src/one-body-problem-data/myglobalfrictiondata.hh

+#ifndef SRC_ONE_BODY_PROBLEM_DATA_MYGLOBALFRICTIONDATA_HH
+#define SRC_ONE_BODY_PROBLEM_DATA_MYGLOBALFRICTIONDATA_HH
+
+#include <dune/common/function.hh>
+
+#include <dune/tectonic/globalfrictiondata.hh>
+
+#include "patchfunction.hh"
+
+template <class LocalVector>
+class MyGlobalFrictionData : public GlobalFrictionData<LocalVector::dimension> {
+private:
+  using typename GlobalFrictionData<LocalVector::dimension>::VirtualFunction;
+
+public:
+  MyGlobalFrictionData(Dune::ParameterTree const &parset,
+                       ConvexPolyhedron<LocalVector> const &segment)
+      : C_(parset.get<double>("C")),
+        L_(parset.get<double>("L")),
+        V0_(parset.get<double>("V0")),
+        a_(parset.get<double>("strengthening.a"),
+           parset.get<double>("weakening.a"), segment),
+        b_(parset.get<double>("strengthening.b"),
+           parset.get<double>("weakening.b"), segment),
+        mu0_(parset.get<double>("mu0")) {}
+
+  double const &C() const override { return C_; }
+  double const &L() const override { return L_; }
+  double const &V0() const override { return V0_; }
+  VirtualFunction const &a() const override { return a_; }
+  VirtualFunction const &b() const override { return b_; }
+  double const &mu0() const override { return mu0_; }
+
+private:
+  double const C_;
+  double const L_;
+  double const V0_;
+  PatchFunction const a_;
+  PatchFunction const b_;
+  double const mu0_;
+};
+#endif

