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Experimental Modal Analysis By block

1.2.1. Experimental Modal Analysis By block#

The previous tutorial tutoEMA has focused on the identification of SIMO or MIMO transfers.

For some test cases, it is necessary to perform several identification by blocks because pole shifts are expected between these blocks.

Here are examples of typical parameters defining the blocks :

  • Temperature

  • Input location

  • Input level

  • Sensor batches

  • Pre-loading

  • ...

SDT provides tools to easily navigate between blocks, perfom the identification for each block and finally post-treat the result (pole tracking, clustering, main shape extraction,...)

The following tutorial highlights the procedure identify parametric transfers on the DemoGartBy example in which each block of transfers depends on the temperature.

Step 1 : Load wireframe and parametric transfers#

:::{dropdown} Run step . Expand to display source code.

[XF,wire]=demosdt('DemoGartBy');
[ci,cf]=iicom('dockid',struct('model',wire,'XF',XF));

::: Load the curve containing all the measurement blocks and eventually the wireframe.

Store them in the dock Id with the command

% Example of measurement blocks with GARTEUR
[XF,wire]=demosdt('DemoGartBy'); 
% Open dock with measurement blocks in curve 'Test'
[ci,cf]=iicom('dockid',struct('model',wire,'XF',XF));

:::{figure} ../_images/TutoBy_1.png :width: 100% :name: TutoBy_1 :::

Step 2 : Switch to By mode#

:::{dropdown} Run step . Expand to display source code.

% Simulate click on button "Init By Mode"
iicom(ci,'SetIdent',struct('ByMode','do'))

::: To initialize the identification by block, on tab Ident, expand IDopt and click on Init By Mode. :::{figure} ../_images/TutoBy_2a.png :width: 50% :name: TutoBy_2a ::: In the Ident tab, a block of buttons By has appeared. :::{figure} ../_images/TutoBy_2b.png :width: 50% :name: TutoBy_2b ::: These button help in the navigation between block through all the procedure of identification by blocks. All the blocks are listed in the pop button on the top right (here 11 temperatures). You can increase or decrease the selected block by clicking on the + or - buttons or directly selecting the wanted one in the list. When one block is selected, measurement corresponding to this block only is stored in the curve Test and eventually previous identification results.

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