g1x, g2x;
|
||||
|
||||
tmp0 = v0.x() + v1.x();
|
||||
f1x = tmp0 + v2.x();
|
||||
tmp1 = v0.x()*v0.x();
|
||||
tmp2 = tmp1 + v1.x()*tmp0;
|
||||
f2x = tmp2 + v2.x()*f1x;
|
||||
f3x = v0.x()*tmp1 + v1.x()*tmp2 + v2.x()*f2x;
|
||||
g0x = f2x + v0.x()*(f1x + v0.x());
|
||||
g1x = f2x + v1.x()*(f1x + v1.x());
|
||||
g2x = f2x + v2.x()*(f1x + v2.x());
|
||||
|
||||
scalar f1y, f2y, f3y, g0y, g1y, g2y;
|
||||
|
||||
tmp0 = v0.y() + v1.y();
|
||||
f1y = tmp0 + v2.y();
|
||||
tmp1 = v0.y()*v0.y();
|
||||
tmp2 = tmp1 + v1.y()*tmp0;
|
||||
f2y = tmp2 + v2.y()*f1y;
|
||||
f3y = v0.y()*tmp1 + v1.y()*tmp2 + v2.y()*f2y;
|
||||
g0y = f2y + v0.y()*(f1y + v0.y());
|
||||
g1y = f2y + v1.y()*(f1y + v1.y());
|
||||
g2y = f2y + v2.y()*(f1y + v2.y());
|
||||
|
||||
scalar f1z, f2z, f3z, g0z, g1z, g2z;
|
||||
|
||||
tmp0 = v0.z() + v1.z();
|
||||
f1z = tmp0 + v2.z();
|
||||
tmp1 = v0.z()*v0.z();
|
||||
tmp2 = tmp1 + v1.z()*tmp0;
|
||||
f2z = tmp2 + v2.z()*f1z;
|
||||
f3z = v0.z()*tmp1 + v1.z()*tmp2 + v2.z()*f2z;
|
||||
g0z = f2z + v0.z()*(f1z + v0.z());
|
||||
g1z = f2z + v1.z()*(f1z + v1.z());
|
||||
g2z = f2z + v2.z()*(f1z + v2.z());
|
||||
|
||||
// update integrals
|
||||
integrals[0] += n.x()*f1x;
|
||||
integrals[1] += n.x()*f2x;
|
||||
integrals[2] += n.y()*f2y;
|
||||
integrals[3] += n.z()*f2z;
|
||||
integrals[4] += n.x()*f3x;
|
||||
integrals[5] += n.y()*f3y;
|
||||
integrals[6] += n.z()*f3z;
|
||||
integrals[7] += n.x()*(v0.y()*g0x + v1.y()*g1x + v2.y()*g2x);
|
||||
integrals[8] += n.y()*(v0.z()*g0y + v1.z()*g1y + v2.z()*g2y);
|
||||
integrals[9] += n.z()*(v0.x()*g0z + v1.x()*g1z + v2.x()*g2z);
|
||||
}
|
||||
|
||||
integrals[0] *= r6;
|
||||
integrals[1] *= r24;
|
||||
integrals[2] *= r24;
|
||||
integrals[3] *= r24;
|
||||
integrals[4] *= r60;
|
||||
integrals[5] *= r60;
|
||||
integrals[6] *= r60;
|
||||
integrals[7] *= r120;
|
||||
integrals[8] *= r120;
|
||||
integrals[9] *= r120;
|
||||
|
||||
scalar T0;
|
||||
vector T1, T2, TP;
|
||||
// mass
|
||||
mass = integrals[0];
|
||||
|
||||
compVolumeIntegrals
|
||||
(
|
||||
points,
|
||||
faces,
|
||||
cFaces,
|
||||
fNorm,
|
||||
fW,
|
||||
// center of mass
|
||||
cM = vector(integrals[1], integrals[2], integrals[3])/mass;
|
||||
|
||||
T0,
|
||||
T1,
|
||||
T2,
|
||||
TP
|
||||
);
|
||||
// inertia relative to origin
|
||||
J.xx() = integrals[5] + integrals[6];
|
||||
J.xy() = -integrals[7];
|
||||
J.xz() = -integrals[9];
|
||||
J.yx() = J.xy();
|
||||
J.yy() = integrals[4] + integrals[6];
|
||||
J.yz() = -integrals[8];
|
||||
J.zx() = J.xz();
|
||||
J.zy() = J.yz();
|
||||
J.zz() = integrals[4] + integrals[5];
|
||||
|
||||
const scalar density = 1.0; /* assume unit density */
|
||||
// inertia relative to center of mass
|
||||
J -= mass*((cM & cM)*I - cM*cM);
|
||||
|
||||
scalar mass = density * T0;
|
||||
|
||||
/* compute center of mass */
|
||||
r = T1 / T0;
|
||||
|
||||
/* compute inertia tensor */
