<!-- 
 Example: Box, circumferentially uniform scheme (CUS)
 Ref:
    Yu, Wenbin, Dewey H. Hodges, and Jimmy C. Ho.
    “Variational Asymptotic Beam Sectional Analysis – An Updated Version.”
    International Journal of Engineering Science 59 (October 2012): 40–64.
    https://doi.org/10.1016/j.ijengsci.2012.03.006.


 Unit system:
 - Length: inch
 - Mass: slug (lb * sec^2 / inch)
 - Density: slug / inch^3 (lb * sec^2 / inch^4)
 - Force: lbf
 - Pressure: psi
-->

<cross_section name="box_cus" format="1">

  <include></include>

  <analysis>
    <!-- Timoshenko beam model -->
    <model>1</model>
  </analysis>

  <general>
    <!-- Global mesh size -->
    <mesh_size>0.01</mesh_size>

    <element_type>2</element_type>

    <!-- Mesh element shape: 3/tri/triangle or 4/quad/quadrilateral -->
    <!-- <element_shape>4</element_shape> -->

    <!-- Quadrilateral meshing controls (used when element_shape = 4) -->
    <!-- <transfinite_auto>1</transfinite_auto> -->
    <!-- <transfinite_corner_angle>3.141592653589793</transfinite_corner_angle> -->
    <!-- <transfinite_recombine>1</transfinite_recombine> -->
    <!-- <recombine>1</recombine> -->
    <!-- <recombine_angle>45</recombine_angle> -->
  </general>


  <!-- Geometry -->
  <baselines>

    <!-- Four corners of the box -->
    <point name="bl">-0.4765 -0.265</point>  <!-- Bottom left -->
    <point name="tl">-0.4765 0.265</point>  <!-- Top left -->
    <point name="tr">0.4765 0.265</point>  <!-- Top right -->
    <point name="br">0.4765 -0.265</point>  <!-- Bottom right -->

    <!-- Outer profile of the box -->
    <baseline name="bl_all" type="straight">
      <!-- 
        The first and last points are the same to close the shape.
        The order of the points defines the direction of the baseline.
        In this example, the direction is counter-clockwise.
      -->
      <points>tl,tr,br,bl,tl</points>
    </baseline>

  </baselines>


  <!-- Materials and laminae database -->
  <materials>

    <material name="mat_1" type="orthotropic">
      <density>1.353e-04</density>
      <elastic>
        <e1>20.59e+06</e1>
        <e2>1.42e+06</e2>
        <e3>1.42e+06</e3>
        <g12>0.87e+06</g12>
        <g13>0.87e+06</g13>
        <g23>0.696e+06</g23>
        <nu12>0.30</nu12>
        <nu13>0.30</nu13>
        <nu23>0.34</nu23>
      </elastic>
    </material>

    <lamina name="la_mat_1">
      <material>mat_1</material>
      <thickness>0.005</thickness>
    </lamina>

  </materials>


  <!-- Layup definitions -->
  <layups>

    <layup name="layup_1">
      <!-- For each layer, assign fiber angle and number of plies (angle:nplies) -->
      <layer lamina="la_mat_1">15:6</layer>
    </layup>

  </layups>


  <!-- Component definitions -->
  <component name="main">

    <!-- Since all four walls have the same layup, we can define a single segment -->
    <segment name="sg_all">

      <baseline>bl_all</baseline>

      <!--
        In this example, the base line is defined as the outer profile
        and we want to create the layup inward. Since the base line is in the
        counter-clockwise direction, hence the "direction" of the layup should be "right".
      -->
      <layup direction="right">layup_1</layup>

    </segment>

  </component>

</cross_section>
