Feature/multiphase material

include/mesh.tcc

@@ -476,8 +476,9 @@ bool mpm::Mesh<Tdim>::generate_material_points(
       unsigned before_generation = this->nparticles();
       bool checks = false;
       // Get material
-      std::vector<std::shared_ptr<mpm::Material<Tdim>>> material;
-      for (auto m_id : material_ids) material.emplace_back(materials_.at(m_id));
+      std::vector<std::shared_ptr<mpm::Material<Tdim>>> materials;
+      for (auto m_id : material_ids)
+        materials.emplace_back(materials_.at(m_id));
 
       // If set id is -1, use all cells
       auto cset = (cset_id == -1) ? this->cells_ : cell_sets_.at(cset_id);
@@ -501,8 +502,8 @@ bool mpm::Mesh<Tdim>::generate_material_points(
           status = this->add_particle(particle, checks);
           if (status) {
             map_particles_[pid]->assign_cell(*citr);
-            for (unsigned phase = 0; phase < material.size(); phase++)
-              map_particles_[pid]->assign_material(material[phase], phase);
+            for (unsigned phase = 0; phase < materials.size(); phase++)
+              map_particles_[pid]->assign_material(materials[phase], phase);
             pids.emplace_back(pid);
           } else
             throw std::runtime_error("Generate particles in mesh failed");
@@ -543,8 +544,8 @@ bool mpm::Mesh<Tdim>::create_particles(
     // Particle ids
     std::vector<mpm::Index> pids;
     // Get material
-    std::vector<std::shared_ptr<mpm::Material<Tdim>>> material;
-    for (auto m_id : material_ids) material.emplace_back(materials_.at(m_id));
+    std::vector<std::shared_ptr<mpm::Material<Tdim>>> materials;
+    for (auto m_id : material_ids) materials.emplace_back(materials_.at(m_id));
     // Check if particle coordinates is empty
     if (coordinates.empty())
       throw std::runtime_error("List of coordinates is empty");
@@ -563,8 +564,8 @@ bool mpm::Mesh<Tdim>::create_particles(
 
       // If insertion is successful
       if (insert_status) {
-        for (unsigned phase = 0; phase < material.size(); phase++)
-          map_particles_[pid]->assign_material(material[phase], phase);
+        for (unsigned phase = 0; phase < materials.size(); phase++)
+          map_particles_[pid]->assign_material(materials[phase], phase);
         pids.emplace_back(pid);
       } else
         throw std::runtime_error("Addition of particle to mesh failed!");
@@ -1724,9 +1725,9 @@ void mpm::Mesh<Tdim>::inject_particles(double current_time) {
     unsigned pid = this->nparticles();
     bool checks = false;
     // Get material
-    std::vector<std::shared_ptr<mpm::Material<Tdim>>> material;
+    std::vector<std::shared_ptr<mpm::Material<Tdim>>> materials;
     for (auto m_id : injection.material_ids)
-      material.emplace_back(materials_.at(m_id));
+      materials.emplace_back(materials_.at(m_id));
 
     // Check if duration is within the current time
     if (injection.start_time <= current_time &&
@@ -1760,8 +1761,8 @@ void mpm::Mesh<Tdim>::inject_particles(double current_time) {
             unsigned status = this->add_particle(particle, checks);
             if (status) {
               map_particles_[pid]->assign_cell(*citr);
-              for (unsigned phase = 0; phase < material.size(); phase++)
-                map_particles_[pid]->assign_material(material[phase], phase);
+              for (unsigned phase = 0; phase < materials.size(); phase++)
+                map_particles_[pid]->assign_material(materials[phase], phase);
               ++pid;
               injected_particles.emplace_back(particle);
             }

include/particles/particle.h

@@ -289,8 +289,20 @@ class Particle : public ParticleBase<Tdim> {
   //! Return neighbour ids
   std::vector<mpm::Index> neighbours() const override { return neighbours_; };
 