src/one-body-problem-data/mygrid.cc

+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <dune/fufem/geometry/polyhedrondistance.hh>
+
+#include "mygrid.hh"
+#include "midpoint.hh"
+#include "../diameter.hh"
+
+#if MY_DIM == 3
+SimplexManager::SimplexManager(unsigned int shift) : shift_(shift) {}
+#endif
+
+// back-to-front, front-to-back, front-to-back
+void SimplexManager::addFromVerticesFBB(unsigned int U, unsigned int V,
+                                        unsigned int W) {
+#if MY_DIM == 3
+  unsigned int const U2 = U + shift_;
+  unsigned int const V2 = V + shift_;
+  unsigned int const W2 = W + shift_;
+
+  simplices_.push_back({ U, V, W, U2 });
+  simplices_.push_back({ V, V2, W2, U2 });
+  simplices_.push_back({ W, W2, U2, V });
+#else
+  simplices_.push_back({ U, V, W });
+#endif
+}
+
+// back-to-front, back-to-front, front-to-back
+void SimplexManager::addFromVerticesFFB(unsigned int U, unsigned int V,
+                                        unsigned int W) {
+#if MY_DIM == 3
+  unsigned int const U2 = U + shift_;
+  unsigned int const V2 = V + shift_;
+  unsigned int const W2 = W + shift_;
+
+  simplices_.push_back({ U, V, W, U2 });
+  simplices_.push_back({ V, V2, W, U2 });
+  simplices_.push_back({ V2, W, U2, W2 });
+#else
+  simplices_.push_back({ U, V, W });
+#endif
+}
+
+auto SimplexManager::getSimplices() -> SimplexList const & {
+  return simplices_;
+}
+
+template <class Grid> GridConstructor<Grid>::GridConstructor() {
+  auto const &A = MyGeometry::A;
+  auto const &B = MyGeometry::B;
+  auto const &C = MyGeometry::C;
+
+  unsigned int const vc = 3;
+
+#if MY_DIM == 3
+  Dune::FieldMatrix<double, 2 * vc, MY_DIM> vertices;
+#else
+  Dune::FieldMatrix<double, vc, MY_DIM> vertices;
+#endif
+  for (size_t i = 0; i < 2; ++i) {
+#if MY_DIM == 3
+    size_t numXYplanes = 2;
+#else
+    size_t numXYplanes = 1;
+#endif
+    size_t k = 0;
+    for (size_t j = 1; j <= numXYplanes; ++j) {
+      vertices[k++][i] = A[i];
+      vertices[k++][i] = B[i];
+      vertices[k++][i] = C[i];
+      assert(k == j * vc);
+    }
+  }
+
+#if MY_DIM == 3
+  for (size_t k = 0; k < vc; ++k) {
+    vertices[k][2] = -MyGeometry::depth / 2.0;
+    vertices[k + vc][2] = MyGeometry::depth / 2.0;
+  }
+#endif
+
+  for (size_t i = 0; i < vertices.N(); ++i)
+    gridFactory.insertVertex(vertices[i]);
+
+  Dune::GeometryType cell;
+#if MY_DIM == 3
+  cell.makeTetrahedron();
+#else
+  cell.makeTriangle();
+#endif
+
+#if MY_DIM == 3
+  SimplexManager sm(vc);
+#else
+  SimplexManager sm;
+#endif
+  sm.addFromVerticesFFB(1, 2, 0);
+  auto const &simplices = sm.getSimplices();
+
+  // sanity-check choices of simplices
+  for (size_t i = 0; i < simplices.size(); ++i) {
+    Dune::FieldMatrix<double, MY_DIM, MY_DIM> check;
+    for (size_t j = 0; j < MY_DIM; ++j)
+      check[j] = vertices[simplices[i][j + 1]] - vertices[simplices[i][j]];
+    assert(check.determinant() > 0);
+    gridFactory.insertElement(cell, simplices[i]);
+  }
+}
+
+template <class Grid> std::shared_ptr<Grid> GridConstructor<Grid>::getGrid() {
+  return std::shared_ptr<Grid>(gridFactory.createGrid());
+}
+
+template <class Grid>
+template <class GridView>
+MyFaces<GridView> GridConstructor<Grid>::constructFaces(
+    GridView const &gridView) {
+  return MyFaces<GridView>(gridView);
+}
+
+template <class GridView>
+template <class Vector>
+bool MyFaces<GridView>::xyCollinear(Vector const &a, Vector const &b,
+                                    Vector const &c) {
+  return isClose2((b[0] - a[0]) * (c[1] - a[1]), (b[1] - a[1]) * (c[0] - a[0]));
+}
+
+template <class GridView>
+template <class Vector>
+bool MyFaces<GridView>::xyBoxed(Vector const &v1, Vector const &v2,
+                                Vector const &x) {
+  auto const minmax0 = std::minmax(v1[0], v2[0]);
+  auto const minmax1 = std::minmax(v1[1], v2[1]);
+
+  if (minmax0.first - 1e-14 * MyGeometry::lengthScale > x[0] or
+      x[0] > minmax0.second + 1e-14 * MyGeometry::lengthScale)
+    return false;
+  if (minmax1.first - 1e-14 * MyGeometry::lengthScale > x[1] or
+      x[1] > minmax1.second + 1e-14 * MyGeometry::lengthScale)
+    return false;
+
+  return true;
+}
+
+template <class GridView>
+template <class Vector>
+bool MyFaces<GridView>::xyBetween(Vector const &v1, Vector const &v2,
+                                  Vector const &x) {
+  return xyCollinear(v1, v2, x) && xyBoxed(v1, v2, x);
+}
+
+template <class GridView>
+MyFaces<GridView>::MyFaces(GridView const &gridView)
+    :
+#if MY_DIM == 3
+      lower(gridView),
+      right(gridView),
+      upper(gridView),
+      front(gridView),
+      back(gridView)
+#else
+      lower(gridView),
+      right(gridView),
+      upper(gridView)
+#endif
+{
+  assert(isClose(MyGeometry::A[1], 0));
+  assert(isClose(MyGeometry::B[1], 0));
+  lower.insertFacesByProperty([&](typename GridView::Intersection const &in) {
+    return isClose(0, in.geometry().center()[1]);
+  });
+#if MY_DIM == 3
+  front.insertFacesByProperty([&](typename GridView::Intersection const &in) {
+    return isClose(MyGeometry::depth / 2.0, in.geometry().center()[2]);
+  });
+
+  back.insertFacesByProperty([&](typename GridView::Intersection const &in) {
+    return isClose(-MyGeometry::depth / 2.0, in.geometry().center()[2]);
+  });
+#endif
+
+  upper.insertFacesByProperty([&](typename GridView::Intersection const &in) {
+    return xyBetween(MyGeometry::A, MyGeometry::C, in.geometry().center());
+  });
+
+  right.insertFacesByProperty([&](typename GridView::Intersection const &in) {
+    return xyBetween(MyGeometry::B, MyGeometry::C, in.geometry().center());
+  });
+}
+
+double computeAdmissibleDiameter(double distance, double smallestDiameter) {
+  return (distance / 0.0125 / MyGeometry::lengthScale + 1.0) * smallestDiameter;
+}
+
+template <class Grid, class LocalVector>
+void refine(Grid &grid, ConvexPolyhedron<LocalVector> const &weakPatch,
+            double smallestDiameter) {
+  bool needRefine = true;
+  while (true) {
+    needRefine = false;
+    for (auto &&e : elements(grid.leafGridView())) {
+      auto const geometry = e.geometry();
+
+      auto const weakeningRegionDistance =
+          distance(weakPatch, geometry, 1e-6 * MyGeometry::lengthScale);
+      auto const admissibleDiameter =
+          computeAdmissibleDiameter(weakeningRegionDistance, smallestDiameter);
+
+      if (diameter(geometry) <= admissibleDiameter)
+        continue;
+
+      needRefine = true;
+      grid.mark(1, e);
+    }
+    if (!needRefine)
+      break;
+
+    grid.preAdapt();
+    grid.adapt();
+    grid.postAdapt();
+  }
+}
+
+#include "mygrid_tmpl.cc"

