Files
mfem/examples/contact.cpp
T
2023-07-13 15:34:41 -07:00

298 lines
6.8 KiB
C++

// Contact example
//
// Compile with: make contact
//
// Sample runs: ./contact -m1 block1.mesh -m2 block2.mesh -at "5 6 7 8"
#include "mfem.hpp"
#include <fstream>
#include <iostream>
//#include "nodepair.hpp"
using namespace std;
using namespace mfem;
Vector GetNormalVector(Mesh & mesh, const int elem, const double *ref)
{
ElementTransformation *trans = mesh.GetElementTransformation(elem);
const int dim = mesh.Dimension();
const int spaceDim = trans->GetSpaceDim();
MFEM_VERIFY(spaceDim == 3, "");
Vector n(spaceDim);
IntegrationPoint ip;
ip.Set(ref, dim);
trans->SetIntPoint(&ip);
//CalcOrtho(trans->Jacobian(), n); // Works only for face transformations
const DenseMatrix jac = trans->Jacobian();
int dimNormal = -1;
int normalSide = -1;
const double tol = 1.0e-8;
for (int i=0; i<dim; ++i)
{
const double d0 = std::abs(ref[i]);
const double d1 = std::abs(ref[i] - 1.0);
const double d = std::min(d0, d1);
// TODO: this works only for hexahedral meshes!
if (d < tol)
{
MFEM_VERIFY(dimNormal == -1, "");
dimNormal = i;
if (d0 < tol)
{
normalSide = 0;
}
else
{
normalSide = 1;
}
}
}
MFEM_VERIFY(dimNormal >= 0 && normalSide >= 0, "");
MFEM_VERIFY(dim == 3, "");
std::vector<Vector> tang(2);
int tangDir[2] = {-1, -1};
{
int t = 0;
for (int i=0; i<dim; ++i)
{
if (i != dimNormal)
{
tangDir[t] = i;
t++;
}
}
MFEM_VERIFY(t == 2, "");
}
for (int i=0; i<2; ++i)
{
tang[i].SetSize(3);
Vector tangRef(3);
tangRef = 0.0;
tangRef[tangDir[i]] = 1.0;
jac.Mult(tangRef, tang[i]);
}
Vector c(3); // Cross product
c[0] = (tang[0][1] * tang[1][2]) - (tang[0][2] * tang[1][1]);
c[1] = (tang[0][2] * tang[1][0]) - (tang[0][0] * tang[1][2]);
c[2] = (tang[0][0] * tang[1][1]) - (tang[0][1] * tang[1][0]);
c /= c.Norml2();
Vector nref(3);
nref = 0.0;
nref[dimNormal] = 1.0;
Vector ndir(3);
jac.Mult(nref, ndir);
ndir /= ndir.Norml2();
const double dp = ndir * c;
// TODO: eliminate c?
n = c;
if (dp < 0.0)
{
n *= -1.0;
}
return n;
}
// Coordinates in xyz are assumed to be ordered as [X, Y, Z]
// where X is the list of x-coordinates for all points and so on.
void FindPointsInMesh(Mesh & mesh, Vector const& xyz)
{
const int dim = mesh.Dimension();
const int np = xyz.Size() / dim;
MFEM_VERIFY(np * dim == xyz.Size(), "");
mesh.EnsureNodes();
//FindPointsGSLIB finder(MPI_COMM_WORLD);
FindPointsGSLIB finder;
finder.Setup(mesh);
finder.FindPoints(xyz);
/// Return code for each point searched by FindPoints: inside element (0), on
/// element boundary (1), or not found (2).
Array<unsigned int> codes = finder.GetCode();
/// Return element number for each point found by FindPoints.
Array<unsigned int> elems = finder.GetElem();
/// Return reference coordinates for each point found by FindPoints.
Vector refcrd = finder.GetReferencePosition();
/// Return distance between the sought and the found point in physical space,
/// for each point found by FindPoints.
