Line data    Source code

       1              : // Copyright 2024, UChicago Argonne, LLC
       2              : // All Rights Reserved
       3              : // Software Name: NEML2 -- the New Engineering material Model Library, version 2
       4              : // By: Argonne National Laboratory
       5              : // OPEN SOURCE LICENSE (MIT)
       6              : //
       7              : // Permission is hereby granted, free of charge, to any person obtaining a copy
       8              : // of this software and associated documentation files (the "Software"), to deal
       9              : // in the Software without restriction, including without limitation the rights
      10              : // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      11              : // copies of the Software, and to permit persons to whom the Software is
      12              : // furnished to do so, subject to the following conditions:
      13              : //
      14              : // The above copyright notice and this permission notice shall be included in
      15              : // all copies or substantial portions of the Software.
      16              : //
      17              : // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      18              : // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      19              : // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      20              : // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      21              : // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      22              : // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
      23              : // THE SOFTWARE.
      24              : 
      25              : #include "neml2/models/solid_mechanics/elasticity/GreenLagrangeStrain.h"
      26              : #include "neml2/tensors/SR2.h"
      27              : #include "neml2/tensors/R2.h"
      28              : #include "neml2/tensors/mandel_notation.h"
      29              : 
      30              : namespace neml2
      31              : {
      32              : register_NEML2_object(GreenLagrangeStrain);
      33              : 
      34              : OptionSet
      35            2 : GreenLagrangeStrain::expected_options()
      36              : {
      37            2 :   OptionSet options = Model::expected_options();
      38            2 :   options.doc() =
      39              :       "Green-Lagrange strain, \\f$ E = \\frac{1}{2} (C - I) \\f$, where \\f$ C = F^T F \\f$ "
      40            2 :       "is the right Cauchy-Green tensor and \\f$ I \\f$ is the identity tensor.";
      41              : 
      42            6 :   options.set_input("deformation_gradient") = VariableName(FORCES, "F");
      43            2 :   options.set("deformation_gradient").doc() = "The deformation gradient";
      44              : 
      45            6 :   options.set_output("strain") = VariableName(STATE, "E");
      46            2 :   options.set("strain").doc() = "The Green-Lagrange strain";
      47              : 
      48            2 :   return options;
      49            0 : }
      50              : 
      51            1 : GreenLagrangeStrain::GreenLagrangeStrain(const OptionSet & options)
      52              :   : Model(options),
      53            1 :     _E(declare_output_variable<SR2>("strain")),
      54            2 :     _F(declare_input_variable<R2>("deformation_gradient"))
      55              : {
      56            1 : }
      57              : 
      58              : void
      59            2 : GreenLagrangeStrain::set_value(bool out, bool dout_din, bool /*d2out_din2*/)
      60              : {
      61            2 :   if (out)
      62              :   {
      63            1 :     const auto C = R2(_F).transpose() * _F;
      64            1 :     _E = 0.5 * (SR2(C) - SR2::identity(_F.options()));
      65            1 :   }
      66              : 
      67            2 :   if (dout_din)
      68              :   {
      69            1 :     const auto I = R2::identity(_F.options());
      70            6 :     const auto dC_dF = R4(at::einsum("...jm,...ni,...jk", {I, I, _F})) +
      71            7 :                        R4(at::einsum("...jm,...nk,...ji", {I, I, _F}));
      72            1 :     _E.d(_F) = 0.5 * full_to_mandel(dC_dF);
      73            1 :   }
      74            6 : }
      75              : 
      76              : } // namespace neml2