<OpenGeoSysProject>
  <meshes>
    <mesh>domain.vtu</mesh>
    <mesh>left.vtu</mesh>
    <mesh>right.vtu</mesh>
    <mesh>top.vtu</mesh>
    <mesh>bottom.vtu</mesh>
    <mesh>arc.vtu</mesh>
  </meshes>
  <processes>
    <process>
      <name>SD</name>
      <type>SMALL_DEFORMATION</type>
      <integration_order>4</integration_order>
      <constitutive_relation id="*">
        <type>LinearElasticIsotropic</type>
        <youngs_modulus>E</youngs_modulus>
        <poissons_ratio>nu</poissons_ratio>
      </constitutive_relation>
      <specific_body_force>0 0.</specific_body_force>
      <process_variables>
        <process_variable>displacement</process_variable>
      </process_variables>
      <secondary_variables>
        <secondary_variable internal_name="epsilon" output_name="epsilon" />
        <secondary_variable internal_name="sigma" output_name="sigma" />
      </secondary_variables>
      <initial_stress>sigma0</initial_stress>
    </process>
  </processes>
  <time_loop>
    <processes>
      <process ref="SD">
        <nonlinear_solver>basic_newton</nonlinear_solver>
        <convergence_criterion>
          <type>PerComponentDeltaX</type>
          <norm_type>NORM2</norm_type>
          <abstols>1.e-09 1.e-09</abstols>
          <reltols>1.e-09 1.e-09</reltols>
        </convergence_criterion>
        <time_discretization>
          <type>BackwardEuler</type>
        </time_discretization>
        <time_stepping>
          <type>IterationNumberBasedTimeStepping</type>
          <t_initial>0.0</t_initial>
          <t_end>345600.0</t_end>
          <initial_dt>10000</initial_dt>
          <minimum_dt>1e1</minimum_dt>
          <maximum_dt>17280</maximum_dt>
          <number_iterations>1 4 10 15 20 25 31</number_iterations>
          <multiplier>1.5 1.3 1.2 1.1 0.8 0.7 0.6</multiplier>
        </time_stepping>
      </process>
    </processes>
    <output>
      <type>VTK</type>
      <prefix>kirsch</prefix>
      <data_mode>Ascii</data_mode>
      <compress_output>false</compress_output>
      <timesteps>
        <pair>
          <repeat>1</repeat>
          <each_steps>1</each_steps>
        </pair>
      </timesteps>
      <variables>
        <variable>displacement</variable>
        <variable>epsilon</variable>
        <variable>sigma</variable>
      </variables>
      <suffix>ts{:timestep}_t_{:time}</suffix>
    </output>
  </time_loop>
  <media>
    <medium id="*">
      <phases>
        <phase>
          <type>Solid</type>
          <properties>
            <property>
              <name>density</name>
              <type>Constant</type>
              <value>0.0</value>
            </property>
          </properties>
        </phase>
      </phases>
    </medium>
  </media>
  <parameters>
    <parameter>
      <name>E</name>
      <type>Constant</type>
      <value>5e9</value>
    </parameter>
    <parameter>
      <name>nu</name>
      <type>Constant</type>
      <value>.3</value>
    </parameter>
    <parameter>
      <name>zero</name>
      <type>Constant</type>
      <value>0.0</value>
    </parameter>
    <parameter>
      <name>initial_displacement</name>
      <type>Constant</type>
      <values>0 0</values>
    </parameter>
    <parameter>
      <name>sigma0</name>
      <type>Function</type>
      <expression>0.0</expression>
      <expression>if (sqrt(x^2 + (y + 857)^2)>6.5) -20e6; else 0.0</expression>
      <expression>0.0</expression>
      <expression>0</expression>
    </parameter>
    <parameter>
      <name>sigma_top</name>
      <type>Constant</type>
      <value>-20e6</value>
    </parameter>
    <parameter>
      <name>decay_function</name>
      <type>Function</type>
      <expression>if (t>1.728e+5) 0.0; else 1 - t/ 1.728e+5;</expression>
    </parameter>
  </parameters>
  <process_variables>
    <process_variable>
      <name>displacement</name>
      <components>2</components>
      <order>2</order>
      <initial_condition>initial_displacement</initial_condition>
      <compensate_non_equilibrium_initial_residuum>true</compensate_non_equilibrium_initial_residuum>
      <boundary_conditions>
        <boundary_condition>
          <mesh>left</mesh>
          <type>Dirichlet</type>
          <component>0</component>
          <parameter>zero</parameter>
        </boundary_condition>
        <boundary_condition>
          <mesh>bottom</mesh>
          <type>Dirichlet</type>
          <component>1</component>
          <parameter>zero</parameter>
        </boundary_condition>
        <boundary_condition>
          <mesh>top</mesh>
          <type>Neumann</type>
          <component>1</component>
          <parameter>sigma_top</parameter>
        </boundary_condition>
        <boundary_condition>
          <mesh>arc</mesh>
          <type>ReleaseNodalForce</type>
          <time_decay_parameter>decay_function</time_decay_parameter>
        </boundary_condition>
      </boundary_conditions>
    </process_variable>
  </process_variables>
  <nonlinear_solvers>
    <nonlinear_solver>
      <name>basic_newton</name>
      <type>Newton</type>
      <max_iter>10</max_iter>
      <linear_solver>general_linear_solver</linear_solver>
    </nonlinear_solver>
  </nonlinear_solvers>
  <linear_solvers>
    <linear_solver>
      <name>general_linear_solver</name>
      <eigen>
        <solver_type>BiCGSTAB</solver_type>
        <precon_type>ILUT</precon_type>
        <max_iteration_step>10000</max_iteration_step>
        <error_tolerance>1e-20</error_tolerance>
      </eigen>
      <petsc>
        <parameters>-ksp_type bcgs
                    -pc_type bjacobi
                    -ksp_rtol 1.e-18 -ksp_atol 1.e-18
                    -ksp_max_it 4000</parameters>
      </petsc>
    </linear_solver>
  </linear_solvers>
</OpenGeoSysProject>