src/one-body-problem-data/mygrid.hh

+#ifndef SRC_ONE_BODY_PROBLEM_DATA_MYGRID_HH
+#define SRC_ONE_BODY_PROBLEM_DATA_MYGRID_HH
+
+#include <dune/common/fmatrix.hh>
+#include <dune/grid/common/gridfactory.hh>
+
+#include <dune/fufem/boundarypatch.hh>
+#include <dune/fufem/geometry/convexpolyhedron.hh>
+
+#include "mygeometry.hh"
+
+template <class GridView> struct MyFaces {
+  BoundaryPatch<GridView> lower;
+  BoundaryPatch<GridView> right;
+  BoundaryPatch<GridView> upper;
+
+#if MY_DIM == 3
+  BoundaryPatch<GridView> front;
+  BoundaryPatch<GridView> back;
+#endif
+
+  MyFaces(GridView const &gridView);
+
+private:
+  bool isClose(double a, double b) {
+    return std::abs(a - b) < 1e-14 * MyGeometry::lengthScale;
+  };
+
+  bool isClose2(double a, double b) {
+    return std::abs(a - b) <
+           1e-14 * MyGeometry::lengthScale * MyGeometry::lengthScale;
+  };
+
+  template <class Vector>
+  bool xyBoxed(Vector const &v1, Vector const &v2, Vector const &x);
+
+  template <class Vector>
+  bool xyCollinear(Vector const &a, Vector const &b, Vector const &c);
+
+  template <class Vector>
+  bool xyBetween(Vector const &v1, Vector const &v2, Vector const &x);
+};
+
+class SimplexManager {
+public:
+  using SimplexList = std::vector<std::vector<unsigned int>>;
+
+#if MY_DIM == 3
+  SimplexManager(unsigned int shift);
+#endif
+
+  void addFromVerticesFBB(unsigned int U, unsigned int V, unsigned int W);
+  void addFromVerticesFFB(unsigned int U, unsigned int V, unsigned int W);
+
+  SimplexList const &getSimplices();
+
+private:
+  SimplexList simplices_;
+
+#if MY_DIM == 3
+  unsigned int const shift_;
+#endif
+};
+
+template <class Grid> class GridConstructor {
+public:
+  GridConstructor();
+
+  std::shared_ptr<Grid> getGrid();
+
+  template <class GridView>
+  MyFaces<GridView> constructFaces(GridView const &gridView);
+
+private:
+  Dune::GridFactory<Grid> gridFactory;
+};
+
+double computeAdmissibleDiameter(double distance, double smallestDiameter);
+
+template <class Grid, class LocalVector>
+void refine(Grid &grid, ConvexPolyhedron<LocalVector> const &weakPatch,
+            double smallestDiameter);
+
+#endif

src/one-body-problem-data/mygrid_tmpl.cc

+#ifndef MY_DIM
+#error MY_DIM unset
+#endif
+
+#include "../explicitgrid.hh"
+#include "../explicitvectors.hh"
+
+template class GridConstructor<Grid>;
+
+template struct MyFaces<GridView>;
+
+template MyFaces<GridView> GridConstructor<Grid>::constructFaces(
+    GridView const &gridView);
+
+template void refine<Grid, LocalVector>(
+    Grid &grid, ConvexPolyhedron<LocalVector> const &weakPatch,
+    double smallestDiameter);