+ protected:
+  //! Initialise particle material container
+  //! \details This function allocate memory and initialise the material related
+  //! containers according to the particle phase, i.e. solid or fluid particle
+  //! has phase_size = 1, whereas two-phase (solid-fluid) or three-phase
+  //! (solid-water-air) particle have phase_size = 2 and 3, respectively.
+  //! \param[in] phase_size The material phase size
+  void initialise_material(unsigned phase_size = 1);
+
  private:
   //! Compute strain rate
+  //! \param[in] dn_dx The spatial gradient of shape function
+  //! \param[in] phase Index to indicate phase
+  //! \retval strain rate at particle inside a cell
   inline Eigen::Matrix<double, 6, 1> compute_strain_rate(
       const Eigen::MatrixXd& dn_dx, unsigned phase) noexcept;
 

include/particles/particle.tcc

@@ -7,10 +7,8 @@ mpm::Particle<Tdim>::Particle(Index id, const VectorDim& coord)
   cell_ = nullptr;
   // Nodes
   nodes_.clear();
-  // Set material pointer to null
-  material_.emplace_back(nullptr);
-  material_id_.emplace_back(std::numeric_limits<unsigned>::max());
-  state_variables_.emplace_back(mpm::dense_map());
+  // Set material containers
+  this->initialise_material(1);
   // Logger
   std::string logger =
       "particle" + std::to_string(Tdim) + "d::" + std::to_string(id);
@@ -24,9 +22,8 @@ mpm::Particle<Tdim>::Particle(Index id, const VectorDim& coord, bool status)
   this->initialise();
   cell_ = nullptr;
   nodes_.clear();
-  material_.emplace_back(nullptr);
-  material_id_.emplace_back(std::numeric_limits<unsigned>::max());
-  state_variables_.emplace_back(mpm::dense_map());
+  // Set material containers
+  this->initialise_material(1);
   //! Logger
   std::string logger =
       "particle" + std::to_string(Tdim) + "d::" + std::to_string(id);
@@ -253,6 +250,18 @@ void mpm::Particle<Tdim>::initialise() {
   this->properties_["displacements"] = [&]() { return displacement(); };
 }
 
+//! Initialise particle material container
+template <unsigned Tdim>
+void mpm::Particle<Tdim>::initialise_material(unsigned phase_size) {
+  material_.resize(phase_size);
+  material_id_.resize(phase_size);
+  state_variables_.resize(phase_size);
+  std::fill(material_.begin(), material_.end(), nullptr);
+  std::fill(material_id_.begin(), material_id_.end(),
+            std::numeric_limits<unsigned>::max());
+  std::fill(state_variables_.begin(), state_variables_.end(), mpm::dense_map());
+}
+
 //! Assign material state variables from neighbour particle
 template <unsigned Tdim>
 bool mpm::Particle<Tdim>::assign_material_state_vars(
@@ -386,9 +395,10 @@ bool mpm::Particle<Tdim>::assign_material(
   try {
     // Check if material is valid and properties are set
     if (material != nullptr) {
-      material_[phase] = material;
-      material_id_[phase] = material_[phase]->id();
-      state_variables_[phase] = material_[phase]->initialise_state_variables();
+      material_.at(phase) = material;
+      material_id_.at(phase) = material_[phase]->id();
+      state_variables_.at(phase) =
+          material_[phase]->initialise_state_variables();
       status = true;
     } else {
       throw std::runtime_error("Material is undefined!");

tests/mesh_test_2d.cc

@@ -578,7 +578,7 @@ TEST_CASE("Mesh is checked for 2D case", "[mesh][2D]") {
         // Gauss point generation
         Json jgen;
         jgen["type"] = "gauss";
-        jgen["material_id"] = mid;
+        jgen["material_id"] = {0};
         jgen["cset_id"] = 1;
         jgen["particle_type"] = "P2D";
         jgen["check_duplicates"] = false;
@@ -595,7 +595,7 @@ TEST_CASE("Mesh is checked for 2D case", "[mesh][2D]") {
         // Gauss point generation
         Json jgen;
         jgen["type"] = "inject";
-        jgen["material_id"] = mid;
+        jgen["material_id"] = {0};
         jgen["cset_id"] = 1;
         jgen["particle_type"] = "P2D";
         jgen["check_duplicates"] = false;