#include <config.h> #include <fenv.h> #define RIGIDBODYMOTION3 #include <dune/common/bitsetvector.hh> #include <dune/common/parametertree.hh> #include <dune/common/parametertreeparser.hh> #include <dune/grid/uggrid.hh> #include <dune/grid/onedgrid.hh> #include <dune/grid/geometrygrid.hh> #include <dune/grid/utility/structuredgridfactory.hh> #include <dune/grid/io/file/gmshreader.hh> #include <dune/fufem/boundarypatch.hh> #include <dune/solvers/solvers/iterativesolver.hh> #include <dune/solvers/norms/energynorm.hh> #include <dune/gfe/rotation.hh> #include <dune/gfe/unitvector.hh> #include <dune/gfe/realtuple.hh> #include <dune/gfe/cosseratenergystiffness.hh> #include <dune/gfe/cosseratvtkwriter.hh> #include <dune/gfe/geodesicfeassembler.hh> #include <dune/gfe/riemanniantrsolver.hh> // grid dimension const int dim = 2; // Image space of the geodesic fe functions #ifdef RIGIDBODYMOTION3 typedef RigidBodyMotion<double,3> TargetSpace; #endif // Tangent vector of the image space const int blocksize = TargetSpace::TangentVector::dimension; using namespace Dune; #if 0 void dirichletValues(const FieldVector<double,dim>& in, FieldVector<double,3>& out, double homotopy) { out = 0; for (int i=0; i<dim; i++) out[i] = in[i]; out[1] += homotopy; } #endif void dirichletValues(const FieldVector<double,dim>& in, FieldVector<double,3>& out, double homotopy ) { double angle = 8*M_PI; angle *= homotopy; // center of rotation FieldVector<double,3> center(0); center[1] = 0.5; FieldMatrix<double,3,3> rotation(0); rotation[0][0] = 1; rotation[1][1] = std::cos(angle); rotation[1][2] = -std::sin(angle); rotation[2][1] = std::sin(angle); rotation[2][2] = std::cos(angle); FieldVector<double,3> inEmbedded(0); for (int i=0; i<dim; i++) inEmbedded[i] = in[i]; inEmbedded -= center; rotation.mv(inEmbedded, out); out += center; } /** \brief A constant vector-valued function, for simple Neumann boundary values */ struct NeumannFunction : public Dune::VirtualFunction<FieldVector<double,dim>, FieldVector<double,3> > { NeumannFunction(const FieldVector<double,3> values, double homotopyParameter) : values_(values), homotopyParameter_(homotopyParameter) {} void evaluate(const FieldVector<double, dim>& x, FieldVector<double,3>& out) const { out = 0; out.axpy(homotopyParameter_, values_); } FieldVector<double,3> values_; double homotopyParameter_; }; int main (int argc, char *argv[]) try { //feenableexcept(FE_INVALID); typedef std::vector<TargetSpace> SolutionType; // parse data file ParameterTree parameterSet; ParameterTreeParser::readINITree("cosserat-continuum.parset", parameterSet); ParameterTreeParser::readOptions(argc, argv, parameterSet); // read solver settings const int numLevels = parameterSet.get<int>("numLevels"); int numHomotopySteps = parameterSet.get<int>("numHomotopySteps"); const double tolerance = parameterSet.get<double>("tolerance"); const int maxTrustRegionSteps = parameterSet.get<int>("maxTrustRegionSteps"); const double initialTrustRegionRadius = parameterSet.get<double>("initialTrustRegionRadius"); const int multigridIterations = parameterSet.get<int>("numIt"); const int nu1 = parameterSet.get<int>("nu1"); const int nu2 = parameterSet.get<int>("nu2"); const int mu = parameterSet.get<int>("mu"); const int baseIterations = parameterSet.get<int>("baseIt"); const double mgTolerance = parameterSet.get<double>("mgTolerance"); const double baseTolerance = parameterSet.get<double>("baseTolerance"); const bool instrumented = parameterSet.get<bool>("instrumented"); std::string resultPath = parameterSet.get("resultPath", ""); // read problem settings std::string path = parameterSet.get<std::string>("path"); std::string gridFile = parameterSet.get<std::string>("gridFile"); // /////////////////////////////////////// // Create the grid // /////////////////////////////////////// typedef std::conditional<dim==1,OneDGrid,UGGrid<dim> >::type GridType; shared_ptr<GridType> grid; FieldVector<double,dim> lower = parameterSet.get<FieldVector<double,dim> >("lower"); FieldVector<double,dim> upper = parameterSet.get<FieldVector<double,dim> >("upper"); if (parameterSet.get<bool>("structuredGrid")) { array<unsigned int,dim> elements = parameterSet.get<array<unsigned int,dim> >("elements"); grid = StructuredGridFactory<GridType>::createCubeGrid(lower, upper, elements); } else grid = shared_ptr<GridType>(GmshReader<GridType>::read(path + "/" + gridFile)); grid->globalRefine(numLevels-1); SolutionType x(grid->size(dim)); // ///////////////////////////////////////// // Read Dirichlet values // ///////////////////////////////////////// BitSetVector<blocksize> dirichletNodes(grid->size(dim), false); BitSetVector<1> neumannNodes(grid->size(dim), false); GridType::Codim<dim>::LeafIterator vIt = grid->leafbegin<dim>(); GridType::Codim<dim>::LeafIterator vEndIt = grid->leafend<dim>(); for (; vIt!