src/one-body-problem-data/patchfunction.hh

+#ifndef SRC_ONE_BODY_PROBLEM_DATA_PATCHFUNCTION_HH
+#define SRC_ONE_BODY_PROBLEM_DATA_PATCHFUNCTION_HH
+
+#include <dune/common/function.hh>
+#include <dune/common/fvector.hh>
+#include <dune/common/parametertree.hh>
+
+#include <dune/fufem/geometry/polyhedrondistance.hh>
+
+class PatchFunction
+    : public Dune::VirtualFunction<Dune::FieldVector<double, MY_DIM>,
+                                   Dune::FieldVector<double, 1>> {
+private:
+  using Polyhedron = ConvexPolyhedron<Dune::FieldVector<double, MY_DIM>>;
+
+  double const v1_;
+  double const v2_;
+  Polyhedron const &segment_;
+
+public:
+  PatchFunction(double v1, double v2, Polyhedron const &segment)
+      : v1_(v1), v2_(v2), segment_(segment) {}
+
+  void evaluate(Dune::FieldVector<double, MY_DIM> const &x,
+                Dune::FieldVector<double, 1> &y) const {
+    y = distance(x, segment_, 1e-6 * MyGeometry::lengthScale) <= 1e-5 ? v2_
+                                                                      : v1_;
+  }
+};
+
+#endif

src/one-body-problem-data/segmented-function.hh

+#ifndef SRC_ONE_BODY_PROBLEM_DATA_SEGMENTED_FUNCTION_HH
+#define SRC_ONE_BODY_PROBLEM_DATA_SEGMENTED_FUNCTION_HH
+
+#include <dune/common/function.hh>
+#include <dune/common/fvector.hh>
+#include <dune/common/parametertree.hh>
+
+#include "mygeometry.hh"
+
+class SegmentedFunction
+    : public Dune::VirtualFunction<Dune::FieldVector<double, MY_DIM>,
+                                   Dune::FieldVector<double, 1>> {
+private:
+  bool liesBelow(Dune::FieldVector<double, MY_DIM> const &x,
+                 Dune::FieldVector<double, MY_DIM> const &y,
+                 Dune::FieldVector<double, MY_DIM> const &z) const {
+    return x[1] + (z[0] - x[0]) * (y[1] - x[1]) / (y[0] - x[0]) >= z[1];
+  };
+  bool insideRegion2(Dune::FieldVector<double, MY_DIM> const &z) const {
+    return liesBelow(MyGeometry::K, MyGeometry::M, z);
+  };
+
+  double const _v1;
+  double const _v2;
+
+public:
+  SegmentedFunction(double v1, double v2) : _v1(v1), _v2(v2) {}
+
+  void evaluate(Dune::FieldVector<double, MY_DIM> const &x,
+                Dune::FieldVector<double, 1> &y) const {
+    y = insideRegion2(x) ? _v2 : _v1;
+  }
+};
+#endif

src/one-body-problem-data/weakpatch.hh

+#ifndef SRC_ONE_BODY_PROBLEM_DATA_WEAKPATCH_HH
+#define SRC_ONE_BODY_PROBLEM_DATA_WEAKPATCH_HH
+
+template <class LocalVector>
+ConvexPolyhedron<LocalVector> getWeakPatch(Dune::ParameterTree const &parset) {
+  ConvexPolyhedron<LocalVector> weakPatch;
+#if MY_DIM == 3
+  weakPatch.vertices.resize(4);
+  weakPatch.vertices[0] = weakPatch.vertices[2] = MyGeometry::X;
+  weakPatch.vertices[1] = weakPatch.vertices[3] = MyGeometry::Y;
+  for (size_t k = 0; k < 2; ++k) {
+    weakPatch.vertices[k][2] = -MyGeometry::depth / 2.0;
+    weakPatch.vertices[k + 2][2] = MyGeometry::depth / 2.0;
+  }
+  switch (parset.get<Config::PatchType>("patchType")) {
+    case Config::Rectangular:
+      break;
+    case Config::Trapezoidal:
+      weakPatch.vertices[1][0] += 0.05 * MyGeometry::lengthScale;
+      weakPatch.vertices[3][0] -= 0.05 * MyGeometry::lengthScale;
+      break;
+    default:
+      assert(false);
+  }
+#else
+  weakPatch.vertices.resize(2);
+  weakPatch.vertices[0] = MyGeometry::X;
+  weakPatch.vertices[1] = MyGeometry::Y;
+#endif
+  return weakPatch;
+};
+#endif

