Experimental modal analysis
============================


* Select from the menu "DA Tools > Modal analysis > Experimental Modal Analysis > EMA Polyreference Fitting"

:math:`\Rightarrow` The "EMA Polyreference Fitting" widget appears in the main window.


.. image:: images/PolyreferenceWidget.png
    :width: 6in
    :height: 4.1173in


.. _RefImage_PolyreferenceWidget.png:


* Check the "Hammer Test" box on the widget.


* Write "mart" in the text window where "Filter" is written in gray.


* Select the "TimeSeries" entry from the tree and drag it into the "Reference" window.


* Write "(?! mart)" in the text window where "Filter" is written in gray.


* Select the "TimeSeries" entry from the tree and drag it into the "Response" window.


* Click on the "Compute" button

:math:`\Rightarrow` Frequency response curves appear in the graphics window.


.. image:: images/EMAWidget_FRF_computed.png
    :width: 6in
    :height: 4.111in


.. _RefImage_EMAWidget_FRF_computed.png:


* Click on the "Proceed" button

:math:`\Rightarrow` The second tab entitled "Pole selection" appears.


* Enter 3 in the "Fmin" box.


* Enter 12 in the "Fmax" box.


* Select "Acceleration" on the "Format" line.


* Click on the "Compute" button.

:math:`\Rightarrow` A graph with a purple curve, red dots, and black crosses appears.


.. image:: images/10000201000005050000037669E9B6814C83B7A7.png
    :width: 6in
    :height: 4.1366in


.. _RefImage_10000201000005050000037669E9B6814C83B7A7.png:


* The purple curve has 2 peaks with 2 black cross lines. Place the mouse on one of the crosses on the first peak, click with the right mouse button and click on "Add Pole".


* Do the same on one of the black crosses on the 2nd peak.

:math:`\Rightarrow` The frequencies and depreciations of the selected clusters appear in the "Selected Poles" window.


.. image:: images/1000020100000190000000C0A4811117AC33CADA.png
    :width: 3.3055in
    :height: 1.5866in


.. _RefImage_1000020100000190000000C0A4811117AC33CADA.png:


* Click on the "Proceed" button.


* Click on the "Compute" button.

:math:`\Rightarrow` The calculated modal responses appear in the graphics window.


.. image:: images/10000201000004F20000030F28E1116DDA606BD8.png
    :width: 6in
    :height: 3.7102in


.. _RefImage_10000201000004F20000030F28E1116DDA606BD8.png:


* Click on the "Proceed" button.


* In the tree, select the "Mesh" object and drag it onto the blue background of the new window.

:math:`\Rightarrow` The mesh of the studied structure appears in the Viewer window.

To make the ColorBar appear: Go to the "Edit" menu, select "Preferences" and check the "Display color bar" box


.. image:: images/DA_mode_shape1.png
    :width: 6in
    :height: 3.7055in


.. _refImage_10000201000004F20000030E0D3 FBBF14D3B7B95 .png: