 <OpenGeoSysProject>

   <meshes>

     <mesh>bar1to6.vtu</mesh>

     <mesh>bar1to6_top.vtu</mesh>

     <mesh>bar1to6_bottom.vtu</mesh>

   </meshes>

   <processes>

     <process>

       <name>Mechanics</name>

       <type>LARGE_DEFORMATION</type>

       <integration_order>2</integration_order>

       <constitutive_relation>

         <type>MFront</type>

         <behaviour>SaintVenantKirchhoff</behaviour>

         <material_properties>

           <material_property name="YoungModulus" parameter="E" />

           <material_property name="PoissonRatio" parameter="nu" />

         </material_properties>

       </constitutive_relation>

       <specific_body_force>0 0 0</specific_body_force>

       <process_variables>

         <process_variable>displacement</process_variable>

       </process_variables>

       <secondary_variables>

         <secondary_variable internal_name="sigma" output_name="sigma" />

         <secondary_variable internal_name="epsilon" output_name="epsilon" />

         <secondary_variable internal_name="deformation_gradient" output_name="deformation_gradient" />

         <secondary_variable internal_name="volume_ratio" output_name="volume_ratio" />

       </secondary_variables>

     </process>

   </processes>

   <media>

     <medium>

       <phases>

         <phase>

           <type>Solid</type>

           <properties>

             <property>

               <name>density</name>

               <type>Constant</type>

               <value>1</value>

             </property>

           </properties>

         </phase>

       </phases>

     </medium>

   </media>

   <time_loop>

     <processes>

       <process ref="Mechanics">

         <nonlinear_solver>basic_newton</nonlinear_solver>

         <convergence_criterion>

           <type>DeltaX</type>

           <norm_type>NORM2</norm_type>

           <abstol>1e-13</abstol>

         </convergence_criterion>

         <time_discretization>

           <type>BackwardEuler</type>

         </time_discretization>

         <time_stepping>

           <type>FixedTimeStepping</type>

           <t_initial>0</t_initial>

           <t_end>0.05</t_end>

           <timesteps>

             <pair>

               <repeat>1</repeat>

               <delta_t>0.01</delta_t>

             </pair>

           </timesteps>

         </time_stepping>

       </process>

     </processes>

     <output>

       <type>VTK</type>

       <prefix>bar1to6_torsion</prefix>

       <timesteps>

         <pair>

           <repeat>1</repeat>

           <each_steps>1</each_steps>

         </pair>

       </timesteps>

       <variables />

       <suffix>ts{:timestep}_t_{:time}</suffix>

     </output>

   </time_loop>

   <parameters>

     <parameter>

       <name>E</name>

       <type>Constant</type>

       <value>1</value>

     </parameter>

     <parameter>

       <name>nu</name>

       <type>Constant</type>

       <value>.3</value>

     </parameter>

     <parameter>

       <name>displacement0</name>

       <type>Constant</type>

       <values>0 0 0</values>

     </parameter>

     <parameter>

       <name>zero</name>

       <type>Constant</type>

       <value>0</value>

     </parameter>

     <parameter>

       <name>translation_z</name>

       <type>Function</type>

       <expression>3*t</expression>

     </parameter>

     <parameter>

       <name>rotation_x</name>

       <type>Function</type>

       <expression>var R := sqrt(x^2 + y^2); var phi := if (R == 0, 0, atan2(y, x)); var theta := if (phi < 0, phi + 2 * pi, phi); R * cos(theta + pi * t) - x</expression>

     </parameter>

     <parameter>

       <name>rotation_y</name>

       <type>Function</type>

       <expression>var R := sqrt(x^2 + y^2); var phi := if (R == 0, 0, atan2(y, x)); var theta := if (phi < 0, phi + 2 * pi, phi); R * sin(theta + pi * t) - y</expression>

     </parameter>

   </parameters>

   <process_variables>

     <process_variable>

       <name>displacement</name>

       <components>3</components>

       <order>1</order>

       <initial_condition>displacement0</initial_condition>

       <boundary_conditions>

         <boundary_condition>

           <mesh>bar1to6_bottom</mesh>

           <type>Dirichlet</type>

           <component>0</component>

           <parameter>zero</parameter>

         </boundary_condition>

         <boundary_condition>

           <mesh>bar1to6_bottom</mesh>

           <type>Dirichlet</type>

           <component>1</component>

           <parameter>zero</parameter>

         </boundary_condition>

         <boundary_condition>

           <mesh>bar1to6_bottom</mesh>

           <type>Dirichlet</type>

           <component>2</component>

           <parameter>zero</parameter>

         </boundary_condition>

         <boundary_condition>

           <mesh>bar1to6_top</mesh>

           <type>Dirichlet</type>

           <component>0</component>

           <parameter>rotation_x</parameter>

         </boundary_condition>

         <boundary_condition>

           <mesh>bar1to6_top</mesh>

           <type>Dirichlet</type>

           <component>1</component>

           <parameter>rotation_y</parameter>

         </boundary_condition>

         <boundary_condition>

           <mesh>bar1to6_top</mesh>

           <type>Dirichlet</type>

           <component>2</component>

           <parameter>translation_z</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>SparseLU</solver_type>

         <scaling>true</scaling>

         <precon_type>DIAGONAL</precon_type>

         <max_iteration_step>10000</max_iteration_step>

         <error_tolerance>1e-16</error_tolerance>

       </eigen>

     </linear_solver>

   </linear_solvers>

   <test_definition>

     <vtkdiff>

       <file>bar1to6_torsion_ts_5_t_0.050000.vtu</file>

       <field>displacement</field>

       <absolute_tolerance>1e-14</absolute_tolerance>

       <relative_tolerance>1e-15</relative_tolerance>

     </vtkdiff>

     <vtkdiff>

       <file>bar1to6_torsion_ts_5_t_0.050000.vtu</file>

       <field>NodalForces</field>

       <absolute_tolerance>1e-14</absolute_tolerance>

       <relative_tolerance>1e-15</relative_tolerance>

     </vtkdiff>

     <vtkdiff>

       <file>bar1to6_torsion_ts_5_t_0.050000.vtu</file>

       <field>sigma</field>

       <absolute_tolerance>1e-14</absolute_tolerance>

       <relative_tolerance>1e-15</relative_tolerance>

     </vtkdiff>

     <vtkdiff>

       <file>bar1to6_torsion_ts_5_t_0.050000.vtu</file>

       <field>epsilon</field>

       <absolute_tolerance>1e-14</absolute_tolerance>

       <relative_tolerance>1e-15</relative_tolerance>

     </vtkdiff>

     <vtkdiff>

       <regex>bar1to6_torsion_ts_5_t_0.050000.vtu</regex>

       <field>deformation_gradient</field>

       <absolute_tolerance>5e-15</absolute_tolerance>

       <relative_tolerance>1e-16</relative_tolerance>

     </vtkdiff>

     <vtkdiff>

       <regex>bar1to6_torsion_ts_5_t_0.050000.vtu</regex>

       <field>volume_ratio</field>

       <absolute_tolerance>5e-15</absolute_tolerance>

       <relative_tolerance>1e-16</relative_tolerance>

     </vtkdiff>

   </test_definition>

 </OpenGeoSysProject>