src/one-body-problem.cc

+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_IPOPT
+#undef HAVE_IPOPT
+#endif
+
+#include <atomic>
+#include <cmath>
+#include <csignal>
+#include <exception>
+#include <fstream>
+#include <iostream>
+#include <iomanip>
+
+#include <dune/common/bitsetvector.hh>
+#include <dune/common/exceptions.hh>
+#include <dune/common/fmatrix.hh>
+#include <dune/common/function.hh>
+#include <dune/common/fvector.hh>
+#include <dune/common/parallel/mpihelper.hh>
+#include <dune/common/parametertree.hh>
+#include <dune/common/parametertreeparser.hh>
+
+#include <dune/grid/common/mcmgmapper.hh>
+#include <dune/istl/bcrsmatrix.hh>
+#include <dune/istl/bvector.hh>
+
+#include <dune/fufem/boundarypatch.hh>
+#include <dune/fufem/formatstring.hh>
+
+#include <dune/solvers/norms/energynorm.hh>
+#include <dune/solvers/solvers/loopsolver.hh>
+#include <dune/solvers/solvers/solver.hh>
+#include <dune/tnnmg/problem-classes/convexproblem.hh>
+
+#include <dune/tectonic/geocoordinate.hh>
+#include <dune/tectonic/myblockproblem.hh>
+#include <dune/tectonic/globalfriction.hh>
+#include <dune/fufem/hdf5/file.hh>
+
+#include "assemblers.hh"
+#include "diameter.hh"
+#include "enumparser.hh"
+#include "enums.hh"
+#include "gridselector.hh"
+#include "hdf5-writer.hh"
+#include "hdf5/restart-io.hh"
+#include "matrices.hh"
+#include "program_state.hh"
+#include "one-body-problem-data/bc.hh"
+#include "one-body-problem-data/mybody.hh"
+#include "one-body-problem-data/mygeometry.hh"
+#include "one-body-problem-data/myglobalfrictiondata.hh"
+#include "one-body-problem-data/mygrid.hh"
+#include "one-body-problem-data/weakpatch.hh"
+#include "spatial-solving/solverfactory.hh"
+#include "time-stepping/adaptivetimestepper.hh"
+#include "time-stepping/rate.hh"
+#include "time-stepping/state.hh"
+#include "time-stepping/updaters.hh"
+#include "vtk.hh"
+
+size_t const dims = MY_DIM;
+
+Dune::ParameterTree getParameters(int argc, char *argv[]) {
+  Dune::ParameterTree parset;
+  Dune::ParameterTreeParser::readINITree("one-body-problem.cfg", parset);
+  Dune::ParameterTreeParser::readINITree(
+      Dune::Fufem::formatString("one-body-problem-%dD.cfg", dims), parset);
+  Dune::ParameterTreeParser::readOptions(argc, argv, parset);
+  return parset;
+}
+
+static std::atomic<bool> terminationRequested(false);
+void handleSignal(int signum) { terminationRequested = true; }
+
+int main(int argc, char *argv[]) {
+  try {
+    Dune::MPIHelper::instance(argc, argv);
+    auto const parset = getParameters(argc, argv);
+
+    MyGeometry::render();
+    MyGeometry::write();
+
+    using GridView = Grid::LeafGridView;
+    using MyAssembler = MyAssembler<GridView, dims>;
+    using Matrix = MyAssembler::Matrix;
+    using Vector = MyAssembler::Vector;
+    using LocalVector = Vector::block_type;
+    using ScalarMatrix = MyAssembler::ScalarMatrix;
+    using ScalarVector = MyAssembler::ScalarVector;
+
+    auto const weakPatch =
+        getWeakPatch<LocalVector>(parset.sub("boundary.friction.weakening"));
+
+    // {{{ Set up grid
+    GridConstructor<Grid> gridConstructor;
+    auto grid = gridConstructor.getGrid();
+
+    refine(*grid, weakPatch,
+           parset.get<double>("boundary.friction.smallestDiameter"));
+
+    double minDiameter = std::numeric_limits<double>::infinity();
+    double maxDiameter = 0.0;
+    for (auto &&e : elements(grid->leafGridView())) {
+      auto const geometry = e.geometry();
+      auto const diam = diameter(geometry);
+      minDiameter = std::min(minDiameter, diam);
+      maxDiameter = std::max(maxDiameter, diam);
+    }
+    std::cout << "min diameter: " << minDiameter << std::endl;
+    std::cout << "max diameter: " << maxDiameter << std::endl;
+
+    auto const leafView = grid->leafGridView();
+    auto const leafVertexCount = leafView.size(dims);
+
+    std::cout << "Number of DOFs: " << leafVertexCount << std::endl;
+
+    auto myFaces = gridConstructor.constructFaces(leafView);
+
+    BoundaryPatch<GridView> const neumannBoundary(leafView);
+    BoundaryPatch<GridView> const &frictionalBoundary = myFaces.lower;
+    BoundaryPatch<GridView> const &surface = myFaces.upper;
+
+    // Dirichlet Boundary
+    Dune::BitSetVector<dims> noNodes(leafVertexCount);
+    Dune::BitSetVector<dims> dirichletNodes(leafVertexCount);
+    for (size_t i = 0; i < leafVertexCount; ++i) {