|
||||
J.xx() = density * (T2[1] + T2[2]);
|
||||
J.yy() = density * (T2[2] + T2[0]);
|
||||
J.zz() = density * (T2[0] + T2[1]);
|
||||
J.xy() = J.yx() = - density * TP[0];
|
||||
J.yz() = J.zy() = - density * TP[1];
|
||||
J.zx() = J.xz() = - density * TP[2];
|
||||
|
||||
///* translate inertia tensor to center of mass */
|
||||
//J[XX] -= mass * (r[1]*r[1] + r[2]*r[2]);
|
||||
//J[YY] -= mass * (r[2]*r[2] + r[0]*r[0]);
|
||||
//J[ZZ] -= mass * (r[0]*r[0] + r[1]*r[1]);
|
||||
//J[XY] = J[YX] += mass * r[0] * r[1];
|
||||
//J[YZ] = J[ZY] += mass * r[1] * r[2];
|
||||
//J[ZX] = J[XZ] += mass * r[2] * r[0];
|
||||
// Apply density
|
||||
mass *= density;
|
||||
J *= density;
|
||||
}
|
||||
|
||||
|
||||
void Foam::momentOfInertia::massPropertiesShell
|
||||
(
|
||||
const pointField& pts,
|
||||
const triFaceList& triFaces,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
)
|
||||
{
|
||||
// Reset properties for accumulation
|
||||
|
||||
mass = 0.0;
|
||||
cM = vector::zero;
|
||||
J = tensor::zero;
|
||||
|
||||
// Find centre of mass
|
||||
|
||||
forAll(triFaces, i)
|
||||
{
|
||||
const triFace& tri(triFaces[i]);
|
||||
|
||||
triPointRef t
|
||||
(
|
||||
pts[tri[0]],
|
||||
pts[tri[1]],
|
||||
pts[tri[2]]
|
||||
);
|
||||
|
||||
scalar triMag = t.mag();
|
||||
|
||||
cM += triMag*t.centre();
|
||||
|
||||
mass += triMag;
|
||||
}
|
||||
|
||||
cM /= mass;
|
||||
|
||||
mass *= density;
|
||||
|
||||
// Find inertia around centre of mass
|
||||
|
||||
forAll(triFaces, i)
|
||||
{
|
||||
const triFace& tri(triFaces[i]);
|
||||
|
||||
J += triPointRef
|
||||
(
|
||||
pts[tri[0]],
|
||||
pts[tri[1]],
|
||||
pts[tri[2]]
|
||||
).inertia(cM, density);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
void Foam::momentOfInertia::massPropertiesSolid
|
||||
(
|
||||
const triSurface& surf,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
)
|
||||
{
|
||||
triFaceList faces(surf.size());
|
||||
|
||||
forAll(surf, i)
|
||||
{
|
||||
faces[i] = triFace(surf[i]);
|
||||
}
|
||||
|
||||
massPropertiesSolid(surf.points(), faces, density, mass, cM, J);
|
||||
}
|
||||
|
||||
|
||||
void Foam::momentOfInertia::massPropertiesShell
|
||||
(
|
||||
const triSurface& surf,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
)
|
||||
{
|
||||
triFaceList faces(surf.size());
|
||||
|
||||
forAll(surf, i)
|
||||
{
|
||||
faces[i] = triFace(surf[i]);
|
||||
}
|
||||
|
||||
massPropertiesShell(surf.points(), faces, density, mass, cM, J);
|
||||
}
|
||||
|
||||
|
||||
Foam::tensor Foam::momentOfInertia::applyParallelAxisTheorem
|
||||
(
|
||||
scalar mass,
|
||||
const vector& cM,
|
||||
const tensor& J,
|
||||
const vector& refPt
|
||||
)
|
||||
{
|
||||
// The displacement vector (refPt = cM) is the displacement of the
|
||||
// new reference point from the centre of mass of the body that
|
||||
// the inertia tensor applies to.