Vector dist = finder.GetDist();
MFEM_VERIFY(dist.Size() == np, "");
MFEM_VERIFY(refcrd.Size() == np * dim, "");
MFEM_VERIFY(elems.Size() == np, "");
MFEM_VERIFY(codes.Size() == np, "");
bool allfound = true;
for (auto code : codes)
if (code == 2) { allfound = false; }
MFEM_VERIFY(allfound, "A point was not found");
cout << "Maximum distance of projected points: " << dist.Max() << endl;
for (int i=0; i<np; ++i)
{
cout << "Point " << i << ": (";
for (int j=0; j<dim; ++j)
{
cout << xyz[i + (j*np)];
if (j == dim-1)
{
cout << ")" << endl;
}
else
{
cout << ", ";
}
}
cout << " element: " << elems[i] << endl;
cout << " element " << elems[i] << " vertices:" << endl;
Array<int> vert;
mesh.GetElementVertices(elems[i], vert);
for (auto v : vert)
{
cout << " " << v << endl;
}
cout << " reference coordinates: (";
for (int j=0; j<dim; ++j)
{
cout << refcrd[(i*dim) + j];
if (j == dim-1)
{
cout << ")" << endl;
}
else
{
cout << ", ";
}
}
Vector normal = GetNormalVector(mesh, elems[i], refcrd.GetData() + (i*dim));
cout << " normal vector: ";
normal.Print();
IntegrationPoint ip;
ip.Set(refcrd.GetData() + (i*dim), dim);
ElementTransformation *trans = mesh.GetElementTransformation(elems[i]);
Vector phys(trans->GetSpaceDim());
trans->Transform(ip, phys);
cout << " physical coordinates: ";
phys.Print();
}
}
int main(int argc, char *argv[])
{
// 1. Parse command-line options.
const char *mesh_file1 = "block1.mesh";
const char *mesh_file2 = "block2.mesh";
Array<int> attr;
OptionsParser args(argc, argv);
args.AddOption(&mesh_file1, "-m1", "--mesh1",
"First mesh file to use.");
args.AddOption(&mesh_file2, "-m2", "--mesh2",
"Second mesh file to use.");
args.AddOption(&attr, "-at", "--attributes-surf",
"Attributes of boundary faces on contact surface for mesh 2.");
args.Parse();
if (!args.Good())
{
args.PrintUsage(cout);
return 1;
}
args.PrintOptions(cout);
Mesh mesh1(mesh_file1, 1, 1);
Mesh mesh2(mesh_file2, 1, 1);
const int dim = mesh1.Dimension();
MFEM_VERIFY(dim == mesh2.Dimension(), "");
attr.Sort();
cout << "Boundary attributes for contact surface faces in mesh 2" << endl;
for (auto a : attr)
{
cout << a << endl;
}
Array<int> bdryFaces2; // TODO: remove this?
std::set<int> bdryVerts2;
for (int b=0; b<mesh2.GetNBE(); ++b)
{
if (attr.FindSorted(mesh2.GetBdrAttribute(b)) >= 0)
{
bdryFaces2.Append(b);
Array<int> vert;
mesh2.GetBdrElementVertices(b, vert);
for (auto v : vert)
{
bdryVerts2.insert(v);
}
}
}
int npoints = bdryVerts2.size();
Vector xyz(dim * npoints);
xyz = 0.0;
cout << "Boundary vertices for contact surface vertices in mesh 2" << endl;
int count = 0;
for (auto v : bdryVerts2)
{
cout << v << ": " << mesh2.GetVertex(v)[0] << ", "
<< mesh2.GetVertex(v)[1] << ", "
<< mesh2.GetVertex(v)[2] << endl;
for (int i=0; i<dim; ++i)
{
xyz[count + (i * npoints)] = mesh2.GetVertex(v)[i];
}
count++;
}
MFEM_VERIFY(count == npoints, "");
FindPointsInMesh(mesh1, xyz);
return 0;
}