.. _fea_build_fea_testbench:

Building the Test Bench
-----------------------
TestBenches can be as simple as a few blocks for computation, or complex as many
references that send and recieve data from different programs to compute
large scale behavioral studies. The generic FEA TestBench consists of:

* Tool Features
* System Under Test
* Test Injection Points

.. tip:: If you wish to start the tutorial here, open the FEA_tutorial_part2.xme.

Tool Features
^^^^^^^^^^^^^

Before we can start building the TestBench, we have to give it a home folder.

1. Right-click on the **Root folder** and choose :menuselection:`Insert Folder
   --> Testing`.
2. Right-click on the new **Testing** folder and choose :menuselection:`Insert
   model --> StructuralFEATestBench`.
3. Rename this **Simple_Cube_FEA**.
4. Double-left-click **Simple_Cube_FEA** to open the blank TestBench canvas.

Next, we'll add a **Mesh Parameters** object which allows us to specify to Patran,
the meshing software, how we want to generate the mesh.

5. In the `Part Browser`, locate **Mesh Parameters** and drag it into the workspace.
6. Select the **Mesh Parameters** and change the values in the **Attributes tab**
   of the Object Inspector as shown below.

.. figure:: images/IMAGE12_5.png
   :alt: Solid Modeling Demo

Now we'll add a Workflow which tells our tool what task(s) it needs to execute
to properly run our FEA TestBench.

7. In the `GME Browser` Right-click on **Testing** and choose
   :menuselection:`Insert Folder --> Workflow Definitions`.
8. Right-click on the new **Workflow Definitions** folder and choose
   :menuselection:`Insert Model --> Workflow`.
9. Rename this `Workflow` **CADAssembly**.
10. Right-click on the new **CADAssembly** workflow and choose
    :menuselection:`Insert Atom --> Task --> CyPhy2CAD`.

.. figure:: images/IMAGE12_75.png
   :alt: Solid Modeling Demo

11. Redirect back to **Simple_Cube_FEA**, locate the **WorkflowRef** in the
    `Part Browser` and drag it into the workspace.
12. Left-click the **CADAssembly** `workflow` and drop it on top of the WorkflowRef.
13. Rename the 'WorkflowRef' **CADAssembly**.

.. figure:: images/IMAGE12_9.png
   :alt: Solid Modeling Demo

System Under Test
^^^^^^^^^^^^^^^^^

A **SystemUnderTest** part tells the tool what we are trying to analyze in
the TestBench. This acts much like a reference to our **Cube_Assembly**
`Component Assembly`, which is in turn a reference to our **Simple_Cube** `Component`.

1. In the `Part Browser`, locate the object **System Under Test** and drag
   it into the workspace.
2. In the GME Browser, left click the Cube_Assembly and drop it on top of the
   **System Under Test**.

.. figure:: images/IMAGE13.png
   :alt: Solid Modeling Demo

.. note:: There *must* be a blue circle with an R inside in the top right corner
          of the SystemUnderTest object indicating that this is a reference to
          the Component Assembly.

We have now told the tool what to analyze, but we haven't specified how to do so yet.
To do that we'll add a **TestInjectionPoint**.

Test Injection Point
^^^^^^^^^^^^^^^^^^^^

We will now specify what is happening to the CAD model we have referenced
and where these actions are taking place on the model. For our FEA analysis
we care greatly about how the part reacts when loaded under certain conditions.
For simplicity, the Cube will be fixed at its base, while having a downward load
applied to the top. (Imagine this as placing a large book over
the entire top surface of a table and analyzing how the table responds to
the newly applied load.) Intuitively, we know it is most fitting to treat this
as a pressure (Weight of book / Area of cube).

1. Locate the **TestInjectionPoint** in the `Part Browser` and drag it into the
   workspace.
2. Left-click **Cube_Assembly** and drop it on top of the `TestInjectionPoint`.

.. figure:: images/IMAGE14.png
   :alt: Solid Modeling Demo

.. note:: If the Surface_reference_points are not fully displaying their names, change
   the **Port Label Length** in the preferences tab of the object inspector to 0.