+      if (myFaces.right.containsVertex(i))
+        dirichletNodes[i][0] = true;
+
+      if (myFaces.lower.containsVertex(i))
+        dirichletNodes[i][1] = true;
+
+#if MY_DIM == 3
+      if (myFaces.front.containsVertex(i) || myFaces.back.containsVertex(i))
+        dirichletNodes[i][2] = true;
+#endif
+    }
+
+    // Set up functions for time-dependent boundary conditions
+    using Function = Dune::VirtualFunction<double, double>;
+    Function const &velocityDirichletFunction = VelocityDirichletCondition();
+    Function const &neumannFunction = NeumannCondition();
+
+    MyAssembler const myAssembler(leafView);
+
+    MyBody<dims> const body(parset);
+
+    Matrices<Matrix> matrices;
+    myAssembler.assembleElasticity(body.getYoungModulus(),
+                                   body.getPoissonRatio(), matrices.elasticity);
+    myAssembler.assembleViscosity(body.getShearViscosityField(),
+                                  body.getBulkViscosityField(),
+                                  matrices.damping);
+    myAssembler.assembleMass(body.getDensityField(), matrices.mass);
+
+    ScalarMatrix relativeFrictionalBoundaryMass;
+    myAssembler.assembleFrictionalBoundaryMass(frictionalBoundary,
+                                               relativeFrictionalBoundaryMass);
+    relativeFrictionalBoundaryMass /= frictionalBoundary.area();
+    EnergyNorm<ScalarMatrix, ScalarVector> const stateEnergyNorm(
+        relativeFrictionalBoundaryMass);
+
+    // Assemble forces
+    Vector gravityFunctional;
+    myAssembler.assembleBodyForce(body.getGravityField(), gravityFunctional);
+
+    // Problem formulation: right-hand side
+    std::function<void(double, Vector &)> computeExternalForces =
+        [&](double _relativeTime, Vector &_ell) {
+          myAssembler.assembleNeumann(neumannBoundary, _ell, neumannFunction,
+                                      _relativeTime);
+          _ell += gravityFunctional;
+        };
+
+    using MyProgramState = ProgramState<Vector, ScalarVector>;
+    MyProgramState programState(leafVertexCount);
+    auto const firstRestart = parset.get<size_t>("io.restarts.first");
+    auto const restartSpacing = parset.get<size_t>("io.restarts.spacing");
+    auto const writeRestarts = parset.get<bool>("io.restarts.write");
+    auto const writeData = parset.get<bool>("io.data.write");
+    bool const handleRestarts = writeRestarts or firstRestart > 0;
+
+    auto dataFile =
+        writeData ? std::make_unique<HDF5::File>("output.h5") : nullptr;
+    auto restartFile = handleRestarts
+                           ? std::make_unique<HDF5::File>(
+                                 "restarts.h5",
+                                 writeRestarts ? HDF5::Access::READWRITE
+                                               : HDF5::Access::READONLY)
+                           : nullptr;
+    auto restartIO = handleRestarts
+                         ? std::make_unique<RestartIO<MyProgramState>>(
+                               *restartFile, leafVertexCount)
+                         : nullptr;
+
+    if (firstRestart > 0) // automatically adjusts the time and timestep
+      restartIO->read(firstRestart, programState);
+    else
+      programState.setupInitialConditions(parset, computeExternalForces,
+                                          matrices, myAssembler, dirichletNodes,
+                                          noNodes, frictionalBoundary, body);
+
+    MyGlobalFrictionData<LocalVector> frictionInfo(
+        parset.sub("boundary.friction"), weakPatch);
+    auto myGlobalFriction = myAssembler.assembleFrictionNonlinearity(
+        parset.get<Config::FrictionModel>("boundary.friction.frictionModel"),
+        frictionalBoundary, frictionInfo, programState.weightedNormalStress);
+    myGlobalFriction->updateAlpha(programState.alpha);
+
+    Vector vertexCoordinates(leafVertexCount);
+    {
+      Dune::MultipleCodimMultipleGeomTypeMapper<
+          GridView, Dune::MCMGVertexLayout> const vertexMapper(leafView);
+      for (auto &&v : vertices(leafView))
+        vertexCoordinates[vertexMapper.index(v)] = geoToPoint(v.geometry());
+    }
+
+    using MyVertexBasis = typename MyAssembler::VertexBasis;
+    auto dataWriter =
+        writeData ? std::make_unique<
+                        HDF5Writer<MyProgramState, MyVertexBasis, GridView>>(