|
||||
|
||||
vector d = (refPt - cM);
|
||||
|
||||
return J + mass*((d & d)*I - d*d);
|
||||
}
|
||||
|
||||
|
||||
Foam::tmp<Foam::tensorField> Foam::momentOfInertia::meshInertia
|
||||
(
|
||||
const polyMesh& mesh
|
||||
)
|
||||
{
|
||||
tmp<tensorField> tTf = tmp<tensorField>(new tensorField(mesh.nCells()));
|
||||
|
||||
tensorField& tf = tTf();
|
||||
|
||||
forAll(tf, cI)
|
||||
{
|
||||
tf[cI] = meshInertia(mesh, cI);
|
||||
}
|
||||
|
||||
return tTf;
|
||||
}
|
||||
|
||||
|
||||
Foam::tensor Foam::momentOfInertia::meshInertia
|
||||
(
|
||||
const polyMesh& mesh,
|
||||
label cellI
|
||||
)
|
||||
{
|
||||
List<tetIndices> cellTets = polyMeshTetDecomposition::cellTetIndices
|
||||
(
|
||||
mesh,
|
||||
cellI
|
||||
);
|
||||
|
||||
triFaceList faces(cellTets.size());
|
||||
|
||||
forAll(cellTets, cTI)
|
||||
{
|
||||
faces[cTI] = cellTets[cTI].faceTriIs(mesh);
|
||||
}
|
||||
|
||||
scalar m = 0.0;
|
||||
vector cM = vector::zero;
|
||||
tensor J = tensor::zero;
|
||||
|
||||
massPropertiesSolid(mesh.points(), faces, 1.0, m, cM, J);
|
||||
|
||||
return J;
|
||||
}
|
||||
|
||||
|
||||
// ************************************************************************* //
|
||||
|
||||
@ -25,6 +25,9 @@ Class
|
||||
momentOfInertia
|
||||
|
||||
Description
|
||||
Calculates the inertia tensor and principal axes and moments of a
|
||||
polyhedra/cells/triSurfaces. Inertia can either be of the solid body or
|
||||
of a thin shell.
|
||||
|
||||
SourceFiles
|
||||
momentOfInertia.H
|
||||
@ -34,34 +37,86 @@ SourceFiles
|
||||
#ifndef momentOfInertia_H
|
||||
#define momentOfInertia_H
|
||||
|
||||
#include "tensor.H"
|
||||
#include "primitiveMesh.H"
|
||||
#include "tetPointRef.H"
|
||||
#include "triFaceList.H"
|
||||
#include "triSurface.H"
|
||||
#include "polyMesh.H"
|
||||
#include "polyMeshTetDecomposition.H"
|
||||
|
||||
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
||||
|
||||
namespace Foam
|
||||
{
|
||||
|
||||
////- Moment of inertia around cell centre for single cell.
|
||||
//tensor momentOfInertia
|
||||
//(
|
||||
// const pointField&,
|
||||
// const faceList&,
|
||||
// const cell&,
|
||||
// const point& cc
|
||||
//);
|
||||
/*---------------------------------------------------------------------------*\
|
||||
Class momentOfInertia Declaration
|
||||
\*---------------------------------------------------------------------------*/
|
||||
|
||||
class momentOfInertia
|
||||
{
|
||||
|
||||
public:
|
||||
|
||||
static void massPropertiesSolid
|
||||
(
|
||||
const pointField& pts,
|
||||
const triFaceList& triFaces,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
);
|
||||
|
||||
static void massPropertiesShell
|
||||
(
|
||||
const pointField& pts,
|
||||
const triFaceList& triFaces,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
);
|
||||
|
||||
static void massPropertiesSolid
|
||||
(
|
||||
const triSurface& surf,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
);
|
||||
|
||||
static void massPropertiesShell
|
||||
(
|
||||
const triSurface& surf,
|
||||
scalar density,
|
||||
scalar& mass,
|
||||
vector& cM,
|
||||
tensor& J
|
||||
);
|
||||
|
||||
static tensor applyParallelAxisTheorem
|
||||
(
|
||||
scalar mass,
|
||||
const vector& cM,
|
||||
const tensor& J,
|
||||
const vector& refPt
|
||||
);
|
||||
|
||||
// Calculate the inertia tensor for all cells in the mesh
|
||||
static tmp<tensorField> meshInertia
|
||||
(
|
||||
const polyMesh& mesh
|
||||
);
|
||||
|
||||
// Calculate the inertia tensor the given cell
|
||||
static tensor meshInertia
|
||||
(
|
||||
const polyMesh& mesh,
|
||||
label cellI
|
||||
);
|
||||
};
|
||||
|
||||
// Calculate
|
||||
// - centre of mass
|
||||
// - inertia tensor around (0,0,0)
|
||||
void momentOfIntertia
|
||||
(
|
||||
const pointField&,
|
||||
const faceList&,
|
||||
const cell&,
|
||||
point& r,
|
||||
tensor& Jorigin
|
||||
);
|
||||
|
||||
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
||||
|
||||
|
||||
Reference in New Issue
Block a user