3. In the `Part Browser` locate the **Face** object and drag it into the workspace.
   Change the `Face Icon name` in the `Preferences` tab of the `Object Inspector`
   to **Surface.png**.
4. Double left-click the face to edit it. Inside, drop a **ReferencePoint**
5. Direct back to **Simple_Cube_FEA**. Copy this edited **Face** and paste 1 more
   (for the bottom and top faces of the cube).
6. Rename the faces **Face_Ref_Top** and **Face_Ref_Bottom**.
7. Connect these faces to **SURF_REF_TOP** and **SURF_REF_BOTTOM**.
8. In the `Part Browser` locate the **DisplacementConstraint** object and drag it
   into the workspace.
9. Double left-click the **DisplacementConstraint** to edit it.
   Add in a **Rotation** and **Translation** part.
10. Select the Rotation part, and in the `Attributes` tab of the`Object Inspector`
    change the X,Y,Z directions from **Scalar** to **Free**.

.. figure:: images/IMAGE15.png
   :alt: Solid Modeling Demo

11. Direct back to the `Simple_Cube_FEA` and connect the **DisplacementConstraint**
    to **Face_Ref_Bottom**.
12. In the `Part Browser`, drag and drop the **PressureLoadParam** into the workspace.
13. Double left-click the **PressureLoadParam** and add in a **PressureLoad**.
14. In the 'Object Inspector' set the ``value`` to **15**.
15. To assign proper units: in the GME Browser, left-click the plus box next to
    :menuselection:`UnitLibrary QUDT --> TypeSpecifications --> Units`. Locate
    Megapascal and drop it on top of the **PressureLoad**.

.. figure:: images/IMAGE16.png
   :alt: Solid Modeling Demo

16. Copy (Ctrl+C) the Pressure load and paste it inside of **Simple_Cube_FEA**.
17. Connect this to the **PressureLoadParam**.
18. Connect the **PressureLoadParam** to the **Face_Ref_Top**.

.. figure:: images/IMAGE17.png
   :alt: Solid Modeling Demo

We have now specified that we want to place a 15MPa pressure over
the entire top surface of the cube while keeping the entire bottom surface
from translating in any direction. Next we must specify how we want to solve
this problem and what data we want to solve for.

1. Left-click on a blank space in the canvas; in the `Object Inspector` change
   the `Solver Type` to **PATRAN_NASTRAN** and the `ElementType` to **Plate4**.
2. In the *Part Browser* add a **StructuralFEAComputation**. Double left-click to
   edit the part.
3. Add in a **FactorOfSaftey** and **MisesStress** aspect, then redirect back to
   **Simple_Cube_FEA**.
4. Connect the **TestInjectionPoint** to the **StructuralFEAComputation** by
   left-clicking on the box borders of both.

.. figure:: images/IMAGE18.png
   :alt: Solid Modeling Demo

5. In the Part Browser add two (2) **Metric** parts. Rename these **FactorOfSaftey**
   and **MisesStress**.
6. Connect these to their **StructuralFEAComputation** counterparts.

.. figure:: images/IMAGE19.png
   :alt: Solid Modeling Demo

When conducting an FEA TestBench, we are generally interested in simulating a load and
seeing the reaction of a part. In our case, we only want to see values that do not exceed
the ultimate strength of the Cube. We can set this as a **Metric Constraint** that limits
values to always exceed a factor of safety of 1.0.

7. In the `Part Browser` locate **Metric Constraint** and drag it onto the canvas.
8. Rename this **ReserveFactorRequirement**.
9. Set the `TargetValue` to **1.0**.
10. Connect this to the **FactorOfSaftey** metric.

This constraint does not change how the user views the data but how the TestBench
Manifest sorts data. This is generally good practice as it will help debug a
design space if parts continually fail the factor of saftey requirement. Our now
complete TestBench should look like this:

.. figure:: images/IMAGE20.png
   :alt: Solid Modeling Demo