+                        *dataFile, vertexCoordinates, myAssembler.vertexBasis,
+                        surface, frictionalBoundary, weakPatch)
+                  : nullptr;
+    MyVTKWriter<MyVertexBasis, typename MyAssembler::CellBasis> const vtkWriter(
+        myAssembler.cellBasis, myAssembler.vertexBasis, "obs");
+
+    IterationRegister iterationCount;
+    auto const report = [&](bool initial = false) {
+      if (writeData) {
+        dataWriter->reportSolution(programState, *myGlobalFriction);
+        if (!initial)
+          dataWriter->reportIterations(programState, iterationCount);
+        dataFile->flush();
+      }
+
+      if (writeRestarts and !initial and
+          programState.timeStep % restartSpacing == 0) {
+        restartIO->write(programState);
+        restartFile->flush();
+      }
+
+      if (parset.get<bool>("io.printProgress"))
+        std::cout << "timeStep = " << std::setw(6) << programState.timeStep
+                  << ", time = " << std::setw(12) << programState.relativeTime
+                  << ", tau = " << std::setw(12) << programState.relativeTau
+                  << std::endl;
+
+      if (parset.get<bool>("io.vtk.write")) {
+        ScalarVector stress;
+        myAssembler.assembleVonMisesStress(body.getYoungModulus(),
+                                           body.getPoissonRatio(),
+                                           programState.u, stress);
+        vtkWriter.write(programState.timeStep, programState.u, programState.v,
+                        programState.alpha, stress);
+      }
+    };
+    report(true);
+
+    // Set up TNNMG solver
+    using NonlinearFactory = SolverFactory<
+        dims,
+        MyBlockProblem<ConvexProblem<GlobalFriction<Matrix, Vector>, Matrix>>,
+        Grid>;
+    NonlinearFactory factory(parset.sub("solver.tnnmg"), *grid, dirichletNodes);
+
+    using MyUpdater = Updaters<RateUpdater<Vector, Matrix, Function, dims>,
+                               StateUpdater<ScalarVector, Vector>>;
+    MyUpdater current(
+        initRateUpdater(parset.get<Config::scheme>("timeSteps.scheme"),
+                        velocityDirichletFunction, dirichletNodes, matrices,
+                        programState.u, programState.v, programState.a),
+        initStateUpdater<ScalarVector, Vector>(
+            parset.get<Config::stateModel>("boundary.friction.stateModel"),
+            programState.alpha, *frictionalBoundary.getVertices(),
+            parset.get<double>("boundary.friction.L"),
+            parset.get<double>("boundary.friction.V0")));
+
+    auto const refinementTolerance =
+        parset.get<double>("timeSteps.refinementTolerance");
+    auto const mustRefine = [&](MyUpdater &coarseUpdater,
+                                MyUpdater &fineUpdater) {
+      ScalarVector coarseAlpha;
+      coarseUpdater.state_->extractAlpha(coarseAlpha);
+
+      ScalarVector fineAlpha;
+      fineUpdater.state_->extractAlpha(fineAlpha);
+
+      return stateEnergyNorm.diff(fineAlpha, coarseAlpha) > refinementTolerance;
+    };
+
+    std::signal(SIGXCPU, handleSignal);
+    std::signal(SIGINT, handleSignal);
+    std::signal(SIGTERM, handleSignal);
+
+    AdaptiveTimeStepper<NonlinearFactory, MyUpdater,
+                        EnergyNorm<ScalarMatrix, ScalarVector>>
+        adaptiveTimeStepper(factory, parset, myGlobalFriction, current,
+                            programState.relativeTime, programState.relativeTau,
+                            computeExternalForces, stateEnergyNorm, mustRefine);
+    while (!adaptiveTimeStepper.reachedEnd()) {
+      programState.timeStep++;
+
+      iterationCount = adaptiveTimeStepper.advance();
+
+      programState.relativeTime = adaptiveTimeStepper.relativeTime_;
+      programState.relativeTau = adaptiveTimeStepper.relativeTau_;
+      current.rate_->extractDisplacement(programState.u);
+      current.rate_->extractVelocity(programState.v);
+      current.rate_->extractAcceleration(programState.a);
+      current.state_->extractAlpha(programState.alpha);
+
+      report();
+
+      if (terminationRequested) {
+        std::cerr << "Terminating prematurely" << std::endl;
+        break;
+      }
+    }
+  } catch (Dune::Exception &e) {
+    Dune::derr << "Dune reported error: " << e << std::endl;
+  } catch (std::exception &e) {
+    std::cerr << "Standard exception: " << e.what() << std::endl;
+  }
+}