=vEndIt; ++vIt) { #if 0 // Boundary conditions for the cantilever example if (vIt->geometry().corner(0)[0] < 1.0+1e-3 /* or vIt->geometry().corner(0)[0] > upper[0]-1e-3*/ ) { // Only translation dofs are Dirichlet for (int j=0; j<3; j++) dirichletNodes[grid->leafIndexSet().index(*vIt)][j] = true; } if (vIt->geometry().corner(0)[0] > upper[0]-1e-3 ) neumannNodes[grid->leafIndexSet().index(*vIt)][0] = true; #endif #if 0 // Boundary conditions for the twisted-strip example if (vIt->geometry().corner(0)[0] < lower[0]+1e-3 or vIt->geometry().corner(0)[0] > upper[0]-1e-3 ) { // Only translation dofs are Dirichlet for (int j=0; j<3; j++) dirichletNodes[grid->leafIndexSet().index(*vIt)][j] = true; } #endif #if 1 // Boundary conditions for the cantilever example if (vIt->geometry().corner(0)[0] < 1.0) { // Only translation dofs are Dirichlet for (int j=0; j<3; j++) dirichletNodes[grid->leafIndexSet().index(*vIt)][j] = true; } if (vIt->geometry().corner(0)[1] < -239 ) neumannNodes[grid->leafIndexSet().index(*vIt)][0] = true; #endif } ////////////////////////////////////////////////////////////////////////////// // Assemble Neumann term ////////////////////////////////////////////////////////////////////////////// typedef P1NodalBasis<GridType::LeafGridView,double> P1Basis; P1Basis p1Basis(grid->leafView()); BoundaryPatch<GridType::LeafGridView> neumannBoundary(grid->leafView(), neumannNodes); std::cout << "Neumann boundary has " << neumannBoundary.numFaces() << " faces\n"; // ////////////////////////// // Initial solution // ////////////////////////// vIt = grid->leafbegin<dim>(); for (; vIt!=vEndIt; ++vIt) { int idx = grid->leafIndexSet().index(*vIt); x[idx].r = 0; for (int i=0; i<dim; i++) x[idx].r[i] = vIt->geometry().corner(0)[i]; // x[idx].q is the identity, set by the default constructor } //////////////////////////////////////////////////////// // Main homotopy loop //////////////////////////////////////////////////////// // Output initial iterate (of homotopy loop) CosseratVTKWriter<GridType>::write(*grid,x, resultPath + "cosserat_homotopy_0"); for (int i=0; i<numHomotopySteps; i++) { double homotopyParameter = (i+1)*(1.0/numHomotopySteps); std::cout << "Homotopy step: " << i << ", parameter: " << homotopyParameter << std::endl; // //////////////////////////////////////////////////////////// // Create an assembler for the energy functional // //////////////////////////////////////////////////////////// const ParameterTree& materialParameters = parameterSet.sub("materialParameters"); NeumannFunction neumannFunction(parameterSet.get<FieldVector<double,3> >("neumannValues"), homotopyParameter); std::cout << "Material parameters:" << std::endl; materialParameters.report(); CosseratEnergyLocalStiffness<GridType::LeafGridView, P1Basis::LocalFiniteElement, 3> cosseratEnergyLocalStiffness(materialParameters, &neumannBoundary, &neumannFunction); GeodesicFEAssembler<P1Basis,TargetSpace> assembler(grid->leafView(), &cosseratEnergyLocalStiffness); // ///////////////////////////////////////////////// // Create a Riemannian trust-region solver // ///////////////////////////////////////////////// RiemannianTrustRegionSolver<GridType,TargetSpace> solver; solver.setup(*grid, &assembler, x, dirichletNodes, tolerance, maxTrustRegionSteps, initialTrustRegionRadius, multigridIterations, mgTolerance, mu, nu1, nu2, baseIterations, baseTolerance, instrumented); //////////////////////////////////////////////////////// // Set Dirichlet values //////////////////////////////////////////////////////// for (vIt=grid->leafbegin<dim>(); vIt!=vEndIt; ++vIt) { int idx = grid->leafIndexSet().index(*vIt); if (dirichletNodes[idx][0] and vIt->geometry().corner(0)[0] > upper[0]-1e-3) { // Only the positions have Dirichlet values dirichletValues(vIt->geometry().corner(0), x[idx].r, homotopyParameter); } } // ///////////////////////////////////////////////////// // Solve! // ///////////////////////////////////////////////////// std::cout << "Energy: " << assembler.computeEnergy(x) << std::endl; //exit(0); solver.setInitialSolution(x); solver.solve(); x = solver.getSol(); // Output result of each homotopy step std::stringstream iAsAscii; iAsAscii << i+1; CosseratVTKWriter<GridType>::write(*grid,x, resultPath + "cosserat_homotopy_" + iAsAscii.str()); } // ////////////////////////////// // Output result // ////////////////////////////// CosseratVTKWriter<GridType>::write(*grid,x, resultPath + "cosserat"); // finally: compute the average deformation of the Neumann boundary // That is what we need for the locking tests FieldVector<double,3> averageDef(0); for (size_t i=0; i<x.size(); i++) if (neumannNodes[i][0]) averageDef += x[i].r; averageDef /= neumannNodes.count(); std::cout << "mu_c = " << parameterSet.get<double>("materialParameters.mu_c") << " " << "kappa = " << parameterSet.get<double>("materialParameters.kappa") << " " << numLevels << " levels, average deflection: " << averageDef << std::endl; // ////////////////////////////// } catch (Exception e) { std::cout << e << std::endl; }