[Tests] Added an unit test for PermeabilityMohrCoulombFailureIndexModel

Tests/MaterialLib/TestMPLPermeabilityMohrCoulombFailureIndexModel.cpp

+/**
+ * \file
+ * \copyright
+ * Copyright (c) 2012-2020, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ * Created on June 8, 2020, 9:17 AM
+ */
+
+#pragma once
+
+#include <gtest/gtest.h>
+
+#include <Eigen/Eigen>
+#include <boost/math/constants/constants.hpp>
+
+#include "MaterialLib/MPL/Medium.h"
+#include "MaterialLib/MPL/Properties/CreatePermeabilityMohrCoulombFailureIndexModel.h"
+#include "MaterialLib/MPL/Properties/PermeabilityMohrCoulombFailureIndexModel.h"
+#include "MaterialLib/MPL/Utils/FormEigenTensor.h"
+#include "MathLib/KelvinVector.h"
+#include "ParameterLib/ConstantParameter.h"
+#include "TestMPL.h"
+#include "Tests/TestTools.h"
+
+TEST(MaterialPropertyLib, PermeabilityMohrCoulombFailureIndexModel)
+{
+    ParameterLib::ConstantParameter<double> k0 =
+        ParameterLib::ConstantParameter<double>("k0", 1.e-20);
+    double const kr = 1.0e-19;
+    double const b = 3.0;
+    double const c = 1.0e+6;
+    double const phi = 15.0;
+    double const k_max = 1.e-10;
+
+    auto const k_model = MPL::PermeabilityMohrCoulombFailureIndexModel<3>(
+        "k_f", k0, kr, b, c, phi, k_max, nullptr);
+
+    const int symmetric_tensor_size = 6;
+    using SymmetricTensor = Eigen::Matrix<double, symmetric_tensor_size, 1>;
+
+    // Under failure, i,e stress beyond the yield.
+    SymmetricTensor stress;
+    stress[0] = -1.36040e+7;
+    stress[1] = -1.78344e+7;
+    stress[2] = -1.36627e+7;
+    stress[3] = -105408;
+    stress[4] = -25377.2;
+    stress[5] = -1.39944e+7;
+
+    MPL::VariableArray vars;
+    vars[static_cast<int>(MPL::Variable::stress)].emplace<SymmetricTensor>(
+        stress);
+
+    ParameterLib::SpatialPosition const pos;
+    double const t = std::numeric_limits<double>::quiet_NaN();
+    double const dt = std::numeric_limits<double>::quiet_NaN();
+
+    auto const k = MPL::formEigenTensor<3>(k_model.value(vars, pos, t, dt));
+
+    double const k_expected = 1.1398264890628033e-15;
+
+    ASSERT_LE(std::fabs((k_expected - k(0, 0))) / k_expected, 1e-10)
+        << "for expected changed permeability " << k_expected
+        << " and for computed changed permeability." << k(0, 0);
+
+    // Stress outside of the yield surface. No change in permeability
+    stress[0] = -1.2e+7;
+    stress[1] = -1.5e+7;
+    stress[2] = -1.2e+7;
+    stress[3] = -1e+5;
+    stress[4] = -2200.2;
+    stress[5] = -8e+5;
+    vars[static_cast<int>(MPL::Variable::stress)] = stress;
+    auto const k_non_f =
+        MPL::formEigenTensor<3>(k_model.value(vars, pos, t, dt));
+
+    auto const k_non_f_expected = k0(t, pos)[0];
+
+    ASSERT_LE(std::fabs(k_non_f_expected - k_non_f(0, 0)) / k_non_f_expected,
+              1e-19)
+        << "for expected untouched permeability" << k_non_f_expected
+        << " and for computed untouched permeability." << k_non_f(0, 0);
+
+    // Stress at the apex. No change in permeability.
+    const double val =
+        2.0 * c / std::tan(phi * boost::math::constants::degree<double>());
+    stress[0] = 0.7 * val;
+    stress[1] = 0.3 * val;
+    stress[2] = 0.3 * val;
+    stress[3] = 0.0;
+    stress[4] = 0.0;
+    stress[5] = 0.0;
+    vars[static_cast<int>(MPL::Variable::stress)] = stress;
+    auto const k_apex_f =
+        MPL::formEigenTensor<3>(k_model.value(vars, pos, t, dt));
+
+    ASSERT_LE(std::fabs(k_max - k_apex_f(0, 0)) / k_max, 1e-19)
+        << "for expected untouched permeability" << k_non_f_expected
+        << " and for computed untouched permeability." << k_apex_f(0, 0);
+}