src/one-body-problem.cfg

+# -*- mode:conf -*-
+gravity         = 9.81  # [m/s^2]
+
+[io]
+data.write      = true
+printProgress   = false
+restarts.first  = 0
+restarts.spacing= 20
+restarts.write  = true
+vtk.write       = false
+
+[problem]
+finalTime       = 1000  # [s]
+
+[body]
+bulkModulus     = 0.5e5 # [Pa]
+poissonRatio    = 0.3   # [1]
+[body.elastic]
+density         = 900   # [kg/m^3]
+shearViscosity  = 1e3   # [Pas]
+bulkViscosity   = 1e3   # [Pas]
+[body.viscoelastic]
+density         = 1000  # [kg/m^3]
+shearViscosity  = 1e4   # [Pas]
+bulkViscosity   = 1e4   # [Pas]
+
+[boundary.friction]
+C               = 10    # [Pa]
+mu0             = 0.7   # [ ]
+V0              = 5e-5  # [m/s]
+L               = 2.25e-5 # [m]
+initialAlpha    = 0     # [ ]
+stateModel      = AgeingLaw
+frictionModel   = Regularised
+[boundary.friction.weakening]
+a               = 0.002 # [ ]
+b               = 0.017 # [ ]
+[boundary.friction.strengthening]
+a               = 0.020 # [ ]
+b               = 0.005 # [ ]
+
+[timeSteps]
+scheme = newmark
+
+[u0.solver]
+maximumIterations = 100000
+verbosity         = quiet
+
+[a0.solver]
+maximumIterations = 100000
+verbosity         = quiet
+
+[v.solver]
+maximumIterations = 100000
+verbosity         = quiet
+
+[v.fpi]
+maximumIterations = 10000
+lambda            = 0.5
+
+[solver.tnnmg.linear]
+maxiumumIterations = 100000
+pre                = 3
+cycle              = 1  # 1 = V, 2 = W, etc.
+post               = 3
+
+[solver.tnnmg.main]
+pre   = 1
+multi = 5 # number of multigrid steps
+post  = 0

src/one-body-sample.parset

-# -*- mode:conf -*-
-timeSteps = 10000
-endOfTime = 15
-
-verbosity = quiet
-printProgress = false
-
-writeVTK = false
-
-enableTimer = false
-
-timeSteppingScheme = newmark
-
-[grid]
-refinements = 4
-
-[body]
-E = 5e7
-nu = 0.3 # The closer we get to 0.5, the more wiggly everything gets
-density = 5000
-height = 1
-width = 5
-
-[solver]
-tolerance = 1e-10
-damping = 0.5
-minimal_correction_reduction = 0.5
-
-[solver.tnnmg]
-maxiterations = 1000000
-fixed_point_iterations = 10000
-fixed_point_tolerance = 1e-10
-
-[solver.tnnmg.linear]
-maxiterations = 1000000
-pre   = 3
-cycle = 1  # 1 = V, 2 = W, etc.
-post  = 3
-
-[solver.tnnmg.main]
-pre   = 1
-multi = 5 # number of multigrid steps
-post  = 0
-
-[localsolver]
-steps = 1
-
-[boundary.friction]
-mu0 = 0.6
-mumin = 0.0
-a = 0.010
-b = 0.015
-V0 = 1e-6
-L = 1e-5
-initial_state = 4.54e-05 # exp(-10)
-state_model = Dieterich