Initial setting of a unidirectional fiber-reinforced composite geometry

examples/mechanics/CMakeLists.txt

@@ -10,4 +10,7 @@ target_link_libraries(CrackBranching LINK_PUBLIC CabanaPD)
 add_executable(FragmentingCylinder fragmenting_cylinder.cpp)
 target_link_libraries(FragmentingCylinder LINK_PUBLIC CabanaPD)
 
-install(TARGETS ElasticWave KalthoffWinkler CrackBranching FragmentingCylinder DESTINATION ${CMAKE_INSTALL_BINDIR})
+add_executable(FiberReinforcedComposite fiber_reinforced_composite.cpp)
+target_link_libraries(FiberReinforcedComposite LINK_PUBLIC CabanaPD)
+
+install(TARGETS ElasticWave KalthoffWinkler CrackBranching FragmentingCylinder FiberReinforcedComposite DESTINATION ${CMAKE_INSTALL_BINDIR})

examples/mechanics/fiber_reinforced_composite.cpp

@@ -0,0 +1,138 @@
+/****************************************************************************
+ * Copyright (c) 2022 by Oak Ridge National Laboratory                      *
+ * All rights reserved.                                                     *
+ *                                                                          *
+ * This file is part of CabanaPD. CabanaPD is distributed under a           *
+ * BSD 3-clause license. For the licensing terms see the LICENSE file in    *
+ * the top-level directory.                                                 *
+ *                                                                          *
+ * SPDX-License-Identifier: BSD-3-Clause                                    *
+ ****************************************************************************/
+
+#include <fstream>
+#include <iostream>
+
+#include "mpi.h"
+
+#include <Kokkos_Core.hpp>
+
+#include <CabanaPD.hpp>
+
+// Generate a unidirectional fiber-reinforced composite geometry
+void kalthoffWinklerExample( const std::string filename )
+{
+    // ====================================================
+    //             Use default Kokkos spaces
+    // ====================================================
+    using exec_space = Kokkos::DefaultExecutionSpace;
+    using memory_space = typename exec_space::memory_space;
+
+    // ====================================================
+    //                   Read inputs
+    // ====================================================
+    CabanaPD::Inputs inputs( filename );
+
+    // ====================================================
+    //                Material parameters
+    // ====================================================
+    double rho0 = inputs["density"];
+    double E = inputs["elastic_modulus"];
+    double nu = 1.0 / 3.0;
+    double K = E / ( 3.0 * ( 1.0 - 2.0 * nu ) );
+    double G0 = inputs["fracture_energy"];
+    // double G = E / ( 2.0 * ( 1.0 + nu ) ); // Only for LPS.
+    double delta = inputs["horizon"];
+    delta += 1e-10;
+
+    // ====================================================
+    //                  Discretization
+    // ====================================================
+    // FIXME: set halo width based on delta
+    std::array<double, 3> low_corner = inputs["low_corner"];
+    std::array<double, 3> high_corner = inputs["high_corner"];
+    std::array<int, 3> num_cells = inputs["num_cells"];
+    int m = std::floor( delta /
+                        ( ( high_corner[0] - low_corner[0] ) / num_cells[0] ) );
+    int halo_width = m + 1; // Just to be safe.
+
+    // ====================================================
+    //                    Force model
+    // ====================================================
+    using model_type1 = CabanaPD::ForceModel<CabanaPD::PMB>;
+    model_type1 force_model1( delta, K, G0 );
+    using model_type2 = CabanaPD::ForceModel<CabanaPD::LinearPMB>;
+    model_type2 force_model2( delta, K / 10.0, G0 / 10.0 );
+
+    // ====================================================
+    //                 Particle generation
+    // ====================================================
+    // Does not set displacements, velocities, etc.
+    auto particles = CabanaPD::createParticles<memory_space, model_type2>(
+        exec_space(), low_corner, high_corner, num_cells, halo_width );
+
+    // ====================================================
+    //            Custom particle initialization
+    // ====================================================
+
+    std::array<double, 3> system_size = inputs["system_size"];
+
+    auto rho = particles->sliceDensity();
+    auto x = particles->sliceReferencePosition();
+    auto type = particles->sliceType();
+
+    // Fiber-reinforced composite geometry
+    int Nfx = inputs["fiber_numbers"][0]; // Number of fibers in x-direction
+    int Nfy = inputs["fiber_numbers"][1]; // Number of fibers in y-direction
+    double Rf = inputs["fiber_radius"];
+
+    // Fiber grid spacings
+    double dxf = system_size[0] / Nfx;
+    double dyf = system_size[1] / Nfy;
+
+    auto init_functor = KOKKOS_LAMBDA( const int pid )
+    {
+        // Density
+        rho( pid ) = rho0;
+
+        // Set x- and y-coordinates of grid point
+        double xi = x( pid, 0 );
+        double yi = x( pid, 1 );
+
+        // Find nearest fiber grid center point
+        double Ixf = floor( xi / dxf );
+        double Iyf = floor( yi / dyf );
+        double XI = 0.5 * dxf + dxf * Ixf;
+        double YI = 0.5 * dyf + dyf * Iyf;
+
+        if ( ( xi - XI ) * ( xi - XI ) + ( yi - YI ) * ( yi - YI ) <
+             Rf * Rf + 1e-10 )
+            type( pid ) = 1;
+    };
+    particles->updateParticles( exec_space{}, init_functor );
+
+    // ====================================================
+    //                   Create solver
+    // ====================================================
+    auto models = CabanaPD::createMultiForceModel(
+        *particles, CabanaPD::AverageTag{}, force_model1, force_model2 );
+    auto cabana_pd = CabanaPD::createSolverFracture<memory_space>(
+        inputs, particles, models );
+
+    // ====================================================
+    //                   Simulation run
+    // ====================================================
+    cabana_pd->init();
+    cabana_pd->run();
+}
+
+// Initialize MPI+Kokkos.
+int main( int argc, char* argv[] )
+{
+    MPI_Init( &argc, &argv );
+    Kokkos::initialize( argc, argv );
+
+    kalthoffWinklerExample( argv[1] );
+
+    Kokkos::finalize();
+    MPI_Finalize();
+}

examples/mechanics/inputs/fiber_reinforced_composite.json

@@ -0,0 +1,15 @@
+{
+    "num_cells"              : {"value": [500, 100, 500]},
+    "system_size"            : {"value": [1.0, 0.2, 1.0], "unit": "m"},
+    "density"                : {"value": 8000, "unit": "kg/m^3"},
+    "elastic_modulus"        : {"value": 191e+9, "unit": "Pa"},
+    "fracture_energy"        : {"value": 42408, "unit": "J/m^2"},
+    "horizon"                : {"value": 0.002, "unit": "m"}, 
+    "fiber_numbers"          : {"value": [20, 6]}, 
+    "fiber_radius"           : {"value": 0.01, "unit": "m"}, 
+    "final_time"             : {"value": 2e-7, "unit": "s"},
+    "timestep"               : {"value": 1e-7, "unit": "s"},
+    "timestep_safety_factor" : {"value": 0.85},
+    "output_frequency"       : {"value": 1},
+    "output_reference"       : {"value": true}
+}